A study on soil biological properties of artificial grassland over different cultivation times in Bayanbulak.

The artificial grassland in Bayanbulak was used as an example to examine the relationship between soil microorganism numbers,enzyme activities,and soil factors over different lengths,0(CK),4,8,15 and 20 years of cultivation.The numbers of soil microorganisms increased initially,reached maximum at 4years,and then decreased with time.The order of microbial numbers in all grasslands was bacteriaactinomycetefungi. The numbers of soil microorganisms in the 0-20cm soil layer was higher than that in the 20-40cm layer. Soil microbes reached their maximum and minimum in August and September,respectively.The order of soil catalyse activities was the same as that of microbe numbers,but the order of soil urease activity was 480 2015years.However,the two enzyme activities were higher in the 0-20cm soil layer than those in the 20- 40cm layer.Stepwise regression showed that the numbers of soil microorganisms,soil urease activity,and catalase activity were mainly affected by available nitrogen and by urease activity,total phosphorus and soil organic matter,total phosphorus and pH value,respectively.