Sustainable cropping systems for dairy farmers in the Northeast, II

Sustainable cropping systems for dairy farmers in the Northeast, II

Summary

The goal of this Agroecosystems project is to develop sustainable dairy cropping systems that minimize environmental impacts and off-farm inputs; and are productive, and profitable. To achieve this, we designed the NESARE Sustainable Dairy Cropping Systems Farm to produce all the forage, feed, and fuel for a 65 cow, 240 acre dairy farm, while conserving soil, nutrients, biodiversity, and energy. In spring 2010, we initiated two diverse, 6-year crop rotations using farm-scale equipment at 1/20th scale on 12 acres of Penn State’s Agronomy Research Farm. Within each crop rotation we are evaluating innovative management practices to address key issues: i. manure management in no-till cropping systems 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. With the crop yield and quality that we measure, and a dairy nutrition model, we simulate the dairy herd’s milk production. To identify system performance and opportunities to improve practices, we are evaluating multiple performance indicators: crop yield and quality, soil health, nutrient conservation, greenhouse gas emissions, weed and insect populations; energy use and production, and farm profitability.

Objectives/Performance Targets

There are two major objectives of this project: i. to identify how to enhance the sustainability of dairy cropping systems and dairy farms in the Northeast by integrating best management practices with innovative technologies, ii. to promote adoption of the cropping system practices by farmers.

Accomplishments/Milestones

NESARE Dairy Cropping Systems Research Changes

In 2014, we continued evaluating the cropping systems (Appendix Tables) with the few changes that we had made in 2013, and we made one additional change in the Manure Rotation (see 2014-2015 Cropping Schematic). We have found that the yield and costs of producing spring canola are limited by spring weed pressure, premature bolting, and pest pressure (i.e. flea beetles in 2013). In 2013, we also realized that we needed more low protein forage for the dry cows and heifers that is more appropriate for their maintenance diet needs and prevents these maintenance animals producing manure with excess N. We had been planting spring canola following a winter rye cover crop that manure was applied to the previous fall after corn silage harvest. Therefore, we decided to allow the winter rye to grow longer and harvest it for ryelage rather than terminating it to plant spring canola. This is also a more common dairy farming practice in the Northeast, and offered us the opportunity to evaluate two strategies to produce additional dairy forage and green manure crops instead if spring canola. The two forage/green manure cropping strategies that we are now comparing are cereal rye underseeded with red clover for ryelage and red clover forage and green manure versus ryelage, followed by sorghum sudangrass followed by crimson clover for green manure planted in late August (see 2014-2015 Cropping Schematic).

Winter of 2014 was exceptionally cold with many days below freezing and multiple heavy snowfalls. Winter canola in the pest rotation and crimson clover in the manure rotation did not survive the 2014 winter; only the rye and red clover cover crops survived. In an attempt to produce some canola, we planted spring canola where the winter canola had winter-killed, but soon after it germinated flea beetles rapidly defoliated the canola seedlings. So, we planted sorghum-sudangrass in the winter canola crop entry in the Pest rotation in 2014.

Forage and Feed Quality Laboratory Simulations

At every crop harvest in the NESARE Dairy Cropping Systems Trial, we continue to collect three subsamples for forage or feed quality analysis from each of our main management treatments in the MANURE and PEST rotations. In many cases, processing is needed to prepare a crop sample that is representative of on-farm storage or processing. Data collected on forage and feed quality in conjunction with yield data will be used to develop rations for the virtual dairy herd as Virginia Ishler has done in the past. This data is not presented in this report at this time.

Manure Rotation: Yields

Crop yields were collected for each crop entry point in the MANURE rotation in 2014; data was analyzed with a split-plot, mixed ANOVA model using PROC MIXED of SAS for all crops that received manure in the rotation. Forage crop yields for all harvests were analyzed with a repeated measures split-plot, mixed ANOVA model. When significant interactive effects were found, the SLICE function was used to determine statistical significance.

Similar to the results found in 2013, the effect of manure management on yields for crops that received manure in 2014 was not significant (p = 0.64; Table 1). When crop yields were analyzed individually to compare injection manure with broadcast manure treatments, however, yield for rye silage that had manure broadcasted and a top-dress N fertilizer application in spring was 10% higher than for rye silage that had received injected manure and no top-dress spring N application (p = 0.02; Table 1). Finally, sorghum sudangrass yield following rye silage that had manure broadcasted was 22% higher following ryelage than sorghum-sudangrass that followed ryelage with injected manure injected (p = 0.05; Table 1). Rye silage that had manure broadcasted received an additional 23 kg N/A that the manure injection treatment did not receive, due to presumed conservation of nitrogen by injecting manure. However, manure injection is applied in 76.2 cm rows, while rye silage and sorghum sudangrass are planted in 19 cm rows, so it is also possible that due to the wide spacing between manure bands limited nutrient availability to more rye and sorghum-sudangrass plants in the narrower rows.

