Urea and Manure Effects on Soil Nitrogen and Corn Dry Matter Yields1
- Rongjing Xie and
- A. F. MacKenzie2
Fresh (FC) and composted (CC) cow (Bos taurus) manures, liquid hog (Sus scrofa domesticus) manure (HM), and urea (U) were applied as N sources for silage corn (Zea mays L., hybrid W844) production on a Chicot (Hapludalfs) and a St. Benoit soil (Eutrochrepts) at rates of 0 to 240 N ha−1. Soil NO3-N levels were significantly increased while soil NH4-N levels were only temporary increased by N additions. Highest NO3-N levels were noted 30 and 60 d (June and July) after N applications for the St. Benoit and the Chicot soils respectively. Hog manure resulted in more NO3-N compared with FC and CC manures. One to 5 kg manure-N was found to be equivalent to 1 kg of urea-N in terms of increasing soil NO3-N levels at the end of growing season. Differences between surface spreading or incorporating of manures on corn dry matter yields (DMY) and N uptake were not significant. Nitrogen uptake increased with increases in N application rates and was higher with HM than with CC or FC manures. Regression between DMY or N uptake and N application rates showed linear relationships with manure-N and quadratic relationships with urea-N. In 1984, 1 to 4 kg manure-N resulted in similar corn DMY as 1 kg urea-N. Cumulative effects of treatments on yields and on nutrient uptake observed in second and third years were greater on the St. Benoit soil than on the Chicot soil.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .