To enhance dairy farm sustainability in Pennsylvania and the Northeastern US, we have been evaluating two diverse, six-year no-till crop rotations designed to produce all the feed and forage for a typical-sized PA dairy farm (65 cows, 240 acre dairy) since 2010.
Using farm scale equipment, in each 6-year crop rotation, we compared enhanced conservation practices for manure or weed and insect management to typical no-till Pennsylvania cropping practices on 14 acres. In the manure rotation we compared manure injection to surface application. In the pest rotation, we compared a combination of reduced-herbicide weed control practices to standard herbicides, and used integrated pest management to manage slug and insect pests.
We also included a typical no-till, corn-soy rotation with pre-emptive insect control practices to help assess efficacy of IPM compared to this insurance-based management of insect pests, not to produce feed for the dairy farm. Using the crop yield and quality results of each year and a dairy nutrition computer model, we simulated milk production and compared the whole farm performance of two cropping scenarios (the two, 6-year enhanced conservation cropping systems compared to the two, 6-year typical no-till cropping systems). Weather conditions and feed and milk prices varied over the seven years, enabling us to evaluate and modify the cropping systems to sustain the herd in years with weather limitations and assess economic viability over time.
Based on what we have learned, we made some modifications to the diverse rotations in 2013 and 2016, and the diverse cropping scenarios have produced the majority of the dairy feed and forage, and were profitable. Manure injection conserved more nutrients, required less inorganic nitrogen fertilizer, and maintained similar crop yields. The reduced herbicide practices controlled weeds and maintained crop yield and quality similarly to the standard herbicide system in most crops in most years.
Compared to the corn-soy rotation, IPM was successful in maintaining yield while minimizing costs associated with insect pest management. In 2016, we initiated a conservation tillage treatment in the corn-soybean rotation to track soil, nutrient, and crop dynamics in comparison to continued no-till. We have also begun planning research with some cooperating commercial farms to integrate into outreach programs on: i. managing for whole farm feed production, environmental protection and farm profitability with fall manure applications to double-cropped winter annual forages,ii. the use of IPM and conservation of insect biodiversity to control pests, and iii. conservation practices for soil quality and cropping system performance.
Dairy farming is well suited to the topography, soils, and climate of Pennsylvania and much of the northeastern US. And although milk sales account for the most agricultural sales in Pennsylvania, dairy farm profitability is not reliable and often threatened by fluctuations in the milk price, feed costs, and costs of feed production. Dairy and livestock farmers also face regulations and often incur significant costs to meet government regulations to reduce soil and nutrient losses, particularly in the Chesapeake Bay watershed.
In 2014 in Pennsylvania, 66% of agronomic crops were planted with no-till, providing soil conservation and soil health benefits. No-till as well as cover crop systems pose some new challenges and require different manure, weed, and pest management compared to conventional and conservation till cropping systems. This sustainable dairy cropping systems project was developed to address these challenges, by an interdisciplinary research and extension team with input from an advisory panel that includes farmers, long-term farming systems researchers, and NRCS personnel. We designed and evaluated two diverse, six-year no-till crop rotations designed to produce all the feed and forage for a typical-sized Pennsylvania dairy farm. In one rotation (the manure rotation) we compared manure injection to the typical no-till practice: surface manure application. In the pest rotation, we compared a combination of reduced-herbicide weed control practices to standard herbicides, and used integrated pest management to manage slug and insect pests. We also included a typical no-till, corn-soy rotation with pre-emptive insect control practices to help assess efficacy of IPM compared to this insurance-based management of insect pests, not to produce feed for the dairy farm.
The objectives of this project: i. to identify strategies to enhance the sustainability of dairy cropping systems and dairy farms in the Northeast, ii. to promote adoption of the cropping system practices by farmers.
We initiated two diverse, 6-year dairy crop rotations using farm-scale equipment at 1/20th scale of 240 acres on 12 acres of Penn State’s Agronomy Research Farm near University Park, PA. Cropping system strategies include no till, manure injection, cover crops, a cover crop roller, perennial legumes, green manure crops, and winter canola. Within each crop rotation we have evaluated innovative management strategies to address no-till management challenges: i. no-till manure management to conserve manure nutrients and reduce losses to the environment with shallow-disk manure injection; and ii. reducing herbicide and insecticide use with cultural and mechanical integrated weed management practices, and biological and integrated pest management practices for insect and slug management.
To examine the effect of diverse rotations managed with IPM practices on insect pests and beneficial insect populations, a corn-soybean grain rotation was also included for comparison purposes at the experimental site on an additional 2 acres (see 2016 Cropping Schematic). In the corn-soybean rotation, we compared the manure management strategies (injected or broadcast manure), inorganic fertilizer, and in 2016 we included a minimum tillage (Chisel) treatment to evaluate the effects of tillage on soil health parameters. In addition, our USDA ARS team established twelve lysimeter plots (50 x 90 ft.) on a slope to compare total nutrient losses and crop uptake between manure and crop management strategies on an additional 1.3 acres.
The Northeast SARE experiment is a nested split-split plot, full crop entry design. All crop phases of each rotation are planted each year on 0.25 acre plots that are replicated four times (12 crop entries for the 2 year rotations, 2 crop entries for the corn-soybean rotation X 4 replications = 56 plots). Each crop entry is the main plot (120 ft. x 90 ft.) that is divided in half (60 ft by 90 ft) to compare the management strategies over time (ex. inject manure or broadcast manure).
In 2014 and 2015, we compared green manure crops (red clover vs. crimson clover); the manure rotation has nested split-split plots (30 x 90 ft.) within both manure management strategies. According to the results of our dairy nutrition model, which develops rations for the virtual dairy herd, the farm was already producing sufficient high quality forage in the manure rotation and there was a need for more low quality forage production for dry cows and heifers. Therefore, we replaced red clover with rye silage while still having the crimson clover crop at the split-split plots. Crimson clover and rye silage are planted after two or three cuts of sorghum sudangrass, respectively. In the pest rotation there are nested split-split plots (30 x 90 ft.) within the reduced herbicide treatment in the soybean and corn crops that compare two post-planting weed control strategies (high-residue cultivator or post-emergent herbicide). Since the cultivator requires wider row spacing (30 inch, 76 cm) than is typical for no-till soybeans, we have also included split-split plots in the soybean standard herbicide treatment to compare the soybean row spacing of 30 inch (76 cm) to a more typical 15 inch (38 cm) row spacing.
We are evaluating multiple performance indicators: crop yield and quality, soil health, nutrient conservation, greenhouse gas emissions, weed and insect populations; and farm profitability. We continue to collect three subsamples for forage or feed for quality analysis from each of our main management treatments in the MANURE and PEST rotations at every crop harvest in the Northeast SARE Dairy Cropping Systems Trial. We simulate making corn, alfalfa-grass, sorghum sudan, and rye silage and soybean roasting in the laboratory prior to submitting them to Dairy One for forage quality analysis. The dairy scientist, Virginia Ishler, uses the quality and yield data to develop rations for the virtual dairy herd, and a dairy nutrition model to simulate a dairy herd’s milk production under the two different cropping system scenarios: the enhanced conservation cropping systems (the inject manure and reduced herbicide managements) compared to the more typical (broadcast manure and standard herbicide managements).
Crop yields were collected for each crop entry point in the MANURE and PEST rotation in each year. Crop quality was simulated and analyzed for three of the four blocks from the MANURE and PEST rotations. Data were analyzed with a split-plot, mixed ANOVA model using PROC MIXED of SAS for all crops that received manure or reduced herbicides in the rotation. When significant, interactive effects were found, the SLICE function was used to determine statistical significance.
Broadcast and injection manure application methods were replicated 6 times in 12 field lysimeter plots. Manure was either injected with a shallow disk injector or broadcasted in fall prior to planting a winter annual or in spring prior to corn. The manure application rate for broadcast and injection treatments was 48 Mg ha-1 (21 T A-1). The concentration of P in overland and subsurface flow was measured from field plots with earthen berms to capture overland flow and tile drains placed just above limestone bedrock to capture subsurface flow. There is an outlet for surface runoff and shallow lateral flow for all 12 plots in 2 collection houses. The phosphorous concentration was multiplied by the flow measurements to calculate the phosphorus load which can also be described as loss. Data were analyzed using Proc Mixed procedure of SAS with repeated measures. Manure application methods and sampling dates were considered as fixed effects and year and blocks were random. We used the Slice statement to test the hypothesis that P losses would be higher from broadcast treatment after high rainfall and manure application.
