Effects of adding humus from aged refuse on physical properties of landscaping soil
Jin Yisheng,Guo Xiaoping,Zhang Chengliang
1. School of Soil and Water Conservation,Beijing Forestry University,Key Lab. of Soil & Water Conservation and Desertification Combating of the Ministry of Education,100083,Beijing,China;2. Environmental Protection Research Institute of Light Industry,100089,Beijing,China
Abstract:Humus soil from aged refuse, as a green matrix, could increase contents of soil organic matters and nutrients, but will also have certain effects on soil physical and water properties. In this study, we compared the soil physical and water properties after adding different proportions of aged refuse and soil (0%, 25%, 50% and 75%) in the field and lab with soil physics and hydrodynamics methods. The results showed that: 1) When the mass proportion of aged refuse and soil was 25%, soil physical properties (density, porosity, etc. ) and water characteristics were not significantly changed except that the soil sand content was increased. When the proportion was 50%, soil density, capillary porosity and water saturation rate had no significant changes, but the total soil porosity decreased evidently and the soil sand content and saturated hydraulic conductivity increased significantly. Soil physical properties and water features were significantly affected at the proportion of 75%, and compared with the control, the soil sand content increased by 217%, the soil saturated moisture content decreased by 11%, the capillary water content decreased by 26%, the soil saturated hydraulic conductivity increased by 93%, and the amount of soil available water reduced by 24.9%. 2) The Gardner model fitted well with soil water characteristic curves for different treatments. 3) Addition of aged refuse in a mass proportion rangeof 25% to 50% to the soil as green matrix was more appropriate.