Similarly to 2013, when 1^st and 2^nd year crop entry points for alfalfa plus orchardgrass were compared by each cutting for residual effects of different manure management, no significant differences in yield were found in 2014 (Table 3A).

Lysimeter Plots: Trade-offs in Nitrogen Conservation Under Alternative Manure Management Strategies

Graduate student, Emily Duncan is working toward developing an N balance for the lysimeter site for broadcast and inject manure treatments, but cannot summarize and do the statistical analysis on the water and soil lab dataset until the complete set of samples is analyzed. Emily has also been working on a paper detailing the physical characteristics of the plots (hydrology, geology, etc.) using ground penetrating radar in conjunction with water flow and soil information from the individual plots. This work is providing valuable information to help us understand and apply the water flow and quality data obtained from the site.

The lysimeter team has continued monitoring water quality at the site. They also sampled ammonia emissions from fall application of injected and broadcast manure. Preliminary examination of the data indicated that ammonia emissions were higher under broadcast than inject manure treatments as noted in the past.

Pest Rotation: Yields

Crop yields were collected for each crop entry point in the PEST ROTATION in 2014; data was analyzed with a split-plot, mixed ANOVA model using PROC MIXED of SAS for all crops that were managed with reduced herbicide practices in the rotation. Forage crop yields for all harvests were analyzed with a repeated measures split-plot, mixed ANOVA model. When significant interactive effects were found, the SLICE function was used to determine statistical significance.

Unlike in 2013, the weed management comparisons, reduced herbicide (RH) and standard herbicide (SH), were not significantly different across crop entry points in the GRAIN rotation (Table 2). A ‘weed management x crop interaction’ significant effect was observed (Table 2), due to significantly lower yields for RH treatments compared with SH treatments in the first year alfalfa stands (p-value [slice] = 0.0006; Table 2). When crop yields were analyzed individually to compare the reduced herbicide with standard herbicide treatment, however, the reduced and standard herbicide treatments did not differ for any crops (Table 2).  

When weed management for 1^st,2^nd, and 3^rd year crop entry points for alfalfa (SH) and alfalfa, triticale, and orchardgrass (RH) were compared across cuttings, there were no significant differences in yield p = 0.12; Table 3B). In 2013, there was a significant ‘cutting by weed management’ effect for the 2^nd year forage stand; while in 2014, there was a significant ‘cutting by weed management’ effect for the 1^st and 3^rd year forage stands (p = st year stands in 2014, there was a significantly higher yield in the SH treatment compared with the RH treatment for the July and August cuttings (p = 0.015 and p = rd year stands in 2014, the RH treatment yield was significantly higher compared with the SH treatment for the June cutting (p = 0.001; Table 3B).

Soybean and Corngrain Weed Management: Banding Herbicides and High Residue Cultivation

In the Pest Rotation, a standard herbicide regime in soybeans and corn silage was compared to a reduced herbicide regime, which included banding herbicide in a 25 cm (10”) band over the row at planting and was followed by two high residue cultivation events. From 2010-2012, we made this comparison with corn grain. Since some farmers and particularly no-till farmers prefer using a post-herbicide to high residue cultivation, in 2013, we developed a nested split-split plot treatment to compare using high residue cultivation following banded herbicide at-planting with using a post-herbicide spray. Additionally, in 2013 we switched from using a no-till drill to plant soybeans to a planter in an effort to improve soybean establishment and yield across treatments. We also changed from 19 cm (7.5”) drilled soybeans to 38 cm (15”) planted soybeans to compare with the 76 cm (30”) planted soybeans. Our advisory panel indicated to us that many no-till farmers now use planters and plant 38 cm row soybeans to improve seed placement. We collected data on rye cover crop biomass before soybean planting, crop population, weed biomass before harvest, and grain yield in 4 treatments in the soybeans: 38 cm row and 76 cm row soybeans nested in the SH treatment and 76 cm row soybeans that had herbicide banded at planting with either high residue cultivation or broadcast herbicide as a post spray and nested in the RH treatment. Data was analyzed using a nested split-plot MIXED ANOVA model analyzed in SAS.

For soybeans in 2014, rye could not be terminated early due to weather conditions. Because of this the rye residue was rolled before soybean planting. Soybeans in the RH treatments were planted on 30 in (76 cm) rows while the SH treatment was planted on either 15 in (38 cm) or 30 in (76 cm) rows. While there were some difficulties planting into heavy residues, it was not as detrimental as in years past. Data was collected on the rye cover crop biomass before planting, crop population, weed density before and after the post-emergence treatments, weed biomass before harvest, and grain yield in the 4 treatments: SH planted on 76 cm or 38 cm rows and RH with herbicide banded at planted with either two high residue cultivations in season or a broadcast herbicide. Data was analyzed using a nested split-plot MIXED ANOVED model analyzed in SAS. There were no significant differences in rye biomass or yield. However, the RH treatment with high residue cultivation had more weed biomass than the other three treatments (Table 4).