Nitrous oxide emissions
Soil N2O samples were collected in 2015 and 2016 from soils planted to corn in 3 blocks of the experiment. The crop rotations (fall/summer) selected for this study were alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) + corn (Zea maize L.), crimson clover (Trifolium incarnatum L.) +corn, soybean (Glycine max L . Merr.) + corn with spring broadcast manure, soybean + corn with injected manure with a shallow disk injector (10 cm depth), and soybean + corn with liquid urea ammonium nitrate (UAN) fertilization.
N2O fluxes were measured with vented static chambers (78.5 cm x 40.5 cm) from each treatment plot during the corn growing season. Chamber frames were placed perpendicularly across two corn rows in two locations in each plot, for a total of 36 frames (6 treatments x 3 blocks x 2 repetitions). The sampling was two times a week during the first 61 days after cover crops were terminated and manure was applied. In the following period, sampling had intervals from 7 to 31 days. Measurements were taken prior to and during the period of anticipated N2O fluxes to capture profile of gas emissions during entire growing season. Fluxes were measured between 9:00 to 12:00 h to minimize diurnal variation in the flux pattern. Samples were collected at 0, 10, 20 and 30 minutes and analyzed with a gas chromatography. The rate of N2O emissions (g N-N2O/ha/d) was calculated from the four data points using linear regression. Cumulative N2O emissions were calculated by linear interpolation. Soil temperature (Model HI 145, Hanna Instruments) and volumetric soil water content (Model ML3 ThetaProbe, Delta-T Devices) were measured at the soil surface (0-10 cm) every time gas samples were taken. Soil samples (3, 2.5cm diameter cores/plot) were collected once a week from the surface layer (0-5cm) and analyzed for ammonium (NH4+) and nitrate (NO3–). Inorganic nitrogen was extracted with 2 M KCl following the method of Mulvaney (1996), with nitrate and ammonium in extracts determined by flow injection analyzer at the USDA Agricultural Research Service laboratory. Daily air temperature and precipitation data were obtained from the NRCS-ARS SCAN site at Rocksprings, Pennsylvania (http://wcc.sc.egov.usda.gov/reportGenerator).
Data were analyzed in SAS with PROC mixed using the repeated measures procedure with cropping system treatment as a fixed effect, blocks as a random effect, and with repeated measures with sampling data as a repeated fixed effect. To compare the cumulative N2O emissions, yields, N2O emissions per unit grain yield, and N2O emissions per unit of N applied among treatments, analysis of variance was conducted and tests for differences in mean cumulative were performed using SAS PROC MIXED. Treatments were considered statistically different at P ≤ 0.05. In order to determine the main environmental and management drivers of N2O emissions, we used Random Forests. Random Forests is a technique for multivariate analysis that uses a recursive partitioning method for classification and regression.
Soil Carbon Sampling
Soil samples were collected from soils planted to corn, soybean and established canola from the three crop rotations in Spring 2016 from 0-5cm and 5-15 cm depth to compare: 1) soil carbon (C) levels from diverse no-till dairy crop rotations, 2) different methods of nitrogen (N) application in the corn-soy rotation and 3) to evaluate the effect of summer tillage vs no tillage in the pest rotation. In broadcast manure plots, 15 soil cores per plot were collected from random locations in the sampled crop entries at the main management or submanagement plot level. In the injected manure plots to account for the 30 inch spatial separation of the bands, four sets of five soil cores 6 inches apart across the crop row were collected, for a total of 20 soil cores per plot. The soil samples were sent to the North Carolina State Soil Testing Lab where they were analyzed for elemental carbon. Data was analyzed with SAS using a MIXED nested split plot ANOVA model.
Activity Density of Insects and Slugs
We assessed activity density based on the number of individual slugs and arthropods under shingle traps. Each week, we counted the number of millipedes, gray garden slugs, marsh slugs, banded slugs, ground beetles, and wolf spiders under 1 ft2 pieces of white roofing shingles.
Weather conditions over the past seven years provided a range of opportunities to assess cropping system performance. Rainy fall (2011, 2012) and spring (2011, 2012) conditions had high slug density activity and years with dry mid-summer weather (2011, 2012, and 2016) had some reduction of corn and perennial forage crop production (Figure 1). With unusually warm early spring temperatures in 2012, 2015, and 2016 (Figure 2), canola flowered early and during the unusually cold winter with limited snow cover of 2014, winter canola and crimson clover died. Compared to 2015, 2016 was a drier growing season (Figure 1). In spite of higher rainfall in May 2016 (3.43 inches) compared to 2015 (1.37 inches), precipitation totaled 6.46 inches during the months of June and July in 2016, whereas it totaled 12.87 during the same period of time in 2015. Despite 2016 being a drier year compared to 2014 and 2015, we did not observe drastic yield losses compared to the previous years (Table 1 & 4).
Manure Rotation: Yields
With the exception of the second year alfalfa stand yield in 2016, crop yields were similar between the broadcast and inject manure treatments (Table 1). The alfalfa yield was 15.6% higher in the BM treatment (the variety without leafhopper resistance) compared to the IM treatment which was the leafhopper resistant variety (17.2 and 15.6 Mg ha-1, respectively) suggesting the possibility of the resistance trait contributing to a yield drag. In contrast to 2015, the crop × manure management interaction effect on crops yield was not significant in 2016. Corn silage yields in manure rotation were slightly lower in 2016 compared to 2015 which could probably be explained by lower rainfall in the months of June and July in 2016 compared to the same time period in 2015.
PhD student Emily Duncan successfully defended her dissertation in May, 2016, completing four studies:
Study 1: Development and hydrologic evaluation of the plot scale lysimeters were described. Because variability in quantities of both surface and subsurface nutrient loading varied among plots, multi-year data on water flow from each plots was compared and revised treatment blocking pairing were recommended (See the outreach for the related publication).
Study 2: Manure injection (shallow disk) was shown to greatly reduce ammonia emission (>90%), but to significantly increase direct emissions of nitrous oxide (up to 150%), compared to unincorporated applications of dairy manure. While the increased N loss as nitrous oxide offsets only a small fraction on the N conserved by reducing ammonia emission, the impact of the nitrous oxide as a greenhouse gas must be considered when evaluating the overall benefit of manure injection (See the outreach for the related publication).
Study 3: The entire N balance was compared between shallow disk injection and unincorporated, broadcast application of dairy slurry. Greatly decreased ammonia losses with injected had the greatest impact on the N balance. No significant differences in N losses to either surface or subsurface were seen between manure application treatments. Despite greater conservation of manure N with injection, no significant differences in corn silage yield were observed. However, greater concentrations of late season stalk nitrate in injected plots suggested that yields could have been maintained with less N when manure was injected. Manuscript to be submitted to a journal this month.
Study 4: The Integrated Farming Systems model was used to simulate dairy manure management scenarios, including application method (injection vs. broadcast) and storage capacity. Expanding manure storage to 12 months and injecting minimized nitrate leaching losses, but cost of construction of 12 month manure storage capacity greatly reduced net returns for the farm. Injection of manure with 6 months of storage appeared to provide the best balance between economic return and environmental protection.
Lysimeter Phosphorus analysis for 2012-2015
The effect of sampling date was always significant in both overland and subsurface phosphorus losses in all of the years (Figures 3 & 4). The main effect of treatments (manure application methods) was significant in the overland loss (2014) and also in the subsurface loss (2015) with the broadcast having more P loss compared with the injection. On most of the occasions, significant P loss were typically observed after rainfall events or after manure application followed by a rainfall (Figure 3). On a few occasions, manure injection resulted in a higher P loss compared with broadcast [1/31/13 and 3/13/15 in the overland loss (Figure 3) and 6/4/12 in subsurface loss (Figure 4)]. Despite significant higher P losses in the broadcast or injection treatments in some sampling dates (Figures 3 & 4), the differences between treatments were not significant in each year. Large spikes in both overland and subsurface P losses occurred and were associated with either rainfall or manure application followed by a rainfall.
When total annual P l loss was calculated and analyzed, using “year” as the repeated measure component of the analysis, BM and IM treatments did not differ significantly; years, however, differed significantly which could presumably be explained by annual rainfall differences during this study (Figure 5). The Karst topography of the experimental site (characterized by underground drainage systems with sinkholes and cracks) and hydrologic variability of the plots likely explain some of the inconsistence differences between the broadcast and injection methods in both overland and subsurface losses. In addition, since manure was only applied once a year in 2013, 2014, and 2015, manure and soil P levels may not have been high enough to result in consistent loss or differences that could be detected with high variability hydrologic conditions. These results support the Emily Duncan research on the hydrology of the plots that indicated the current treatment pairing and current blocking based on landscape position is not representative of hydrologic similarities and should be re-assigned to new treatment pairs and new blocks to reflect similarity in historical subsurface and overland flows.
