Location: Columbia Plateau Conservation Research Center
2023 Annual Report
Objectives
Obj. 1: Extend the N replacement approach to soft white winter wheat for guiding precision management of fertilizer N and crop residue to optimize soil microbial processes and maximize the biological potential of soil.
1A: Evaluate grain protein concentration and yield response to N under varying levels of water to define the critical protein level and fertilizer N equivalent to a unit change in protein for popular cultivars of soft white winter wheat.
1B: Determine whether uniformity of protein levels in the crop can be achieved with the precision N replacement approach.
1C: Adapt instruments and algorithms to support on-farm implementation of the N replacement approach to precision fertilizer management in dryland wheat production systems.
1D: Evaluate the effects of residue management (standing, distributed on the soil surface, or removed) on the plant-available N, precipitation capture efficiency, crop productivity, weed density, and microbial activity during the 13 months of fallow.
Obj. 2: Identify whether soil microbial communities adapted to dry environments benefit plant fitness under water limited conditions.
2A: Identify the composition of microbial consortia naturally adapted to low water availability.
2B: Determine whether cultivar selection and N management can be manipulated to shift the structure and function of microbial communities to benefit plants under water stress.
Obj. 3. Develop resilient cropping systems and strategies that increase resilience, improve economic returns, and enhance ecosystem services; assess their economic and environmental performance of various cropping systems in concert with their supporting components; and develop decision support systems for optimizing agronomic production in these cropping systems.
3A: Compare economic returns from the variable N replacement approach based on previous season’s site-specific SWW crop yield data and conventional uniform N placement based on field bulk soil sampling and laboratory testing.
3B: Increase dryland farming resilience by developing cropping systems more intensive and diverse than the conventional winter wheat-fallow system.
3C: Investigate the yields and economic returns of alternative crops following winter wheat and winter wheat following cover crops across low and intermediate precipitation zones using current and future climate scenarios.
Obj. 4. Increase the sustainability resilience and tolerance of the dryland crop production system to biotic and abiotic stressors through improved understanding of developmental, environmental, and management factors that limit plant health and growth, including but not limited to stress tolerance, water use efficiency, and disease resistance.
4A: Evaluate stress indicators and yield components of wheat in alternative cropping systems compared to wheat-fallow with relation to soil water availability, disease incidence, and rotational crop morphology.
4B: Investigate crop response to water deficit, high temperature, and/or nitrogen availability.
Approach
1A: A winter wheat-fallow Cultivar-Fertility Study located at 2 sites in the low and intermediate precipitation zone in Eastern Oregon will include 3 soft white winter wheat cultivars fertilized with inorganic nitrogen (N) at 4 rates. The study will be repeated for 3 years. Yield and grain protein concentration (GPC) measured with near-infrared spectroscopy will define the critical GPC, an indicator of crop N deficiency or adequacy.
1B: A N-Replacement Study will follow 1A in which plots will be split and fertilized based on 1) amount of N needed to achieve target protein based on the critical GPC, and 2) university recommendations based on soil N and potential yield. Select plots will be analyzed for inorganic N, nutrient cycling capacity, microbial community composition, N leaching and gaseous N loss.
1C: The GPC measurements from the relatively inexpensive AvaSpec2048 spectrophotometer will be compared to data from dry combustion. Publicly available software will be adapted from Yield Editor software in collaboration with ARS, Columbia Missouri.
1D: Winter wheat residue in the 2 precipitation zones 1) cut high, left standing, 2) cut high, flattened, 3) cut low, spread, 4) cut low, removed. Measurements include yield, soil/air temperature, air movement, soil water content, inorganic N, and microbial nutrient-cycling activity.
2A: Rhizosphere and bulk soil microbial communities will be characterized from plots replicated in the low and intermediate precipitation zones. Soils will be analyzed for chemistry and enzymes related to carbon and N-cycling, and microbial composition.
2B: Rhizosphere soils collected from different cultivars of 1A at 2 N rates will be analyzed for nutrient cycling activity and communities sequenced from treatments promoting or inhibiting activity. Microbial communities will be evaluated for benefit to wheat in a microbial transfer potting experiment.
