| Applying nitrogen fertilizer is an important measure to gain high and stable yield of rice.In production,the main types of nitrogen fertilizer was available nitrogen fertilizer.With the increasing of nitrogen application amount,the nitrogen fertilizer productivity and nitrogen fertilizer use efficiency were decreasing and the difficulty of improving the quality of rice was increasing,as well as a series of problems was producing,such as water eutrophication and ecological environment deterioration.The controlled-release nitrogen fertilizers can effectively solve these problems.Among all controlled-release nitrogen fertilizers,S-type controlled-release nitrogen fertilizer(S fertilizer)is most outstanding performance.The S-type controlled-release nitrogen fertilizers were widely applied abroad.And there was also a few studies on S-type controlled release fertilizer in China,while,the system studies of S-type controlled release fertilizer on rice yield formation,nutrient absorption and utilization,and root system were few.Therefore,in order to clarify the differences respone of S-type control-reselease nitrogen fertilizer on different rice varieties and anlysis causes,as well as provide references for rationally applying S-type control-reselease nitrogen fertilizer and achieving high grain yielding in Wuyunjing 24,the six different rice varieties(nitrogen efficiency rice L68,Nitrogen inefficient rice L2,conventional indica rice Yangdao 6,indica hybrid rice Fengyouxiangzhan,late season medium maturity Wuyunjing 24,early season late maturity Wuyujing 3)were used as rice materials.The experiment treatments of variety comparative,application rates,application timing and application ratio of S-type control release fertilizer were adopted.The main results are as follows:1.The grain yielding of six different rice varieties could be improved under treatments of S-type control-reselease nitrogen fertilizers,the increase of grain yield ranged from 6.53%to 18.57%and average increase was 12.56%.From the amount of application,compared with non nitrogen fertilizer treatment,S fertilizer increased the yield of Wuyunjing 24,especially at treatment of 3g pure nitrogen per pot,the increase ration about 200.04%.From the application timing,the earlier S fertilizer application timing,the higher the yield increase.Compared with control treatment,the grain yielding in basal fertilizer treatment increased by 189.97%.In terms of the application ratio,the grain yielding in the treatment of 80%S fertilizer and 20%was highest.In the yield components,the application of S fertilizer increased the number of panicles per pot and the number of spikelets per panicle,the average increase was about 2.63%-6.87%,and significantly increased the number of spikelets per pot by 12.13%in average,but there was no significant difference on filling grain percentage and 1000-grain weight.From the amount of application,compared with conventional nitrogen fertilizer,different S fertilizer application amout all improved the number of panicle and spikelets per panicle,while decreased filling grain percentage and 1000-grain weight in Wuyunjing 24.From the application timing,the panicle number and spikelet number per panicle were higher in the treatment of appling S fertilizer at basal timing than in the treatments of applying S fertilizer at other application timing,but filling grain percentage decreased and the 1000-grain weight had no advantage.In terms of application rate,the panicle numbers per pot and the spikelets numbers per panicle were close to the maximum and the spikelets numbers per pot was higher,but the filling grain percentage and 1000-grain weight had no advantag at treatment of 80%S fertilizer and 20%nitrogen treatment than at other treatments.From the correlation degree,grain yielding was closely related to panicle number and spikelets numbers per panicle.2.In the term of sink-source,effective leaf area,efficient leaf area,total leaf area at heading stage at treatment of S fertilizer are lower than treatments of conventional nitrogen fertilizer.While,the leave senescence was delaying after the heading stage,leaf area in the maturity period was larger at treatment of S fertilizer than treatments of conventional fertilizer.From the perspective of application amount of fertilizer,effective leaf area,effeicient leaf area,total leaf area at heading stage and leaf area at maturity were higher at all different S fertilizer application treatments than of non fertilizer treatments.The leaf area at heading stage was largest at S fertilizer treatment with 4.5g pure N,the leaf area at maturity was largest at S fertilizer treatment with 3g pure N treatment.From the perspective of application period,compared with non nitrogen fertilizer treatment,effective leaf area,efficient leaf area and total leaf area at heading,leaf area at maturity of were larger at S fertilizer treatment.From the perspective of application ratio,the treatment with 