Effects Of Nitrogen Fertilizer Dosages And Basal Application Of Silicon And Zinc Fertilizer On Yield,Quality And Disease Resistance Of Rice

Field experiments were conducted in a local farmer's paddy field in Zhangdian,Jiangyan city,Jiangsu Province,China during the rice growing season of 2017 and 2018.One japonica rice(Oryza sativa L.)varieties which are widely grown in local production,Huaidao 5,were used in this study.Different levels of nitrogen fertilizer(Pure Nitrogen 0,255,300 and 345 kg hm-2)and basal silicon-zinc fertilizer(zinc fertilizer alone,silicon-fertilizer application alone and silicon-zinc fertilizer application in combination)were set up and using the no silico-zinc fertilization treatment as a control.The effects of silico-zinc fertilization with different nitrogen on rice yield formation,material production,and rice grain quality were investigated.The main findings of the study were as follows:1.As nitrogen application rate increased,the yield of rice showed a tendency to increase and then decrease.The yield was the highest when the nitrogen application rate was 300 kg hm-2.The second was the conventional nitrogen application rate(345 kg hm-2),which yielded was 3.4%less than that of 300 kg hm-2,and again the 255 kg hm-2 treatment.Under the same nitrogen level,the yield of the treatment of base fertilizer combined with silicon and zinc fertilizer was as follows:silicon zinc fertilizer combined application>silicon fertilizer application alone? single zinc fertilizer application>no silicon zinc fertilizer application.Among the treatments of different nitrogen fertilizer and basal application of silicon and zinc fertilizer,the yield of 300 kg hm-2 basal application of silicon and zinc fertilizer was the highest,which was 8.3%and 7.3%higher than that of only 300 kg hm-2 nitrogen fertilizer,and 8.45%and 15.79%higher than that of 345 kg hm-2 nitrogen fertilizer treatment,respectively;The yield of 255 kg hm-2 combined with silicon and zinc fertilizer was also higher than that of 345 kg hm-2,with an average increase of 0.74%.The number of panicles per unit area increased significantly with the increase of nitrogen application rate.Basal application of silicon and zinc fertilizer increased the number of panicles per unit area and the number of grains per panicle,and the effect of zinc application was significantly higher than that of silicon fertilizer.2.With the increase of nitrogen application rate,LAI,dry matter accumulation at jointing stage,heading stage and maturity stage,and dry matter accumulation at sowing jointing stage and jointing heading stage increased significantly,while effective leaf area rate,high-efficiency leaf area rate and dry matter accumulation at heading maturity stage increased first and then decreased,after heading,the highest dry matter accumulation was 300 kg hm-2,followed by 345 kg hm-2.Under the same level of nitrogen fertilizer,LAI at the main growth stage of basal application of silicon and zinc fertilizer was as follows:single application of zinc fertilizer>single application of silicon and zinc fertilizer>application of silicon and zinc fertilizer>no application of silicon and zinc fertilizer.The dry matter accumulation of the whole population was as follows:single application of zinc fertilizer>combined application of silicon and zinc fertilizer>single application of silicon fertilizer>no application of silicon and zinc fertilizer.The results showed that the dry matter accumulation in sowing jointing stage was as follows:single application of zinc fertilizer>combined application of silicon and zinc fertilizer>single application of silicon fertilizer>no application of silicon and zinc fertilizer.At jointing heading stage and heading maturity stage,silicon and zinc fertilizer combined application>single zinc fertilizer application>silicon fertilizer application alone>no silicon and zinc fertilizer application.3.With the increase of nitrogen application rate,the accumulation of zinc and silicon increased at first and then decreased,and nitrogen uptake increased significantly,with the highest accumulation of zinc and silicon of 300 kg hm-2,the highest nitrogen accumulation was 345 kg hm-2.The results showed that the zinc accumulation in the treatment of the same nitrogen application rate was as follows:single application of zinc fertilizer>silicon zinc fertilizer combined application>no silicon and zinc fertilizer>single silicon fertilizer application;the silicon accumulation amount in the jointing stage was as follows:single silicon fertilizer>zinc silicon fertilizer combined application>single zinc fertilizer>no silicon and zinc fertilizer;at the heading stage and maturity stage,it was single application of silicon fertilizer>silicon and zinc fertilizer combined aplication>no silicon fertilizer application Zinc