Balancing tillage, soil loss, and profitability

Profitability and environmental sustainability are major objectives in crop production. Decisions on whether to till and what operation to use have direct impact on these objectives. Because of potential adverse affects on soil erosion, structure, aggregate stability, and general soil health, potential for benefits should be carefully considered prior to field operations. Tillage objectives include soil loosening, incorporation of fertilizer or pesticide, weed control, and surface leveling after prior tillage to accommodate planting. Reducing surface residue cover may allow topsoil to warm faster in spring, promote soil drying, and alter the environment for some disease pathogens. Conversely, soil on sloping areas is exposed to longer term degradation by erosion and moisture loss in dry conditions is counterproductive

Impact of Drainage Water Management on Crop Yield

The objectives of this project were to study nitrate loading in subsurface drainage and corn-soybean yield response under various drainage water management practices. This experiment explores various drainage strategies to reduce nitrate loading to surface waters in southeast Iowa

Reducing Nitrate-N Losses to Achieve Water Quality Goals

Nutrient losses from agricultural systems in the Mississippi River basin have contributed to the hypoxic zone in the Gulf of Mexico. In 2008, in response to this challenge, the U.S. EPA‘s Hypoxia Task Force released an action plan for a national strategy to reduce, mitigate, and control hypoxia in the northern Gulf of Mexico and improve water quality in the Mississippi River basin (www.epa.gov/ms-htf). The action plan indicated that significant (i.e., 45%) reductions in riverine nitrogen and phosphorus loads are needed to achieve the goal of reducing the size of the hypoxic zone, and improve water quality in the basin. One of the main items in the 2008 action plan was the call for state-level nutrient reduction strategies. As a result, the twelve states bordering the Mississippi and Ohio Rivers have developed and begun implementing comprehensive nutrient reduction strategies (www.epa.gov/ms-htf/hypoxia-taskforce-nutrient-reduction-strategies). Iowa was one of the first states to conduct a scientific assessment of the potential nutrient reduction of different agricultural management practices and the level of implementation that might be needed to reach the goal of 45% reduction (www.nutrientstrategy.iastate.edu)

Meeting the nitrate reduction goal: What will it take?

The Iowa Nutrient Reduction Strategy is a science and technology-based framework developed to assess and reduce nutrient loss to Iowa waters and the Gulf of Mexico. The strategy addresses methods and practices to reduce total loads of nitrogen and phosphorus from both municipal and industrial point sources and agricultural nonpoint sources by a combined 45% (INRSSA, 2013). The approach was developed in response to the 2008 Gulf Hypoxia Action Plan that calls for Iowa and other states in the Mississippi River watershed to develop strategies to reduce nutrient loadings to the Gulf of Mexico and ultimately reduce the size of the gulf hypoxic zone

Impact of Drainage Water Management on Crop Yield, Drainage Volume, and Nitrate Loss

The objectives of this study were to determine the impact of shallow, controlled, conventional, and no drainage on crop yields, subsurface drainage volumes, and nitrate loss through subsurface drainage. This research investigates whether drainage water management reduces nitrate loadings to downstream surface waters

Can conservation complement agriculture?

Agriculture will need to produce at least 70% more food by 2050 to ensure global food security (FAO 2009). However, increased productivity has historically come with on-farm and societal costs such as increased soil erosion and nutrient run-off. While conservation is often considered separate from the needs of agriculture, recent research at ISU suggests that targeted conservation practices can positively impact management of farm land, especially for preventing soil erosion and nutrient run-off