Effects of plant residues on soil structure

The effects of organic manure,tstraw-paper-pulping waste using ammonium sulphite(SWUA)and chemical fertilizer on the soil structure of sandy Loamy paddy are studied．The resuts show that the soil porosity．water-stable aggregate and water-holding ability of organic manure treatments are significantly higher than those of other treatments among organic manure treatments，plant residue is the most favourable to improve soil structure，and the diameter of pore in which water can most actively move is O．O5～O．1Omm among capillary．There is a significant linear relationship between the porosity 0．O5～0．10mm in diameter and the water-holding capacity of soil．