For corn silage in 2014, there was no nested treatment within the standard herbicide regime but there was a nested treatment in the reduced herbicide regime, which included banding herbicide over the crop row at planting followed by either high residue cultivation or post herbicide. Due to this unbalanced design, pairwise comparisons were made among the three treatments on rye cover crop biomass before corn grain planting, weed biomass before harvest, and corn silage yield using a split-plot MIXED ANOVA model analyzed in SAS. There were no significant differences in the rye biomass or in the corn silage yield, but the RH treatment with cultivation had significantly greater weed biomass (Table 5). While there was a trend for higher weed biomass  in RH plots with cultivation, weed populations remained well below a level that could have been detrimental to crop yields.

Across Rotations Yields:

We have a number of opportunities to make comparisons among our two diverse rotations (PEST and MANURE rotations) and the one low-diversity rotation (C-S rotation) (Project Schematic).

Similarly to 2013, soybean yield in 2014 did not significantly differ between the PEST and C-S Rotations and also did not differ for RH vs. SH and IM vs. BM treatments nested in each rotation respectively (Table 6B).

Similarly to 2013, corn grain yield in 2014 was higher in the MANURE Rotation than in the C-S Rotation (p = 0.01; Table 6C). This might partly be explained by the fact that corn grain in the MANURE Rotation followed two years of alfalfa + orchardgrass, which add significant amounts of organic N to the system, and we have found that soil organic matter and water stable aggregation were higher after two years of perennial crops (see Figures 1A and 1B). There were no significant differences between the two injection and broadcast manure treatments in either rotation.

Across Rotations: Insects and Slugs

Among corn grain plots in both a conventional rotation and two diverse rotations, we compared the differences in pest damage and predation. Over the 2014 season, we assessed European Corn Borer damage, determined activity density of slugs and arthropods, and observed predation using sentinel prey, and tracked the seasonal trends in potato leafhopper populations.

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. In May and June, millipedes had highest activity densities that were higher than the other sampling dates (Figures 2A and 2B), probably due to higher soil moisture levels in these months. In June, millipedes had significantly higher activity density in the Manure rotation than the Control rotation (Figure 2B). Millipedes tend to be more abundant where there is more residue, so this difference likely reflects the amount of residue in these plots. Ground beetle populations increased in July and August becoming the most abundant arthropod we detected (Figures 2C and 2D). September showed a decline in ground beetles and an increase in gray garden slug populations (Figure 2E). There was a slight decline in gray garden populations in October as marsh slug populations increased (Figure 2F). It appears that there was a progression in activity densities across spring, summer, and fall with millipedes, ground beetles, and then slugs having the highest abundance in turn.

Sentinel Prey in Corn

The most common predators observed in our sentinel prey experiments were ants, ground beetles, spiders, and slugs. Based on the number of feeding observations recorded, ground beetles were consistently more abundant in the Manure rotation compared to the Control rotation (Figures 3A-3F). The Manure rotation had significantly more predation at night in June (Figure 4A) and July (Figure 4B) compared to the control. There was no significant difference in the amount of predation in August among rotations (Figure 4C), indicating that more diverse rotations foster better populations of predatory arthropods earlier in the year, improving early season pest control.

We also compared average predation among treatments. We found no significant difference among treatments in June (Figure 5A) and August (Figure 5C), but in July the injected manure treatment in the Manure rotation had significantly more predation (Figure 5B). This result may be attributable to the type of application. Broadcast manure treatments involve spraying the top of the soil while directly injected manure spreads the nutrients deeper into the soil, which may increase access for soil microorganisms. The benefits of increased soil microorganisms may have a cascading effect that benefits the predators during the middle of the season.

European Corn Borer

We assessed European Corn Borer (ECB) by recording feeding damage and lodged corn plants. There was minimal damage caused by ECB in the non-Bt corn in both the Pest and Manure rotations, and this damage was statistically similar to the minimal damage to Bt corn in the Control rotation (Table 7). Consistent with previous years, these results continue to suggest that ECB populations are very low and that less expensive non-Bt corn hybrids are viable options for farmers.

Seasonal Trend of Potato Leafhopper in Alfalfa

For both first and second year alfalfa in mid-June and early August, potato leafhoppers had major peaks in population (Figures 6A and 5B). Compared to the first year alfalfa treatment on August 1^st, the alfalfa + grass treatment had significantly more leafhoppers and the alfalfa + grass + nurse crop had significantly less leafhoppers (Figure 6A). On June 20^th for both first and second year alfalfa, the alfalfa + grass and alfalfa treatments were above the economic threshold (Figures 6A and 6B). This was the only time that the plots were sprayed with insecticides. Harvesting the alfalfa at the beginning of each month reduced leafhopper populations significantly in August.

