曝气滴灌水气传输机制与滨海棉田土壤-植物系统响应

Areation drip irrigation is a kind of new irrigation technology, which could improve soil aeration by water and air coupling, and increase crop production and water and fertilizer use efficiency effectively. The Yellow River delta is an important cotton production region in China. In this region, fresh water shortage, soil salinization and poor soil air-permeability are main factors restricting cotton production. So it is an effective way to boost the sustainable development of cotton production with areation drip irrigation. Field and greenhouse experiments will be carried out to investigate infiltration characteristics and water and air distribution law,and influence of water and air coupling on discharge rate of drip emitter, to evaluate the uniformity of water and air distribution along the way and discharge of irrigation emitter, to determine the suitable drip irrigation tube length which could satisfy the uniform distribution of water and air so as to advance suitabie technology parameters for areation drip irrigation. Through field experiments, effects of areation drip irrigation on water, nutrients, air and heat of rhizosphere soil will be expounded. The dynamic response of micro soil environment factors such as microorganism and enzyme activity will be investigated. The influence of areation drip irrigation on Eco-physiological parameters of cotton in saline field will be studied. And influences of areation time, areation quantity and irrigation amount on cotton roots, soil characteristics, cotton yield and water use efficiency will be analyzed. Then high efficiency irrigation model of water and air coupling for areation drip irrigation will be achieved. Results of this research could provide theoretical basis for areation drip irrigation science and will also provide technological support for water saving and efficient irrigation of costal saline cotton field.

曝气滴灌是一种新型的灌水技术，通过水气耦合改善了土壤通气状况，能有效提高作物产量和水肥利用效率。黄河三角洲是我国重要的棉花产区，淡水短缺、土壤盐化和通透性差是制约当地棉花生产的主要因素，采取曝气滴灌技术是解决上述问题的有效途径。拟通过室内试验，研究曝气滴灌入渗特征和水气分布规律，研究水气耦合对滴头出水量的影响，评价毛管沿程水气分布及灌水器出流的均匀性，确定满足水气分布均匀的滴灌毛管长度，提出曝气滴灌的适宜技术参数指标。通过田间试验，研究曝气滴灌对盐碱地棉花生理生态指标的影响，分析不同加气比率和灌前土壤水分阈值对土壤特性、作物根系、水分利用率及产量的影响，掌握土壤微生物和酶活性等土壤微环境因子的动态响应，阐明曝气滴灌对盐碱棉田根围的生态环境效应，获得曝气滴灌水气耦合的高效灌溉制度。本研究可为曝气滴灌技术的科学应用提供理论依据，为滨海盐碱棉田节水高效灌溉提供技术支撑。

1针对现有曝气滴灌技术存在的问题，本研究基于循环曝气技术，研发了一种水气耦合高效灌溉系统，将加气比例由12%提高到30%以上，并可实现水肥气自动精量控制。本研究针对工作压力和活性剂浓度2个关键因素，研究了压力和活性剂对曝气滴灌氧气总传质系数的影响，明确了循环曝气滴灌系统的主要影响因素，为提高曝气地下滴灌系统效率提供了理论依据。研究了曝气滴灌入渗特征和水气分布规律，提出了基于水动力理论的水气分布均匀度计算模型，对毛管沿程水气分布及灌水器出流的均匀性进行了评价，确定了满足水气分布均匀的滴灌毛管长度。.研究了循环曝气地下滴灌对棉花、冬小麦、温室辣椒和番茄等作物生长发育及产量和品质的影响，得到了高产优质条件下，不同作物较为适宜的工作压力和滴灌带埋深等技术指标。结果显示，循环曝气地下滴灌对冬小麦的干物质积累，及植株的蒸腾作用都有增强作用，还可以改善冬小麦的产量和品质。与对照处理相比曝气处理番茄产量提高了20.72%，曝气处理较对照处理水分利用效率提高了20.72%，曝气处理VC含量增加了13.25%，可溶性固形物增加了8.62%，糖酸比增加了22.05%，曝气处理的总酸含量降低了15.50%，硬度降低了11.19%。通过上述研究，阐明了曝气滴灌对作物根围的生态环境效应，获得曝气滴灌水气耦合的高效灌溉制度。 .本项目研究成果在《Science of the Total Environment》、《Journal of Cleaner Production 》、《Acta Agriculturae Scandinavica：Section B - Plant Soil Science》《农业工程学报》、《土壤学报》和《生态学报》等国内外期刊发表论文20余篇，在科学出版社出版《水气耦合高效灌溉理论与技术》专著1部，获得国家发明专利10件，获得山东省、河南省科技进步二等奖2项，培养研究生5名。