基于加气水滴灌的土壤环境调节机理研究

土壤是粮食安全、水安全和更广泛的生态系统安全的基础.我国水资源贫乏,且分布不均.传统农业采用的大水漫灌方式用水量大,还会破坏土壤团粒结构,造成土壤板结、土地盐碱化等土壤退化现象.地下滴灌技术节水效果明显,水的有效利用率超过95%;但也会在一定程度上破坏土壤结构.研究表明,使用加气水滴灌不但能增加作物产量,还能提高作物品质.本文综述了滴头埋深、加气滴灌频率、灌水量、植物生育期、加气方式与设备等几个因素对加气水滴灌效果的影响,总结了加气水滴灌对土壤水环境、气环境、微生物环境、营养环境和矿物环境的影响规律,并提出加气水滴灌对土壤环境的调节机理.加气水滴灌会改变土壤结构,其水、气、微生物、营养和矿物质等土壤环境的变化一方面是土壤结构变化的结果,另一方面又会促进土壤结构的变化.同步辐射X射线计算机断层扫描的原位实验结果也证实了加气水滴灌能改变土壤的结构.

Mechanism of soil environmental regulation by aerated drip irrigation

Soil is the foundation of food security, water safety and wider ecosystem security. China's water resources is featured by its poverty and uneven distribution. Flood irrigation in traditional agriculture not only uses large amount of water, but also destroys soil aggregate structure, resulting in soil degradation, such as soil compaction and soil salinization. Underground drip irrigation have obvious water saving efficiency with the effective utilization rate of water larger than 95%, but it will also destroy the soil structure to a certain extent. It has been reported in many researches that using aerated water drip irrigation can not only increase crop yields, but also improve crop quality. The influence of several factors such as the burial depth of drop head, the frequency of dripping, the amount of irrigation, the growth period of plant, the mode of aerating and the equipment and so on, and the effects of the aerated drip irrigation on the water environment, the air environment, the microbial environment, the nutrient environment and the mineral environment of soil are summarized. And the regulation mechanism of soil environment by the aerated drip irrigation is put forward. The changes in water, gas, microorganism, nutrition and minerals are the result of the change of soil structure. The experimental results of in situ synchrotron radiation X-ray computed tomography confirmed that aerated drip irrigation can change the structure of soil.