不同种植年限苜蓿地亚硝化菌、反硝化菌和固氮菌的垂直分布

摘要

本文对西辽河平原不同种植年限苜蓿地亚硝酸细菌、反硝化细菌、固氮菌的垂直分布规律进行研究,结果表明,苜蓿地的亚硝酸细菌数量5月份比4月份减少4个数量级,固氮菌的数量在2个不同种植年限苜蓿地无明显差异,反硝化细菌在2年生苜蓿地中多于5年生苜蓿地,2年生苜蓿地的亚硝酸细菌多于5年生苜蓿地.试验期间土壤中反硝化细菌最多,固氮菌次之,亚硝酸细菌最少.%This study deals with the vertical distribution of nitrifying bacteria,denitrifying bacteria and nitrogen-fixing bacteria in the alfalfa crops of different ages in Xiliaohe Plain.The results showed that alfalfa crops in April had more nitrifying bacteria (about 104) than that in May.The amount of nitrogen-fixing bacteria did not have obvious difference between the 2-year-old and 5-year-old alfalfa crops.However,the 2-year-old alfalfa crops had higher amount of denitrifying bacteria than that of the 5-year-old alfalfa crops.During the studying period,the amount of soil denitrifying bacteria was most abundant,followed by the nitrogen-fixing bacteria,with the nitrifying bacteria the least in alfalfa crops.