在磷钾供应条件下,以贡选l号为材料,研究了田间套作大豆干物质积累及钾肥利用率的动态变化.结果表明,套作大豆干物质积累量和钾素吸收量均随生育时期推进而持续增加,均符合“S”形曲线,可用Logistic方程y=k/(1+ae-bx)拟合.干物质积累速率前期缓慢,随后迅速上升,出苗后79.3d达到高峰后缓慢下降,钾肥吸收速率与干物质积累速率趋势一致,但最大吸收速率出现时间(出苗后73.6d)早于干物质积累最大速率出现时间.钾肥利用率呈现先升高后降低的趋势,最高阶段利用率与最大吸收速率出现时间基本一致(出苗后75d ～ 90d).施用磷钾提高了钾素吸收速率、干物质积累速率、钾肥积累利用率和阶段利用率,但没有改变其变化趋势.%Glycine max (L. ) Merri cv Gongxuan 1 was used to investigate the dynamics of dry matter accumulation and potassium (K) utilization efficiency. The materials were relay strip intercropped under varied phosphorus (P) and K treatments. Results indicated that the dry matter accumulation and K absorption continuously increased as S curves with plant growth, and could be estimated by Logistic regression equations y =k/{ +ae~'") . Dry matter accumulation rate increased slowly at early stage, and accelerated to the peak at 79. 3d after germination, and then gradually decreased after that. The trend of K absorption rate and dry matter accumulation rate were coherent, but the time of the maximum absorption rate appeared (at 73. 6d after germination) earlier. During the soybean growth, K cumulative utilization efficiency increased first, and reached the topmost at the same time (at 75d ~90d after germination) as K absorption rate did. The P and K application improved K absorption rate, dry matter accumulation rate, K accumulation utilization efficiency and utilization efficiency at different growth stages, but did not alter their changing trends during the soybean - growth period.
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