3: Economic benefit from replacement N management and intensified cropping systems will be evaluated. An alternative crop trial (AC) and cover crop trial (CC) will be conducted. The winter wheat (WW)-chemical fallow (CF) system will be intensified in a low precipitation (<250 mm) site as a WW-AC-CF rotation and at a high precipitation (<420-mm) site as a WW-AC rotation. The CC trial will be conducted at both sites as WW-cover crop fallow. Each trial will be initiated at a new location for three replicate years. A calibrated model will be provided within a crop simulation platform that will be useful for determining the different alternative crops and cover crops that producers are likely to consider.
4: The plant stress response and yield differences will be evaluated in the alternative and cover crop trials. Soil water availability, disease incidence, soil nutrient cycling, soil chemistry and yield traits will be quantified in each of the trials. Multiple regressions will be used to model the yield and stress variables as a function of the abiotic stressors. Results will identify benefits or detriments of alternative cropping systems to the primary wheat crop in terms of herbicide use, disease incidence, nutrient availability, soil quality, and water availability.
Progress Report
This is the final report for project 2074-12210-001-000D, Attaining High Quality Soft White Winter Wheat through Optimal Management of Nitrogen, Residue and Soil Microbes, which will be replaced by the new project, Optimizing and Enhancing Sustainable and Profitable Dryland Wheat Production in the Face of Climate and Economic Challenges, when it completes Office of Scientific Quality Review.
Substantial results were realized over the five-year project. In support of Objective 1, the critical grain protein concentration of soft white winter wheat was determined for dryland cropping systems in the low and intermediate annual precipitation regions. The critical grain protein concentration can be used to indicate areas within fields where nitrogen nutrition was inadequate for optimum wheat yield. The amount of nitrogen equivalent to a unit change in grain protein concentration was found to be similar across different cultivars of winter wheat. Together with harvest maps showing levels of grain protein in the previous season, farmers can use the nitrogen equivalent to derive the nitrogen fertilizer requirements for precision fertilizer application in the next season. The first of a two-year trial evaluating the nitrogen recommendations based on either conventional testing of soil fertility or alternative mapping of grain nitrogen levels was completed at two sites in the low and intermediate precipitation regions. Concurrent research in Objective 1 evaluated the effects of residue management (cut high, residue retained or removed) on soil moisture, soil temperature, near-surface humidity, near-surface wind speed, and grain yield at the two sites. The experiment is complete with a full dataset for analysis by the new hydrologist. Products of the research conducted in Objective 1 include the adaptation of affordable spectrophotometer for on combine grain protein analysis, development of the Yield Editor grain yield/protein mapping software (collaboration with USDA-ARS scientists in Columbia, Missouri), and the design and production of a no-till research plot drill. The drill is equipped with openers designed to cut through residue typical of our region and has the capability for variable rate nitrogen application and depth control for seed and fertilizer placement. Overall, this project’s work on grain protein and the development of the Yield Editor software will largely serve as a basis for new research in the National Program 212 developing on-combine grain nitrogen sensing technology for precision agriculture.
Significant progress was made in evaluating the belowground effects of cultivar and fertilizer management on soil biological nutrient cycling activity for Objectives 1 and 2. Site-to-site differences in precipitation largely overshadowed differences in either cultivar or fertility for nitrogen-cycling activity, specifically arylamidase (removal of amino acids from proteins, peptides, or arylamides) and potential ammonia oxidation (nitrification step). The site with the lowest organic matter, yield and annual precipitation demonstrated the greatest biological capacity to cycle nitrogen. Soil DNA extractions and protocol optimizations for the DNA sequencing in Objective 2 are complete. The ongoing microbial community assessments will evaluate 1) temporal changes in the bacterial and fungal communities over the cropping system and 2) the community response to cultivar and nitrogen fertilizer application rates.
