Effects Of Straw Application With Different Years On Soil Biochemical Properties And The Development Of Maize

A field experiment with four treatment of straw no application, straw application two years, three years and four years was carried out in order to further improve the soil fertility, well coordinate the relationship among soil- crop – production and provide theoretical basis for promoting the technology of straw application in northeast area of China. Photosynthetic physiological, basic physiological metabolism, maize population quality, soil physical and chemical properties were determined on the spring maize at the stage of jointing, silking, filling and milk. The results of the study were expected to explore the ecological benefit and economic benefit of straw application. Some main conclusions were drawn as follows:1. Straw application significantly influenced soil physical and chemical properties. Along with the increasing years of straw application, the field capacity increased gradually. The field capacity of straw application for four years increased by 5.8% compared to straw no application and increased by 3.97% compared to straw application with two years. Soil urease activity, soil invertase activity, soil organic matter content and the biomass of soil microorganisms showed a trend of gradual decline as a whole, but they only decreased by a small margin under the condition of straw application. Soil urease activity, soil invertase activity, soil organic matter content of straw application were 3.3%、2.6%、4.3% higher than straw no application, Straw application supply energy for the microorganism in topsoil, thus stimulated its biological activity, and increased the quantity of microorganism.2. Straw application had significant influence on the photosynthesis rate of maize. The chlorophyll content and PEPCase activity of maize showed rising trend as the increase of straw application years. The photosynthesis rate under the condition of straw application was 9.2% higher than straw no application and had more significant influence on milk stage of maize.3. Straw application had significant influence on the basic physiological metabolism of maize. Soluble protein content, reducing sugar content, nitrate reductase activity and sucrose synthase under the condition of straw application were 7.7%、13.8%、8.9%、8.8% higher than straw no application during earlier stage. Soluble protein content, nitrate reductase activity under the condition of straw application were 25%、15.8% higher than straw no application during later stage, however, sugar content and sucrose synthase were 15.5%、4.3% lower than straw no application.4. Straw application with different years had no significant effect on seedling emergence, ear height, plant height, the area of ear-leaf, which indicated that the short-term effects of straw application can’t change the physical traits of maize itself.5. Straw application can significantly increase the ear kernel number and 100 kernel weight which were 9.4%、4.3% higher than straw no application. Barren tip length was lower than straw no application by 0.037 cm. Straw application greatly increased the yield of spring maize. The maize yield got highest with straw application for four years, up to 11673 kg/hm2 and got lowest with straw no application by 10359 kg/hm2.The corn yield of straw application were higher than no application, which was higher by 3.92%, 9.06% and 12.61% respectively. Straw application had no significant influence on Barren tip length. The sequence of every factor for maize yield was ear kernel number, 100 kernel weight and Barren tip length.