Effect of Chemical Fertilizer Reduction Combined with Microbial Fertilizer on Rice Growth and Yield in Light Gray Calcareous Soil Area
In order to study the impact of microbial fertilizer application on rice agronomic traits and yield,a single-factor field experiment was conducted in the light gray calcareous soil area in Ningxia.Four treatments were set:soil-based fertilization(M1),soil-based fertilization with a 10%reduction+base application of microbial fertilizer(M2),soil-based fertilization with a 15%reduction+base application of microbial fertilizer(M3),and soil-based fertilization with a 20%reduction+base application of microbial fertilizer(M4).The effects of chemical fertilizer reduction combined with microbial fertilizer on rice plant height,tiller dynamics,SPAD values,and yield in the light gray calcareous soil area were observed and analyzed.The results show that:chemical fertilizer reduction combined with microbial fertilizer can promote rice growth,enhance tillering ability,and improve photosynthetic characteristics.Specifically,the M2 treatment resulted in a 5.68%increase in plant height,a 7.75%increase in maximum tiller number,and a 0.48%increase in chlorophyll SPAD values compared to the M1 treatment.There was a significant positive correlation between the rice grain yield and plant height,panicle number,and thousand-grain wight,indicating that microbial fertilizer application mainly increases yield by enhancing rice growth and improving panicle number and thousand-grain weight.The chemical fertilizer reduction combined with microbial fertilizer mainly increase rice yield by improving the number of effective panicles,thousand-grain weight,and panicle number.The grain yields of the four treatments were in the order of M2,M1,M3,and M4,and the yield of the M2 treatment was 3.09%higher than that of the M1 treatment.It can be concluded that applying 750 kg/hm2 of microbial fertilizer with a 10%reduction in chemical fertilizers is the best fertilization strategy,resulting in the highest yield of 8,351.55 kg/hm2.