Nutrient Management/Soil Conservation

I. Fall Manure Nutrient Conservation Satellite Experiment:

Many dairy farms in Pennsylvania have limited manure storage capabilities, requiring farmers to empty their manure storage approximately every 6 months. Manure is typically applied to fields in the fall after a harvest and before planting in the spring. With little plant growth occurring in the late fall and winter before spring planting of summer crops, fall manure applications raise many concerns regarding nutrient run off, leaching, and volatilization. Integrating different practices such as the use of cover crops, applying manure at optimal times and using nutrient conserving application methods can minimize nutrient losses.

This past year, from the fall of 2013 to the fall 0f 2014, we conducted a field experiment to compare the conservation of fall manure nutrients associated with two manure application practices to winter annual crops and the subsequent corn silage crop. Manure was applied either in the early fall, after a typical corn silage harvest, or later in the fall, when temperatures become cooler. At each time of application, manure was either broadcasted or injected to a rye crop grown either as a cover crop or for silage (Figure 7). In this randomized block design with six replicates, there were also five fertilizer treatments that did not receive manure. Five rates of fertilizers (0, 30, 60, 90, 150 lbs (NH₄)₂ SO₄/A), were applied to corn to generate a yield response curve and estimate the fertilizer equivalence of each manure treatment.

We hypothesized that more nitrogen will be conserved and corn yields will be greater after i) manure is injected rather than broadcasted, ii) a late fall application of manure rather than an early fall application, and iii) a rye cover crop rather than rye grown for silage. By injecting manure, volatilization of nitrogen can be greatly reduced. Similarly, applying manure later in the fall will also reduce volatilization as well as the mineralization of nitrogen. While winter rye grown over the winter can retain nutrients in the soil and prevent erosion, when harvested for silage in the spring, it will have a longer growth period to take up nitrogen and export it out of the agricultural system in the form of harvested biomass.

Rye Cover Crop Experiment: Rye biomass and nutrient uptake, corn yields, and ammonia gas measurements

In treatments where rye was managed as a cover crop, there was no difference in rye biomass or nitrogen uptake among the manure application treatments (Figure 8A and 8B). However, corn yield following the rye cover crop that was injected with manure was ##% higher than corn yield following rye cover crop with broadcasted manure (Figure 9A). While soil samples have not been analyzed yet, differences in corn yields are likely due to the termination of rye before rapid growth and nutrient uptake, leaving unutilized nitrogen from the fall manure application in the soil. Injecting manure likely conserved more nitrogen than treatments with broadcasted manure. Ammonia gas measurements in the late fall were undetectable when manure was both broadcasted and injected, but in the early fall, ammonia measurements were ## and ##% lower after injecting manure when measured 5 minutes and 5 hours after manure application respectively (Figure 10).

The measurement of ammonia gas after the early fall application and undetectable ammonia gas measurements made in the late fall could also explain the differences in corn yields based on time of manure application. With undetectable ammonia emissions in the late fall, and higher corn silage yields after a late fall application, it is likely that there the reduction of nitrogen volatilization is a benefit of delaying manure applications (Figure 9B).

Ryelage Experiment: Ryelage biomass and nutrient uptake and corn yields

Although there was only a ten-day difference between the time of cover crop termination and ryelage harvest, ryelage yields averaged 4.32 and 5.53 Mg ha^-1 after broadcasted and injected manure respectively, compared to cover crop biomass that averaged about 1.88 and 1.79 Mg ha^-1 after broadcast and injected manure respectively (Figure 8A). When rye was managed as silage, the yield and nitrogen uptake was ##% and ##% higher when injected with manure than when broadcasted (Figure 8A and 8B). This is likely because more nitrogen was conserved when the manure was injected and was available to the rye during rapid growth.

Following the same trend, corn silage yields after ryelage were higher when injected with manure (Figure 9C). However, corn silage yields after ryelage did not differ based on the time of application (Figure 9D). Despite an increase of nitrogen uptake by ryelage injected with manure, it appears that there was more nitrogen conserved from injection that was available to both the rye and corn than after broadcasted manure.

Because the rye silage did take up more of the fall-applied nitrogen than the rye cover crop, less nitrogen was available for the subsequent corn crop than after a rye cover crop (Figure 8B). Albeit lower corn yields after ryelage than after a rye cover crop, the total biomass harvested from this management system was greater than the total dry matter produced in the rye cover crop-corn silage management (Figure 11). Where the cover crop was terminated, there was no living vegetation for 22 days before corn was planted. The terminated cover crop could not utilize the available nitrogen in that time period, but the ryelage crop did and produced greater biomass as well as greater nitrogen uptake. Nitrogen is a dynamic nutrient; it is possible that without living vegetation and root system, some of the nitrogen that was available in the early spring, was lost probably through leaching. Ryelage provided an extended period of live cover, likely to optimize the retention of nutrients, prevent losses to the environment, and increase farmers’ economic return.

