Laboratory experiments on the effects of antecedent moisture and residue application on aggregation of different soils |
| |
| Institution: | 1. State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China;2. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China;3. Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14850, USA;1. University of Guilan, Rasht, Iran;2. Department of Soil Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran;3. Department of Irrigation Eng., Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran;4. Faculty of Environmental Sciences, Environmental Future Centre, Griffith University, Nathan, Queensland 4111, Australia;1. School of Material Science and Engineering, Guilin University of Electronic Technology, 1# Jinji Road, Guilin 541004, China;2. Guangxi Key Laboratory of Information Materials and Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, Guilin University of Electronic Technology, Guilin 541004, China |
| |
| Abstract: | Aggregation of fine particles (<50 μm and <2μm) in a weakly structured or fragile soil with different amounts of residue and antecedent moisture was investigated using a hydrometer technique. Results indicated that aggregation of particles <50 μm was a linear function of addition and incorporation of residues, ranging from about 16% (w/w) for the non-residue soil treatment to about 50% (w/w) for the soil treated with 1.87% (w/w) residue.Studies of 5 soils with contrasting textural properties and different antecedent moisture conditions, showed that maximum aggregation of particles <50μm ranged from about 30% (w/w) on the coarse-textured Miles soil to 90% (w/w) for the soils which were high in clay and organic matter. Aggregation of particles <50 μm was a parabolic function of antecedent moisture with maximum aggregation occurring at a matric moisture potential of about −15 MPa. At high antecedent moisture, aggregation of particles <50 μm in the fragile soils was <20% (w/w), whereas aggregation of particles <50 μm at high antecedent moisture for two soils high in organic matter and clay was 40–50% (w/w). At high moisture content, aggregation of particles <2 μm on fragile soil ranged from almost 0 on the Miles to a high of about 45% (w/w) on the Abilene. In contrast, aggregation at high antecedent moisture of particles <2μm for two soils high in clay and organic matter ranged from 65 to 70%.These studies demonstrated that residue and antecedent moisture affect the stability of fine particles which can affect the structural properties of soils. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
