Location:2009 Annual Report
1a. Objectives (from AD-416)
Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. • Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. • Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. • Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. • Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. • Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. • Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. • Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems.
1b. Approach (from AD-416)
Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic-based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Formerly 5354-21660-001-00D (8.08).
3. Progress Report
1. Optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. Field trials were using field corn, winter wheat, switchgrass (Panicum virgatum), and polyculture mix with low, intermediate, high productivity levels by maintaining three irrigation water regimes (50, 75, and 100% of evapotranspiration (ET)). Initial measurements of above- and below-ground productivity, nutrient export, and C sequestration were made using a combination of field and laboratory studies employing standard C pool analyses and tracer (13C) analyses in this first year of the study. Measures of C-sequestration potential by laboratory incubations and 13C analyses have been set up for both the fall 2008 and spring 2009 soil samplings. 2. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement. A field trial evaluating the application of agricultural-based energy co-products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers was established. Potato was planted in plots containing each of three rates (112, 168 and 224 kg N/ha) of each amendment. Assessments of the soil nutrient, potato quality, and effects on soil pathogens and plant parasitic nematodes are evaluated. 3. Determine the impact of reduced tillage on soil conservation, soil physical properties, and the yield and quality response of potato and rotational crops. The Columbia Plateau Portable Wind Tunnel will be used to measure wind erosion and dust (i.e. PM10) emissions under the reduced and conventional tillage and crop this fall, 2009. 4. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. The field research has been completed and analysis of data from the field trials are in progress. 5. Soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments to optimize physiological development of potato under irrigated organic cropping systems. This study was conducted on C and N cycling in organic production of potatoes on certified fields broken from CRP land utilizing certified chicken composts. Data analysis and evaluation are in progress. 6. Integrate sweet corn hybrids with weed suppressive traits into organic specialty crop production systems. Yield and weed suppression of four sweet corn hybrids differing in canopy development were compared against three weed management levels that consisted of various sequences of rotary hoeing and cultivation in field trials.
1. White mustard seed meal suppresses weeds in organic onions. Weeds are the primary limitation and expense ($800-$6,000/acre) to organic onion production. ARS scientists at Prosser, WA found that mustard (Sinapis alba) seed meal applied at 1 to 2 ton/acre after the 2 leaf stage of onion growth controlled annual weeds without significant injury to onions. Use of mustard seed meal may be useful to producers of organic crops for weed suppression and help reduce excessive costs of hand weeding which can range from $800 to $6,000 per acre.
2. Low glucosinolate mustard seedmeal failed to suppress weeds. Mustard (Sinapis alba) varieties vary in glucosinolate content, which may affect weed growth suppression properties of the seed meal. ARS scientists at Prosser, WA found that mustard seed meal produced from seed containing high and low levels of glucosinolate differed in their ability to suppress weed growth. Mustard seed containing high levels of sinalbin suppressed weeds much greater than seed meal derived from seed lines bred for low glucosinolate levels. These results help identify the active compounds in mustard meal and refine the use patterns of mustard meal for weed suppression. Use of mustard seed meal may be useful to producers of organic crops for weed suppression and help reduce excessive costs of hand weeding.
3. Establishing Switchgrass for Biofuel and Forage Production. Seeding and Growth Stages. There is a need for more agronomic information on energy crops. Switchgrass (Panicum virgatum) and other selected perennial warm-season grasses (WSG) have been promoted as potential cellulosic bioenergy crops and have been shown to be adapted to the hotter and irrigated regions of the Pacific Northwest. ARS scientists at Prosser, WA published two Extension Bulletins that will assist growers in understanding warm-season grass development and biomass production. This research provides growers fundamental knowledge of the planting guidelines and production practices of switchgrass as an energy crop in the Pacific Northwest.
5. Significant Activities that Support Special Target Populations
Organic on-farm research project related to Milestone 3.A. were conducted on a organic high value vegetable farm located near Connell, WA. An on-farm Field day was conducted on June 17th, 2009, Two presentations:1) Carbon and N cycling 2) Cover Crop control using a roller crimper. Approx. 60 participants.
Nitzan, N., Boydston, R.A., Batchelor, D., Crosslin, J., Hamlin, L., Brown, C.R. 2009. Hairy Nightshade is an Alternative Host of Spongospora subterranea, the Potato Powdery Scab Pathogen. American Journal of Potato Research. 86:297-303. DOI 10.1007/s12230-009-9083-1