Summary

In summary, after the first year of data collection, we found that compared to broadcasting manure, manure injection increased rye silage biomass and N uptake but did not affect rye cover crop biomass or N uptake. However, when corn silage was planted after rye, there was a benefit of injecting manure compared to broadcasting it across both rye cover and rye silage regimes. Corn silage yields as well as total biomass produced, were higher after manure was injected in the fall compared to broadcast. Injecting manure for both rye cover crop and silage likely conserved more nitrogen and resulted in higher corn yields. When corn yields augmented the ryelage yields, the total harvested dry matter was higher than when preceded by the rye cover crop.

Data from the 2013-2014 study is still being analyzed and interpreted. The corn silage yields collected from treatments with the different fertilizer rates will be used to calculate a yield response curve and determine manure nitrogen availability for different manure application times and methods. Deep soil samples taken prior to corn planting will be analyzed to estimate nitrogen leaching. These results along with the determined manure nitrogen availability will be used to further estimate and understand the nitrogen budget associated with the different manure conservation management strategies. We have replicated this study for the fall 2014-2015 growing season. In addition to the same field study, a satellite experiment on the Kepler lysimeter plots located at Rock Springs Research farm was also initiated for the 2014-2015 growing season. In this lysimeter study, an early application of broadcasted and injected manure to a rye crop are being compared to provide a more accurate quantification of nitrogen losses.

II. Nitrous Oxide Measurements Across Rotations:

Nitrous oxide fluxes were measured from closed chambers placed over the crop residues and manure on the soil surface. The chamber design followed USDA-ARS GRACEnet Project Protocols Chapter 3, Chamber-Based Trace Gas Flux Measurements (Parkin et al, 2011). The sampling was biweekly prior to and during the period of anticipated N₂O fluxes to capture the profile of gas emissions from 19 May to 29 July, 2014 of the corn growing season. The samples were collected from four treatments in which corn was planted after four different crops: i. alfalfa and orchardgrass, ii. red clover, iii. soybean and iv. rye cover crop that followed soybean. Manure was broadcast in the spring prior to corn planting and sidedress nitrogen fertilizer was applied during the corn growing season.

Of the four blocks in the field experiment, three blocks (Block I, II and IV) of each treatment were sampled and nitrous oxide was measured in two locations in each treatment-plot. Two chamber frames were placed perpendicularly across two corn rows in two locations in each plot, for a total of 24 frames (4 treatments x 3 blocks x 2 repetitions). Samples were collected at 10, 20 and 30 minutes after placing the cover over the frame. For time 0, we sampled and used an average of the atmospheric air. With this data, by doing a linear regression with the four data points we calculated a rate of grams of Nitrous oxide emission per hectare per day. Gas samples were analyzed using a Varian 3800 gas chromatograph with an electron capture detector and an automated computer that controlled the sample injection system.

Data were analyzed in SAS with PROC Mixed with repeated measures. The previous crop treatment and date of measurement were fixed effects and blocks was random. The slice command was used to test for significant differences between crop treatments at each date.

Results

Crop treatment, date and the interaction of crop treatment by date were significant. On day 142, 155, 157, 161 and 164 nitrous oxide emissions differed significantly between the crop treatments (Figure 13). In general, nitrous oxide emissions tended to peak in treatments about 5 to 10 days after manure was applied. It is likely that this happened because corn plant nitrogen demand was not high when nitrogen was available from the manure and previous crop residues, resulting in excess N that could be denitrified particulary when precipitation events (Figure 14) also contributed to low soil oxygen, which favors denitrification. Later in the growing season, when the side-dress fertilizer N was applied nitrous oxide emissions were lower. This is likely partly because the fertilizer N was more rapidly taken up by the established and actively growing corn.

The alfalfa treatment received the same amount of manure as the soybean and red clover treatments, however, the peaks of nitrous oxide in alfalfa were significantly higher than the other treatments (Figure 13). This is likely because the alfalfa and grass contributed a large amount of nitrogen and organic matter that enhanced microbial denitrification.

III. Soil Health Indicator Measurements:

We collected soil samples from a number of crop entries that were of interest for soil health assessment over time in 2010, when we initiated the experiment and again in spring 2013. In this report we discuss comparisons of soil across the rotations in the corn entries, and crop entries that had zero to two years of prior perennials. For water stable macro-aggregates, we collected ten random soil samples from each main treatment comparison plot (ex. RH vs SH, IM vs. BM) at a 0-15 cm depth. Soil samples were stored in air-tight containers in a cooler and sieved as soon to obtain 1-2 mm macroaggregates which were then air-dried at room temperature for 24 hours. We measured % WSA by modifying the standard wet-sieving technique and used slaking to detect the differences among the treatment. Four grams of the air-dried 1-2 mm aggregates were transferred to the 0.26 mm size sieve of the standard sieving machine (Five Star Cablegation and Scientific Supply, Kimberly, ID). The samples were then submerged in distilled water for 5 minutes before the sieving for 5 minutes. Soil that remained on the sieve was then dispersed using a rubber-tipped rod to gently rub aggregates across sieve for 20 seconds disintegrate sand particles from the aggregates. Sand particles were retained on the sieve, and the soil that passed through the sieve was collected in another can, oven dried (110?C) and weighed to estimate sand-corrected stable aggregate mass. The percent water stable aggregates were calculated as:

WSA = (sand-corrected stable soil/ [Unstable soil + sand-corrected stable soil]) x 100

For soil organic matter, ten random soil cores were collected per main treatment at 0-5 cm and 5-15 cm depths, and composited into a single sample for each depth. Soils were finely ground, the soil samples were sent to the North Carolina State Soil Testing Lab where they were analyzed for elemental carbon. We used the equation developed by Ranney (1969) to convert percent carbon to percent organic matter (Percent organic matter = 0.35 + 1.80 x percent organic carbon).

