加气灌溉对麦秸秆还田后土壤还原性与水稻生长的影响

为揭示添加微纳米气泡的加气灌溉对秸秆还田条件下稻麦轮作区水稻生长的影响，并提出合理进气量的加气灌溉方式，设置6个处理（无秸秆还田不加气灌溉（CK）、小麦秸秆还田不加气灌溉（ST）、小麦秸秆还田+进气量0.3L/min加气灌溉（SO1）、小麦秸秆还田+进气量0.5L/min加气灌溉（SO2）、小麦秸秆还田+进气量0.7L/min加气灌溉（SO3）和小麦秸秆还田+进气量0.9L/min加气灌溉（SO4））开展水稻盆栽试验，观测不同处理下的土壤还原性状况以及水稻生长规律。结果表明：秸秆还田会显著增强土壤的还原性状况，微纳米加气灌溉可以改善土壤还原性，且随着进气量的增加改善效果逐渐增强，当进气量为0.9L/min时，土壤活性还原性物质含量、Fe2+含量、Mn2+含量最高可降低48.66%、56.11%和42.76%；进气量在0.5~0.7L/min时的加气灌溉能够促进水稻的生长发育，缓解秸秆还田带来的水稻生长前期生长受到抑制的问题，促进水稻根系良好生长，利于水稻光合作用的有效性，促进干物质积累，从而提高水稻产量，微纳米加气灌溉处理较无秸秆还田以及秸秆还田不加气灌溉处理最高可增产19.7%。综合考虑添加微纳米气泡的加气灌溉对于改善秸秆还田后土壤的还原性以及对水稻生长发育的影响，推荐使用溶解氧质量浓度为8.06mg/L的微纳米气泡水（SO3处理）对稻麦轮作区秸秆还田后的水稻进行灌溉。

Effects of Aerated Irrigation on Rice Growth and Soil Reducibility under Wheat Straw Returning Conditions

In order to reveal the effects of micro-nano aerated irrigation on rice growth under straw returning condition in wheat-rice rotation area and put forward the optimal aerated irrigation method, rice pot experiments were conducted and six experiment treatments were set up, i.e., no straw returning with no aeration irrigation treatment (CK), wheat straw returning with no aeration irrigation treatment (ST), wheat straw returning with 0.3L/min air intake micro-nano aerated irrigation treatment (SO1), wheat straw returning with 0.5L/min air intake micro-nano aerated irrigation treatment (SO2), wheat straw returning with 0.7L/min air intake micro-nano aerated irrigation treatment (SO3), and wheat straw returning with 0.9L/min air intake micro-nano aerated irrigation treatment (SO4). The soil reduction characteristics and rice growth under different treatments were observed. Results showed that straw returning could enhance the soil reducibility significantly. Micro-nano aerated irrigation could improve the soil reducibility, and the improvement effect would be enhanced gradually with the increase of air intake volume. When the air intake volume was 0.9L/min, the contents of soil reductive organic matter, Fe2+ and Mn2+ could be reduced by 48.66%, 56.11% and 42.76%, respectively. Aerated irrigation with an air intake of 0.5~0.7L/min could promote the growth and development of rice, alleviate the problem of the rice growth inhibition in the early stage caused by straw returning, and promote the growth of rice roots, which was conducive to rice photosynthesis, promoting the accumulation of dry matter, and thereby increasing the rice yield. The highest yield improvement could be reached 19.7% after aerated irrigation. Considering the effect of micro-nano aerated irrigation on soil reducibility and rice growth, micro-nano bubble water with dissolved oxygen concentration of 8.06mg/L (SO3 treatment) was recommended to irrigate rice under straw returning conditions in wheat-rice rotation areas.