生草对果园土壤理化性状的影响研究进展

Effects of living mulch on soil physical and chemical properties in orchards:a review

果园生草栽培模式对土壤理化性状的影响是果园集约、高效、生态、可持续生产的重要基础。生草栽培可降低土壤容重4.7%-13.0%,提高水稳性土壤团聚体含量,进而改善土壤的导水性能和保水性能,也有助于拦截降雨,提高雨水的利用率;干旱少雨的季节可能会出现牧草与果树争水的现象,需要通过选择适宜的草种及加强田间管理等措施来减小争水对果树造成的不利影响;生草有助于土壤有机碳的积累,连续生草6年可使土壤表层有机碳增加19.6%-27.8%,有机碳的累积量会随生草年限的增加而增加;生草覆盖可调节果园土壤温度,增加土壤微生物的多样性和酶活性;生草还可以促进土壤养分的有效性,同时豆科牧草也可通过固氮作用提高氮素利用效率,总体而言,果园多年种植牧草对土壤养分的积累具有正效应。本研究可为有关的研究工作和生草模式的进一步推广应用提供依据。

A review has been undertaken to provide a basis for further research on and the application of living mulch practices in orchards.The effects of living mulch on soils’physical and chemical properties make an im-portant contribution to intensive,efficient,ecological and sustainable production.Forage cultivation can reduce soil bulk density by 4.7%-13.0% and improve the content of soil aggregates,thus enhancing hydraulic prop-erties and water retention capacity.Forage cultivation can also help to raise rainfall interception and improve water use efficiency.Forage grass will compete for water with fruit trees in drought seasons,though adverse effects can be reduced by selecting appropriate grass varieties and strengthening field management.Forage grass cover can improve soil organic carbon （SOC）content.SOC can be improved by 19.6% -27.8% after planting forage grass for 6 years.The accumulation of SOC increases as the duration of forage planting increa-ses.Living mulch can help to adjust soil temperature,which enhances microbial diversity and enzymatic activi-ty.Living mulch will directly deplete soil nutrients,but the increase in the number of microorganisms can pro-mote the decomposition of organic matter that increases nutrients.Moreover,legumes add nutrients through nitrogen fixation.Living mulch usually has a positive effect on soil nutrient accumulation.