Irrigation Method And Fertilizer Application Rate Effect On Rice Population Quality And Fertilizer Utilization

In 2020,four fertilizer application levels of F1,F2,F3 and F4(pure N: 0,7.5,10.0,12.5Kg/667m2 and N:P2O5:K2O=1:0.6:1.2,respectively)were set for fertilizer transportation in Meifa village,Xidu Town,Hengyang City,with two irrigation methods,wet irrigation(G1)and conventional irrigation(G2),as the material.The effects of different irrigation methods and fertilizer application levels on the growth and development,yield and fertilizer utilization of super hybrid early rice were investigated.The main findings were as follows.(1)Irrigation methods had some effects on rice tillering,and fertilizer application amount had significant effects on tillering.Under different fertilizer treatments,the number of tillers was highest in high fertilizer treatment,followed by medium fertilizer and lowest in no fertilizer,which indicated that high fertilizer was beneficial to rice plants to promote tillering;under water-fertilizer intercropping,G2F4 had the highest number of tillers,reaching 14.63,and was significantly different from other treatments.(2)Leaf area index differed somewhat under different water management modes,and the difference was more significant among treatments under fertilizer transport.The leaf area index of G2 under conventional irrigation was greater than that of G1 under wet irrigation.The leaf area index of G2F4 was the highest among treatments under water-fertilizer intercropping at tiller bloom,gestation and filling stage and G1F4 at flush stage,and the highest leaf area index reached 2.86,5.36,6.75 and 4.28 in each period,respectively.(3)The effect of fertilizer application on SPAD values was greater than that of irrigation methods.Under different irrigation methods,wet irrigation G1 was slightly larger than conventional irrigation G2 at the tillering bloom and gestation periods,and the difference between the two irrigation modes was only 2.2% and 4.5%.Under different fertilizer application,the SPAD values increased with the process of fertility and the increase of N application;F1,F2,F3 and F4 showed significant differences in SPAD values under different irrigation methods,and F4 showed highly significant differences with F1.(4)Aboveground dry matter accumulation increased with the increase of fertilizer application,and the effect of irrigation method on dry matter accumulation was not significant,and the overall performance of G2 was slightly larger than G1 during the whole reproductive period.under the mutual crop of water and fertilizer,the plant dry matter weight of G2F4 treatment was the highest at tiller bloom,gestation,flush and filling stage,and the plant dry matter weight of G1F4 treatment was the highest at maturity,compared with the lowest dry matter weight treatment in each period G1F1,G2F1,G1F1,G1F1,G1F1 and G1F1 were higher: 11.13%,69.34%,51.87%,52.32% and 25.65%,respectively.(5)The irrigation method had some effect on the yield,the yield of wet irrigation G1 was slightly lower than that of conventional irrigation G2.The fertilization level had a greater effect on the yield,among the treatments with different fertilization levels,the highest yield was achieved with F3 treatment i.e.150kg/ha of N application,7.271 Ton/ha for G2F3 treatment and 7.151 Ton/ha for G1F3 treatment,with a difference of 1.68%.The yield decreased instead when N application exceeded 150kg/ha.(6)Under water-fertilizer intercropping,the nitrogen utilization rate of rice plants showed that: nitrogen contribution rate,nitrogen agronomic utilization rate,and nitrogen physiological utilization rate were the highest in G1F3 treatment,reaching: 24.50%,11.68kg/kg,and 35.31 kg/kg,respectively;nitrogen fertilizer bias productivity was the highest in G2F2 treatment,reaching 49.91 kg/kg.