Increasing Crop Water Use Efficiency in Advanced No-Till Systems

Final Report for SW02-005

Project Type: Research and Education
Funds awarded in 2002: $22,980.00
Projected End Date: 12/31/2005
Matching Non-Federal Funds: $38,600.00
Region: Western
State: Montana
Principal Investigator:
Dr. Perry Miller
Montana State University
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Project Information

Abstract:

Winter pulse agronomy experiments focusing on no-till techniques were conducted at Amsterdam, MT, 2002 – 2005, leveraged with additional funding from the USDA Cool Season Food Legume Program and the Montana Fertilizer Tax Advisory. All field experimentation was conducted in the context of a persistent drought cycle where annual crop-year rainfall ranged from 1.9 to 2.9 inches less than the previous 30-yr average for this area. The first experiment examined optimal seeding rates for winter lentil and pea when sown mid-September in tall wheat stubble. The second experiment compared the response of winter lentil and pea to fall seeding dates and stubble height, using high yielding spring cultivars as the performance controls. The third experiment, begun in 2003, compares forage yield and quality from winter and spring pea treatments with barley. Timely rain was received in September of 2001, 2002 and 2004 to germinate winter pea and lentil treatments, but not in 2003. Consequently the 2004 winter pea and lentil trial failed to establish. Building partially from the small investment from WSARE in this winter legume research we were successful in obtaining a grant through the USDA-CSREES Integrated Organic Program to continue investigation of winter pea green manure specific to wheat-based organic cropping systems in Montana. In that study we will be examining the effect of termination strategies on soil N and water, as well as the influence on soil P dynamics, and the causal incidence of seedling disease and weeds in subsequent winter wheat crops. A highly novel aspect of this new research direction is exploration of non-tillage methods for green manure growth termination. Winter pulse agronomy experiments using no-till techniques were conducted at Amsterdam, MT, 2002 – 2003. In 2004 winter pulse planting failed completely due to abnormally dry fall soil conditions that prevented germination and trials were re-established in September 2004 for data collection in 2005. Seeding date and seeding rate were more critical factors than stubble height for winter pulse production. Winter pea and lentil yields were competitive with, but not superior to, standard spring types. However, winter types appear superior to spring types for pea forage production.

This research has resulted in the following conclusions: 1) Seeding rates for white-flowered winter lentil or pea should be 50% greater than that for spring types until methods promoting winter survival equal to pigmented types are discovered; 2) Tall stubble (30-35 cm) can provide a yield advantage over short stubble (10 cm) but was not critical for winter survival in a southwestern Montana environment; 3) If seedbed moisture is adequate, winter pea and lentil seeding date should not be delayed past mid-September. Seeding date is a more critical decision than stubble height; 4) Grain yields of winter pea and lentil were lower or equal to spring controls due to slow seed development rates; 5) Forage yield potential and forage quality of winter pea was generally superior to spring pea, especially for the pigmented ‘Austrian’ type; 6) Austrian winter pea had seed yields similar to a pigmented spring type forage pea.

Project Objectives:

1) Quantify effect of crop residue management on crop-available water, winter crop survival and stubble microclimate effects.

2) Compare growth, productivity, and crop water-use-efficiency of spring vs. winter crop growth habits.

3) Extend new knowledge about residue management and crop rotations to farmers, industry reps and research colleagues.

Introduction:

