Location: Northwest Irrigation and Soils Research
Project Number: 2054-12000-013-000-D
Project Type: In-House Appropriated
Start Date: Dec 14, 2021
End Date: Dec 13, 2026
Objective 1: Develop improved practices and strategies for managing inputs in irrigated cropping systems to increase soil health, optimize crop productivity and quality, and minimize negative environmental impacts. Sub-objective 1A: Identify effects of fertilizer source, timing of application, and nitrification/urease inhibitors on nutrient cycling and field-scale nutrient budgets. Sub-objective 1B: Identify effects of past manure application rate and frequency on biological indicators of soil health, nutrient cycling, and field-scale nutrient budgets. Sub-objective 1C: Determine the efficacy of cover crops and minimum tillage to reduce offsite transport of soil nutrients in a dairy forage crop rotation receiving manure. Sub-objective 1D: Determine the long-term agronomic economic effects of manure applications on crops, soil nutrient (primarily N, C, and P) cycling, and soil health indicators. Sub-objective 1E: Determine effects of crop rotation, tillage, and residue management on residue breakdown rates and nutrient cycling in irrigated cropping systems. Sub-objective 1F: Evaluate aboveground biomass yield, forage quality, and nutrient cycling of sorghum-sudangrass hybrids under multiple management practices (row spacing, number of cuttings, and cultivar). Objective 2: Quantify gaseous emissions from dairy production facilities and manure-amended soils to improve nutrient cycling and reduce environmental impact of these systems. Sub-objective 2A: Determine the effect of manure application rate and frequency on soil GHG emissions. Sub-objective 2B: Determine the effect of manure, cover crop, and minimum tillage on soil GHG emissions. Sub-objective 2C: Determine ammonia transport and dry deposition in the Magic Valley region and improve accuracy of deposition models.
Resilient irrigated cropping systems in concentrated dairy production regions require proper management of nutrients to maximize agricultural production while minimizing environmental impacts. Dairy farms in the region generally have more cows and produce more milk than in the past. With the increased number of cattle comes an increased production of manure that must be managed. Crop production coexists in the region with a diverse assortment of crops with varying nutrient needs to meet yield and quality goals. The current project will address crop production and environmental issues that results from concentrated dairy and crop production. Broadly, the project objectives are to improve crop nutrient use efficiency, minimize nutrient and greenhouse gas losses to the environment, investigate novel crops, and determine the impact of crop residues in the agroecosystem. These objectives will lead to improved management practices for irrigated cropping systems in semi-arid environments. Research consists of several continuing long-term studies along with newly developed projects. Objective 1 is focused on how inputs are managed and effect the agroecosystem. The objective is comprised of seven studies. Long-term studies will evaluate the impact of synthetic fertilizers (with and without nitrification inhibitors in one study) and dairy manure on crop response, nutrient cycling, and soil health. New studies will evaluate impacts of novel cropping approaches, including forage cover crops and grasses such as sorghum-sudangrass, on crop production, nutrient cycling, and soil health. Additionally, these studies will address the impact of crop rotation, tillage, and residue management practices on these factors as well. Objective 2 contains three projects focused on determining gaseous emissions from dairy facilities and manure-amended soils. Long term manure application rate effects on greenhouse gas emissions will be studied. A second study will measure the effects of manure, cover crop, and minimum tillage on greenhouse gas emissions. The final project will determine regional ammonia nitrogen transport to improve models that predict ammonia depositions from the atmosphere to the soil surface.