华中地区旱地氮素矿化的能力

Nitrogen mineralization potentials of 15 soil samples were studied by the methods of soil aerobic incubation, and the correlation between the potentials and the amounts of nitrogen taken up by rye grass (Lolium multiflorum Lam.) in pot culture was calculated. The soils were collected from Hubei Province in Central China. Soil nitrogen mineralization potentials (N_O) were calculated and optimized by a quick-BASIC program. N_O ranged from 60 mg kg^-1 to 340 mg kg^-1, which accounted for 9.1% to 34.6% of the total nitrogen content. Among the examined soils, yellow-brown soil collected from Wuhan had the largest N_O and brown-red soil from Xianning had the smallest one. The mineralization rate constants (k) ranged from 0.00556 d^-1 to 0.01280 d^-1, in average 0.00882 d^-1. Chao soil from Wuhan had the greatest k while yellow-cinnamon soil from Zhaoyang had the smallest one. There were apparent differences between mineralization parameters (N_O and k) optimized and non-optimized ones. Optimized N_O had a better correlation than non-optimized N_O with the amount of nitrogen accumulated in the aerial parts of rye grass. N_O, N_O × k and N_t(accumulated mineralized nitrogen within time t) could be used as indexes of soil nitrogen supply. Among them N_t was the best, which was significantly correlated with the amounts of nitrogen accumulated in the aerial parts of rye grass harvested at three different times.

Nitrogen mineralization potentials of upland soils in Central China

Nitrogen mineralization potentials of 15 soil samples were studied by the methods of soil aerobic incubation, and the correlation between the potentials and the amounts of nitrogen taken up by rye grass (Lolium multiflorum Lam.) in pot culture was calculated. The soils were collected from Hubei Province in Central China. Soil nitrogen mineralization potentials (N_O) were calculated and optimized by a quick-BASIC program. N_O ranged from 60 mg kg^-1 to 340 mg kg^-1, which accounted for 9.1% to 34.6% of the total nitrogen content. Among the examined soils, yellow-brown soil collected from Wuhan had the largest N_O and brown-red soil from Xianning had the smallest one. The mineralization rate constants (k) ranged from 0.00556 d^-1 to 0.01280 d^-1, in average 0.00882 d^-1. Chao soil from Wuhan had the greatest k while yellow-cinnamon soil from Zhaoyang had the smallest one. There were apparent differences between mineralization parameters (N_O and k) optimized and non-optimized ones. Optimized N_O had a better correlation than non-optimized N_O with the amount of nitrogen accumulated in the aerial parts of rye grass. N_O, N_O × k and N_t(accumulated mineralized nitrogen within time t) could be used as indexes of soil nitrogen supply. Among them N_t was the best, which was significantly correlated with the amounts of nitrogen accumulated in the aerial parts of rye grass harvested at three different times.