Effects Of Sulfur-Coating Residue On Acid-Base Balance And Oxidation-Reduction Equilibrium In Soil And Growth Of Crops

In order to assess the effects of sulfur-coating residue on growth of crop and soil chemical properties, a series of batch experiments were conducted. There were three levels of sulfur-coating application in this experiment. The effects of differential coating on the acid-base balance and oxidation-reduction equilibrium in soil and the growth of crops were studied. This paper presented warning to the sulfur-coating residual problems of SCU and presented the reasonable application of SCU on crops. Main research results and conclusions were as follows:1. Within a range rate of sulfur-coating(from 0 to 5.44g),the residue did not promote the growth and yield of corn significantly, but it promoted growth of rice and increase rice tillering number.2. Sulfur-coating residue did not affect the soil pH value significantly in the growth of corn. Soil pH value was increasing because of soil buffering at later growth stage of corn. In the 68th days, exchangeable acidity and exchangeable Al³⁺ in soil of Typic Hapli-Udic Argosols were increased significantly. However, at the other growth stage, sulfur-coating residue did not affect the content of exchangeable acidity, exchangeable Al³⁺ and exchangeable H⁺ significantly. During the growth period of corn, sulfur-coating residue did not affect the content of exchangeable acidity, exchangeable Al³⁺ and exchangeable H⁺ in soil of Carbonatic Ochri-Aquic Cambosols.3. Sulfur-coating residue did not affect the content of exchangeable calcium in soil of Typic Hapli-Udic Argosols significantly during the growth period of corn. Exchangeable magnesium of soil increased as rate of sulfur-coating was increased. It did not affect the content of exchangeable calcium and natrium significantly in Carbonatic Ochri-Aquic Cambosols, but it increased the content of exchangeable magnesium and potassium. 4. When it came to the increasing the use of sulfur-coating, the content of water-soluble HCO₃^- and Cl^- in soil of Typic Hapli-Udic Argosols decreased. It was more and more obvious during the growth period of corn.. It did not show significant difference comparing with conventional processing.5. Sulfur-coating collected from sulfur-coated fertilizer did not affect oxidation- reduction potential in soil of Typic Hapli-Udic Argosols significantly in all growth of rice. Soil reductive material volume was not increased significantly. Compared with CK treatment, the content of soil reductive material volume was reduced, and the differences were significant. The contents of Fe²⁺ and Mn²⁺ increased significantly at the elongation stage of rice in soil of Typic Hapli-Udic Argosols, but the contents of soil Fe²⁺ and Mn²⁺ did not affect the growth of rice. The content of soil Fe²⁺ and Mn²⁺ dropped sharply after the flowerpot of water was drained in rice maturity stage.