Effects On Soil Microbial Physiologies Colony And Enzyme Activities Under Different Tillages

Based on different tillages experiment in Dingxi, changes of soil microbial physiologies colony and soil enzyme activies were studied in four treatments(no-tillage and straw covered, plough with straw incorporated, no-till without straw, conventional cultivation and no straw).The results showed as follows:1. No-tillage and covered straws could increase soil microbial physiologies colony number1) Two rotations, the number of soil microbial physiologies colony was higher in conditions than in tillage conditions. contrast to tillage conditions, soil ammoniation bacteria, nitrify bacteria , nitrogen-fixing bacteria , organic phosphate bacteria and inorganic phosphate bacteria number increased 67.92%,97.03%,49.76%,19.70%and 21.65% in no-tillage conditions.2) Two rotations, straws covered could significantly increase soil microbial physiologies colony number. Compared with no-straw covered,soil ammoniation bacteria, nitrify bacteria , nitrogen-fixing bacteria , organic phosphate bacteria and inorganic phosphate bacteria number increased 156.96%,164.63%,49.94%,28.40% and 33.20% in straws covered.3) Two rotations, the number of soil microbial physiologies colony reduced with the increment of soil depth.2. No-tillage and covered straws could increase soil enzyme activiesTwo rotations, soil enzyme activies were higher in no-tillage conditions than in tillage conditions, soil enzyme activies were higher in straw covered conditions than in no-straw covered conditions.Two rotations, soil urease, alkaline phosphatase and cellulose activities reduced with the depth of the soil.Soil catalase activities increased with the depth of the soil.3. The correlation of soil microbial physiologies colony and soil enzyme activiesTwo rotations, the correlation coefficient of soil microbial physiologies colony number, soil enzyme activies, soil microbial physiologies colony number and soil enzyme activies reached significant level. In pear field, it is a negative correlation between soil catalase activies and cellulose activies, alkaline phosphatase activies.