Project Number: 5368-12000-010-00
Project Type: Appropriated

Start Date: Oct 01, 2011
End Date: Oct 31, 2015

Objective:
Objective 1. Determine the effects of fertilizer source and fertilizer additives on nutrient budgets in irrigated agricultural systems. (Tarkalson 0.5, Leytem 0.5, Dungan 0.2, Ippolito 0.15). Subobjective 1.1. Identify effects of fertilizer source, and nitrification and urease inhibitors on ammonia and greenhouse gas emissions from soils under irrigation. Subobjective 1.2. Identify effects of fertilizer source, and nitrification and urease inhibitors on carbon, nitrogen, and phosphorus cycling and losses from soils under irrigation. Subobjective 1.3. Identify effects of fertilizer source, and nitrification and urease inhibitors on crop nutrient removal from soils under irrigation. Objective 2. Develop utilization practices for agricultural byproducts to increase nutrient and water use efficiency. (Lentz 0.5, Lehrsch 0.4, Ippolito 0.1). Subobjective 2.1. Identify effects of biochar and other amendments on soil carbon, nitrogen, and micronutrient budgets and water availability over time. Subobjective 2.2. Identify the effects of agricultural byproducts and soil water content on the emissions of carbon dioxide and nitrous oxide gases from freezing and thawing soils.

Approach:
The research for all objectives will be conducted at the ARS Northwest irrigation and soils laboratory in Kimberly, ID. Project objectives will be achieved through three main studies conducted at different scales to improve our understanding and management of soil nutrients. Research for Objective 1 involves a five year field study comparing soil ammonia and greenhouse gas emissions, soil nutrient cycling and crop nutrient uptake from selected fertilizer or manure treatments combined with nitrification and urease inhibitors. More detailed field and laboratory studies will be used for Objective 2.1 to identify the effects of biochar and other amendments on nutrient cycling. Research in Objective 2.2 entails a laboratory study to collect detailed information about greenhouse gas emissions from soils during freeze thaw cycles. This project will broaden scientific knowledge of nutrient cycling in the agricultural fields to which dairy manures and fertilizers are applied, determine if selected agricultural byproducts and amendments can assist in managing nutrients and reducing emissions in arid agricultural systems, and help us better understand nutrient cycling within the broader system through validated process based models. Data from this project will be provided to scientists and organizations to improve and validate nutrient cycling models, and for other related analysis (USDA and USEPA greenhouse gas inventories, the Integrated Farm System (IFSM) model, the Voluntary Reporting of Greenhouse Gases Carbon Management Evaluation Tool (COMET-VR), the Daily Century Model (DayCent), and Dairy Management Inc. life cycle analysis).