加气灌溉对根区土壤肥力质量与作物生长的影响

Water, fertilizer, gas, heat, and light are the five major elements that ensure the growth and development of crops. Traditional irrigation methods not only consume a large amount of water but also lead to insufficient soil aeration and destruction of the granular structure. The balance among the five elements is broken, resulting in soil degradation phenomena such as soil compaction and salinization, thus reducing the soil fertility quality and having an adverse impact on the growth and development of crops. This paper reviews the research background of aerated irrigation, the evaluation indicators of soil fertility quality under aerated irrigation conditions, the impacts of aerated irrigation on the soil and soil fertility quality, and the impacts of aerated irrigation on crop growth. It also summarizes the influence laws of aerated irrigation on the soil microenvironment, enzyme environment, nutrient environment, and crop roots as well as the regulation mechanisms of aerated irrigation on the soil microenvironment and crop roots. A large number of studies have shown that aerated irrigation can effectively improve the soil structure and hydraulic characteristics in the root zone, enhance the soil permeability in the crop root zone, significantly increase the numbers of bacteria, fungi, and actinomycetes in the soil of the crop root zone, improve the activities of catalase and urease in the soil, and improve the soil microenvironment in the crop root zone; aerated irrigation can increase the contents of available nitrogen and available phosphorus in the soil, improve the soil fertility quality, promote the absorption of nutrients by roots and the growth and development of crops, improve the utilization efficiency of irrigation water, and increase the crop yield by up to more than 10%. Finally, it summarizes the problems existing in aerated irrigation at the present stage, such as the research and development of aeration equipment, the aeration time and frequency, and the influence mechanisms of aerated irrigation on the soil, microorganisms, crop roots, and ecological environment. It is proposed that aerated irrigation is currently in the exploratory stage of quantitative research and further research on the coupling mechanism of water - soil - gas - crop in aerated irrigation is still needed.

水、肥、气、热、光是保障作物生长发育的五大要素,传统的灌溉方式不但用水量大,还会导致土壤通气性不足、团粒结构破坏,五要素之间的平衡被打破,造成土壤板结、盐碱化等土壤退化现象,从而土壤肥力质量下降,对作物生长发育造成不利影响。综述了加气灌溉研究背景、加气灌溉条件下土壤肥力质量评价指标、加气灌溉对土壤和土壤肥力质量的影响、加气灌溉对作物生长的影响,总结了加气灌溉对土壤微环境、酶环境、营养环境和作物根系的影响规律以及加气灌溉对土壤微环境和作物根系的调节机理。大量研究表明,加气灌溉能够有效改善根区土壤结构和水力学特性,增强作物根区土壤通透性,明显增加作物根区土壤中细菌、真菌和放线菌的数量,提高土壤中过氧化氢酶与脲酶活性,改善作物根区土壤微环境;加气灌溉可以增加土壤中速效氮和速效磷的含量,提高土壤肥力质量,促进根系对营养物质的吸收和作物的生长发育,提高灌溉水利用效率,作物增产高达10%以上。最后总结了现阶段加气灌溉还存在加气设备研发、加气时间与频次问题以及加气灌溉对土壤、微生物、作物根系、生态环境等的影响机制问题,提出了目前加气灌溉处于定量研究的探索阶段,还需要对加气灌溉中水-土-气-作物的耦合机制进一步开展研究。