生物炭-土壤结皮覆盖垄沟集雨种植对土壤物理和水力特性的影响

Effects of ridge-furrow rainwater harvesting mulched with biochar-soil crust on soil physical and hydraulic properties

摘要:

【目的】探寻我国黄土高原区适宜垄沟集雨种植有机覆盖模式。【方法】采用完全随机设计,测定不同生物炭-土壤结皮(无生物炭覆盖平作、土壤结皮、单倍生物炭-土壤结皮和双倍生物炭-土壤结皮)覆盖垄沟集雨种植下土壤物理和水力特性。【结果】生物炭-土壤结皮覆盖显著提高表层土壤总孔隙度、团聚体和有效水,土壤总孔隙度和有效水随施炭量增加而增加,对集雨垄的影响明显大于对种植沟的影响,对浅层土壤(0~20 cm)的影响明显大于对深层土壤(20~40 cm)的影响。对浅层土壤与无生物炭覆盖平作相比,单倍生物炭-土壤结皮覆盖和双倍生物炭-土壤结皮覆盖的土壤总孔隙度分别提高6.9%~7.7%和16.8%~23.2%;土壤结皮覆盖、单倍生物炭-土壤结皮覆盖和双倍生物炭-土壤结皮覆盖的0.5~1.0 mm粒径土壤水稳性团聚体分别增加58.9%~65.9%、134.2%~159.4%和165.3%~180.6%,有效水分别增加3.8%~4.9%、4.4%~5.5%和6.5%~7.3%。【结论】在垄沟集雨种植中,适宜的有机覆盖模式为双倍生物炭-土壤结皮。未来生物炭研究应聚焦于土壤结构变化规律与紫花苜蓿可持续发展相结合方面。

Abstract:

【Objective】To identify the suitable orhanic mulching pattern for ridge-furrow rainwater harvesting in the Loess Plateau region of China.【Method】A completely randomized design was carried out to study the effects of different biochar-soil crusts mulching modes (flat plating without biochar, soil crust, single biochar-soil crust, and double biochar-soil crust) on soil physical and hydraulic properties.【Result】Biochar-soil crust mulching significantly increased surface soil total porosity, water-stable aggregates, and available water content, all of which increased with increasing biochar application rate. The impact of biochar-soil crust mulching on the ridge soil was obviously higher than that on the furrow soil, while a more pronounced effect on shallow soil (0~20 cm) than on deep soil (20~40 cm). For shallow soils, compared to flat planting without biochar application, the soil total porosity under the single and double biochar-soil crust mulching increased by 6.9%~7.7% and 16.8%~23.2%, respectively. The proportion of 0.5~1.0 mm diameter water-stable aggregates under the soil crust, single biochar-soil crust, and double biochar-soil crust mulching increased by 58.9%~65.9%, 134.2%~159.4%, and 165.3%~180.6%, respectively, while the available water content increased by 3.8%~4.9%,4.4%~5.5%, and 6.5%~7.3%, respectively.【Conclusion】Double biochar-soil crust is the optimal organic mulching pattern in ridge-furrow rainwater harvesting. Future biochar research should focus on integrating soil structure change laws with the sustainable development of alfalfa.