When annual overland and subsurface P losses were summed, as shown in figure 6, it was only in 2014 that broadcast manure had significantly higher total P loss then inject manure. Increased P losses after three years of manure application in 2014 may be due to higher precipitation events that contributed to high P loss in that year.
Factors contributing to nitrous oxide emissions from corn fields in no-till dairy crop rotations
Nitrous oxide (N2O) is a potent greenhouse gas released from agricultural soils primarily as a by-product of the microbial process of nitrification and denitrification. Traditional corn and soybean productions systems rely heavily on N inputs from inorganic fertilizers and account for the highest N2O emissions among major cropping systems in the US (Del Grosso et al., 2005). To better manage the sustainability of the cropping system, legume crops can be included into corn systems to reduce inorganic fertilizer use, and manure can be used to replace inorganic fertilizer. However, the efficacy of these approaches to reducing N2O emissions is uncertain because of the interaction of multiple factors that regulate several different N2O producing processes in soil (Venterea et al., 2012). Research has typically been limited to studying the effect of one or two sources of N inputs on N2O emissions from an individual system; however, systems of interest often have more than two sources and factors that may interact with each other. This study investigated how different cropping practices that include differences in crop residues, N inputs (dairy manure and inorganic fertilizer), fallow period, timing of N amendment applications and environmental conditions influence N2O emissions from no-till soil planted to corn.
N2O Emission Research Conclusions
Nitrogen source effect on soil N2O emissions
In 2015, elevated N2O emissions were observed from the legume treatments about 15 days after the previous crops were terminated and spring manure was applied (Figure 9). During this period, daily mean fluxes in alfalfa + orchard grass and crimson clover treatments varied from 2.26 to 50.86 kg N-N2O ha-1 d-1 and 1.17 to 101.07 kg N-N2O ha-1 d-1, respectively. By 45 days after the cover crops were terminated and manure was applied, the emissions were lower, varying in the alfalfa + orchardgrass treatment from -0.01 to 7.26 kg N-N2O ha-1 d-1 and in the crimson clover from 0.09 to 6.35 kg N-N2O ha-1 d-1. As in 2015, elevated N2O emissions were found 15 days after the previous crops were terminated and spring manure was applied in 2016 (Figure 10). In 2016, peaks in May happened more often than in 2015, most likely in response to the higher amount of precipitation. In 2016, daily mean fluxes in alfalfa + orchard grass and crimson clover treatments varied from 16.8 to 72.1 kg N-N2O ha-1 d-1 and 15.0 to 70.1 kg N-N2O ha-1 d-1, respectively. Nitrogen input from symbiotic N fixation from the legumes, manure and weather conditions favored denitrification early in the season. Nitrate and NH4+ soil levels increased slowly early in spring after manure was applied and cover crops were terminated (Figures 7 & 8). In 2015 and 2016, based on pre-side dress nitrate tests, the legume treatments did not need supplemental application of inorganic fertilizer later in the season, whereas, the broadcast manure treatment needed inorganic fertilizer to achieve the corn crop yield goals. In 2015, high emissions occurred from the soybean with broadcast manure treatment early in the spring after manure was applied and later in the season when inorganic fertilizer was applied. In contrast in 2016, emissions in the broadcast manure treatment were low early in the season and also after inorganic fertilizer application. Emissions in response to inorganic fertilizer application in the soybean with broadcast manure treatment varied between the years likely because in 2015, inorganic fertilizer application coincided with a heavy rainfall.
Method of manure application and soil N2O emissions
Unincorporated, broadcast manure application covered the soil surface, whereas injecting manure with the shallow disk injector left minimal manure on the soil surface. In 2015 and 2016, N2O emissions from the soybean treatment with injected manure were elevated compared to the broadcast treatment, and UAN treatment with daily mean fluxes in 2015 that varied from 0.6 to 420.6 kg N-N2O ha-1 d-1, and in 2016 from 0.3 to 121.96 kg N-N2O ha-1 d-1 (Figure 9). The higher emissions in this treatment were likely because manure injection created a 10 cm deep band of concentrated N, high moisture and organic matter, which favored the process of denitrification. In 2015, the soybean with broadcast manure treatment had elevated emissions 15 days after manure application. In contrast, emissions remained low early in the season in 2016. Based on pre-side dress nitrate tests, the injected manure treatment did not need supplemental application of inorganic fertilizer later in the season, whereas, the broadcast manure treatment needed inorganic fertilizer to achieve the corn crop yield goals. This is likely because injected manure conserved more ammonical N and less was lost. In 2015, 4 days after inorganic fertilizer application N2O emissions in the soybean with broadcast manure and UAN treatment was significantly higher compared to the soybean with injected manure. Nitrous oxide emissions were likely favored by precipitation events that happened after UAN application. In 2015, large N2O emissions shortly after mid-season, side-dress inorganic fertilizer application likely resulted from precipitation events that created conditions favorable for denitrification (Figure 9). In 2016, a dry period after inorganic fertilizer application limited the denitrification potential and overall N2O emissions (Figure 10).
Cumulative N2O emissions per unit N applied
In 2015 and 2016, corn with injected manure had significantly higher potential for N2O emissions than corn with inorganic fertilizer (Table 2). Cumulative N2O emission per unit of N applied in the corn with injected and broadcast manure was higher than corn with inorganic fertilizer treatment. In both years, cumulative N2O emission per unit of N applied from treatments with winter crop residues with manure and with no winter crop residues and manure, were not significantly different. In 2015 and 2016, the UAN treatment had the lowest N2O cumulative emission per unit grain yield and per unit N applied.
In 2015, average grain yield was 9.2 Mg ha-1 and was not significantly different among the treatments that received organic N inputs from manure and/or crop residues (Table 2). In contrast, in 2016 grain yields averaged was 10.5 Mg ha-1 and was significantly lower in the alfalfa and orchargdrass treatment compared to the crimson clover treatment. In 2015 and 2016, N2O emissions per unit of grain yields were significantly lower in the soybean with fertilizer treatment compare to the soybean with injected manure. Integration of legumes and grasses in the cropping did not reduce N2O emissions per unit of grain yield relative to the soybean with inorganic fertilizer treatment.
Main drivers contributing to N2O fluxes
The random forest analysis explained 48.07 % of variation in N2O emissions. Days after manure application was identified as the most important variable, followed by days after previous crop termination, soil nitrate levels and soil moisture (Figure 11). These results suggest that timing of manure application and crop residue termination with crop uptake is critical to reduce N2O emissions.
Crop rotations, organic fertilizer application, increasing plant residue are some of the practices that have the potential to increase the sustainability of crop production. Integration of legumes and grasses in these cropping systems contributed to meet yield goals and reduced the use of inorganic fertilizer, however they did not reduce direct N2O emissions. Elevated soil N2O emissions were observed between 15-42 days after previous crops termination and spring manure application. Although manure injection has many benefits that include reducing soil disturbance, reducing ammonia losses, phosphorus runoff, and conserving manure nutrients, we observed higher N2O emissions in 2015 and 2016 compared to surface application with manure or inorganic fertilizer. More N was conserved when manure was injected and no supplemental inorganic fertilizer was added to meet yield goals, but the higher N availability and carbon concentration in the 10 cm injection band likely favored N2O production by denitrification. To account for various factors driving N2O emissions, we used Random Forest analysis. The variables included explained about 48% of the variability in the N2O emissions. Time after manure application, days after previous crop residue termination, soil nitrate, and moisture were identified as the main measured variables driving N2O emissions. These results suggest that to reduce N2O emissions, N application events should be synchronized with plant N demand, managers should avoid applying N when there is a high chance of precipitation and apply an N rate based on soil N availability and yield goals.
2016 Soil Carbon Results
Following the spring tillage in the canola crop entry (Pest rotation) in August, in the top 5cm of soil in the no-till plots (SH) had 35% more soil carbon compared to those that were tilled to terminate alfalfa (RH treatment) (Figure 14). By contrast, the tillage treatment had higher soil C at 5-15 cm soil depth compared to the no-till treatment (1.4 vs 1.2%), which could be due to the moldboard plow burying the alfalfa to this deeper soil level where it is more protected from decomposition. Soil carbon levels were also higher in the 0-5 cm depth in the no-till treatments compared to the tilled treatments in the soybean crop entry, two years after tillage (Figure 15). Further, in the corn in the Pest rotation, three years after tillage was applied, no till plots tended to have higher C from depth of 0-5cm compared to the tillage treatment (1.8 vs. 1.4% respectively); however, the difference between tillage and no-till treatments was not significant in the soil 5-15 cm soil depth (Figure 16).