80%of S fertilizer and 20%of conventional nitrogen fertilizer has a certain advantage on effective leaf area,efficient leaf area and total leaf area at heading than other application ratio treatments.Compared with conventional nitrogen fertilizer,S fertilizer significantly inproved sink capacity of different cultivars,the increase ratio was about 13.97%.From the perspective of application amount,the sink capacity at treatments of S fertilizer was obviously higher than that at treatments of conventional treatment,especially at treatment of S fertilizer with 3g nitrogen pure N,the increase ratio was approximately 261.82%.From the perspective of application timing,the earlier S fertilizer application,the greater sink capacity.The maxium sink capacity was at treatment of S fertilizer as basal fertilizer.From the perspective of application rate,the sink capacity was largest at treatment of 80%S fertilizer and 20%of conventional nitrogen fertilize.From the results of correlation analysis,grain yielding was closely related with sink capacity.3.In the term of dry matter production and distribution,dry matter production before heading at S fertilizer treatment was lower,compared with conventional nitrogen fertilizer,while,biological yielding and economic coefficient were both higher.From the perspective of application amount,dry matter production at all S type fertilizer application rate were higher than that at treatment of conventional nitrogen fertilizer,while lower economic coefficient.From the perspective of apply timing,the earlier S fertilizer appliciation,the more dry matter production at heading,biological yield and economic coefficient.From the fertilizer apply ratio,the treatment with 80%S fertilizer and 20%conventional nitrogen fertilizer had highest dry matter production and economic coefficient4.In terms of nitrogen uptake and utilization,S fertilizer could dramatically increase amount of nitrogen uptake,nitrogen fertilizer use efficiency,nitrogen agronomic use efficiency and nitrogen fertilizer partial productivity at maturiey in six rice varieties,while decreased nitrogen use efficiency for gain output.From the perspective of application amount,amount of nitrogen uptake by whole plant at heading stage and maturity at treatments of different S fertilizer were mainly higher than non nitrogen treatment.And from fertilizer application timing,the earlier S fertilizer application,the more amount of nitrogen uptake,nitrogen use efficiency,nitrogen agronomic use efficiency and nitrogen fertilizer partial productivity.Meanwhile,from the perspective of slow release nitrogen fertilizer application percentage,with the increase application of slow release fertilizer,amount of nitrogen uptake,nitrogen use efficiency,nitrogen agronomic use efficiency and nitrogen fertilizer partial productivity showed trend of first rising and then falling,the maxium value reached at the treatment of 80%S fertilizer and 20%conventional nitrogen fertilizer.5.In terms of Phosphorous uptake and utilization,S fertilizer significantly improved amount of phosphorous uptake at maturity in six varieties.The higher application amount of S fertilizer,the higher amount of phosphorous uptake on the maturity stage.The earlier S fertilizer application,the higher amount of phosphorous uptake at maturity stage.With increasing of S fertilizer application ratio,amount of phosphorus uptake by whole plant over the maturity period showed the trend first rising and then falling and reaching the maxium value at treatment of 80%S fertilizer and 20%conventional nitrogen.S fertilizer is of the greatest benefit to phosphorus use efficiency for gain output in Mature when applying slow released fertilizer as base fertilizer,while no noticeable trend on the two indicators through other treatment.6.In terms of the root system,compared with conventional nitrogen fertilizer,S fertilizer treatment has certain advantage on total length of adventitious root single plant,dry weight per plant,total absorption area,active absorption area,while less the number of adventitious roots per plant and lower root vigor per plant on 30 days after cultivation,and showed greater advantage(compared with that in the first 30 days)on both total length of adventitious roots per plant,root dry weight per plant and root vigor per plant.Therefore,adding to the number of single plant adventitious roots and the total length of adventitious rootndry root weight per plantnroot vigor per plant is conducive to raising production amount of nitrogen uptake,nitrogen use efficiency,nitrogen agronomic use efficiency and nitrogen fertilizer partial productivity.7.According to results of current study,under pot culture,the yield and nitrogen fertilizer use efficiency acheieved highest value at treatment of S fertilizer as base fertilizer with 3g pure nitrogen and fertilizer application ratio at 80%S fertilizer with 20%converntional nitrogen in wuyunjing24. |
PDF Full Text Request