Wide-scale adoption of no-till cropping systems represents the greatest potential advance in sustainability of dryland agriculture, serving SARE’s listed goals for sustainable agriculture.
Satisfy human food and fiber needs: Advanced no-till systems increase production efficiency through increased water-use-efficiency and diversify farm products (Zentner et al. 2002).
Enhance environmental quality and the natural resource base upon which the agricultural economy depends: Advanced no-till systems prevent soil erosion, build soil quality, and promote diverse biological communities above and below ground (Duebbert 1987, Larney et al. 1994, Aase and Pikul 1995).
Make the most efficient use of nonrenewable and on-farm resources and, where appropriate, integrate natural biological cycles and controls:Advanced no-till systems reduce fuel use, extend tractor life, increase fertilizer and herbicide use efficiency, use grain legumes to offset fertilizer use, and promote active soil microbial communities (Biederbeck et al. 1997, Elliot and Stott 1997).
Sustain the economic viability of farm operations and their communities: Extensive farmer testimony from semiarid regions attests to enhanced timeliness of field operations, increased management intensity, and increased crop input efficiencies. (Zentner 2002)
Enhance the quality of life for farmers/ranchers and society as a whole: No-till systems increase time to effect decisions on working farms. Advanced no-till systems will play a vital role in greenhouse gas mitigation through enhanced soil carbon storage. (Drinkwater et al. 1998, Robertson et al. 2000)
The adoption of no-till management remains low in Montana (<15%), similar to the national rate (Conserv. Tillage Info. Ctr., Purdue, IN). Why? Are no-till systems inherently less profitable? Evidence from other semiarid cropping regions (e.g. Argentina, Australia, Brazil, Canada), where farmers are linked more tightly to globally depressed agricultural markets, shows adoption rates that are two to five times greater than that in the USA (Veseth 1999). Economic success is tied to increasing water-use-efficiency and crop diversity, through adopting advanced no-till systems.
Increasing crop-available water is a difficult challenge in a low rainfall region such as Montana. In eastern regions of the northern Plains, the formation of a ‘duff’ layer (accumulated crop residues on the soil surface) has been instrumental in minimizing evaporative water loss from the soil, effectively providing more water for the crop (Domitruk et al. 1997). In the western half of the northern Plains, annual precipitation averages 11-14″ with significant variability, which encourages the practice of summer fallow to manage production risk. Many Montana producers have observed that inherently low crop biomass, coupled with the practice of summer fallow, prevents sufficient crop residue accumulation in Montana, even after six or more years of no-till experience. These farmers are interested in ‘adding value’ to crop residues, by leaving crop stubble as tall as possible to create a favorable microclimate for crop growth. Montana researchers have been challenged by producers to investigate stubble microclimate effects. The farmer co-P.I. on this project feels so strongly about the need for this research that his family has donated $100,000 to Montana State University earmarked to purchase equipment for low-disturbance direct-seeding and micrometeorological instrumentation needed to interpret and extend research results.

Research

Materials and methods:

Research sites will feature medium to heavy textured soils, in areas with 13-inch average annual precipitation, with rainfall concentrated (50% of annual total) in April, May and June. Snow cover is intermittent during the winter period due to frequent warm periods. Air temperatures during the winter months fluctuate widely, occasionally dropping below -20oC. The objectives of this study will be used to extend investigative lines in current and planned experiments funded partially from other sources (Cool Season Food Legume Special Project and Montana Fertilizer Tax Advisory). Objective one will be served by installing micrometeorological monitoring equipment in a current study which compares two stubble heights (4 and 12″) for both productivity of both spring and winter types of pea and lentil. Objective two will be met by requesting additional funding from the Montana Fertilizer Tax Advisory to investigate the role of annual broadleaf forages in no-till cropping systems, including both spring and winter types of pea.

1) Quantify effect of crop residue management on crop-available water, winter crop survival and stubble microclimate effects. (Miller, Wraith)
In both phases, georeferenced gravimetric soil samples will coincide with winter (i.e. fall) and spring crop seeding dates to compare soil water accumulation over winter. In both project phases, survival of winter types of lentil and pea will be compared by measuring stand densities in late fall and spring. In stubble management plots within one replicate, automated measurements of microclimatic conditions including air temperature and windspeed at two heights, relative humidity, solar irradiance at ground level and above the canopy, and soil temperatures will be collected. These continuous time series will facilitate interpretation of factors influencing measured crop responses, and thus promote transfer of our results to other regions. Temperature, windspeed, and humidity profiles within the near-land-surface boundary layer are critical to canopy water use efficiency, as greater vapor pressure deficits exist outside this layer (Campbell and Norman, 1998). Greater stubble height should extend both the magnitude and the vertical height of logarithmic boundary layers and thus impact direct soil evaporative losses and crop water relationships.

