Influence of Reduced Tillage, Fertilizer Placement, and Soil Afforestation on CO2 Emission from Arable Sandy Soils

Nitrous Oxide Emissions from Claypan Soils Due to Nitrogen Fertilizer Source and Tillage/fertilizer Placement Practices

Effects of fertilizer placement on solute leaching under ridge tillage and no tillage

Elevated nitrate concentrations in ground water can be a problem in agricultural areas, especially where soils are sandy. Tillage operations, such as ridge tillage (RT) and no tillage (NT) can reduce runoff and erosion but leaching of soluble nutrients could adversely impact groundwater. In a 2-year study, Br was used to trace the effects of fertilizer placement on solute movement under corn (Z...

Tillage and Fertilizer Placement for the Corn-soybean Rotation

The information presented is part of ongoing research to identify effective conservation tillage systems and phosphorus (P) and potassium (K) fertilizer placements for corn and soybeans. The rate of adoption of the no-till system by Iowa producers has decreased after a marked increase during the late 80s and early 90s. Actually, the area of no-till corn has decreased slightly since 1994. Severa...

Temporal Variability of Soil Co2 Emission after Conventional and Reduced Tillage Described by an Exponential Decay in Time Model

To study Assessing the impact of tillage practices on soil carbon losses dependents it is necessary to describe the temporal variability of soil CO2 emission after tillage. It has been argued that large amounts of CO2 emitted after tillage may serve as an indicator for longer-term changes in soil carbon stocks. Here we present a two-step function model based on soil temperature and soil moistur...

Optimum Phosphorus Placement for Reduced Tillage Systems

Row-crop agriculture is under pressure to reduce sediment and nutrient losses to surface water resources by practicing less tillage and more precise application and placement of nutrients. Field studies started in 1997 were conducted through 2002 on very low to low P-testing (3 to 5 ppm Bray P1) and medium to high-P testing (11 to 19 ppm Bray P1) sites of a Nicollet-Webster clay loam complex at...