Soil carbon levels did not significantly differ between IM and BM treatments across all of the crop entries in the manure rotation in the top 5cm of soil (1.9 vs 1.8%, respectively) or the 5-15 soil depth (1.4 vs 1.3%, respectively). In the corn-soy rotation (Control), soil C levels in the corn in the three nutrient treatments (FERT, IM, and BM) also did not differ at both soil depths (0-5 and 5-15cm) (Figure 13).
When all crop entries from each rotation were averaged and compared across rotations, the manure rotation had 15 and 18% more soil carbon at 0-5 cm soil depth compared to the pest and control rotations, respectively. The Pest and Control rotations did not differ significantly (Figure 12). Although the manure and pest rotations both include perennials and cover crops, there are likely a number of explanations for why soil C in corn did not differ between the pest and control rotations. As illustrated in Fig 16, in the pest rotation half of the corn entry plots had been tilled three years prior to terminate alfalfa without an herbicide (RH treatment). In addition, in the corn-soy rotation, corn is harvested for grain and the corn stalks are left in the field every other year in the corn-soy rotation contributing significant amounts of corn stalk residue to the top soil layer. By contrast, in the pest rotation, the cover crop after soybean is short-lived, and corn grain was grown in the only corn entry in the six-year rotation until 2012, but the corn stalks were removed for bedding. Since 2013, the corn entry in the pest rotation has been corn silage.
Fall Manure Nutrient Conservation- Satellite Experiment
Although the potential for nutrient loss and water quality impairment is higher when manure is applied in the fall rather than in the spring, limited manure storage drives the decision of northeastern dairy farmers to spread manure in the fall. This study was conducted to evaluate three field management strategies: i) winter rye crop management (managed as a cover crop or silage), ii) method of manure application (broadcasted or injected); and iii) timing of manure application (applied early in the fall or late, September or November respectively); that would reduce nutrient losses from a fall manure application and conserve manure-N for crop utilization in a no-till cropping system with winter rye planted in the fall followed by corn silage planted in the subsequent spring. We hypothesized that injecting manure as compared with broadcasting it; and applying manure late in the fall compared with early fall manure applications would reduce N losses and conserve more for crop utilization.
Previous reports, the 2014 and 2015 Northeast SARE DCS Project Progress Report, focused on the effect of fall manure application method and timing on winter rye and corn silage biomass. In addition to crop biomass, prior to corn planting and following winter rye termination or harvest, we measured soil nitrate to determine if main treatment effects affected residual soil-NO3-N concentrations at different depths within the soil profile. Deep soil cores were obtained in each treatment plot to a depth of 90 cm using a Giddings hydraulic probe (Giddings, Ft. Collins, CO 80522). In treatment plots that received broadcasted manure, three cores were composited based on the depth to produce six samples per plot: 0-15cm, 15-30cm, 30-45cm, 45-60cm, 60-75cm, and 75-90cm. In treatment plots that received injected manure, a different method of sampling was used to avoid under or overestimation of concentrations soil-NO3-N if taken randomly. When the location of the band was unknown, five soil cores were taken perpendicular to the direction of manure application across 76.5cm in 15.2cm increments to cover the distance between injection bands. Cores were separated by location across the 76.5cm and the six depths previously described. When manure bands were marked after a late manure application, sampling was reduced to three soil cores- one on: the manure band, 15.24cm from the band, and 30.48cm from the band. Soil cores were then separated by location and depth. Soil was dried in a greenhouse and ground to 1mm using a hammer mill. Soil samples from the 30-60cm and 60-90cm depths were combined and a total of four depths represented the soil cores taken from plots: 0-15cm, 15-30cm, 30-60cm, 60-90cm. Soil samples were sent to the Pennsylvania State University Agricultural Analytical Services Lab (University Park, PA), to be analyzed for nitrate. Soil-NO3-N concentrations were statistically analyzed using the PROC Mixed procedure in SAS. Data was pooled across years. Each main factor: i) how the winter rye was managed; ii) how the manure was applied; and iii) when the manure was applied; year, and all the interactions with main factors were included in the model as fixed effects. Replicated blocks were nested in year and treated as a random effect. The ‘SLICE’ statement was used to determine least square means and to perform partitioned analyses of LSMEANS to determine the effect of management strategies. Differences were considered significant when p<0.05.
Soil NO3-N Differences by rye crop management
In 2014, soil NO3-N after a cover crop tended to be higher than ryelage at the 0-15cm depth, but the difference was only significant when manure was injected (Figure 17). Soil NO3-N was 71 and 36% higher after a cover crop than after ryelage when manure was injected in early and late fall respectively (Figure 17 b,d). No significant differences in soil NO3-N were found due to rye crop management at deeper soil depths. Similarly in 2015, soil NO3-N tended to be higher when rye was managed as a cover crop than when harvested for ryelage (Figure 17). Differences were significant at shallow depths when manure was applied late in the fall. After a late-broadcasted manure application, soil NO3-N concentrations were 240 and 159% higher after a cover crop than after ryelage at the 0-15 and 15-30cm depth respectively (Figure 17g,h). After a late-injected manure application, soil concentrations were 74 and 155% higher after a cover crop than after ryelage. At the 30-60cm depth, soil NO3-N concentrations were 89, 100, and 59% higher after a rye cover crop than after ryelage, when manure was injected early, broadcasted late, and injected late respectively (Figure 17 f, g, h).
Across both years, winter rye biomass and N-uptake in aboveground biomass was lower when managed as a cover crop than when harvested for ryelage (Table 3). Residual soil NO3-N tended to be higher after a cover crop than after ryelage. The rye cover crop grew for a shorter period of time and more nitrogen was conserved in the soil. Ideally, higher concentrations of NO3-N after a cover crop would remain in the soil for subsequent crop use; but there is also the potential for N-leaching and other pathways of loss in the time period between cover crop termination and subsequent crop establishment.
Soil NO3-N Differences by method of manure application
In 2014, soil NO3-N concentrations at the 0-15cm depth, following a rye cover crop, were 73 and 74% higher after manure was early- and late-injected than when early- and late-broadcasted respectively (Figure 18 a, b). Following a cover crop, soil NO3-N concentrations were 91 and 73% higher after early-injected manure than early-broadcasted at the 30-60 and 60-90cm depths respectively; and 82, 54, and 84% higher after late-injected manure than after late-broadcasted respectively (Figure 18 a, b). Following ryelage, after an early manure application, soil NO3-N was 96% higher after injected manure than broadcasted at the 60-90cm depth (Figure 18 c). After a late manure application, soil NO3 concentrations were 61% higher after injected manure than broadcasted (Figure 18d). In 2015 following a cover crop, soil NO3-N concentrations were 97% higher after early-injected manure than broadcasted at the 30-60cm depth; and 173, 174, 114% higher after late-injected manure than late-broadcasted at the 0-15, 15-30, 30-60cm depths respectively (Figure 18 e, f). Following ryelage, soil concentrations were 435, 168, and 175% higher after late-injected manure than late broadcasted at the 0-15, 15-30, 30-60, and 60-90cm depths respectively (Figure 18h).
Although differences in soil NO3-N due to the method of manure application were not always consistently significant in 2014 or 2015, NO3-N concentrations tended to be higher when manure was injected than when broadcasted. Immediate incorporation of manure using the shallow disc injectors reduced volatilization; increased ryelage biomass in 2014 and 2015 after and early manure application (Table 3); and differences in soil NO3-N tended to persist after broadcasted and injected manure, despite the trend of higher N-uptake when manure was injected (Figure 18, Table 3). At shallow depths, higher concentrations of NO3-N remaining in the soil could be available for the following crop, but also susceptible to other pathways of loss. Higher concentrations of soil NO3-N at the deeper depths following injected manure, will most likely be unavailable to the following corn crop and has a higher potential to be lost by leaching.
Soil NO3-N Differences by method of manure application
In 2014 and 2015, differences in soil NO3-N due to the time of manure application was significant when manure was injected (Figure 19 b, d, f, h). Following a cover crop, soil NO3-N at the 0-15cm depth was 42% higher after late-injected manure than early-injected manure in 2014 and 149% in 2015 (Figure 19 b, f). Further in the soil profile in 2015, soil NO3-N concentrations were 194 and 30% higher after late-injected manure than early-injected at the 15-30 and 30-60cm depth respectively (Figure 19 f). Similarly following ryelage, soil NO3-N at the 0-15 cm depth was 70 and 134% higher after late-injected manure than early-injected in 2014 and 2015 respectively (Figure 19 d, h). At the 30-60cm depth, soil NO3-N concentrations were 43 and 56% higher after a late-injected manure than early-injected in 2014 and 2015 respectively (Figure 19 d, h).
