Project Number: 3645-61660-002-00
Project Type: Appropriated

Start Date: Aug 05, 2008
End Date: Jan 17, 2013

Objective:
Objective 1: Evaluate land use systems over agricultural landscapes to determine the effects of management and landscape setting on N dynamics. Sub-objective 1-1. Compare N availability in grasslands and organic pasture to more intensively managed land use systems serving dairy and beef livestock production. Sub-objective 1-2. Compare N availability in organic production to conventional production systems growing alfalfa, corn, soybean, and small grains. Sub-objective 1-3. Develop environmental and economic partial N budgets to compare grasslands, organic and conventional agronomic, and livestock production systems. Objective 2: Develop and evaluate cropping systems for optimal biomass production that maintain or enhance soil productivity. Sub-objective 2-1. Quantify the effect of conventional and alternative biomass production strategies on soil productivity, measured by changes in soil carbon (C) and N, and total biomass and crop yield. Sub-objective 2-2. Develop energy budgets to compare energy use in biomass production systems and evaluate the use of biomass for bioenergy feedstock versus livestock production.

Approach:
An evaluation of N dynamics including an assessment of availability, defined as mineral N forms available for plant uptake, across cropland, grassland and pasture systems will be conducted. We will evaluate alternatives to a strict C-S rotation, including perennial grasses, an annual grass hybrid, a living mulch and a cover crop, to compare the effectiveness of these strategies to mitigate potential negative impacts of harvest and to provide greater biomass and economic returns.