| Hetao irrigation area is rich in light and heat resources.In recent years,the planting scale of processing tomato has expanded rapidly,which has become the second largest tomato production base in China.However,the problem of local soil salinization and secondary salinization are serious,which restrict the efficient use of land and the sustainable development of agriculture.Under the policy of "not competing for grain with the people,not competing for land with grain",the management of saline alkali land conforms to the national ecological security strategy,and is the necessary process to promote the sustainable development of ecological environment and agriculture.Therefore,the study of the effects of the improvement measures on the physical and chemical properties of the soil,the number of microbial colonies and the growth and development of processing tomatoes were studied to provide scientific theoretical basis for the improvement of local saline alkali land.Therefore,in this study,the soil of moderate saline alkali land was taken as the research object,and the effects of different improvement measures(straw mulching,organic fertilizer combined with desulfurized gypsum,biochar,desulfurized gypsum)on the physical and chemical properties of soil,the number of soil microbial colonies,the growth and development of crops,the yield and quality of soil were studied under the condition of film mulched drip irrigation through field plot experiment The improvement effect of different improvement measures on saline alkali land was compared.The main conclusions are as follows:(1)Biochar,desulfurized gypsum,organic fertilizer combined with desulfurized gypsum and straw mulch can improve the soil water holding capacity of the cultivated layer(0-40cm),and increase soil organic matter,hydrolyzed nitrogen,available phosphorus and available potassium content.Among them,in 0-20cm soil layer,the treatment of desulfurized gypsum(T3)and biochar(T2)significantly increased soil moisture content,with the largest increase of 25.19%and 51.42%,respectively.(2)Desulfurized gypsum,organic fertilizer combined with desulfurized gypsum and straw mulch can reduce the pH value of cultivated layer(0-40cm),of which,desulfurized gypsum(T3)treatment reduces the most,reducing 0.71 units,and biochar has no obvious change rule on the pH value of soil.spring irrigation combined with improvement measures can improve the soil desalination rate,among which the desalination effect of biochar(22.5t/hm2)treatment is the best,the desalination rate range is 28.70%?78.09%.Different improvement measures can effectively inhibit the surface soil salt in the 0-40 cm soil layer,biochar treatment decreased the most,the rate range is 33.82%?44.43%.(3)Biochar,desulfurized gypsum,organic fertilizer combined with desulfurized gypsum and straw mulch can increase the number of bacteria(1.5?8.8 times),actinomycetes(1.2?10.0 times)and fungi(1.1?4.4 times),among which,in the 0-20cm soil layer,biochar(T2)treatment increased the most,with the largest increase of 8.8 times,7.1 times,3.7 times,respectively,and with the increase of depth,the number of soil microorganisms decreases.With the improvement years increasing,the content of soil bacteria,actinomycetes and fungi will increase.The number of soil microorganisms was negatively correlated with soil EC,and there is a good positive correlation between soil microorganism and soil nutrients.The main control factors of soil microbial community were different in different soil layers.In 0-20cm soil layer,EC Value and soil temperature were the key factors for the growth and reproduction of soil microbial community,which explained 80.8%and 13.3%respectively.In 20-40cm soil layer,available phosphorus and organic matter were the key factors for the growth and reproduction of soil microbial community Factors accounted for 82.9%and 7.8%respectively.The number of bacteria and actinomycetes in soil is high,which indicates that soil properties and water and fertilizer conditions are good,and it can be used as a biological index to evaluate soil health.(4)Different improvement measures can promote the growth of plant height and stem diameter of processing tomato,and increase the dry matter accumulation,in which biochar(T2)and desulfurized gypsum(T3)treatment have a significant effect;increase the output of processing tomato,in the first year after application,the output of desulfurized gypsum(T3)treatment is the best,with an increase rate of 53.99%;in the second and third years,biochar(T2)treatment is the best,with an increase rate of 53.99%The range was 55.96%and 55.43%.With the extension of improvement years,the yield is the best The quantity is increasing year by year.(5)Different improvement measures can increase the soluble solids,VC and lycopene of tomato,and change the sugar acid ratio of tomato.The quality of tomato was also slightly different in different time,but with the development of tomato growth period,the content of tomato changed little,which indicated that multiple picking had little effect on the quality of tomato.(6)In the second and third years after the improvement measures were applied,straw returning,biochar,organic fertilizer combined with desulfurized gypsum and desulfurized gypsum still had effect on the improvement of saline alkali land.Considering the changes of soil physical and chemical properties,the number of microbial colonies and the growth index,yield and quality of processing tomato,it is indicated that the application of biochar,desulfurized gypsum,organic fertilizer combined with desulfurized gypsum and straw mulch can improve the saline alkali soil.Among them,biochar(22.5t/hm2)and desulfurization gypsum(37.5t/hm2)were better.From the perspective of short-term benefits(two years),apply desulfurization gypsum(37.5t/hm2)It is more conducive to soil improvement and tomato production,but in terms of long-term benefits(three years),biochar(22.5t/hm2)It is more beneficial to improve salinized farmland. |
PDF Full Text Request