Results:

Water stable aggregates and soil carbon at both depths did not differ significantly among rotations and treatment comparisons in 2010. In 2013, there were some differences among treatments. In the Pest rotation, the crop entry that had been immediately preceeded by two years of alfalfa and orchardgrass or alfalfa had 20% more water stable aggregations (p<0.05) than the crop entry that had no prior years of perennial crops (Figure 1A). When we compared soil in corn phases of the rotation across the three crop rotations, soil of corn that had been recently proceeded by two years of alfalfa and orchardgrass in the manure rotation had 18% more (p <0.1) water stable aggregates than corn that had been proceeded by summer annual crops with or without cover crops or the winter annual double crop canola (Figure 1B).

Soil organic matter did not differ among rotations and crop entries at the 5-15 cm depth, but soil of corn that had been preceded by two years or alfalfa and orchardgrass in the manure rotation had 17% more (p<0.05) organic matter than soil of corn that had been preceded by annual crops with cover crops or the double crop winter canola in the pest rotation (Figure 1C). This difference in the soil organic matter is likely due to a combination of cropping system differences, including the history of perennial crops, management differences, as well as tillage and possibly manure management differences. Soil organic matter may have been reduced 1.5 years prior to soil sampling when half of the pest rotation plots (RH treatments) were broadcast with manure and plowed to terminate the alfalfa and orchardgrass rather than using an herbicide. In the manure rotation, none of the plots were plowed, but two years prior, one quarter of the corn entry plots had manure broadcast and one quarter had received manure injected in 30 inch bands. In the pest rotation, half of the plots had received injected manure 1.5 years prior to sample collection.  Due to the uneven spatial distribution of injected manure in some plots, the ten random soil samples we collected might not have accurately captured the soil organic matter distribution. Therefore, in June 2014 we sampled soil carbon again but with a spatially strategic approach in the plots that had a history of manure injection. Based on the spatial PSNT soil sampling reserach findings of PhD candidate and team member Robert Meinen, in plots that had injected manure we collected three sets of five soil cores that were spaced six inches apart across the 30 inch crop row for a total of 15 soil cores per plot at both 0-5 and 5-15 cm depths. These samples are being analyzed for soil Carbon, and we will use these results to compare soil organic matter in the corn entries across the rotations again.

• Project Crop Schematic
• Figs12_to_13_NitrousOxide
• Appendix Files: Crop Mgmt
• Tables_1_to_6_YieldsWeeds
• Fig1_SoilQualIndicators
• Figs2_to_6_InsectSlug
• Figs7_to_11_ManureTimingExps

Impacts and Contributions/Outcomes

Whole Farm Scale: Energetic Analysis

Penn State’s Farm Energy Analysis Tool (FEAT; http://www.ecologicalmodels.psu.edu/agroecology/feat/) was used to quantify the fossil energy inputs and GHG emissions of the NESARE dairy cropping systems as compared to two other typical dairy farms. The other two farms required less acreage than the NESARE systems but one only grew feed and forage and the other only grew forage on-farm, while the NESARE system grew feed, forage, and fuel on-farm. One take-home message from the paper is that fossil energy inputs can be reduced by growing forage + feed on dairy farms using animal manure and legume crops in rotation with corn and soybean crops rather than importing those feeds. Importing feeds is quite energy intensive relative to growing feeds on a dairy farm, due to the exclusive use of nitrogen fertilizers and reduced tillage on non-integrated grain production farms. The manuscript for this paper is accepted and is online early: GM Malcolm, GGT Camargo, VA Ishler, TL Richard, HD Karsten. 2015. Energy and greenhouse gas analysis of northeast US dairy cropping systems. Agriculture, Ecosystems and Environment 199, 407-417.

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. Rations for all the animal groups are formulated based on the 2001 NRC model and reflect very closely what is fed to the Penn State Dairy Cattle Research Center dairy herd. The financial evaluation of the virtual farm includes enterprise crop budgets, cash flow plans, and FINPACK year-end financial analysis. The virtual farm is divided into two scenarios: broadcast manure/standard herbicide (BMSH) and injected manure/reduced herbicide (IMRH). The same assumptions regarding the herd size, equipment, and farmstead are constant between the two scenarios. The economic analyses evaluate how feed inventory and forage quality affect the profitability of the virtual farm. These two indicators have significant implications for crop sales and purchased feed costs, which strongly influence if a dairy operation is sustainable and profitable.

