增氧处理对稻田土壤微生物量碳、氮和酶活性的影响

Effect of Aeration Treatment on Soil Microbial Biomass Carbon,Nitrogen and Enzyme Activities in Paddy Field

【目的】探讨增氧方式对稻田土壤微生物量碳、氮和土壤酶活性的影响。【方法】以中旱221(旱稻)、中浙优8号(水稻)和IR45765-3B(深水稻)为材料,研究微纳米气泡水增氧灌溉、干湿交替灌溉、淹水灌溉对稻田土壤微生物量碳、氮,土壤氮代谢作用强度和土壤氮素转化相关酶活性的影响。【结果】微纳米气泡水增氧灌溉和干湿交替灌溉可以显著提高稻田土壤微生物生物量碳、氮,中旱221、中浙优8号和IR45765-3B的增氧处理较淹水灌溉处理微生物生物量碳、氮分别增加了30.0%~46.1%和7.1%~92.1%,并且增氧处理降低了3个水稻品种的微生物量碳氮比;与淹水灌溉相比,微纳米气泡水增氧灌溉和干湿交替灌溉有助于提高稻田土壤脲酶、蔗糖酶、过氧化氢酶、蛋白酶、羟胺还原酶活性,降低硝酸还原酶活性和亚硝酸还原酶活性。【结论】微纳米气泡水增氧灌溉和干湿交替灌溉改善稻田土壤的氧化特性,提高土壤酶活性、微生物量碳、氮和硝化强度,有助于改善土壤环境和肥力状况,协调了C、N代谢的平衡。

【Objective】It is of great importance to elucidate the effects of different aeration methods on soil microbial biomass carbon,nitrogen and soil enzyme activities in paddy fields,【Method】Using Zhonghan 221(upland rice),Zhongzheyou 8(rice)and IR45765-3B(deepwater rice)as materials,the effects of the micro-nano bubble water aeration irrigation(MBWI),dry-wet alternate irrigation(AWD)and flooding irrigation(WL)on soil microbial biomass carbon,nitrogen in paddy soil,nitrogen metabplic intensity and activities of enzymes related to nitrogen transfomation were studied.【Result】Soil microbial biomass C and N could be significantly increased by micro-bubble aeration irrigation and dry-wet alternate irrigation.The soil microbial biomass C and N increased by 30.0%~46.1%and 7.1%~92.1%in Zhonghan 221,Zhongzheyou 8 and IR45765-3B,respectively.The activities of urease,sucrase,catalase,protease and hydroxylamine reductase in paddy soil were increased by micro-nano bubble water aeration irrigation and dry-wet alternate irrigation compared with flooding irrigation,the nitrate reductase activity and nitrite reductase activity were reduced.【Conclusion】Micro-nano bubble water aerobic irrigation and dry-wet alternate irrigation can improve the oxidation characteristics of paddy soil,increase soil enzyme activities,microbial biomass carbon,nitrogen and nitrification intensity,and contribute to the improvement of soil environment and fertility,strike a balance between C and N metabolism.