长期加气渗灌提升土壤环境与玉米增产机理研究

Mechanism of Long-term Aerated Infiltration Irrigation to Enhance Soil Environment and Increase Corn Yield

摘要:

研究长期加气渗灌技术对红壤土玉米连作体系下土壤肥力变化和玉米产量影响，探明该技术下玉米增产机理，可为加气渗灌技术下作物提质增产提供理论依据。本研究于2017—2023年在国家土壤质量湛江观测实验站开展加气渗灌试验，设置传统地下渗灌（CK）和加气渗灌（OI）2个处理，测定不同处理下土壤通气性、土壤肥力、根系生长、生理特性及产量指标。结果表明，连续实施7a的OI处理相比CK提高土壤通气性及土壤肥力指标，可以显著和极显著提高土壤含氧量、土壤呼吸速率、土壤细菌生物量及土壤脲酶活性，增幅分别为2.13%~22.89%、1.86%~26.67%、28.71%~49.51%及13.59%~103.93%，在改善土壤通气性及肥力的基础上，OI处理下根系长度、根系表面积及根干质量较CK分别提升28.08%~55.69%、24.92%~73.00%及17.16%~44.86%（P＜0.05），同时可以提高玉米农艺性状及生理特性，OI处理下玉米产量较CK提高1.16%~14.42%（P＜0.01）。进一步通过结构方程模型（Structural equation modeling，SEM）分析表明，土壤通气性和土壤肥力指标对根系指标有积极正向影响，经由土壤肥力指标到根系指标改善对产量造成影响的路径系数为0.455（P＜0.01），是玉米产量提高的关键。研究结果可为补充完善加气渗灌技术下作物增产提质机理及该技术的推广应用提供理论基础和实践依据。

Abstract:

Aiming to study the effects of long-term oxygenation and irrigation technology on soil fertility changes and maize yield under maize continuous cropping system in red loam soil, and explore the mechanism of maize yield increasement under this technology, which can provide theoretical basis for crop quality and yield increasement under aerated infiltration technology, relied on the 7a (2017—2023) National Soil Quality Zhanjiang Observatory Experimental Station aerated infiltration experimental base, two treatments of traditional subsurface infiltration irrigation (CK) and aerated infiltration irrigation (OI) were set up, and soil aeration, soil fertility, root growth, physiological characteristics and yield indexes under different treatments were determined. The results showed that the OI treatment, which was implemented continuously for 7a, improved soil aeration and soil fertility indexes compared with CK, and could significantly and very significantly increase soil oxygen content, soil respiration rate, soil bacterial biomass and soil urease activity, with increases of 2.13%~22.89%, 1.86%~26.67%, 28.71%~49.51% and 13.59%~103.93%, respectively. On the basis of improving soil aeration and fertility, root length, root surface area and root dry weight were increased by 28.08%~55.69%, 24.92%~73.00% and 17.16%~44.86% （P<0.05), respectively, in OI treatment compared with CK group, and at the same time, maize agronomic and physiological characteristics could be improved, and maize yield was increased by 1.16%~14.42% （P < 0.01) in OI treatment compared with that in CK group. Further analysis by structural equation modeling (SEM) showed that soil aeration and soil fertility had a positive effect on root indexes, and the path coefficient of the improvement of root indexes through soil fertility was 0.455 （P＜0.01), which was the key to the improvement of maize yield. The results can provide a theoretical basis and practical basis for the improvement of the mechanism of crop yield and quality improvement under aerated percolation irrigation technology and the popularisation of this technology.