Proceedings
Authors
| Filter results4 paper(s) found. |
|---|
1. Soil Fertility Trends in a Long Term Crop Rotataion-Soil Fertility TrialPenn State soil test recommendations are based on fertilizing for crop response at soil test levels below the critical level for response, maintenance fertilization based on expected crop removal in the optimum range just above the critical level, and finally no fertilizer recommended in the high range. Using a sufficiency level approach, a soil that was at the critical level would have a zero recommendation, however this zero recommendation would not be valid for 3 or 4 years until a new soil test... |
2. Making Urea Work in No TillNo-till and reduced tillage production systen~s are widely used today in the United States as well as around the world due to their capacity for reducing soil erosion and topsoil loss, reducing phosphorus movement to surface water, and reducing labor, fuel, and equipment requirements. In no-till systems, an average of 25% of the N applied as broadcast urea can be lost via ammonia volatilization. Therefore, N losses due to ammonia volatilization will decrease corn and wheat yields. independently of... |
3. Crop Sensor-Based N Rates Out-Performed Producer-Chosen N RatesOptimal N fertilizer rate for corn (Zea mays L.) and other crops can vary substantially within and among fields. Current N management practices do not address this variability. Crop reflectance sensors offer the potential to diagnose crop N need and control N application rates at a fine spatial scale. Our objective was to evaluate the performance of sensor-based variable-rate N applications to corn, relative to constant N rates chosen by the producer. Fifty-five replicated on- farm demonstrations... |
4. Using Soil and Tissue Testing to Predict Soybean Yield Response to Foliar Applied Micronutrients in IowaPrior research with foliar application of micronutrients for soybean has shown inconsistent yield responses in Iowa and the western Corn Belt. Iowa has no interpretations for soil or tissue tests for micronutrients in soybean. This study's objectives were to evaluate soybean plant-tissue and grain yield responses to foliar application of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) in Iowa. There were 22 field trials in 2012 and 21 in 2013, which were established in 20 counties and included... |