Consistently across years, there were no differences in soil NO3-N due to time of manure application when manure was broadcasted. Following a cover crop and ryelage, when manure was injected soil NO3-N tended to be higher after a late fall manure application than an early fall application. The length of time that the manure is exposed to the elements and soil microbes is longer when manure is applied earlier in the fall rather than later, leaving manure-N more vulnerable to losses through pathways such as volatilization, run-off, and leaching.
For each management strategy there were agronomic and environmental tradeoffs. Coupling a winter rye with fall manure applications can reduce the erosion, run-off, and leaching. Managing rye as a cover crop trends to leave higher concentrations of soil NO3-N in the soil for the following crop, but with a longer time period between cover crop termination and corn planting, soil NO3-N is vulnerable to losses. Soil NO3-N following a ryelage crop has the potential to increase total forage production, but will require additional fertilization to optimize crop yields. Injecting manure reduces volatilization and conserves more nitrogen in the soil. With trends of higher soil NO3-N concentrations in the soil after injected manure than broadcasted manure, more NO3-N could be conserved for subsequent crop utilization, but could be lost by leaching. Similarly, delaying fall manure applications can also reduce volatilization losses, and the observed trends of higher soil NO3-N after late injected manure than early injected can be available to the following crop, but can also be lost.
Pest Rotation: Yields
Crop yields did not differ between the reduced herbicide (RH) and standard herbicide (SH) treatments for all of the crop entries, except for the 3rd year alfalfa-orchardgrass and alfalfa stands in 2016 (Table 4). The third year SH alfalfa yielded 35% more than RH alfalfa and orchardgrass. There appear to be two factors that could explain the lower yield of the RH treatment. The pure SH alfalfa produced higher yields than the alfalfa and orchardgrass RH mixture in late June and mid-August harvests (data not shown), possibly because alfalfa is more productive under dry, warm summer conditions then orchardgrass. And because this forage entry was terminated in August to plant canola, the autumn yield that the orchardgrass might have produced in the RH treatment in fall was not realized. In addition, the alfalfa in the RH treatment was the potato leafhopper (PLH) resistant variety, and the SH alfalfa was not PLH resistant. And as discussed earlier in the manure rotation yield results, the leaf hopper resistant alfalfa variety planted with orchardgrass yielded 15% less then the non-resistant alfalfa planted with orchardgrass this year in the second year stands. In the manure rotation, both treatments had alfalfa and orchardgrass and both were also harvested in autumn, suggesting there was a yield-drag associated with the PLH trait this year in both rotations in these older stands.
Across Rotations Yields:
We also compared corn and soybean yields among the two diverse rotations (PEST and MANURE rotations) where pests are managed with IPM to the low-diversity rotation (C-S rotation) where pre-emptive pest control practices are used (Project Schematic). Similar to 2015, soybean yield in 2016 did not differ between the PEST and C-S rotations and did not differ between RH vs. SH and IM vs. BM treatments nested in each rotation respectively (Table 5). Corn grain yield in 2016 was also similar in the MANURE and C-S Rotation (p = 0.25; Table 5), and there were no significant differences between the two injection and broadcast manure treatments in either rotation.
Canola populations and slug activity density and damage assessments (2015-2016)
In the pest rotation, winter canola is planted after alfalfa and is either terminated with plowing to eliminate an herbicide (RH) or with an herbicide (SH treatment). The 2015, canola populations counted 40 days after planting did not differ between the tilled RH and no-till SH treatments (Figure 20). In 2016 however, tilled RH treatment had 34% more canola plants compared to the SH (Figure 20). Average slug activity density between 10/6/2016 and 11/8/2016 was 150% higher in the no-till SH plots compared to the tilled RH treatment in 2016 (Figure 21) . In spite of higher slug activity densities in the no-till, SH treatment, slug damage to the canola plants did not differ significantly between the treatments in both years (Figure 22). The lack of a significant plant damage difference between the treatments in both years, may be because slugs consumed canola seedlings prior to the plant populations and damage assessments were conducted 40 days after planting.
In previous years, we had planted canola in mid-September when we found slug activity tended to increase. In those years slug activity density was typically higher in the SH treatment, and canola populations were reduced compared to the RH treatment. Therefore, to improve the establishment on no-till SH canola, in 2012 we began terminating the alfalfa earlier in order to plant the canola by Aug. 25-27. In 2016, however the dry weather limited alfalfa regrowth after the third harvest, delaying our ability to terminate the alfalfa early with an herbicide. In 2016 canola was delayed until September 8, compared with August 28 , in 2015. Although the dry fall weather also limited the canola plant establishment in 2016, this delayed planting also likely coincided more the increased slug population activity in mid-September, contributing to the lower SH canola plant populations.
Integrated Pest Management, Scouting, Insect and Slug Control
Our efforts in implementing Integrated Pest Management in the two diverse dairy crop rotations in 2016 continued to focus on evaluating foster strong predator populations, which in turn can reduce pest populations, including slugs and caterpillars, and the damage these pests cause. In particular, we scouted slug populations and damage by slugs, presence of European corn borer in corn plots, and potato leafhopper population assessments in first and second year alfalfa plots. By contrast in the corn-soybean control rotation, there are no cover crops that might provide predatory habitat and both the seed insecticide treatment and the insecticide sprays at corn planting can reduced predator populations.
Slug Damage In Corn
Slug damage was assessed by randomly selecting either two or four 10ft lengths of a split-split plot depending on treatment. Each corn plant was examined within the 10ft length. Plant damage at the V2 growth stage was predominately given a 0 or 1 rating (0-10% damaged). Within the Pest Corn Silage (CS Pest) rotation there was a significant decrease in the number of plants damaged compared to the manure rotation. Within the pest rotation an average 3.1 plants were damaged compared the range of 5.3 to 7.7 in the other rotations. This decrease in the CS Pest rotation continued into the V5 stage (Figure 23) with an average of 7.3 plants damaged. Part of this decrease in plant damage in the CS Pest rotation may be explained by the significant decrease in the number of plants per 10ft found during the V5 stage (Figure 25). This difference could be indicative of poor corn establishment in CS Pest rotation compared to the other rotations. There was also a significant decrease in plants damaged in the Manure Corn Silage (CS Manure) rotation at the V5 stage compared to the to the Control rotation. However, unlike the CS Pest, following the trend that we have seen in previous years of more diverse corn rotations having reduced slug damage compared to the Control rotation, the corn grain plants in the Manure rotation did not have less damage then the pest rotation (Figure 24). Plant damage rating at V5 was predominately ranked as 1-2 (10-20 % damaged), and tended to occur on the oldest leaves on the plant (data not shown).
The soil disturbance by the high residue cultivator and tillage in previous years in the RH treatment may explain this difference. The manure and control rotations had not had any tillage or soil disturbance in the past six year. In the pest rotation, the RH main-management (half of the corn plot) was tilled 2,5 years ago to terminate alfalfa instead of using an herbicide in the no-till SH treatment. And the year prior to corn planting, one quarter of the RH plots were cultivated twice with a high-residue cultivator to control weeds in soybean (HR sub-management). This soil disturbance in prior years to a portion of the Pest rotation corn plots may explain the lower corn plant slug damage, as this fall and in some previous years, slug activity density was lower and canola populations were higher in the tilled RH treatment plots compared to the no-till herbicide SH treatment plots. We also observed some reduction in slug activity density in the RH treatments in corn in previous years.
European Corn Borer (ECB) Damage
At the end of August, we assessed European corn borer populations in the corn plots by recording feeding damage and lodged corn plants. Overall, there was an insignificant amount of European corn borer damage in all corn rotations and the treatments did not differ significantly (Figure 26). All the rotations had an average number of tunnels below the economic threshold of 1 ECB (tunnel) per corn plant (Figure 26). Though plants within the control plots were the least damaged of all rotations, the amount of damage was very minor amoung the treatments. Lodged plants were not found in the Control rotation and the corn silage after the interseeded cover crops (CS Int) treatment in the Manure rotation. The number of lodged plants was significantly higher within the non-interseeded corn silage treatment planted after alfalfa and orchardgrass (CS AOg2) in the Manure rotation, and the corn silage in the Pest rotation (CS Pest), compared to the other three treatments. Transitioning to a BT corn variety for the corn grain in the Manure (CG Manure) rotation as mentioned last year maybe premature as the difference was not significant between the corn grain in the manure and control rotations, and both were below the economic threshold.