Cropping enterprise budgets are being edited for 2013 and 2014. After that, Virginia Ishler will generate cash flow plans for the dairy operation and add to our on-going FINPACK year-end whole-farm financial analysis. Details regarding the benefits of cash flow plans and FINPACK for conducting dairy farm economics can be found in the ‘NESARE 2010-2012 Summary Report’ for this project.

Outreach

Advisory Panel Meeting:

We met on March 26, 2014 to update the advisory panel on recent project activities, challenges in the crop rotation, for which we wanted input, and a summary of some of our main findings for the first four years of the project. The advisory panel member comments were extremely appreciated as the team continues to fine tune our crop rotations to be sustainable and profitable.

Field Day 2014:

The project team hosted a field day on July 1, 2014 that was designed to inform crop production practitioners about some of the lessons being learned from the multi-year project.   Approximately 45 were in attendance. The group was comprised mostly of farmers, but also included representatives of NRCS, PA Conservation districts, several NGOs, graduate and undergraduate students, and research and extension faculty and staff from Penn State and several nearby institutions. Some attendees completed a field day survey (Fig. 14) and indicated a strong increase in working knowledge of the various topics shared during the event.

PSU TRIAD Sustainable Cropping Systems Symposium (4^th ANNUAL):

This NESARE Agroecosystems project is one of three sustainable cropping systems research and outreach projects currently underway at Penn State. The “Finding the Right Mix: Multifunctional Cover Crop Cocktails for Organic Systems” (OREI-CCC) experiment, completed its first full field season in 2013 and seeks to identify benefits and costs of using different cover crop mixtures in organic crop production. The Reduced-Tillage Organic Systems Experiment (ROSE), also funded by USDA-OREI, completed its first full field season in 2011 and is investigating pest and soil management challenges associated with reduced-tillage organic feed grain production systems.

In 2014, the annual TRIAD Sustainable Cropping Systems Symposium was held on the Penn State Campus with team members from OREI-CCC, ROSE, and NESARE dairy cropping system projects. The symposium is a joint meeting of all faculty, graduate students, and post-doctoral researchers from the cropping systems projects as well as others interested from the College of Agriculture at Penn State. The goal of the event was to share project objectives, methods of investigation, and current results to promote synergy among the teams. Posters were developed and graduate students and post-doctoral researchers gave brief presentations. Dr. Matt Liebmen, who is the Henry A. Wallace Endowed Chair for Sustainable Agriculture at Iowa State University, attended and contributed to vibrant conversations about the importance of incorporating perennial crops into cropping systems for soil preservation. Nearly forty people attended in 2014.

Manure Injection NRCS CIG Project:

In fall 2014, we completed a video with funding from a NRCS CIG grant about manure injection with commentary from manure haulers and a farmer.  It is posted at the following website and will be linked to our project website:

https://www.youtube.com/watch?v=FfnGxE_kyEI&list=UUNU2NyimqTDKEieQAIzXrYA.

Members of our team have also contributed to producing a cover crop video that features farmers and extension educators explaining why and how they use cover crops in agronomic cropping systems.

EPA Watershed Center for Nutrient Solutions Grant:
Members of our project are contributing cropping systems data and insight from this NESARE Agroecosystem project to a project that was funded by the EPA Centers for Water Research on National Priorities Related to a Systems View of Nutrient Management in 2013.  The interdisciplinary project titled “Center for Integrated Multi-scale Nutrient Pollution Solutions” is led by James Shortle and Robert Brooks and multiple Co-PIs whom are organized in seven teams.  Peter Kleinman is a Co-PI and leader of a team that includes Douglas Beegle and Heather Karsten, and two post-doctoral watershed modelers recently hired by this EPA grant to Optimize “Tactical Nutrient” Management Programs and Define Their “Strategic” Boundaries”. The project provides the opportunity for us to examine how applying some of our conservation dairy cropping system strategies versus other nutrient management tactices at the watershed scale could impact nutrient loads and water quality at the watershed scale. For more information see the project website: http://agsci.psu.edu/aec/research-extension/research-centers/center-for-nutrient-solutions

USDA-NIFA Dairy CAP Grant
The USDA-NIFA CAP grant that was funded in 2012 is supporting a graduate student and some undergraduate student research assistantance to measure nitrous oxide emissions over the growing season (described earlier) across all three rotations in corn phases of our rotations, as well as a number of soil measurements (chemical, biological and physical) in those corn phases of the rotation. The NIFA CAP grant supports a MS soil science graduate student from the University of Wisconsin whom is comparing water relations in corn plots in two contrasting rotations in our project and in a long-term cropping systems reserach trial in Wisconsin. We are also contributing inights from this research to developing educational materials for residential education and extension that describe strategies for dairy farms adpat to and mitigate climate change.

