Effects Of Organic-inorganic Compound Fertilizer Application Rate On Rice Yield,Nutrient Uptake And Economic Benefits

Rice is one of the major food crops in China and is of great importance to ensure national food security.Fertilization is an important way to improve crop yield,and the increasing rice yield in recent decades has been attributed to the high input of chemical fertilizers.However,a series of agricultural environmental quality problems have been increasingly highlighted due to the increasing application rates of chemical fertilizers and unreasonable application.Fertilizer reduction and efficiency increase is the way to protect ecological environment,improve arable land quality,realize high-quality agricultural development,and promote crop yield increase and farmers’income increase.Organic-inorganic application combines the characteristics of persistence of organic fertilizer and quick-acting of chemical fertilizer,which is an important way to reasonably utilize resources,improve soil fertility and reduce chemical fertilizer use.In this study,multi-site field experiments were conducted to study the effects of application of two organic-inorganic compound fertilizers(Xiangyun-XY and Yishizhuang-YSZ)on rice yield and yield composition factors,nutrient uptake,fertilizer utilization and economic benefits,with a view to providing a theoretical basis for the rational application of organic-inorganic compound fertilizers on rice.The main results were as follows:(1)Among the 13 test sites,appropriate application of organic-inorganic compound fertilizer significantly increased rice yield.Compared with the treatment without fertilizer,the average yield increase of each treatment with XY organic-inorganic compound fertilizer at each experimental site was 1098 kg/hm~2～2268 kg/hm~2,an average increase of15.8%～33.7%;the average yield increase of each treatment with YSZ organic-inorganic compound fertilizer was 938 kg/hm~2～2242 kg/hm~2,with an average increase of13.6%～33.1%.Rice yield was in a‘linear plus platform’relationship with the application rates of organic-inorganic compound fertilizer.XY organic-inorganic compound fertilizer at the appropriate application rates of 480 kg/hm~2～827 kg/hm~2 at each experimental site increased the yield by 83 kg/hm~2～1261 kg/hm~2 compared with the conventional fertilizer treatment,an increase of 0.9%～17.1%;YSZ organic-inorganic compound fertilizer at the appropriate application rates of 463 kg/hm~2～991 kg/hm~2 at each experimental site increased the yield by 143 kg/hm~2～1283 kg/hm~2 compared with the conventional fertilizer treatment,an increase of 1.3%～17.9%.(2)Appropriate application of organic-inorganic compound fertilizers significantly increased the absorption of N,P and K in the above-ground of rice plants.Compared with the treatment without fertilizer,the average increase in n N,P and K accumulation in the above-ground of rice plants under the application of XY organic-inorganic compound fertilizer at each experimental site were 46.0%～103.5%,36.8%～84.8%and 57.9%～115.4%,respectively;The average increase in N,P and K accumulation in the above-ground of rice plants under the application of YSZ organic-inorganic compound fertilizer at each experimental site were 36.5%～108.1%,22.2%～80.4%and 38.7%～108.8%,respectively.Compared with conventional fertilization treatments,the average increase in N,P and K accumulation in the above-ground of rice plants under the application of XY organic-inorganic compound fertilizer at each experimental site were-1.1%～36.3%,-0.6%～32.8%and-1.3%～33.7%,respectively;The average increase in N,P and K accumulation in the above-ground of rice plants under the application of YSZ organic-inorganic compound fertilizer at each experimental site were-7.5%～40.4%,-11.1%～30.1%and-12.7%～30.5%,respectively.(3)Appropriate application of organic-inorganic compound fertilizer significantly improved the fertilizer utilization rate of rice.Compared to conventional fertilization treatments,the average increase of rice agronomic utilization rate,fertilizer bias productivity and fertilizer contribution for each treatment with XY organic-inorganic compound fertilizer at each experimental site were 107.1%～275.0%,-4.4%～235.1%and16.2%～100.2%,respectively.The average increase of rice agronomic utilization rate,fertilizer bias productivity and fertilizer contribution for each treatment with YSZ organic-inorganic compound fertilizer at each experimental site were 118.7%～238.4%,-3.7%～230.2%and 1.4%～103.3%.(4)Appropriate application of organic-inorganic compound fertilizer significantly improved the economic efficiency of rice.Compared with the treatment without fertilizer,the increase of output value of each treatment of XY organic-inorganic compound fertilizer was 15.6%～25.4%;the increase of output value of each treatment of YSZ organic-inorganic compound fertilizer was 9.9%～25.9%.Compared to conventional fertilization treatments,the net income of XY organic-inorganic compound fertilizer increased by 451yuan/hm~2～4196 yuan/hm~2,and the production to investment ratio increased by 0.43～3.09;the net income of YSZ organic-inorganic compound fertilizer increased by 450yuan/hm~2～4100 yuan/hm~2,and the production to investment ratio increased by 0.02～2.60.In conclusion,both XY and YSZ organic-inorganic compound fertilizers applied in appropriate rates could significantly improve rice yield,nutrient uptake and economic benefits.The recommended application rates of XY and YSZ organic-inorganic compound fertilizers under this experimental conditions were 480 kg/hm~2～827 kg/hm~2 and 463kg/hm~2～991 kg/hm~2,respectively.