Effects of Chemical Fertilizer Reduction on Soil Microbiological and Microbial Biomass in Wheat Field
In order to explore the effects of chemical fertilizer reduction with organic fertilizer application on soil microbes,winter wheat was planted under diffierent fertilizer treatments.4 chemical fertilizer（NPK） levels of 100%,70%,50% and 30%,and three organic fertilizer（M） level of 18 000,25 500 and 34 500 kg·km-2（representing with LM,MM and HM,respectively） were selected in the experiment with single NPK application as CK.In the treatments with 100% NPK,the explicating amount of urea,diammonium phosphate and potassium sulfate per hectare were 251.8,255.7 and 375.2 kg·km-2,respectively）.The serial dilution plate culture method and chloroform evaporated method were used to determine the difference of soil microbial carbon,nitrogen contents and the distribution of microbial flora with different treatment.The results indicated that the together application of organic and inorganic fertilizers significantly increased the content of soil microbial carbon and nitrogen,the number of microbes such as bacteria,nitrogen-fixing bacteria,actinomyces,but did not affect the number of soil fungus.The effect of fertilizers rose with the increasing of organic fertilizer under no reducing of chemical fertilizer.the best treatment was 50%NPK ＋ MM when reducing chemical fertilizer.It illustrated that moderate fertilizer reduction with matching application of organic fertilizer could improve soil microbial biomass in favor of soil fertility.
NETL
NSTL
万方数据
维普
