A Preliminary Study on Dynamics and Models of N, P, K Absorption for High-Yield Cotton

摘要

The field experiments were carried out to investigate the dynamics and models of N, P and K absorption for the cotton plants with a lint of 3 000 kg ha~(-1) in Xinjiang. The main results were as follows: The contents of N, P_2O_5, K_2O in cotton leaves, stems, squares and bolls decreased obviously with the time over the whole growth duration and the falling extent was greater in high-yield cotton than in CK. Contents of N in leaves, squares and bolls, in particular in the leaves of fruit-bearing shoot was higher in high-yield cotton than in CK. Contents of P_2O_5 in squares and bolls and that of K_2O in stems were higher in high-yield cotton than in CK during the whole growing period. The accumulations of N, P_2O_5 and K_2O in the cotton plants could be described with a logistic curve equation. There was the fastest nutrient uptake at about 90 d for N, 92 d for P_2O_5 and 85 d for K_2O after emergence, respectively. Total nutrient accumulation of N, P_2O_5 and K_2O was 385.8, 244.7 and 340.3 kg ha~(-1), respectively. Approximately 12.5 kg N, 8.0 kg P_2O_5 and 11.1 kg K_2O were needed for producing 100 kg lint with the leaves and stems under the super high yield condition of 3 000 kg ha~(-1) in Xinjiang.