不同磷钾处理下套作大豆干物质积累及钾肥利用率的动态变化

Dynamics of dry matter accumulation and potassium utilization in relay strip intercropped soybean under different phosphorus and potassium levels

在磷钾供应条件下,以贡选1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/（1＋ae-bx）.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.