Sentinel Prey Assessment
We assessed the predation within each corn rotation by the use of 16 sentinel waxworms per corn plot. We recorded how many waxworms survived over two twelve-hour periods (within 24hrs) to assess the predation during the day (until 8:30pm) and night (until 8:30am the next morning). There were no significant differences in the number of waxworms that survived in July, or August between all corn rotations in either the day or night assessment (Figure 27). In June, there was a siginificant decrease in waxworm survival at night between the Manure and Pest rotation where approximately 18% fewer waxworms survived in the Manure than in the Pest rotation. Waxworm survivial at night in all rotations during August is the lowest survival rate in the past three years. This rate may indicate a higher predator pressure than in previous years, perhaps due to drought conditions experienced in late July and August. Though there was no significant predation difference this year between the control and diverse rotations in June.
Potato Leafhopper Populations
The increase in potato leafhopper populations in 2016 was similar to what we have seen in previous years with the height of their presence occurring in late June and early July (Figure 28). We understand that the leafhopper resistance trait is not fully expressed in the establishment year, but leafhopper resistant alfalfa varieties appear to be effective in significantly reducing population numbers, which is best seen in late July as the leafhopper population increased. The drought that occurred around the same time as the leafhopper population peak made it diffcult to harvest rather than spray insecticides to reduce their numbers, yet visually we observed that the majority of the leafhopper resistant varieties appeared to avoid much damage and being sprayed until harvest. These varieties, both in the short and long term, have reduced the frequency of insecticide use, allowing us to harvest the alfalfa at the most opportune time.
Information that we have learned from the Northeast SARE Sustainable Dairy Cropping Systems is presented in several outreach and extension type activities including field days, workshops, fact sheets, field visits, online videos, symposiums, and regional and national scientific meetings. Each project year, we have reported our project team’s outreach activities in the annual report or the 2015 progress report. Rather then list them all here again, we refer the reader to those reports and list the 2016 publications and outreach activities here.
Northeast SARE DCS Project Updates
- Karsten, H. D. et al, 2016. Summary of the NESARE Dairy Cropping Systems Project. Northeastern, North Central, and Southern Joint Regional Soil Testing Work Group Meeting. July 19, Rock Springs, PA.
- Jahanzad, E et al. 2016. Summary of the NESARE Dairy Cropping Systems Project. APD Act 49 Manure Hauler CECs: Lessons Learned with Penn State Manure and Nutrient Research. Ag Progress day. August 18, Pennsylvania Furnace, PA.
- Our project was also selected as the NE Climate Hub Pennsylvania project to be featured in an interative NE Climate Hub website with videos and panoramic photos. Photos and a video of the project site was recorded in November 2016 that summarized the project and strategies we are evaluating that could help dairy farms adapt to climate change, including practices such as double-cropping, no-till, cover crops, the cover crop interseeder, the nitrous oxide (greenhouse gas) emissions research. It is anticipated that the edited video and annotated photos will be accessible on the NE Climate Hub website in August 2017.
Nutrient Management Team activities from 2016:
1. Jahanzad, E. et al. 2016. Injecting manure may reduce phosphorus run off in both subsurface and overland flow in no-till corn fields. ASA, CSSA, SSSA, Phoenix, AZ, Nov 6-9.
2. Jahanzad, E. et al. 2016. How manure injection can reduce phosphorus runoff compared to the broadcast application? APD Act 49 Manure Hauler CECs: Lessons Learned with Penn State Manure and Nutrient Research. Ag Progress day. August 18, Pennsylvania Furnace, PA.
3. Jahanzad, E. et al. 2016. Using lysimeter stations to evaluate phosphorus run off in broadcast and inject manure applied no-till corn fields. Northeastern, North Central, and Southern Joint Regional Soil Testing Work Group Meeting. July 19, Rock Springs, PA.
4. Hawkins, J. et al. 2016. Understanding the fate of Phosphorus in alternative fall manure applications on lysimeter plots. Gamma Sigma Delta Research Expo, March 29, State College, PA.
Beegle et al. Extension Activities
1. National Soil Testing Joint Meeting, 7/19/16, Tour of NESARE projects and Lysimeters
2. Ag Progress Days, 8/18/16, Manure Hauler and Broker Training, Tour of NESARE projects and Lysimeters
3. Nutrient Management In Agricultural Systems Class, 9/1/16, Tour of NESARE projects and Lysimeters
4. Farm Bureau Tour, 7/27/16, Tour of NESARE projects and Lysimeters
5. NE Certified Crop Advisor School, 12/29-30/16, Managing Soil Fertility in No-till
“Nutrient Management: Fertilization in a Tight Year” at the following extension meetings:
- Lancaster Co. 1/14/16
- Lehigh Co. 1/20/16
- York Co. 1/28/16
- Union Co. 1/29/16
Graduate Student Extension and Research Talks
1. Fall manure application strategies. Rachel Milliron. Pennsylvania Dairy Summit, University Park, Pennsylvania.
2. What to do with all the poo? Rachel Milliron. Penn State’s Ag progress days Nutrient Management for manure haulers, Rock Springs, Pennsylvania.
3. Fall manure applications, it’s not all crappy. Rachel Milliron. Southwest Ag producer’s meeting, Marion Center, Pennsylvania. Oct, 2015.
4. Ponce de Leon, M. Nitrous Oxide and Greenhouse Gas measurements on manured corn plots. 2016. APD Act 49 Manure Hauler CECs: Lessons Learned with Penn State Manure and Nutrient Research. August 18, State College, Pennsylvania.
Graduate Student Research Poster presentations
1. Ponce de Leon, M. et al. Factors contributing to nitrous oxide emissions from soils planted to corn in no-till dairy crop rotations. ASA, CSSA, and SSSA annual meeting, Phoenix, AZ. November 7-9, 2016.
2. Busch, A. K. et al. 2016. Effects of diversified no-till cropping systems on predators and slug damage in maize. Gama Sigma Delta Research Expo. University Park, PA, March 2016.
3. Busch, A. K. et al. 2016. Effects of diversified no-till cropping systems on predators and slug damage in maize. 6th Annual PSU Sustainable Agriculture Cropping Systems Symposium. University Park, PA, April 2016.
Virtual Dairy/Economics Team from 2016:
Presented results from the NESARE project and how it compares to real world practices and economics:
January 18, 2016 – King AgriSeed program – Virginia – 31 attendees
January 19, 2016 – King AgriSeed program – Cumberland County – 39 attendees
January 20, 2016 – King AgriSeed program – Perry County – 60 attendees
January 21, 2016 – King AgriSeed program – Clarion County – 63 attendees
January 22, 2016 – King AgriSeed program – Berks County – 50 attendees
March 22, 2016 – John Deere – Kansas – 24 attendees
November 8, 2016 – Feed Management Workshop – Dauphin county – 40 attendees
Lancaster Farming column – Research Tests Factors Critical to Sustaining Dairy Operations:
Weed Management Team from 2016:
Curran et al. Extension Activities
1. Curran, W.S. and A.E Klodd. 2016. IWM programs for managing herbicide resistant weeds. Penn State Diagnostic Clinic, July 21 and 22.
2. Bunchek, J., W. Curran, D. Mortensen, and J. Wallace. 2016. Integrating cover crops into Mid-Atlantic no-till grain systems to diversify herbicide resistance management. NEWSS (55).
3. Wallace, J.M., W.S. Curran, M. VanGessel, and D.A. Mortensen. 2016. Winter cover crop strategies for management of horseweed in no-till grain systems. NEWSS (277).
4. Curran, W.S. 2016. Exploring cover crop establishment and termination timing for increased cash crop performance. Pacific Northwest Direct Seed Cropping Systems Conference, Kennewick, WA. January 12.
5. Curran, W.S. 2016. Interseeding cover crops in corn and soybean. Presented a webinar to over 50 people from all over the US on our research progress to date of cover crop interseeding. Broadcast vis Adobe Connect on April 11. (http://extension.psu.edu/plants/sustainable/courses/cover-crop-innovations-webinar-series/webinars/interseeding-cover-crops-in-corn-and-soybean).
6. Caswell, K.E., W.S. Curran, S. Mirsky, G. Roth, M.R. Ryan, and J.M. Wallace. 2016. Evaluation of different cover crops in interseeded corn. Northeast Plant, Pest, and Soils Conf. Vol 1: 136.
