^(15)N示踪法研究固氮芽孢杆菌应用效果

The Effect of bacillus azotofixans by ^(15)N tracing experiment

通过对水稻盆栽试验,应用15N示踪测试技术和土壤农业化学分析方法,研究接种不同剂量固氮芽孢菌对当季水稻的供氮能力,结果表明:在施有机肥的基础上,接种固氮芽孢杆菌能为当季水稻提供氮素,而且,接菌剂量在0.60亿个?pot-1以内,其供氮能力随着接菌剂量的增加而提高;接种剂量从0.15亿个?pot-1增加到0.60亿个?pot-1,其对当季初的氮素供应从88.7mg?pot-1提高至109.7mg?pot-1,并减少水稻对肥料氮和土壤氮的吸收,增加茬后土壤的速效氮积累,接种量以0.15亿个?pot-1～0.30亿个?pot-1较经济。但在一定的施肥基础上,接种固氮菌对水稻的产生量和吸收氮素总量影响不明显。

^15N tracing experiments and soil agricultural chemistry analytical method of azote provision by different amount of bacillus azotofixan in rice show that applying bacillus azotofixan to soil with organic fertilizer can provide azote in different ways. Within 60 million · plant^-1, the amount of azote increases with that of bacillus azotofixan. From 15million/plant to 60 million/plant, the amount ofazote increases from 88.7 mg·plant^-1 to 109.7 mg · plant^-1, thus reducing rice azote absorption from fertilizer and soil and increaing the accumulation of azote in soil after harvest. The economically effective amount of bacillus azotofixan is 15 million · plant^-1 to 30 million ·plant^-1. Yet on a certain amount of fertilizer application, bacillus azotofixan doesn＇t have dramatic effect on yields and azote absorption.