连作胁迫下大豆对营养元素的吸收

１９９５～１９９６年，研究了在田间条件下，黑土和石灰性黑钙土上连作大豆对营养元素的吸收。试验结果表明，连作胁迫对大豆氮的吸收影响不大；对磷、钾的吸收显著降低；而对钙的吸收量却显著地增加，在石灰性黑钙土上表现得最显著，这与大豆连作障碍的严重程度有极好的相关性。对镁的影响不规律。连作胁迫下大豆对微量元素的吸收一般是呈下降趋势，其中硼的降低最为显著。１９９５年，连作大豆体内铁、锰的含量显著降低，在石灰性黑钙土上极为显著，但１９９６年不具规律性。铜在连作大豆体内含量基本是呈下降趋势，锌在１９９５年不具规律性，但１９９６年两点的结果都表明，连作大豆体内锌含量明显降低。

NUTRIENT UPTAKE BY SOYBEAN PLANT UNDER SUCCESSIVE CROPPING STRESS

Field exptriments were conducted in 1995 and 1996 to study the nutrient uptake patterns by successive cropped soybean plant on black soil and calcarous chernozem Results showed that the effect of successive cropping on N uptake was not significant; P and K uptakes were reduced significanty; whereas the uptake of Ca increased remarkably This is very obvious on calcarous chernozem, and is closely correlated with the degree of successive cropping stress The uptake of Mg did not show any regularity Generally, uptake of microelement by soybean under successive cropping stress was lowed, and the most obvious element was B The concentrations of Fe and Mn in soybean plant were reduced greatly in 1995, and this is very clear on calcarous chernozem, but no identical results were observed in 1996 The concentratin of Cu in soybean plant was also reduced As for Zn, the results in 1995 from two sites were not identical, but in 1996, the results from both sites showed that the Zn concentration in successive cropped soybean plant was much lower than that in rotional cropped soybean