Interseeder NRCS CIG Project:

Cover crop interseeding is a new concept that was recently included into this project in 2013. The development of the interseeder and the discovery of its potential to aid farmers in getting acres covered prior to the onset of winter are supported with an NRCS Conservation Innovation Grant (2012-2015). Numerous field days were held during the summer and fall of 2014 at locations where early to mid-June interseeding had taken place this year. Not only were concepts specific to interseeding shared, but remarks that encouraged farmers and their advisors to consider some of the many concepts being investigated in this NE SARE project were also shared. Four Penn State faculty and staff with research and extension responsibilities led the discussions at nearly twenty events in eleven different counties in PA. Nearly 700 agriculturists attended these events. At another two larger events in New York and Maryland, new information regarding cover cropping in general and the interseeding concept in particular was shared with approximately 350 attendees.

Website:

Our project team continues to make use of our website and we are in the process of updating it to reflect our new cropping rotations for 2014-2015. The website can be found at: http://cropsoil.psu.edu/research/cropping-systems. The website describes the project, the treatments being investigated at our research site, brief biographies of personnel involved, and outreach activities that are being planned (see below), links to the NRCS CIG project, and a list of useful documents and videos.

Additional Reporting to Farmers and Professionals:
In 2014, each team presented sustainable management strategies and results from our project at grower and professional meetings or as publications (see below).

1. NESARE Dairy Cropping System Project Updates:

• “ Sustainability of Various Cropping Strategies and Rotations – What Have We Learned?” Heather Karsten. Crops to Cows Conference, Nov. 11, 2014. PSU Dairy Extension Conference, Grantville, PA.
• “Penn State’s Diversified Dairy Cropping Systems Research: Lessons Learned”, Heather Karsten. 2014 Northeast Regional Certified Crop Advisors Training. December 3, 2014. Syracuse, NY.
• “NESARE Diversified Dairy Cropping Systems Research”. Heather Karsten. Centre County Watershed Summit. November 3, University Park, PA

2. Virtual Dairy/Economics Team: Will update in January 2015.

3. Canola and Energy Management Team:

Relevant Publication:

• [ONLINE EARLY] GM Malcolm, GGT Camargo, VA Ishler, TL Richard, HD Karsten. 2015. Energy and greenhouse gas analysis of northeast US dairy cropping systems. Agriculture, Ecosystems and Environment 199, 407-417.

4. Insect/Slug Management Team:

Twelve field day presentations, relating to the NESARE project and insect and slug management in grain and forage systems, were given to 790 attendees.

 Professional Meeting:

• Tooker J.F. 2015. Incorporating conservation biological control into field crop production while minimally influencing farming logistics. Entomological Society of America Meeting.

 Relevant Publication:

• Douglas, M. R., J. R. Rohr, and J. F. Tooker. Neonicotinoid insecticide travels through a soil food chain, disrupting biological control of non-target pests and decreasing soybean yield. Journal of Applied Ecology, in press.  (Published online, Journal of Applied Ecology, DOI: 10.1111/1365-2664.12372)

5. Nutrient Management Team:

Professional Meetings:

• Cropping System Strategies for Quality Forage & Feed Production w/ Reduced Off-Farm Nutrient Inputs. Douglas Beegle. Nov. 11, 2014. PSU Dairy Extension Conference, Grantville, PA.
  
• Duncan, E., Kleinman, PJA., Dell, C., Beegle, D., Saporito, L., Kaye, J., Hamlett, J. 2014. Manure application impact on water and nitrogen balance. Oral presentation for the Tri society meetings (ASA, CSSA, SSSA), Long Beach, CA. 

6. Weed Management Team:

The following field day or campus presentations were given in 2014:

• Curran WS and Cropping System Strategies to Manage Weeds and Pests. William Curran and John Tooker. Nov. 11, 2014. PSU Dairy Extension Conference, Grantville, PA.
• Curran WS (2014) Herbicide resistant weeds and resulting integrated weed management renaissance or fallacy. Botany, Plant Pathology and Weed Science Dept Seminar Series. Purdue University. April 2, 2014. [50 attendees].
• Keene C, Wallace J, Curran W, Dempsey M (2014) Lessons learned from the Reduced-tillage Organic Systems Experiment (ROSE). 4th Annual Sustainable Agriculture Cropping Systems Symposium, Pennsylvania State University. March 21, 2014.

Webinars:

• Curran W, Hoover R, Wallace J (2014) Putting the pieces together: lessons learned from a reduced-tillage organic cropping systems project. April 8 2014. Access:https://www.extension.org

UNDERGRADUATE STUDENT AWARD:

Undergraduate student researcher, Veronica Pasi (Environmental Resource Management Major), received the following award in part for her contributions to the NE-SARE project:

• Undergraduate Research Poster, Physical Sciences Division, Second place. Soil carbon levels in diverse cropping systems. Presented at the Penn State University Undergraduate Research Exhibition.

• Fig14_FieldDayEval2014

Collaborators: