Effects Of Combined Application Of Organic Manure And Chemical Fertilizer On Cotton Growth,Nitrogen Utilization And Yield In Hebei Province

Cotton is an important cash crop in China.Applying organic fertilizer is an effective way to increase crop yield and improve soil fertility.However,only a few chemical fertilizers have been used in some parts of the country so far that crop yields can not be effectively increased,and the fertilizer utilization rate of fertilizers is very low.In addition,improper fertilization is more likely to cause environmental pollution.The effects of organic fertilizer and chemical fertilizer on soil nutrient content change,cotton morphogenesis and dry matter accumulation and distribution,nutrient changes in cotton and cotton yield were discussed.In order to find the optimum ratio of organic fertilizer to chemical fertilizer,a strategy for organic fertilizer and fertilizer application in Hebei cotton region was put forward.We started the location test of cotton organic manure and chemical fertilizer in 2017,which were treated as conventional fertilization（CK）,12.5%organic fertilizer substitution(T_12.5),25%organic fertilizer replacement(T₂₅),37.5%organic fertilizer substitution(T_37.5),50%organic fertilizer replacement（T50）.This article is the first year of the positioning test.The main results are as follows:1.Compared with CK treatment,the substitution of organic manure had no significant effect on plant height and stem diameter.T37.5 treatment could ensure that plant height did not decrease.Compared with the CK treatment,the accumulation of dry matter in the combination of organic manure was not significantly higher than that of the organic manure,and the accumulation of dry matter in the CK treatment was more than that of the organic manure,and the replacement treatment of organic manure decreased by 21.23%,19.18%,7.71%and 9.28%respectively.2.The combined application of organic manure could significantly increase the chlorophyll content（a+b）of main stem functional leaves of cotton,and the chlorophyll content of T50 was the highest at all stages.Substitution of organic fertilizer could increase boll weight of cotton boll,but had no significant effect on boll number per plant.The boll weight of T50 increased significantly by 15.31%,while the boll number per plant decreased by 7.46%.3.The yield of seed cotton and lint was the highest in T50 treatment,and significantly increased by 7.87%and 5.70%compared with CK treatment.The seed cotton yield of T25treatment and T_37.5 treatment increased by 1.69%and 2.57%compared with the yield of CK treated seed cotton respectively.The yield of seed cotton treated by T12.5 was reduced by0.58%compared with CK.Before the cotton boll opening period,the nitrogen accumulation of organic manure was higher than that of CK treatment.Nitrogen accumulation in T50treatments was significantly higher than that in CK at all stages.Compared with CK treatment,the fiber length of T50 treated peach increased significantly by 4.51%,while the uniformity index increased significantly by 2.71%.The fiber length and evenness index of all peach trees treated with organic manure did not increase significantly.4.The combined application of organic manure could increase the partial productivity of nitrogen fertilizer in cotton,and the partial productivity of nitrogen fertilizer treated by T50 increased by 7.87%compared with that of CK treatment.Compared with the CK treatment,the nitrogen accumulation in soil increased by 6.84%in the early flowering period T₂₅,and the soil nitrogen accumulation of T_12.5,T₂₅ and T₅₀ in the flowering period increased by 16.07%,12.81%and 15.85%,respectively.After the opening period,the T25 treatment was significantly reduced by 9.61%.Through the experiment,the conclusion is that 50%organic fertilizer and chemical fertilizer can obtain ideal leaf area index and good source and sink relationship,and can achieve reasonable nutrient utilization efficiency and ideal yield.It has no effect on the fiber quality of the peach,which constitutes the main body of production.It is indicated that the ratio of suitable organic fertilizer to chemical fertilizer can increase the nitrogen accumulation and the partial productivity of nitrogen fertilizer and increase the seed cotton yield of cotton field.