Nitrogen efficiency at three sites in Nigeria as affected by N source and management
1990
Mughogbo, S.K. | Christianson, C.B. | Stumpe, J.M. | Velk, P.L.G. (International Fertilizer Development Center, Muscle Shoals, Alabama (USA))
Nitrogen trials were conducted using **15N-labeled urea and calcium ammonium nitrate in the production of maize (Zea mays L.) at three sites of contrasting agroecology in Nigeria. Split applications of banded, broadcast or point-placed N fertilizer had no consistent effect on grain yield or **15N uptake; however at one N-responsive site, application of N in two splits significantly increased yield and grain **15N uptake over application of N in a single dose. **15N balances showed losses of 11-33 %of applied fertilizer N. On the basis of N distribution in the soil profile, leaching was postulated to have been a problem at the wettest site, whereas ammonia volatilization appeared to have occurred at the less humid trials. **15N uptake by a cowpea (Vigna unguiculata (L.) Walp.) intercrop or relay crop was low in all trails.
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