Growth and nitrogen nutrition of maize (Zea maysL.) in soil treated with the nitrification-inhibiting insecticide Baythroid

摘要

A pot experiment was conducted to compare the uptake and dry matter production potential of NHinf4sup+and NOinf3sup-and to study the effect of Baythroid, a contact poison for several insect pests of agricultural crops, on growth and N uptake of maize (Zea maysL.). Nitrogen was applied as (15NH4)2SO4, K15NO3, or15NH4NO3and in one treatment Baythroid was combined with15NH4NO3. Source of N had, in general, a nonsignificant effect on dry matter and N yield, but uptake of NOinf3sup-was significantly higher than that of NHinf4sup+when both N sources were applied together. Substantial loss of N occurred from both the sources, with NHinf4sup+showing greater losses. Baythroid was found to have a significant positive effect on dry matter yield of both root and shoot; N yield also increased significantly. Uptake of N from both the applied and native sources increased significantly in the presence of Baythroid and a substantial added nitrogen interaction (ANI) was determined. The positive effect of Baythroid was attributed to: (1) a prolonged availability of NHinf4sup+due to inhibition of nitrification, (2) an increased availability of native soil N through enhanced mineralization, and (3) an enhanced root proliferation.