多年种植RRS对根际土壤微生物数量及氮素转化的影响

Effect of planting RRS for many years on rhizosphere soil microorganism quantity and nitrogen transformation

对三年种植抗草甘膦转基因大豆的根际土壤氮素转化进行了研究。结果表明,2007～2009年在大豆花期和结荚期,可培养细菌、氨化细菌、硝化细菌的数量以及硝化作用、氨化作用强度都达到最大值,脲酶活性在鼓粒期达到最大值。在这三年中种植抗草甘膦转基因大豆对根际土壤细菌的生长和繁殖都有显著的抑制作用,2008年细菌数量较2007年有所下降,同时抗草甘膦转基因大豆对根际土壤中氨化细菌数量、硝化细菌数量、氨化作用强度、硝化作用强度以及脲酶都有不同程度的抑制。这说明转基因作物影响了根际土壤中与氮素转化有关的微生物的活力,进而影响氮素转化过程。

Nitrogen transformation of rhizosphere soil where planting RRS for 3 years （2007-2009） was studied. The results showed that culturable bacteria, ammonifying bacteria, nitrifying bacteria and nitrification, ammonification are maximum strength in flowering and podding period and urease activity in the period of grains reach maximum. In the three years of planting RRS rhizosphere soil bacteria growth and reproduction were inhibited markedly, the number of bacteria in 2008 less than in 2007, and decline of RRS in the rhizosphere ammoniation bacteria, denitrifying bacteria, number, number of ammoniflca- tion, nitrification strength and urease have different degrees. It showed that genetically modified crops affected the microorganisms involved in the transformation of nitrogen in the rhizosphere soil and affect N conversion process further.