EFFECTS OF REPEATED BIOGAS SLURRY APPLICATION ON SOIL QUALITYAND BACTERIAL COMMUNITY COMPOSITION UNDER WHEAT-RICE ROTATION ONA COASTAL RECLAIMED FARMLAND

摘要

Biogas slurry.a by-product from anaerobic di-gestion of animal wastes for biogas production, con-tains easily-available plant nutrients and can be used to fertilize crops directly or added with other organic materials and synthetic fertilizers. However, limited information is available regarding the effects of re-peated application ofbiogas slurry on saline soil and crop yields. A field experiment, containing 2 treat-ments with equivalent total Nusage, CF (Full chem-ical N fertilizers application) and BS-C(Using pig manure biogas slurry instead of chemical N ferti-lizer), was conducted for 5 years to evaluate the changes in soil quality, bacterial community and grain yield following repeated applicating biogas slurry to a wheat-rice rotation system in coastal rec-lamation farmlands. Compared with CF,the soil quality under BS-C was considerably enhanced through improving soil organic carbon(increased by 10.5% for wheat season and 71.1% for rice season)and reducing soil pH(decreased 0.21-0.25 units to 7.57-8.42).But the soil EC values increased by 5.9 times for the wheat season, and 60.8% for the rice season. Besides,repeated application of biogas slurry did not change the dominant bacterial phyla and the evenness oftop 20genera for wheat and rice seasons soils, but the composition of the top 20gen-era was altered. Moreover, thegrain yields under BS-C showed an increase of 11.7%(rice)and 34.9%(wheat)compared to CF. Therefore, we concluded that repeated applying biogas slurry could improve the soil quality and grain yields for the wheat-rice rotation system.