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Yield and N uptake of tomato (Lycopersicum esculentum Mill.) and pepper (Capsicum annuum L.) crops in five successive rotations receiving two compound fertilizers (12-12-17 and 21-8-11 N-P2O5-K2O) were studied to determine 1) crop responses, 2) dynamics of NO3-N and NH4-N in different soil layers, 3) N balance and 4) system-level N efficiencies. Five treatments (2 fertilizers, 2 fertilizer rates and a control), each with three replicates, were arranged in the study. The higher N fertilizer rate, 300 kg N ha-1 (versus 150 kg N ha-1), returned higher vegetable fruit yields and total aboveground N uptake with the largest crop responses occurring for the low-N fertilizer (12-12-17) applied at 300 kg N ha-1 rather than with the high-N fertilizer (21-8-11). Ammonium-N in the top 90 cm of the soil profile declined during the experiment, while nitrate-N remained at a similar level throughout the experiment with the lower rate of fertilizer N. At the higher rate of N fertilizer there was a continuous NO3-N accum
Yield and N uptake of tomato (Lycopersicum esculentum Mill.) And pepper (Capsicum annuum L.) crops in five rotations receiving two compound fertilizers (12-12-17 and 21-8-11 N-P2O5-K2O) were studied to determine 1) crop responses, 2) dynamics of NO3-N and NH4-N in different soil layers, 3) N balance and 4) system-level N efficiencies of Five treatments (2 fertilizers, 2 fertilizer rates and a control) With three replicates, were arranged in the study. The higher N fertilizer rate, 300 kg N ha-1 (versus 150 kg N ha-1), returned higher vegetable fruit yield and total aboveground N uptake with the largest crop responses occurred for the low-N fertilizer (12-12-17) applied at 300 kg N ha-1 rather than with the high-N fertilizer (21-8-11). Ammonium-N in the top 90 cm of the soil profile declined during the experiment, while nitrate-N remained at a similar level throughout the experiment with the lower rate of fertilizer N. At the higher rate of N fertilizer there was a cont inuous NO3-N accum