Effects Of Organic Nutrient Replacement Part Of Fertilizer On Rice Growth And Soil Physical And Chemical Properties

In order to explore the effect of replacing some chemical fertilizers with organic nutrients on the growth and development of rice and the physical and chemical properties of soil,and the aftereffect of its application,in 2015,under the premise of applying nitrogen,phosphorus,and potassium nutrients in equal amounts,it was carried out for three consecutive years.Seasonal rice positioning test,set 5 treatments: no fertilizer control(CK),single NPK chemical fertilizer(F),organic fertilizer 3000 kg/hm2 and chemical fertilizer application(M1F),organic fertilizer 3750 kg/hm2 and fertilizer application(M2F),organic fertilizer 4500kg/hm2 and chemical fertilizer application(M3F).The main test results are as follows: 1.Effect of substitution of partial organic fertilizers on growth and development of rice(1)Yield and composition of riceSubstitution of some nutrients with organic nutrients can significantly increase rice yield.The yields of early and late rice and the number of effective spikes per unit area were in the order of F>M1F>M2F>M3F.The number of spikes per unit area and number of grains per spike were both early and late.The yield of late rice was significantly positively correlated,and the yield,the number of spikes per unit area,and the number of grains per pan had no significant difference between M1 F and F treatments.(2)Stem dynamics and SPAD values of riceThe rice stem pod number treatment in early rice sorghum was M2F>M1F>M3F>F>CK in order,and F>M1F>M2F>M3F>CK in late rice.Both early and late rice had high tiller and early spike differentiation.The treatment was higher than the organic fertilizer treatment,and the organic fertilizer treatment at the heading and maturity stages was at or above the F treatment.(3)Nutrient absorption,accumulation and transport of plantsCompared with F treatment,the accumulation of N,P,and K nutrients in the high tiller and spike differentiation stages of rice plants treated with organic manure was relatively low,and the heading date and ripening stage were higher or equal to those of F treatment;the stems and sheaths of early and late rice were grains The nitrogen contribution rate of organic fertilizer treatment was 4.58 to 6.52 percentage points and 2.26 to 14.09 percentage points,respectively,compared with F treatment.The contribution of organic phosphorus by the stem and sheath of early rice was significantly higher than that of F treatment by 13.2 to 14.45 percentage points.There was little change in N fertilizer and P fertilizer contribution to late rice leaves.(4)Heavy metal content in ricePb,Hg,and As were not detected in rice.With the increase of the proportion of organic nutrient-replaced fertilizer,the contents of Cu,Cr,and Cd in rice increased,and the contents of Cu,Cr,and Cd in rice treated with M2 F and M3 F were both high.Treatments,but none have exceeded national food hygiene standards(GB2762-2012).2.Effect of substitution of partial fertilizers with organic nutrients on physical and chemical properties of soilCompared with F treatment,organic manure treatment can reduce soil bulk density,increase soil total porosity,increase soil aeration porosity significantly by 1.11 to 1.89 percentage points,field capacity and maximum water holding capacity increased significantly 2.02 and 1.58 percentages,and significant Increase soil organic matter 2.46~4.57g/kg,total nitrogen 0.092~0.223g/kg,alkaline nitrogen 7.4~15.8mg/kg,available phosphorus 0.82~1.15mg/kg,maintaining soil available potassium content,significantly reducing soil acidity.The soil heavy metal content Hg was not detected,and the Pb content did not change much between treatments.The content of As,Cr,Cu,Cd,and Zn increased with the increase of the proportion of organic fertilizer nutrient replacement chemical fertilizer,but did not exceed the national soil environmental quality level 2 Standard(GB15618-1995).3.Effect of post-effect of substituting part of organic nutrients on growth and development of rice(1)Yield and composition of riceThe previous treatment with organic fertilizer significantly increased production by 17.6%~21.2% compared with CK treatment,which was 2.1%~3.3% higher than F treatment,and there was significant difference between M3 F and F treatments.The fertility rate was increased by 0.4% to 1.1% and 1.6% to 2.2%,respectively,after the organic fertilizer treatment was applied to F and CK treatments.The number of effective spikes per unit area and number of grains per spike of M3 F were significantly higher by 11.5% and 8.8% than that of CK treatment,and slightly higher by 1.6% and 0.7% compared with F treatment,respectively.(2)Stem dynamics,SPAD values and LAI values of riceThe M3 F and F treatments of rice stems were slightly higher than those of the other treatments.The SPAD values were slightly higher when the organic fertilizers were applied than the single fertilizers;the LAI values were higher in the earlier F treatments,and the organic fertilizers were higher in the later treatments,and the organic fertilizers were higher.The decrease in LAI values in the later stages of the treatment compared to the F treatment.(3)Nutrient absorption,accumulation and transport of riceCompared with F treatment,the accumulation of N,P and K nutrients in the high-yielding rice planting stage and heading stage of organic fertilizer treatment was slightly lower,and the spike spike differentiation and maturing stage were slightly higher.The contribution of stem and sheath to grain N and P and the contribution rate of leaf P to grain were highest in M1 F treatment,and the contribution rate of stem and sheath phosphorus to F was significantly different,and the contribution rate of leaf to grain N was significantly higher than that of F once applied organic fertilizer treatment.