Effects of mulching pattern on soil moisture characteristics in Guangxi citrus orchard

【Objective】To explore effects of mulching pattern on soil property and soil moisture in Guangxi citrus orchard,and to provide a theoretical basis for orchard weed and moisture management in this orchard.【Method】Taking a citrus orchard in Guangxi as research object,3 treatments,spraying herbicide(CK),grass-proof cloth coverage(GPC) and natural grass mowing(NGM) were set. After one year of treatment,basic soil physicochemical properties and soil moisture characteristics of the orchard at layers of 0-10 cm,10-30 cm,30-50 cm and 50-70 cm were measured.【Result】Different mulching treatments had significant effects on bulk density,total porosity and organic matter content of the surface soil(0-10 cm),but no significant effects on the deep soil layers. In 0-10 cm soil layer,NGM treatment significantly(P<0.05,the same below) reduced soil bulk density by 7.52% and increased soil organic matter by 7.99%;GPC treatment reduced soil bulk density by 3.01% and soil organic matter by 14.15%. Under the same soil suction,the soil moisture content in 0-10 cm and 10-30 cm soil layers was in the order of GPC>CK>NGM;in 30-50 cm soil layer was CK≈GPC>NGM;and in 50-70 cm soil layer was CK>NGM>GPC. In 0-10 cm soil layer,the highest available water content(0.079 cm³ /cm³ ) was found in NGM treatment;in 30-50 cm and 50-70 cm soil layers,the highest available water content was found in the GPC treatment,which was 11.00% and 18.12% higher than that in CK,respectively. Both GPC and NGM treatments could increase soil moisture content in each layer,and the soil moisture content in 0-10 cm and 10-30 cm layers under GPC treatment had a higher increase,while the soil moisture content in 30-50 cm and 50-70 cm layers under NGM treatment had a greater increase. GPC and NGM treatments could significantly increase soil moisture storage capacity in 0-70 cm layer,in which GPC treatment brought an increase of 2.83%-4.26%,and NGM treatment 4.02%-4.55%.【Conclusion】Natural grass mowing treatment has a good effect on surface soil environment improvement,soil moisture storage and water supply capacity enhancement of citrus orchard,and it also has great advantages of water conservation. Therefore,it is suggested to adopt natural grass mowing management pattern in production.