2) Compare growth, productivity, and crop water-use-efficiency of spring vs. winter crop growth habits. (Miller, Wraith)
Shoot biomass accumulation will be measured bi-weekly, beginning at the spring seeding date. Plant morphology will also be measured (plant height, basal pod height, branching pattern). Measured changes in soil water storage along with precipitation will be used in a water balance approach to determine crop water use (Wraith and Ferguson 1994). In both phases, crop water-use-efficiency will be compared between spring and winter types of pea and wheat, and for spring-sown grasspea, by dividing dry matter forage and grain yield by measured water use. In both phases, yield components will be determined and used with harvest index to interpret yield response. A standard suite of forage and grain quality analyses will be performed, including, crude protein, fiber fractions, relative feed value, protein/oil content, test weight, and seed size. Crop growth patterns will be terminated at early forage (first bloom), late forage (early pod) and normal grain harvest timings. Soil N will be measured pre-plant and post-harvest and spring wheat will be recropped at varying fertilizer N rates across the sites to characterize the crop sequence response (grain yield and quality) relative to water conservation and soil N contribution.

3) Extend new knowledge about residue management and crop rotations to farmers, industry reps and research colleagues. (All participants)
Powerpoint presentations will be prepared, complete with notation, to facilitate extension use of these research concepts. Preliminary and final project reports will be written in a popular style for farmer consumption. It is anticipated that parts of this research project will be featured in numerous extension presentations at farm conferences throughout the northern Plains.

Research results and discussion:

Experiment 1 – Seeding Rate Effects on Winter Lentil and Pea

For both winter lentil and pea, the best seeding rate was 50% greater than the recommended seeding rate for spring types (Table 1). This was due to plant mortality over winter and in early spring. No important relationships with plant height or seed size were observed in 2002. To accomplish acceptable stand densities future research will have to devise methods of achieving nearly 100% overwinter survival or increase winter pea and lentil seeding rates by as much as 50% over that used for their spring counterparts, or a combination of both tactics.

Experiment 2 – Stubble Height and Fall Seeding Date Effects on Winter Lentil and Pea

Yield response to stubble height varied among years. In 2002 (and 2004 for spring pea), seed yields were greater in the tall stubble, while the opposite occurred in 2003 (Figure 2, Tables 2 and 3). The 2003 result may have been an anomaly in that temperatures were unusually cold in October 2002 and April 2003, and the short stubble treatment provided warmer soil temperatures that promoted timely growth of winter lentil and pea seedlings. As a result, significant stand loss occurred for both winter lentil and pea in the tall stubble in 2003. In 2004 there was complete stand failure of all winter pea and lentil treatments so the stubble height blocks were seeded uniformly by the cooperating farmer to a single cultivar of spring pea (cv. Cruiser). Replicated hand-harvested biomass and seed yield samples were taken and all other factors being equal, increased water-use-efficiency is the most likely explanation for the 12-bushel yield advantage in the tall stubble. Tall stubble increased plant height which may improve harvestability of these low stature crops. Stubble height did not have a consistent effect on soil water extraction, however meteorological factors were affected. Wind speeds were reduced within the tall stubble canopy but that did not translate into a significant increase in water use efficiency in 2002.

In 2002, delayed fall seeding delayed flowering and seed fill of winter lentil and pea until after the most severe drought in early July, allowing seed yields to equal that of the earlier date. However, in 2003, stand establishment was very poor for the delayed fall seeding which resulted in much lower grain yields. Consequently, we cannot recommend seeding winter lentil or pea later than mid-September.

