Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2000
Publication Date: N/A
Technical Abstract: Crop yield variability is strongly related to soil properties. As a result, knowing the spatial variability of soil properties of pH, soil texture, "A" horizon depth, coarse textured material depth (greater than 2mm), and depth of carbonates may be useful for understanding crop yield variability. The objectives of this study were to correlate these soil properties with 6 years of corn yield data for a 16 ha field in central Iowa. Yields were measured along 8 transects by combine. Each of the 8 transects consisted of 28 plots, 12.2 m long. One soil core was removed from each plot and "A" horizon depth, coarse textured material depth and carbonate depth were measured in the field. The top 15 cm of each core soil was removed and later analyzed for pH and texture. Regression analysis showed a positive correlation of the 6 year corn yield average verses depth to "A" horizon and depth to coarse textured material. When only the average corn yield of the four years with below normal rainfall was considered, the correlation for both "A" horizon depth and depth of coarse textured materials was even stronger. Regression analysis revealed that coarse textured materials and depth of "A" horizon are an important factor when soil water is limiting yield. PH, depth to carbonates showed no correlations with corn yield. Soil textures are currently being analyzed.