Significant progress was made on the field-based work of Objectives 3 and 4 which were added as part of a new appropriation in fiscal year 2019. The economic analyses of the different cropping systems in this project were not completed due to the ongoing critical vacancy of the agricultural economist; however, supporting data for the analyses have been collected. Two trials on alternative crops and cover crops were completed with two full rotations through a Non-Assistance Cooperative Agreement with Oregon State University. Weed infestation, yield, and yield component measurements are being finalized for the two trial sites. Soil moisture and soil chemical measurements were not successful for the cover crop trial due to instrument failure (moisture) or omission (soil chemistry), but analyses of the soil pathogens, soil chemistry, and nutrient cycling activity in the cash crop phase are either complete or in progress. Pre-plant soil moisture for the second year cash crop demonstrated a significant loss of soil water associated with fall-seeded cover crops in the low but not intermediate precipitation region. The cover crop trials at both sites in addition to the long-term experiments at Pendleton (LTE) were assessed for wheat nitrogen assimilation and plant stress. The LTE contrasts the traditional wheat-fallow system with winter wheat cover cropped with winter pea system managed under different fertility treatments. All major components of wheat biomass (e.g., leaf, stem, grain head, and grain), physiological indicators of stress (e.g., chlorophyll fluorescence, flag leaf transpiration, and canopy temperature from jointing to maturity), and yield components were measured at different growth stages. These data will elucidate the interaction between nitrogen fertility and water use efficiency to help provide an understanding of the overall function of these intensified cropping systems. Collectively, the research demonstrates the potential for intensified crop systems in the low and intermediate regions with fall-seeded cover crops or with flax as an alternative crop in an annual (intermediate precipitation) or two-crop, three-year rotation (low precipitation). This research will bridge into the new project by further evaluating fall-seeded cover crops of field pea, barley, and canola.
Accomplishments
Review Publications
Reyes-Cabrera, J., Adams, C.B., Nielsen, J., Erickson, J. 2023. Yield, nitrogen, and water-use efficiency of grain sorghum with diverse crown root angle. Field Crops Research. 294. Article 108878. https://doi.org/10.1016/j.fcr.2023.108878.
Manley, A., Ravelombola, W., Adams, C.B., Trostle, C., Cason, J., Pham, H., Shrestha, R., Malani, S. 2023. Evaluating USDA guar [Cyamopsis tetragonoloba (L.) Taub.] genotypes for Alternaria leaf blight resistance under field conditions. Euphytica. 219. Article 56. https://doi.org/10.1007/s10681-023-03185-2.
Shrestha, R., Adams, C.B. 2022. Photosynthesis in guar: Recovery from water stress, basic parameter estimates, and intrinsic variation among germplasm. Journal of Crop Improvements. 37(5):626-646. https://doi.org/10.1080/15427528.2022.2121348.
Boote, K., Hoogenboom, G., Ale, S., Adams, C.B., Shrestha, R., Mvuyekure, R., Himanshu, S., Grover, K., Angadi, S. 2023. Adapting the CROPGRO model to simulate growth and yield of guar, Cyamopsis tetragonoloba L, an industrial legume crop. Industrial Crops and Products. 197. Article 116596. https://doi.org/10.1016/j.indcrop.2023.116596.
Sapkota, B.R., Adams, C.B., Kelly, B., Rajan, N., Ale, S. 2022. Plant population density in cotton: Addressing knowledge gaps in stand uniformity and lint quality under dryland and irrigated conditions. Field Crops Research. 290. Article 108762. https://doi.org/10.1016/j.fcr.2022.108762.
Siegfried, J., Adams, C.B., Rajan, N., Hague, S., Schnell, R., Hardin, R. 2022. Combining a cotton 'boll area index' with in-season unmanned aerial multispectral and thermal imagery for yield estimation. Field Crops Research. 291. Article 108765. https://doi.org/10.1016/j.fcr.2022.108765.
Hinson, P.O., Pinchak, B., Adams, C.B., Jones, D., Rajan, N., Kimura, E., Somenahally, A. 2022. Forage and cattle production during organic transition in dual-purpose wheat systems. Agronomy Journal. 115(2):873-886. https://doi.org/10.1002/agj2.21284.
Shrestha, R., Adams, C.B., Abello, F., DeLaune, P., Trostle, C., Rajan, N., Ale, S., Ravelombola, W. 2023. Intensifying dryland wheat systems by integrating guar increased production and profitability. Industrial Crops and Products. 197. Article 116608. https://doi.org/10.1016/j.indcrop.2023.116608.
