Effects Of Diffent Fertilization Treatments On Lettuce Yield, Quality And Soil Properties

In order to increase lettuce yield,improve lettuce quality and soil fertility in Bashang area of northwest Hebei Province,it is necessary to study different fertilizer application techniques.fertilization treatments on the yield,quality and soil properties of lettuce"sheshou 101"were studied in Yunong experimental Base,Guyuan County,Zhangjiakou City through field plot experiment and random block design.Five treatments were set up in the experiment,including no fertilization treatment,single application of chemical fertilizer,single application of organic fertilizer,Organic fertilizer+20%reduction of chemical fertilizer treatment,organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment.The research results are as follows.（1）Compared with single application of chemical fertilizer,single application of organic fertilizer,organic fertilizer+20%reduction fertilizer treatment,organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment significantly increased plant height,maximum leaf area and leaf chlorophyll content（SPAD value）of lettuce in 2021 and 2022.At the same time,the yield of lettuce could reach 58.96 t/hm²in 2021.The yield of lettuce in 2022 would reach 61.80 t/hm²,and the yield in 2022 was4.80%higher than that in 2021.（2）Compared with single application of chemical fertilizer,single application of organic fertilizer,organic fertilizer+20%reduced fertilizer treatment,organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment could significantly increase the VC content and soluble sugar content of lettuce in 2021 and2022,and the nitrate content of lettuce under this treatment was the lowest,nomely382.75 mg/kg in 2021 and 369.07 mg/kg in 2022.Therefore,organic fertilizer+20%reduction fertilizer+microbial agent treatment had the most significant improvement effect on lettuce quality.（3）Compared with single application of chemical fertilizer,single application of organic fertilizer,organic fertilizer+20%reduced fertilizer treatment,organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment could significantly increase the content of available phosphorus,available potassium,organic matter,N0₃^--N content and soil p H,and EC values in 0-20 cm soil layer.After lettuce harvested,N0₃^--N content decreased gradually with the deepening of soil layer in each fertilization treatment,but there was a significant leaching accumulation peak in 40-60cm soil layer in the treatment of single fertilizer,and there was a risk of leaching.At the same time,organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment Reduced application of chemical fertilizer and combined application of organic fertilizer and microbial agent could improve the accumulation of N0₃^--N in 0-40cm soil layer,more effectively maintain N0₃^--N in the root layer of lettuce,and reduce the risk of environmental pollution caused by leaching.However,the single application of chemical fertilizer increased the accumulation of N0₃^--N in the 40-100 cm soil layer,which increased the risk of leaching N0₃^--N into the deep soil and polluted the environment.（4）Compared with other treatments,the number of bacteria in the soil after the application of organic fertilizer+20%chemical fertilizer+microbial agent treatment on lettuce was significantly increased,and the number of fungi was significantly reduced,which was more conducive to the stability of the soil microbial environment and the growth and development of lettuce.A comprehensive analysis of the effects of different fertilization treatments on the yield,quality and soil properties of lettuce under the conditions of this experiment could be obtained.The fertilization treatment of organic fertilizer+20%reduction of chemical fertilizer+microbial agent treatment could achieve high yield and quality of lettuce,improve soil properties,more conducive to the retention of N0₃^--N in the root layer of lettuce and reduced the risk of environmental pollution caused by leaching.It is the most suitable fertilization method for lettuce in Bashang area of northwest Hebei Province.