| Nowadays,with the increasing of environment and health consciousness,organic food is growing rapidly in the world.People’s demand for organic food is increasing rapidly in the whole world.However,as a result of the late start of organic agriculture and strict control of the organic cultivation process,there is still a lack of in-depth study on nutrient uptake and utilization of organic rice.In order to explore the similarities and differences of the organic farming(OF)and conventional farming(NF)methods on the absorption and distr ibution mechanism of major nutrient elements in rice,four types of Japonica rice varieties with different nitrogen utilization efficiency(with high NUE under OF and high NUE under CF,A-dype;with high NUE under OF and low NUE under CF,B-dype;with low NUE under OF and high NUE under CF,C-dype;with low NUE under OF and low NUE under CF,D-type)under organic farming and conventional farming,with blank treatment(CK)as control,studied the growth character indexes of rice,soil nutrient availability,plant nutrient uptake under two cultivation methods,to provide scientific basis for promoting the development of organic agriculture and promoting the sustainable and efficient utilization of nutrients in rice.The main conclusions are as follows:1.The results of different cultivation methods effect on soil nutrient content indicate soil organic matter content in organic farming field was higher than conventional farming field,blank treatment was lowest,and the soil organic matter content in organic and conventional farming field were 7%and 2.76%higher than the blank treatment,which shows that organic cultivation could improve the content of soil organic lmatter.Soil total nitrogen content was little affected by the cultivation methods.Soil available N,P and K in organic fanning field was higher than conventional fanning field,blank treatment was lowest at tillering,jointing,heading and maturing stages.2.Plant height,leaf area and dry matter accumulation under CF higher than OF,CK was lowest at jointing,heading and maturing stages.The difference of leaf area and dry matter weight under OF and CF reached significant level.In all types of rice varieties,the spikes per unit area under CF was significantly higher than under OF,the seed setting rate under OF was obviously reduced.Compared with CF,Grain yield of A,B,C and D type under OFwere reduced 20.67%,17.46%,41.84%and 26.09%,respectively.high NUE under OF rice variety(A and B-types)can maintain a higher grain yield.3.Under the organic and inorganic culture system,the nitrogen content of rice stems and leaves decreased with the advancement of reproductive period,and reached the maximum value at jointing stage.The nitrogen content of stem,leaf and panicle of all types of rice was higher under conventional cultivation,compared with that under organic culture.Under different cultivation patterns,the variation range of N content of class A and class B rice straw was lower than that of class C and class D at each growth stage.The variation range of N content of class A and class B rice leaf was higher than that of class C and class D.And the variation range of N content of class A and class B rice panicle was lower than that of class C and class D.On average,the total nitrogen accumulation under organic cultivation was 77.08%,94.10%and 92.92%of that under conventional cultivation at jointing,heading and maturing stage,respectively.The total amount of nitrogen accumulation under organic cultivation was less than that under conventional cultivation at each growth stage.4.Phosphorus content in rice leaf under CF was highest,and blank treatment was lowest.At jointing stage,the total phosphorus accumulation under OF were lower than under CF in A and C-types,and higher in B and D-types.At heading stage,the total phosphorus accumulation under OF were approximately equal to under CF in D-type;A,B and C-types were lower 17.83%,17.50%and 3.19%than under CF,respectively.At maturing stage,the total phosphorus accumulation under OF was lower than under CF in A type,and higher than under CF in other types.5.Except D-type,the potassium content in leaf and fringe under OF were higher than under CF in other types.The potassium content in stem were higher than under CF in A and C-types at jointing and heading stages,and lower at maturing stage.At jointing stage,the total potassium accumulation under OF in A,B C and D-types were higher 7.20%,12.49%,5.44%and 16.62%than under CF,respectively.At heading and maturing stages,the total potassium accumulation under OF was lower than under CF in A-type,while higher in other types. |
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