From 2014 to 2015

set deep plowing with straw returning (DR) and rotary tillage with straw returning (RR)

took rotary tillage without straw returning (CK) as the control

studied effect of current year and the following year with straw returning on soil available nutrients and microbial biomass under different tillage methods at Plain of Xi Liao River. The results showed that deep tillage with straw returning and rotary tillage with straw returning all could increase in various degrees of soil available nitrogen

potassium content and bacteria

fungi

actinomycetes number

straw returning with deep plowing had more obvious effect

the rotary tillage with straw returning had little effect on soil available phosphorus content. Straw returning the following year

according to average for 3 different soil layers at full ripe stage

compared with CK

the content of available nitrogen in DR and RR increased by 26.60% and 16.34% respectively

available phosphorus increased by 19.81% and 0.92%

available potassium increased by 23.95% and 12.53%

according to total of 3 different soil layers

the number of bacteria increased by 36.46% and 9.8%

the number of fungi increased by 22.10% and 21.90%

the number of actinomycetes increased by 23.55% and 17.38%. Compared with the current year and the following year

the growth rate of soil available nutrient was higher than that in the current year at jointing stage

and the growth rate of other periods was higher than that in the following year

the microbial biomass performance for the following year growth rate was higher than that in the current year. Compared with the control

the soil available nutrients and microbial biomass increased mainly in the 0—10 cm soil layer. Compared with the different growth stages

the soil available nutrients performance for full ripe stage was the biggest at the current year

and the following year at the jointing stage was the biggest.