Insect/Slug Management Team:
Tooker et al. Extension Activities in 2016
1. IPM in a treated/traited world, 23-Feb-16, Adams County Conservation District meeting, Gettysburg, PA.
2. Harnessing diversity to decrease pest problems, 25-Feb-16, Fulton County NRCS meeting, McConnellsburg, PA
3. IPM in a traited and treated world, 15-Mar-16, Vermont Commercial Pesticide Applicator Meeting for Field and Forage Crops, Randolph, VT
4. Planting green for soil health and pest management benefits, 15-Sep-16, Joe Anchors field day, New Columbia, PA
5. To conquer your slugs, you have to think like a slug, 12-Dec-16, Green Armor Seeds Winter Field Day, Catawissa, PA
6. IPM in a Treated/Traited World, 12-Dec-16, Green Armor Seeds Winter Field Day, Catawissa, PA
7. To conquer your slugs, you have to think like a slug, 13-Dec-16, Binkley & Hurst Customer Classic, Lititz, PA
8. Planting Green (presented with Lucas Criswell), 13-Dec-16, Binkley & Hurst Customer Classic, Lititz, PA
9. IPM in no-till to control slugs (and insect pests), 14-Dec-16, 6th Annual Corn Planter Clinic, Shippensburg, PA
Publications in 2016:
1. Snyder, E.M., H.D. Karsten, W.S. Curran, G.M. Malcolm, and J.A. Hyde. 2016. Green Manure comparison between winter wheat and corn: weeds, yields, and economics. Agron. J. 108: 2015-2025.
2. Snyder, E.M., W.S Curran, H.D. Karsten, G.M. Malcolm, S.W. Duiker, and J.A. Hyde. 2016. Assessment of an integrated weed management system in no-till soybean and corn. Weed Sci. 64:712-726.
3. Duncan, E.W., P.J.A. Kleinman, D.B. Beegle, L.S. Saporito, A. Collick, and A. Buda. 2017. Development of field scale lysimeters to assess management impacts on runoff. Transaction of ABSE. In press.
4. Duncan, E.W., C.J. Dell, P.J.A. Kleinman, and D.B. Beegle. 2017. Nitrous oxide and ammonia emissions from injected and broadcast applied dairy slurry. Journal of Environmental Quality. doi:10.2134/jeq2016.05.0171 (to appear in the January 2017 edition)
5. Odette, M., H.E. Gall, L.S. Saporitob, P.J.A. Kleinman. 2016. Estrogen Transport in Surface Runoff from Agricultural Fields Treated with Two Application Methods of Dairy Manure. Journal of Environmental Quality, 45:2007-2015.
6. Milliron, R. 2016. Conserving nitrogen from fall dairy manure applications when coupled with winter annuals before corn silage. M.S. Thesis. The Pennsylvania State University.
Publications in revision or preparation for submission:
1. Malcolm, G.M., E. Synder, H.D. Karsten, W. Curran, and J. Tooker. Establishing and Managing No-till Alfalfa with Annual Companion Crops and IPM for Potato Leafhopper. To be submitted to Agronomy Journal.
2. Karsten, H.D., G. M. Malcolm, D. Beegle, W. Curran, C. Dell. P. Kleinman, T. Richard, V. Ishler, J Tooker and R. Hoover. Evaluating Strategies for Diversified, No-Till Dairy Cropping Systems Designed to Produce All Forage, Feed, and some Fuel. In preparation for submission to Agronomy Journal
3. Jahanzad, E., L. Saporito, H. D. Karsten, P. J.A. Kleinman, C. Dell, D.B. Beegle. Injecting manure may reduce phosphorus runoff compared to broadcast application in no-till corn fields. In preparation for submission to the Journal of Environmental Quality.
4. Milliron, R., H. D. Karsten, D. Beegle, and W. Curran. Influence of fall manure application method and timing on nitrogen conservation when coupled with winter rye. In preparation for submission to the Agronomy Journal.
Other Funding Sources and Awards
1. AFRI Dairy CAP, “Climate Change Mitigation and Adaptation in Dairy Production Systems of the Great Lakes Region” Univ. Wisconsin & 37 Co-PI’s $9,856,576 (PSU:$833,074). 10/2012- 09/2017
2. NIFA Climate Change “Nitrite Ammonification In Manures and Soils Under Adaptive Management for Climate Change. “ MaryAnn Bruns, Heather Karsten, John Regan, and Curtis Dell“, $560,208, 4/01/2016 – 3/31/2019
3. EPA. “Center for Integrated Multi-Scale Nutrient Pollution Solutions”. Shortle, J. (PI) and multiple Co-PI’s $2,498,267, 8/01/13 – 7/31/16
4. NE SARE Professional Development Grant ENE 15-136. “The impact of corn silage selection, harvesting and feeding decisions on income over feed costs. “ V. Ishler, H.Weeks, G.Roth, C.Houser, N.Carutis. $48,874. 10/1/2015-12/30/2018.
5. USDA ARS Cooperative Agreement “Evaluating Strategies to Adapt Northeast Dairy Cropping Systems to Climate Change Projections” $70,000. C. Alan Rotz and Heather Karsten. Jan. 2016- Dec. 2017 with the opportunity for renewal for a second year.
6. NESARE Research & Education. “Getting the most out of cover crops: how timing of termination influences soil health, pest control and improved crop production” Heather D. Karsten, William Curran, Sjoerd Duiker, Ron Hoover, and Chris Houser, and John Tooker. $222,044, 9/14 – 8/18.
Beegle, D. Related Research
- Nitrogen management on Sorghum Sudan grass (Internal funded) Results in the NESARE project indicate that our N recommendations for sorghum sudangrass may not be adequate for optimum production. This experiment is determining the rate and timing response of sorghum sudangrass to fertilizer nitrogen.
- Improving the Efficiency of Injected Manure with a Nitrification Inhibitor (Funded by DOW) One potential drawback to injecting liquid manure is that a micro-zone of conditions ideal for denitrification may be created at the injection point. This project is looking at the impact of adding a nitrification inhibitor (Nitrpyrin) to the manure to reduce the denitrification losses.
Other outreach materials related to the NESARE Dairy Cropping Systems Project:
Additional Project Outcomes
We are currently compiling and comparing the economic performance of the innovative dairy cropping systems in 2015 and 2016. However, in the progress report in 2015, we described the economic comparisons for 2011-2014 (included below). These results indicate that both of the diverse, no-till dairy cropping systems that produce all of the feed and forage for the farm herd and integrate double-crops and cover crops and utilize integrated pest management offer profitable options for dairy farms.
The Virtual Dairy Farm: Economics of Feeding the Herd
The virtual dairy operation was designed to represent a typical Pennsylvania tie-stall barn for the lactating herd and a bedded pack for young-stock and dry cows. Upright silos and Ag Bags are used to ensile forages. All forages, corn grain, soybeans and canola meal are fed to the herd, as a total mixed ration. `The profitability of the farm was evaluated for both scenarios using the FINPACKR Year End Analysis tool (FINAN) over four years (Center for Farm Financial Management, University of Minnesota, 2015). Profitability between the two scenarios was similar using key performance indicators of current ratio (liquidity), return on assets (profitability), debt coverage (repayment capacity), and dairy net return over labor and management per cow (Figure 29). The virtual dairy dealt with real world events such as the volatility of the milk and grain markets. Weather conditions affected forage inventory and quality, which impacted crop sales and milk income.
The virtual farm dealt with drought conditions in 2011 and 2012, which affected the yields of both hay-crop forages and corn silage. The severe drought in 2012 resulted in an increased unit cost/ton for the forages raised because of the low yields. This coupled with the increased market price of purchased feeds caused a substantial increase in feed costs/cow/year in 2013 (Tables 6 and 7). Over the four year period on average the BMSH scenario showed a slight advantage over IMRH when comparing Net Farm Income per cow ($1904 versus $1720). Higher crop sales in the BMSH scenario showed a whole farm profitability advantage because of producing both pure alfalfa and alfalfa/grass mixtures. However, examining the dairy enterprise only (not accounting for cash crop sales), the IMRH scenario showed a slight advantage over BMSH ($758 versus $695). This was the result of incorporating a small grain silage mixture in the rotation that allowed three months of feed for the dry cows and heifers, which saved on the corn silage inventory. The additional small grain silage had ramifications the following fall when corn silage inventory was reduced by 2011 drought conditions. The IMRH had corn silage carry over when the BMSH that did not which effected milk production and milk income, because the BMSH scenario had to feed fresh corn silage, which has shown to reduce production compared to feeding corn silage that is fermented. Due to forage and feed limitations in drier years, 20 acres of corn silage were substituted for wheat in 2013. The wheat straw had been used for bedding and the grain sold off farm. In 2014, 20 acres of canola/red clover was replaced with rye silage/sorghum sudangrass/crimson clover. The additional acreage for corn provides a forage/grain buffer for years when weather limits crop yields, and the rye silage is more suitable quality forage for dry cows and heifers. Evaluating the virtual farm in the real world, the interpretation for both strategies would be sustainable, environmentally compliant and profitable.
