The effects of biochar application on the microbial community

enzyme activity and soil nutrient availability in dryland soils of central Guizhou were studied through pot experiment. The results showed that after applying 5%~15% (biochar/soil mass ratio) biochar to different types of dryland soils

the number of fungi

actinomycetes

bacteria and nitrifying bacteria

ammoniated bacteria and the activity of phosphatase

catalase and urease in yellow soil and yellow sand soil increased obviously

especially in yellow sand soil. The number of actinomycetes

fungi and nitrifying bacteria in the lime soil

as well as the activity of phosphatase and catalase increased significantly

but the number of ammoniated bacteria and urease activity decreased significantly. In addition

the content of available N

P

K

Ca

Mg and B in yellow soil and yellow sand soil increased in different degrees

but the content of available Fe

Mn

Cu and Zn decreased in different degrees. The content of available P

K

Fe

Mn

Cu and B in the lime soil increased in different degrees

but the available N

Ca

Mg and Zn in the lime soil decreased in different degrees. The content of available Zn in these three dryland soils all decreased obviously after applying biochar. The application of 5%~15% biochar in yellow soil

yellow sand soil and lime soil could obviously increase the yield of cabbage and lettuce

of which the yellow sand soil applied with biochar was the best in increasing yield

followed by lime soil. There were significant differences in the changes of soil available nutrients among different types of dryland soils after applying biochar. When applying biochar

a certain proportion of nitrogen

phosphorus

potassium and appropriate amount of trace element fertilizers should be used according to soil characteristics

which could promote the growth of crops.