For winter pea, the spring controls yielded equal or greater than all fall seeding dates (especially 2004). For winter lentil, the spring controls yielded greater than all fall seeding dates in both years. This response was both unexpected and disappointing because our hypothesis was that early flowering winter lentil and pea would escape drought stress and therefore produce higher yields. Despite earlier flowering, and longer flowering periods with the winter pulses, there was no associated yield advantage. Small differences in soil water extraction were observed among the seeding date x cultivar treatments each year with no consistent patterns.

Experiment 3 – Winter Pea Forage and Grain Yield/Quality

Forage yield of winter pea was low but of very high quality when harvested at first flower, offering an important economic advantage over chemical fallow. Water use by pea harvested for maximum forage was equal to harvesting for grain. Further areas of exploration should include the role of early forage harvest of winter pea as part of a comprehensive weed management strategy and firm recommendations for optimal pea forage termination strategies in no-till systems.

Forage Productivity (Tables 4&5)

1. Averaged for all entries, early forage yield (2.8 t/ha) averaged 57% of late forage yield (5.0 t/ha) over two years. However, winter pea early forage yield (2.0 t/ha) averaged only 37% of its late forage yield (5.4 t/ha) indicating a different growth dynamic compared with spring crops. This 2-fold difference in forage productivity has important implications for trade-off between current year economics for harvested forage and soil water conservation for next year’s crop.

2. Winter pea averaged 34% less and 22% greater forage yield than spring pea when harvested at the flower and plump pod stages, respectively.

Forage Quality (Table 2) (Data from 2005 not available at time of this report)

1. In 2003 winter pea forage was very high quality and generally had the highest crude protein values at both sites. Crude protein averaged 44% greater than that from the barley treatments, and 22% greater than that from the spring pea treatments.

2. Relative Feed Value (RFV) was consistently in the ‘Prime’ category (>151) for all pea treatments while the barley treatments most often graded No.1 or No.2.

3. Pea averaged 27% of the forage mixture for the Haybet + Arivka treatment at both forage cuttings at Amsterdam in 2003 but did not affect crude protein. The pure barley stand received 60 lb N/ac while the mixed stand received only 30 and this may account for the lack of response in crude protein.

Due to a variety of factors, including research projects like this one, Montana producers are modifying their cropping systems. Pea and lentil acreage has risen dramatically to over 350,000 acres in 2005 from totals that had never topped 100,000 acres prior to 2004. Even though we have cautioned Montana growers about the risky ‘experimental’ nature of growing winter pea in this environment, there are several farmers experimenting with winter pea for forage, green manure or seed purposes on their own farms in both conventional and organic systems. Thus far the adaptation for winter survival appears broader than researchers thought initially. It is likely that winter pea for forage or green manure production will increasingly become a commonly considered option by organic and conventional farmers.

To that end, this small research investment by WSARE has spawned additional research tracks related to winter pea and lentil potential in Montana.

Research conclusions:

Economic Analysis

This applied agricultural research is highly experimental and may not be suited for credible economic analysis. Regardless, funding resources were not able to cover the expense of a credible independent economic analyst. And agronomic researchers seldom deliver credible economic analyses. However, in the case of winter pea harvested for early forage we have been able to show that subsequent spring wheat yields were equal to those on chem fallow. The economic implication is that a farmer could have grown a small forage crop, saved some weed control operations in during the summer fallow phase, and obtained an economically equivalent wheat crop.

Farmer Adoption

See previous section on Impact of Results/Outcomes.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

Miller, P., D. Wichman and R. Engel. 2005. Sequencing annual legume forage before wheat to increase water-use-efficiency in no-till systems in the northern Great Plains. In (CD-ROM) Agronomy Abstracts ASA, CSSA, SSSA, Madison, WI.

Miller, P.R., K.E. McPhee, C. Chen, F.J. Muehlbauer and D.M. Wichman. 2004. Winter lentil and pea management in Montana, Idaho and Washington. In (CD-ROM) Agronomy Abstracts ASA, CSSA, SSSA, Madison, WI.

