Evolution Of Physical And Chemical Properties Of Soil In Greenhouse Of Fruit And Vegetable In Different Planting Years

In this study,the cultivated soils of different planting years(5 a,8 a,11 a)?Different crop types(cucurbits,nectarines,tomatoes,grapes)in Zichang County were studied.Based on the previous research results,the vegetable plots and farmland were selected as the control.The field physical and chemical properties were used for field and indoor analysis.The research focuses on the analysis and comparison of the evolution of soil physical and chemical properties of different cultivated crops in different years.Through the above research,it aims to predict the trend of soil physical and chemical properties in greenhouses,and to clarify the intrinsic mechanism between different years and crop types and soil physical and chemical factors,in order to support the sustainable development data of greenhouses in Zichang County from the perspective of soil physical and chemical properties.At the same time,it provides basic data for soil salinization and acidification comprehensive treatment in the study area.The main research conclusions are as follows:(1)For a greenhouse of 8 years,no matter what crops are planted in the greenhouse,the depth of the soil layer is(0~60 cm),and the bulk density of the soil increases with the deepening of the soil layer.The maximum water holding capacity,total porosity and capillary porosity of the soil showed a decrease with the increase of soil depth.Through comparative analysis between different crops,it can be seen that after planting the gourd,the soil bulk density of the soil layer(10~40 cm)is significantly lower than that of the open soil,and the bulk density of the nectarine and tomato(0-10 cm)soil layer is significantly reduced.After planting grapes(10~60 cm),soil bulk density increased significantly;planting nectarines and tomatoes significantly increased soil water holding capacity(0~10 cm);after planting gourd,10~40 cm soil layer soil The total porosity increased,while the planting of nectarine only significantly improved the total porosity of the soil layer(0~10 cm);the planting of the gourd and the tomato(0~10 cm)soil layer capillary porosity decreased,planting After the nectarine(0~10 cm),the capillary pores of the soil layer increased.(2)From the perspective of planting years(5~11 a)the content of soil organic matter is parabolic.and the content of soil organic matter and rapidly available phosphorus in the(0~10 cm)layer had an upward trend five years before planting and a downward trend five years later.From the perspective of section level,no matter how many years the vegetable greenhouse has been planted,the content of organic matter and available phosphorus in the surface soil is higher than that in the lower soil.(3)No matter what crops are planted in the greenhouse,the soil organic matter and available phosphorus content at the soil depth of(0~60 cm)show a trend of gradual decrease with the deepening of soil depth.After planting nectarines,gourds and grapes for 8 years,the organic matter content in soil layer(0~20 cm)in vegetable greenhouse increased most significantly,while the organic matter content in soil layer(0~10 cm)only increased significantly when planting tomatoes.However,after planting nectarines and grapes for 8 years,the content of available p in soil layer(0~20 cm)in vegetable greenhouse increased most significantly,while the content of available p in soil layer 0~10 cm only increased significantly when planting calabash and tomato.(4)The pH value of vegetable greenhouse soil decreased with the extension of planting years,and the pH value decreased to a certain extent and increased.Vegetable greenhouse soil acidification phenomenon,and vegetable greenhouse soil acidification and salinization symbiosis,and the tomato eight years of acidification and salinization of the most serious phenomenon,planting 11 years to prevent the occurrence of acidification and salinization.(5)After 8 years of planting calabash and grape,the soil pH value of vegetable greenhouse gradually decreased,and the soil of vegetable greenhouse showed acidification phenomenon,while after 8 years of planting nectarine and tomato,the pH value of deep soil(10~60 cm)gradually increased.(6)The planting of calabash and grape will lead to the sharp increase of total salt content in soil at different sections,the planting of nectarine will lead to the sharp increase of total salt content in(0~10 cm)soil layer,and the planting of tomato will lead to a certain increase of total salt content in all soil sections,but the trend is not obvious.