抗生菌剂在缓解大豆重迎茬根际微生态障碍中的作用

重迎茬问题是造成大豆减产、品质下降的主要原因之一,而施用适宜的抗生菌剂能够改善根际微生态环境,促进大豆正常地生长发育,从而缓解甚至消除重迎茬的危害.本研究对正茬和重茬区大豆进行了抗生菌剂处理,并以常规处理作对照,在不同生育时期分别测定大豆的氮素同化量及根际微生物区系状况.经连续两年小区试验,结果表明:在播种同时施用定向筛选的抗生菌剂,明显改变了重迎茬大豆根际微生物区系组成,在细菌、放线菌数量显著增加的同时,真菌数量明显减少,即提高了B/F、A/F值,增强土壤自净与保健能力.进而改善了重迎茬大豆结瘤固氮状况,促进植株生长发育,增加了单株籽粒重量,提高了籽粒的氮素同化量,缓解了重迎茬大豆的氮素同化生理性障碍.

FUNCTION OF ANTIMICROBIAL AGENT ON DELAYING RHIZOSPHERE MICROBE OBSTACLE OF CONTINUOUS AND ONE YEAR INTERMITTENT CROPPING SOYBEAN

Continuous and one year intermittent cropping problem is one of the primary reasons to the reduction of output and decline of quality in soybean,whereas fertilizing fitting antimicrobial agent can improve rhizosphere microbe and prompt soybean growth.Consequently,it can alleviate or even eliminate the side-effect of continuous and one year intermittent cropping.This paper compared the continuous and one year intermittent cropping soybean which treated by antimicrobial agent with the normal treatment and separately measured nitrogen assimilation quantity and rhizosphere microbe in different growth period.Through two years tests it showed that the constitutes of micro organisms on soybean rhizosphere changed significantly when the screening antimicrobial agent was applied at planting.The number of bacteria and actinomyces increased,at the same time the number of fungi decreased.Thus improved the condition of nodding and nitrogen fixing,prompted soybean growth,enhanced the assimilation of nitrogen on soybean seed,and alleviated the nitrogen assimilation obstade of the contionuous and one year intermittent cropping soybean.