膜下加氧滴灌对新疆棉田土壤环境及棉花生长的影响

With the development of the drip irrigation technique, the oxygation must be the new measures to increase the cotton yield. It has been found that irrigation and plastic film mulched can reduce the oxygen content in soil and cause the stress from the low oxygen, which inhibit the growth of the cotton roots and decrease the absorption of water and nutrition, and then it affect the growth and yield crop；And oxygation can effectively solve the problems. At the present the acreage of cotton is 1233333 hm2 in Xinjiang. Many technical achievements have been obtained about regulating water and fertilizer with the drip irrigation. But there is a little report about the technique of added oxygen to the drip irrigation. The article is research that added oxygen to the drip irrigation affect the rhizosphere soil environment and growth of cotton in Xinjiang by utilizing the theory of Venturi Tube 、the technique of ultramicro bubble aerated irrigation. The article research the regular of the oxygen absorption and consumption of cotton roots and analyze the effect ORP、the absorption of water and nutrition in the cotton soil with adding oxygen by hydroponics experiment、micro-area simulation test and field experiment. The root morphology、the absorption of water and nutrition、the yield and quality of cotton are analyzed with adding oxygen to cotton mulched drip irrigation. It provide the academic supporting for the sustainable development of cotton production and water resources sustainable utilization.

随着滴灌技术的精细化发展，加氧灌溉已成为一种挖掘作物高产潜力的新措施。国内外研究发现灌溉和覆膜会造成土壤氧气含量降低，导致低氧胁迫，抑制作物根系生长引起吸收功能降低，进而影响作物生长和产量，加氧滴灌可有效解决这一难题。目前新疆棉花膜下滴灌面积达到1233333hm2，有关滴灌水肥调控技术研究和应用都取得了很多成果，但在棉花加氧滴灌研究方面还鲜有报道。本研究利用文丘里管原理和超微气泡技术，结合膜下滴灌进行加氧，实施根区水氧调控，进行膜下加氧滴灌对新疆棉田根际土壤环境和棉花生长的影响研究。通过水培试验、微区模拟试验和田间试验，研究棉花的需氧规律和耗氧特征，分析灌溉水溶解氧浓度对棉田土壤ORP、养分和水分的影响，明确膜下加氧滴灌对棉花根系生理形态、水分养分吸收、产量和品质的影响，阐明膜下加氧灌溉对棉花生长发育的影响机制，为新疆棉花及高效节水技术持续发展提供理论依据和技术支撑。

本文主要针对北疆棉花生产中存在膜下滴灌影响棉田土壤空气交换，导致土壤阶段性缺氧，影响棉田土壤养分有效性和棉花对养分的吸收，造成棉花生长受到抑制等科学问题，研究了膜下增氧滴灌对棉田土壤环境及棉花生长的影响机理。通过2014-2015年内外模拟试验研究，开展了棉花的农艺特征、营养特征、生理特征和立地生长环境特征的增氧效果分析，明确了棉花蕾期的耗氧量以及物理增氧和化学增氧对棉花生长的增效机理，初步探明了增氧滴灌对棉田土壤养分、微生物、酶的影响；确定了增氧灌溉可以改善土壤氧环境，提升土壤肥力，促进棉花生长，进而为提升棉花增产潜力提供了理论指导。主要研究结论如下：.（1）室内外模拟试验结果表明，化学增氧以过氧化尿素效果较好，物理增氧以微纳米气泡发生装置效果较好。 .（2）增氧水培试验结果表明，增氧水可显著提高种子发芽率、发芽指数和活力指数；增氧能够显著促进蕾期棉花根体积、根系总吸收面积、根系活性面积、根系生物量、地上部生物量、株高、氮吸收量、磷吸收量、钾吸收量、叶片超氧化物歧化酶（SOD）、叶片过氧化物酶(POD)和叶片过氧化氢酶（CAT）的活性。并探明了棉花蕾期的单株耗氧量为0.00284mg·L-1·h-1-0.00484mg·L-1·h-1，水培溶解氧浓度越高棉花单株耗氧量也越高。.（3）田间增氧试验结果表明，增氧能够促进土壤有机质矿化，提高土壤养分有效性，并促进了棉花对土壤中的养分的吸收从而降低了土壤中养分含量。增氧可以增加棉田土壤中细菌、真菌、微生物数量，抑制了放线菌数量，提高土壤脲酶活性。.（4）田间增氧滴灌能够显著促进棉花生长和产量形成；增氧能够促进棉花对氮、磷、钾的吸收；大田增氧能提升棉花根系活力和叶片植物酶（SOD、POD），从而增强棉花对养分的吸收，提升了棉花抗逆能力。