Each year our project team presents our research results and modification plans to our Advisory panel. The Advisory panel includes three farmers, a crop consultant whom is active with the PA No-Till Alliance, the regional NRCS director, and the PSU Agronomy research farm manager. We value their input and feedback and often implement their recommendations and test their ideas. We ask the Advisory panel about adoption barriers, and how to best present and promote what we have learned; and some have participated in our field days.
Surveys of attendants at our field days and extension meeting programs consistently indicate that participants have a new gained new knowledge or an enhanced understanding of the how to implement the conservation cropping system strategies and dairy feed and forage management approaches, as well as the benefits of these practices; and a high percentage of farmers report that they plan to or are considering adopting the practices (ex. see Field Day survey in 2014 Annual Report).
To promote farmer adoption, we have begun initiating outreach activities with case study farmers to document and assess the benefits of some key practices on commercial farms. As described in our 2016-2019 Northeast SARE Agroecosystems proposal “Advanced Sustainable Cropping Systems for Northeast Dairy Farms” our Dairy Science team (V. Ishler, L. Holden, T. Beck, E. Ranck) has identified case study farms to work with around our key extension theme: “Managing for whole farm feed production and nutrient balance is profitable.”
Three case farms have been identified and investigators will be visiting those farms in December 2016. Farm No.1 is located in Bradford County, PA. They milk 500 cows and currently double crop several hundred acres each year. Farm No.2 is a small farm in Lycoming County, PA with around 40 cows. The acreage under crop farms is only 40 acres and the farmer is interested in learning how to improve dry matter per acre by double cropping. Farm No.3 is in Cambria County, PA. They milk around 200 cows and have over 100 acres that they double crop every year.
We are currently developing a plan and data sheets for extensive data collection about cropping, feeding and dairy production systems as well as financial records for each of the case farms. The project has been sent to the Office for Research Protection and has been deemed “exempt” from reporting for human subjects’ research.
Once the data collection system is in place and data is collected, it will be entered into the Integrated Farm System Model (IFSM). Investigators have met with the lead scientist at USDA who developed the IFSM and have a good understanding of how the model can be used to analyze various scenarios related to double cropping, nutrient balance and whole farm profitability. Using this knowledge we hope to come up with a basic decision making tool that can be used in Extension and outreach.
In addition, Scott Heckman, our NRCS Advisory panel member from Clinton County invited our project team to participate in developing a NRCS Regional Conservation Partnership Project to target additional Farm Bill CSP and EQUIP funds to a region to promote many of the conservation practices we have evaluated and would like to evaluate and promote adoption of on commercial farms. The proposal was lead by the Chesapeake Bay Foundation, NRCS, and a number of regional partners; and members of our Dairy cropping systems project team and with leadership from Kristy Borrelli the Penn State, Northeast SARE Sustainable Agriculture Extension Educator represented our project and PSU Cooperative Extension. We committed to conducting on-farm research on two farms and assisting with RCPP extension activities; and we recently learned that this RCPP grant will be awarded in 2017, providing funds for 3 years that we anticipate will help us recruit case-study farms, as well as monitor the performance of the practices, and with extension outreach activities.
Areas needing additional study
We discussed the areas we have identified as needing additional study in our 2016-2019 Northeast SARE Agroecosystems proposal “Advanced Sustainable Cropping Systems for Northeast Dairy Farms”. In 2016, we initiated the research we proposed through modifications to the cropping systems and the initiation of identifying opportunities to work with case-study farms. To further inform our efforts to optimize double-cropping and fall manure management, a new Agronomy MS graduate student has begun two satellite experiments, described below.
1. Winter cover crop management and manure application timing, method: tools for nutrient conservation
Jonathan Binder, a new graduate student in Agronomy joined the group and started two 2-yr research projects on the topic of nutrient management. One of the experiments was started in September 2016, on the lysimeters to explore manure nutrient management using winter rye for cover or silage. Since dairy producers in the region typically apply manure in autumn, this research will assess winter rye managed for cover or silage, how it influences rye and corn forage production and nutrient losses from agricultural lands. The experiment will test the hypothesis that harvesting cereal rye for silage compared to growing it for a cover crop will reduce fall manure N and P losses to the environment and remove more in the rye crop. We will compare concentrations of N and P in subsurface flow and overland flow between a cereal rye cover crop and cereal rye silage planted in the fall after corn.
The two treatments, rye cover crop and rye silage, are replicated six times and were planted in fall 2016 and broadcasted with dairy manure. The cover crop will be terminated early in spring to allow for a longer growing period for the following corn crop, while the rye silage will be permitted to mature to the boot stage before it is harvested for forage. The hypothesis is that the longer growth period of the rye silage and the harvest of the silage biomass will reduce nutrient losses to the environment and can be managed to produce more total forage of rye silage and corn silage than rye cover crop followed by corn silage. Supplemental nitrogen will be applied after the rye is harvested and an appropriate season-length corn hybrid will be planted after the rye silage .
Jonathan Binder will also be involved in an expansion of an experiment and research questions that were explored by previous graduate student, Rachel Milliron. This five-replicate, full factorial experiment will take place on the Penn State Research Farm and will assess the nutrient conservation capacities of three different manure and crop management approaches: i. early fall vs. late fall manure application, ii. injected vs. broadcasted manure application, and iii. a winter rye cover crop vs. winter rye silage. The experiment will include controls without any rye crop, as well as a set of plots for stepwise inorganic fertilizer application to construct an N-response curve of corn yields to N application. This will allow for calculation of the amount of N available to a corn crop from fall-applied manure following these various manure and croop nutrient-conserving techniques. In addition, plant tissue samples will be collected and analyzed for N and P-concentrations, to compare conservation of manure N and P of the multiple manure and winter annual crop management treatments.
In addition, soil microbial ecologist MaryAnn Burns has joined the project with funds from a NIFA Climate Change grant. With Dr. Bruns as PI, and Karsten and Dell as collaborators her lab is exploring how soils and manures can be managed to counteract denitrification and promote a bacterial process known as nitrite ammonification, the end product of which (ammonium) is not lost directly to the atmosphere. We hypothesize that nitrite ammonification occurs to a significant extent in soils managed using no-till practices and labile carbon amendments, such as animal and green manures, and that manure storage and handling practices can favor nitrite ammonification over denitrification. With funding for a postdoctoral researcher (Arnab Bowmick), a graduate student (Mara Cloutier) and research technician support, we will 1) measure bacterial groups and labile carbon substrates in manures from dairies of varying size and manure handling systems; 2) measure GHGs and temporal and spatial changes in nitrite ammonification in no-till soils and tilled soils in our Sustainable Dairy Cropping Systems project; and 3) conduct soil mesocosm studies to determine relationships between substrates, physicochemical conditions, microbial processes, and GHGs to understand conditions favoring nitrite ammonification.
Further, through a new USDA ARS Cooperative Agreement postdoctoral research associate, Dr. Rishi Prasad has begun work to describe down-scaled climate change projections for three dairy farming locations in Pennsylvania and New York, and is also conducting a review of crop models to compare how they simulate photosynthesis under climate change projection conditions, including elevated carbon dioxide and temperature. He will then explore how to modify IFSM to simulate the our conservation cropping systems, and explore how our conservation dairy cropping systems and strategies and what may help dairy farmers adapt to and mitigate projected climate change, while protecting air and water quality.
Further, in this NESARE sustainable dairy cropping systems project, in some years, terminating cover crop residue 10 days prior to crop planting, contributed to reducing establishment and plant populations of the subsequent crop. Our Advisory panel and farmers suggested that “planting green” or delaying cover crop termination could potentially improve subsequent crop establishment and provide additional soil health and pest control benefits. Working with them, members of our project team developed a NESARE Research and Education grant awarded in 2014. Heidi Myer an Agronomy doctoral graduate student has completed a second field season exploring how to capture more benefits of cover crops by delaying cover crop termination until the subsequent crop is planted on two Penn State research farms and three cooperating commercial farms. Initial results of that research are reported in the project 2016 Northeast SARE Research and Education Annual Report.