fertilizer.The accumulation of zinc in sowing jointing stage and jointing heading stage was as follows:single application of zinc fertilizer>combined application of silicon and zinc fertilizer>no application of silicon zinc fertilizer>single application of silicon fertilizer in the stage of sowing jointing stage and jointing heading stage,and it was shown that single application of silicon fertilizer>no application of silicon zinc fertilizer>combined application of silicon and zinc fertilizer>single application of zinc fertilizer at heading maturity stage.The results showed that the total amount of silicon accumulation before jointing and from jointing to heading stage was single application of silicon fertilizer>combined application of silicon and zinc fertilizer>no application of silicon and zinc fertilizer>single application of zinc fertilizer.In the stage from heading to maturity,the overall performance was no silicon zinc fertilizer>single zinc fertilizer>single silicon fertilizer>combined application of silicon and zinc fertilizer.Before jointing,the amount of nitrogen absorbed by plants was as follows:single application of zinc fertilizer>single application of silicon fertilizer>combined application of silicon and zinc fertilizer>no application of silicon and zinc fertilizer,there was no obvious change rule after jointing.4.With the increase of nitrogen application level,the percentage of brown rice,milled rice,head rice and protein content of rice were significantly increased,hot paste viscosity,final viscosity,reduction value and gelatinization temperature of rice starch increased significantly,percentage of chalky grain,chalkiness,gel consistency,amylose content,maximum viscosity,disintegration value and peak time of rice starch decreased significantly.Under the same nitrogen level and different silicon and zinc fertilizer treatments,the percentage of brown rice was as follows:the combination of silicon and zinc fertilizer>single zinc fertilizer>single silicon fertilizer>no silicon and zinc fertilizer treatment;the percentage of and the percentage of head rice were silicon and zinc fertilizer combined with silicon fertilizer>single silicon fertilizer>single zinc fertilizer>no silicon and zinc fertilizer;the percentage of chalky grain and chalkiness degree were no silicon zinc fertilizer>single zinc fertilizer>silicon and zinc fertilizer combined application>silicon and zinc fertilizer combined application>silicon and zinc fertilizer combined application>no silicon and zinc fertilizer application.Between 0 kg hm-2 and 255 kg hm-2,the amylose content in low nitrogen treatment was as follows:single application of zinc fertilizer>single application of silicon fertilizer>combined application of silicon and zinc fertilizer>no application of silicon and zinc fertilizer;between 300 kg hm-2 and 345 kg hm-2,the expression of amylose content in high nitrogen treatment was as follows:single application of zinc fertilizer>silicon zinc combined application>single application of silicon fertilizer>no silicon and zinc fertilizer.Between 0 kg hm-2 and 255 kg hm-2,gel consistency in low nitrogen treatment was as follows:single application of silicon fertilizer>single application of zinc fertilizer>combined application of silicon and zinc>no application of silicon and zinc fertilizer;between 300 kg hm-2 and 345 kg hm-2,the order of high nitrogen treatment was as follows:single application of zinc fertilizer>single application of zinc fertilizer>single application of silicon fertilizer>no application of silicon and zinc fertilizer.Under the treatment of applying silicon fertilizer,the maximum viscosity,hot paste viscosity,disintegration value,final viscosity,peak time and gelatinization temperature of rice starch increased,while the subtraction value decreased.Under the treatment of applying zinc fertilizer,the highest viscosity,hot paste viscosity,final viscosity,peak time and gelatinization temperature of zinc application treatment were higher than those of silicon and silicon zinc treatment,but the disintegration value was lower than that of silicon and silicon zinc treatment.5.Under different nitrogen levels,leaf blast,Panicle Blast and sheath blight increased with the increase of nitrogen level.The disease index of rice blast and sheath blight of different silicon and zinc fertilizer treatments were also lower than that of control treatment under the same nitrogen level,and the disease index of rice blast and sheath blight in silicon zinc treatment was lower than that in zinc application treatment,and the disease index of rice blast and sheath blight in silicon zinc treatment was lower than that in zinc and silicon treatment.The results showed that the combined application of zinc and silicon was more beneficial to reduce the occurrence of rice blast and sheath blight.