Effects Of Different Organic Manure Substitution On Yield Of Rice And Wheat And Nitrogen And Phosphorus Loss In Farmland

With the development of social economy,people have a higher and higher demand for grain,and the pursuit of high yield has become a constant topic of human beings.The input of fertilizer is an important way to pursue high yield of grain,but the non-point source pollution caused by the application of large amount of fertilizer also poses a threat to human beings.How to reduce agricultural non-point source pollution under the premise of increasing production or not decreasing production has become a long-term research problem of scholars in the industry.As a kind of high quality organic fertilizer resources with wide sources and fertilizers,crop straw and livestock manure can not only fertilize the soil and provide organic and inorganic nutrients for crops,but also realize waste recycling,reduce fertilizer input and reduce environmental pollution caused by fertilizer nutrient loss.This research in 2018-2019 in chaohu town in the position of field experiment,compared with the conventional fertilizer,the nitrogen replacement conditions,such as have no fertilizer(CK),conventional fertilization of chemical fertilizer(CF),100%50%pig pig organic fertilizer(Z1),organic manure(Z2),30%of pig manure(Z3)and100%straw organic fertilizer(J1),50%organic fertilizer(J2)and 30%straw organic fertilizer(J3)instead of chemical fertilizer,a total of eight processing,The effects of different proportions of organic fertilizer instead of fertilizer on rice-wheat yield and its components,crop nutrient uptake,fertilizer utilization rate,soil nutrient and nitrogen and phosphorus loss in farmland surface runoff were studied.The main results are as follows:(1)partial replacement of organic manure with chemical fertilizer can improve crop yield.30%of organic manure with pig manure instead of wheat has the highest yield of 5419.38kg/hm~2,and 50%of organic manure with pig manure instead of rice has the highest yield of 9631.33kg/hm~2.On the whole,the promotion effect of pig manure on crop yield in 2019 was greater than that of straw manure,but the yield of wheat and rice replaced by 100%organic manure was significantly lower than that of conventional treatments.(2)the substitution of different organic fertilizers had little effect on the chlorophyll content(SPAD value)of rice.Except for the minimum SPAD value of blank treatment,there was no significant difference in SPAD value of other fertilization treatments.On the whole,the chlorophyll content in rice leaves declined with the development of rice.(3)partial substitution of organic fertilizer for chemical fertilizer can promote the absorption of nitrogen in rice and wheat.The nitrogen absorption of 50%of pig manure in both rice and wheat was the largest,reaching 139.10kg/hm~2and166.41kg/hm~2,respectively.(4)partial replacement of fertilizer with organic fertilizer could improve the use rate of n fertilizer in rice and wheat,and both 50%and 30%of replacement treatments could improve the use rate of n fertilizer in rice and wheat,and the use rate of n fertilizer in 100%replacement of organic fertilizer was significantly lower than that in single application of chemical fertilizer.The overall performance of nitrogen fertilizer utilization rate was that pig manure organic fertilizer replaced>straw organic fertilizer.(5)partial substitution of organic fertilizer for chemical fertilizer can promote the absorption of phosphorus nutrients in rice and wheat.In both rice and wheat seasons,the phosphorus absorption amount of 50%organic manure replacement treatment of pig manure is the largest,reaching 26.19kg/hm~2and 43.95kg/hm~2,respectively.(6)partial organic fertilizer replacement treatment can improve the utilization rate of rice and wheat phosphate fertilizer,and both 50%and 30%of the replacement treatment can improve the utilization rate of rice and wheat phosphate fertilizer,and the utilization rate of 100%organic fertilizer replacement treatment is significantly lower than that of single application of chemical fertilizer.On the whole,the uptake of phosphorus in rice was higher in the replacement treatment of pig manure than in the replacement treatment of straw manure.(7)organic fertilizer instead of chemical fertilizer treatment on soil organic matter,available p,available k content have obvious promoting effect,in addition to the available k,soil organic matter,total nitrogen and available phosphorus content in100%>50%>30%organic fertilizer instead of processing,in addition,compared with the alternative processing straw organic fertilizer,pig manure instead of chemical fertilizer treatment is more advantageous to improve the soil nutrient.(8)TN losses in wheat and rice were 0.566?4.881kg/hm~2and 1.324?18.28k/hm~2g,respectively.In addition,with the increase of the application amount of organic fertilizer,the TN runoff loss showed a decreasing trend with significant differences.On the whole,the reduction effect of straw organic fertilizer on the total nitrogen loss was better than that of pig manure organic fertilizer.TP runoff loss in wheat and rice was 0.014?0.116 kg/hm~2and 0.044?0.281kg/hm~2,respectively.The TP runoff loss was 100%>50%>and 30%of the total phosphorus loss in the replacement of organic fertilizer,which showed an increasing trend successively.