Miller, P.R., B.G. McConkey, R.P. Zentner, C.A. Campbell, and V.L. Cochran. 2003. Flexible cropping systems in the semiarid Northern Great Plains. p. 87-104 In J.D. Hanson and J.M. Krupinsky (eds.), Proc. Dynamic Cropping Systems: Principles, Processes and Challenges. Bismarck, ND. (Invited review paper)

Presented invited seminar on ‘New Cropportunities for Montana’ at Montana Grain Growers Assoc. annual convention, Billings, MT. Dec 2005.

Presented invited seminar on alternative crops in no-till systems at the Fallon Co. Agronomy Workshop, Baker, MT. Oct 2005.

Discussed research on winter pea forage in no-till systems (Moccasin), and winter canola, diversified crop rotations, soil residual herbicide injury and greenhouse gas interactions with cropping systems (Bozeman) at Montana field days. 2005.

Presented research reports to the Fertilizer Tax Advisory and the Montana Wheat and Barley committees, Bozeman, MT. Feb 2005.

Presented brief overview of ongoing research with green manure crops during interactive panel session on organic research needs between MSU and the Montana Organic Association, Helena, MT. Feb 2005.

Presented invited seminars on pulse crop management in the northern Great Plains and chickpea production practices at the North Dakota Dry Pea and Lentil Association annual meeting, Minot, ND, and the MonDak Pulse Day, Williston, ND. Jan/Feb 2005.

Presented research on cropping systems complexity at Crop and Pest Management School, Bozeman, MT. Jan 2005.

Presented invited seminar on ‘Pulse Research Update’ at Montana Grain Growers Assoc. annual convention, Great Falls, MT. Dec 2004.

Discussed research on winter pulses in no-till systems (Moccasin), legume green manures in organic systems (Big Sandy) and diversified crop rotations (Bozeman) at Montana field days. 2004.

Presented research on flexible cropping systems at 1) Montana Fertilizer Advisory Committee, Bozeman, 2) Montana Ag Business Assoc. Ann. Conf., Great Falls, 3) Crop and Pest Management School, Bozeman, MT, and 4) Western Dakota Crops Day, Hettinger, ND. 2004.

Presented research on soil quality dynamics and crop diversity in long-term northern Great Plains no-till systems at the South Australia No-Till Farmers’ Assoc. annual meeting. Tanunda, South Australia. Feb 2004.

Presented research on diversified cropping systems at the Western Australia No-Till Farmers’ Association annual meetings at Katanning and Perth, Western Australia. Feb 2004.

Presented dryland cropping systems research at the Great Northern Development Corp. Northeastern Montana AG Conference, Wolf Point, MT; Montana Organic Organization farmer conference, Great Falls, MT; MonDak Pulse Day and the NDSU-Williston Res. Ext. Ctr. Field Day, Williston, ND the Crop and Pest Management School, Bozeman, MT, and on television (Montana Ag Live). 2004.

Presented agronomic research in pulse crops at the Ag Horizons conference, Pierre, SD; NDSU-Williston Res. Ext. Center Field Day; AERO farm tours at Great Falls, Scobey and Savage, MT; the Cool Season Food Legume Research Review, Moscow, ID; and television (Montana Ag Live). 2003.

Project Outcomes

Project outcomes:

Economic Analysis

This applied agricultural research is highly experimental and may not be suited for credible economic analysis. Regardless, funding resources were not able to cover the expense of a credible independent economic analyst. And agronomic researchers seldom deliver credible economic analyses. However, in the case of winter pea harvested for early forage we have been able to show that subsequent spring wheat yields were equal to those on chem fallow. The economic implication is that a farmer could have grown a small forage crop, saved some weed control operations in during the summer fallow phase, and obtained an economically equivalent wheat crop.

Farmer Adoption

See previous section on Impact of Results/Outcomes.

Recommendations:

Areas needing additional study

The role of winter pea as a green manure crop for fostering soil quality needs to be explored further in organic and no-till systems.

Weed management strategies for winter lentil grain production is a major obstacle that requires research attention.

Effective chemical termination strategies for early harvested pea forage requires research.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.