Starter Fertilizer Management for Corn and Soybean in the Southern Plains
Abstract
Early plant growth and grain yield may be depressed in no-till cropping systems compared to conventional tillage because of the poor nutrient availability early in the growing season. Oklahoma no-till corn (Zea mays L.) and soybean (Glycine max L.) may benefit from starter fertilizer because it places a band of available nutrients near the root-zone. The objectives of this study were to evaluate the effects of various starter fertilizer placements and rates on full-season corn and soybean in the Southern Plains. Placement methods consisted of in-furrow, 2x2 (5 cm to the side and 5 cm below the seed), and 2x4 (5 cm to the side and 10 cm below the seed). The corn in-furrow treatments received N rates from 11 to 45 kg ha-1. Three additional corn in-furrow treatments were N + Zn, N + S, and N + Zn + S. The N was balanced to 168 kg ha-1 on all in-furrow corn treatments. The corn 2x2 treatments received N rates from 101 to 168 kg ha-1. The corn 2x4 treatments received N rates of 134 and 168 kg ha-1. The soybean in-furrow treatment received an N rate of 6 kg ha-1. The soybean 2x2 treatments received N rates from 11 to 34 kg ha-1. An additional soybean 2x2 treatment was N + Zn + S. Corn in-furrow placement at 11 kg N ha-1 increased early growth without decreasing stand emergence. No differences, for any corn locations, in initial stand counts were observed for 2x2 and 2x4 treatments at rates of 168 kg N ha-1. Corn NDVI decreased as rates increased from 101 to 168 kg N ha-1 in the 2x2 treatments. Corn grain yield was not affected by placement or rate of starter fertilizer. Soybean in-furrow placement at 6 kg N ha-1 significantly reduced stand, but not yield. Soybean stand, early growth, and grain yield was not affected by any of the 2x2 treatments. Our results showed that starter fertilizer placement and rate increased early growth in corn but had a minimal effect on yield when yield potential was low.
Collections
- OSU Theses [15752]