Effects Of Irrigation And Biochar Application On Soil Structure And Tomato Growth In Greenhouse

Protected cultivation is a kind of plant cultivation under the condition of microclimate formed by artificial protective facilities.It is an efficient cultivation method that makes full use of the resources of light,temperature,irrigation,soil and so on.At present,the main problems of facility agriculture planting are low land yield,low product quality,appearance and nutrition quality,and poor safety.Because of the characteristics of high temperature,high humidity and semi closed,the soil quality of protected cultivation is prone to degradation.In order to improve the problem of soil degradation,this study applied biochar reasonably in the soil,changed the physical properties of the soil and provided good conditions for promoting crop growth.Due to the different effects of biochar application on crop growth,yield and quality under different irrigation amounts,the reasonable application of biochar plays an important role in improving soil physical properties,promoting crop growth and increasing crop yield.In order to explore the effects of different irrigation amount and biochar application amount on soil physical properties,crop growth physiological indexes,yield and quality,this study took greenhouse tomato as the research object,set three irrigation amount treatments:T1(1.4 Ep),T2(1.2 Ep),T3(1.0 Ep),and set three different biochar application amount treatments under three different irrigation amounts:B0(0 kg/m~2),B1(2.5 kg/m~2),B2(5.0 kg/m~2).To observe and analyze the response of soil physical properties,tomato growth physiological characteristics,yield and quality to different irrigation and biochar application amount,which has certain significance for realizing agricultural water efficient utilization,improving soil,promoting crop growth and increasing yield.Through observation comparison and data analysis,this study draws the following conclusions:(1)Under T1,T2 and T3 irrigation of tomato seedling stage and mature picking stage,different biochar application amount can improve soil,effectively reduce soil bulk density,improve soil porosity and optimize soil three-phase composition.Among them,soil bulk density,porosity and three-phase composition showed good results in B2 treatment.Compared with B1 and B2 biochar application,B0 treatment reduced soil bulk density by 2.5%~14.3%,increased soil porosity by 1.9%~10.5%,and decreased the percentage of solid phase by-0.7%~6.4%under T1,T2 and T3 irrigation.(2)The maximum water content of soil can be increased by the application of B1and B2 biochar.Compared with B2,the maximum water content of soil can be increased by 21.9%and 32.1%respectively.However,compared with B1,the application of B2 biochar has poor water retention in short term.(3)The application of B1 and B2 biochar can promote the growth of plant height and stem diameter of tomato to some extent,but it is not that the higher the application of biochar,the better the growth of plant height and stem diameter of tomato.The application of biochar for promoting the growth of plant height and stem diameter of tomato is different under different irrigation.(4)Under T1 irrigation,the yield of B1 and B2 increased by 30.9%and decreased by 35.7%compared with that of B0.Under T2 irrigation,the yield of B1 and B2increased by 39.1%and decreased by 35.8%compared with that of B0.Under T3irrigation,the yield of B1 and B2 increased by 83.7%and 176.6%compared with that of B0.The results showed that the application of B2 biochar in T1 irrigation increased the yield of tomato,B1 biochar in T2 irrigation increased the yield of tomato,and B1and B2 in T3 irrigation increased the yield of tomato.(5)Under T1 and T2 irrigation,the application of B1 and B2 biochar increased the stomatal conductance and photosynthetic rate of tomato leaves.Under T1 irrigation,the application of B1 and B2 biochar increased the average photosynthetic rate of tomato leaves by 11.4%and 54.8%compared with B0 treatment,while under T3 irrigation,the application of B1 and B2 biochar inhibited the photosynthetic rate of tomato leaves by16%compared with B0 treatment 7%and 50.6%.(6)Under T1 irrigation,compared with B0 treatment,the content of soluble solid decreased by 8.9%and increased by 7.7%,the content of soluble sugar decreased by8.9%and increased by 8.7%,the content of organic acid increased by 29.5%and 18.1%,the content of VC decreased by 22.8%and 56.3%respectively;under T2 irrigation,compared with B0 treatment,the content of soluble solid in B1 and B2 treatment was increased by 29.5%and 18.1%respectively.The content of soluble sugar increased by15.1%and 19.9%,the content of organic acid increased by 7.4%and 42%,the content of VC decreased by 26.8%and 48.6%respectively.Under T3 irrigation,the content of soluble solid increased by 8.7%and 16.8%,the content of soluble sugar increased by10.7%and 17.2%,and the content of organic acid increased by 7.4%and 42%,respectively.The VC content decreased by 11.7%and increased by 0.3%.