Soil Nutrient Changes And Fertilization Model Optimization Of Greenhouse Cucumber In Different Planting Years

Vegetables,as one of the energy sources required by people's bodies,are very rich in nutrients,mainly including vitaminnou B,vitamin C,cellulose and other nutrients,which have high nutritional value.The addition of exoges fertilizers brings certain economic value for improving the yield and quality of vegetables.However,the difference in soil nutrient status in greenhouse during different years of planting,especially nitrogen nutrient status,makes the appropriate fertilization management measures different for different vegetable fields.This study mainly takes the soil of greenhouse cucumber with different planting years as the research object,Analyze the differences in soil nutrient content after greenhouse cucumber are dead at different planting years,and compares the four main planting years(farmland,2 years,13 years,18 years)of the soil for indoor pot experiment,using 4 kinds of fertilization methods(T1: no nitrogen fertilizer,T2: conventional application of single application of chemical fertilizers,T3: reduction of single application of chemical fertilizers,T4: combined application of chemical fertilizers and organic fertilizers),Analysis of the effects of different fertilization methods on plant and soil nutrients,the results show that:(1)There are some differences in the soil basic nutrient contents of greenhouse cucumber in different planting years.The soil total phosphorus,total potassium,organic matter,available phosphorus,available potassium,electrical conductivity,total nitrogen,microbial biomass nitrogen content and accumulation in the 0~20 cm soil layer are generally higher than the 20~40 cm soil layer,while the soil is in the ammonium state nitrogen content and accumulation,nitrate nitrogen content and accumulation are exactly the opposite.Due to the high humidity in the middle and lower layers of the soil,the movement of water molecules is accelerated,and the activity of microorganisms is frequent,ammonium nitrogen and nitrate nitrogen gradually migrate to the deep layer.The nutrient content of total phosphorus,total potassium,electrical conductivity,available phosphorus and available potassium is higher than that of farmland(CK)as a whole.The cucumbers in the greenhouse in this year have been in a closed and semi-closed environment for a long time,and the soil is washed less by rain.There are more fertilization times.The pH of farmland(CK)soil is significantly higher than other soils,and the soil organic matter content is lower than that of farmland(CK).The soil is washed by rain for many years,and corn is planted in the previous stubble,and the amount of organic fertilizer added is high.The mineral nitrogen in the soil is mainly nitrate nitrogen,and the mineral nitrogen content and accumulation of different planting years show a trend of decreasing first and then increasing.In the range of 0~40 cm soil layer,except for greenhouse cucumbers planted for 16 years,the ratio of soil ammonium nitrogen to total nitrogen in greenhouse cucumber was higher than that of farmland(CK);The proportion of nitrate nitrogen to total nitrogen is lower than that of farmland(CK).The other unmeasured nitrogen,mainly in organic form,has the highest proportion of total nitrogen.(2)Through the pot experiment,it is further judged that the greenhouse cucumber in different planting years should adopt a reasonable fertilization mode.Under farmland(CK)soil,when the cucumber grows to the seedling stage,no fertilizer is added,and the plant is not affected;when the cucumber grows to the fruiting stage,to meet the normal results of the plant during this period,the nutrient absorption is high,but the amount of fertilizer cannot be If it is too large,it will inhibit the absorption of nutrients,and the T3 fertilization mode can be used,that is,the reduction of single fertilizer application.Under the soil with a planting period of 2 years,when the cucumber grows to the seedling stage,the nitrogen,phosphorus,and potassium in the soil cannot meet the vegetative growth of the seedling,and the T2 fertilization mode can be used,that is,the conventional application amount;when the cucumber grows to the fruiting stage,T3 can be used Fertilization mode,that is,the reduction of single application of chemical fertilizers,to meet the absorption of nutrients in the later period.Under the soil with a planting period of 13 years,when the cucumber grows to the seedling stage,no fertilizer needs to be added;when the cucumber grows to the fruiting stage,the T3 fertilization mode can be used,that is,the reduction of single fertilizer application.Under the soil with a planting period of 18 years,when the cucumber grows to the seedling stage,no fertilization is required;when the cucumber grows to the fruiting stage,the T4 fertilization mode is adopted,that is,the combined application of chemical fertilizer and organic fertilizer can timely adjust the soil nutrients,supply root absorption and Transfer to the ground to promote plant fruiting.