Study On Economic And Environmental Effects Of Biological Organic Fertilizer Substituting Chemical Fertilizer On Wheat In Dryland

Excessive application of chemical fertilizer has caused the destruction of the soil micro-ecological environment and agricultural non-point source pollution.The application of bio-organic fertilizer could improve the soil microbial community structure,soil properties,and increase the yield and quality of crops.Wheat yield,nutrient uptake and distribution,water and fertilizer used efficiency,residual nitrate and soil carbon and nitrogen components were studied on dry land under four different fertilization treatments:100% fertilizer(HF),10% bio-organic fertilizer instead of chemical fertilizer(SF1),30% bio-organic fertilizer instead of chemical fertilizer(SF2),and 50% bio-organic fertilizer instead of chemical fertilizer(SF3).The results indicated:1)The substitution of bio-organic fertilizers for chemical fertilizers could significantly increase the number of ears per hectare,the number of grains per ear and the yield of wheat.Among them,SF2 was significantly increased by5.4%,17.1%and 11.2% compared with HF,and the net income of SF2 was significantly increased by 1110 yuan/hm2 compared with HF.2)Nitrogen and phosphorus absorbed by wheat at maturity stage were mainly distributed in grains,and potassium was mainly distributed in stems and leaves.SF1,SF2 and SF3 treatments significantly increased wheat grains nitrogen absorption by 32.6%,45.5% and 34.4% compared with HF;the highest phosphorus and potassium content in grains was SF2,which was significantly increased by 20.1% and23.2% compared with HF.SF2 could also significantly increase the contribution rate of nitrogen absorption after anthesis and phosphorus transfer before anthesis in wheat.3)From the perspective of the overall water storage capacity of 0-200 cm,SF2 increased water consumption compared with HF due to the increase in production,so there was a significant decrease,and the precipitation utilization efficiency of SF2 during the growth period was significantly increased by11.2% compared with HF.4)Compared with HF,SF2 significantly improved the apparent recovery rate,partial productivity,and agronomic efficiency of wheat nitrogen,which were 534%,11%,and 103% respectively.Compared with HF,the partial phosphorus productivity and phosphorus agronomic efficiency of SF2 were significantly increased by 11.2% and 103.0%,the apparent recovery rate of phosphorus in SF3 was significantly improved by 68.6% compared with HF.5)Compared with HF,the nitrogen carried by the three kinds of bio-organic fertilizer substitution treatment crops was significantly increased by 27.4%~40.3%;the residual nitrate nitrogen in the 2m soil was significantly reduced by 7.7%~11.5% compared with HF;The increase of nitrogen and the decrease of residual nitrate nitrogen were the most obvious.The apparent nitrogen loss of SF2 was significantly reduced by 25.5% compared with HF.6)Compared with HF,the soluble,recombined and microbial biomass carbon of SF1 were significantly increased by 37.4%,29.2%,and 41.0%,respectively;Compared with HF,the water-soluble,particulate,microbial biomass carbon and recombinant organic carbon of SF2 were significantly increased by 40.0%,51.3%,45.1% and 40.6%,respectively.Compared with HF,the soluble,water-soluble,recombinant organic carbon,microbial biomass carbon and total organic carbon content of SF3 were significantly increased by 17.1%,58.0%,40.7%,48.0% and 30.8%,respectively.7)Compared with HF,the soluble,recombined and microbial biomass nitrogen content of SF2 was significantly increased by 60.1%,72.2% and 11.2%.compared with HF,the soluble,recombined and microbial biomass nitrogen content of SF3 was significantly increased by 75.6%.63.3% and 15.7%;the particulate organic nitrogen of SF1 and SF2 was significantly increased by 50.5% and 61.3% compared with HF,respectively.In summary,30% bio-organic fertilizer nitrogen instead of chemical fertilizers could help increase wheat yield and water and fertilizer use efficiency,improve soil fertility,and reduce environmental pollution.Therefore,this replacement ratio is suitable for promotion and application under local climate and soil conditions.