南疆连作棉田几种有益细菌的动态变化规律

通过稀释涂布平板法研究农一师二团和三团不同连作年限棉田土壤中好气性自生固氮菌、钾细菌、纤维素分解细菌、无机磷细菌、有机磷细菌等有益土壤细菌的总数分布, 以探讨棉花连作对土壤微生物的影响及土壤微生物对棉花生长的影响。结果表明, 5种细菌菌数均在花铃期达到最高, 苗期最低, 受耕作制度影响, 播前期菌数较高。5种细菌菌数随棉花连作年限的增加没有表现出有规律的变化, 受棉花连作影响较小。好气性自生固氮菌菌数在二团各生育期均比三团高, 其他4种细菌在不同生育期变化各不相同。土壤有益细菌与土壤多种离子养分呈负相关, 自生固氮菌与土壤全氮呈显著正相关。

The Dynamic Changes of Soil Beneficial Bacteria in Cotton Continuous Cropping Soil South Xinjiang

To research the effect of continuous cropping on cotton soil microorganisms and soil microorganisms on grow of cotton, we studied the total numbers of aerobic self-nitrogen-fixing bacteria, potassium bacteria, cellulose decomposing bacteria, phosphate solubilizing bacteria, organic-phosphorus-dissolving bacteria distributed in continuous cropping cotton fields of regimental farm 2 and 3 of the first agricultural division through dilution spread plate method. Results showed that the total numbers of five kinds of bacteria was highest in blooming and bolling periods, lowest in seeding periods and higher in before sowing periods. The total numbers of five kinds of bacteria was no notable regular changes with continuous cropping year. The numbers of aerobic self-nitrogen-fixing bacteria at different cotton growth stages in regimental farm 2 was higher than in regimental farm 3 and the numbers change of other bacteria was varied in different cotton growth stages in regimental farm 2 and 3. Soil beneficial bacteria were negatively correlated with a variety of soil nutrient ion and free-living nitrogen fixing bacteria were significantly positive correlated with soil total nitrogen.