Screening of proportions and molding conditions of seeding substrate with straw and organic fertilizer
Substrate is one of the effective ways to realize the resource utilization of agricultural wastes.To improve the rice seedlings raising effect of substrate,the mixture design experiment was carried out with corn straw and organ-ic fertilizer as the main raw materials,the best formula for rice seedling substrate was obtained by assaying the rice seedling index under different treatments;and the substrate molding technology was optimized by response surface ex-periment to obtain high-quality seedling substrate products.The results showed that crushing straw could significantly(P＜0.05)improve the total porosity and bulk density of the substrate,and increase the seedling index,and organic fertilizer could significantly(P＜0.001)increase the dry weight accumulation of seedlings.The optimized seedling substrate contained 24.84％(volume fraction)of the garden soil,65.78％(volume fraction)of the straw,and 9.38％(volume fraction)of the organic fertilizer.The optimization results of the substrate molding technology showed that the matrix with moisture content greater than 40％was more difficult to be formed,and the pressure appeared a significant effect on the quality of the substrate.The optimal parameters of rice substrate molding were moisture content of 15.099％,pressure of 18.401 kN,and pressure holding time of 4.719 min.The seedling index of rice substrate ob-tained by using the above-mentioned optimal substrate formula was 49.02％higher than that of conventional garden soil,and the breakage rate of substrate obtained by the optimal molding technology was less than 0.3％.
NETL
NSTL
万方数据
