Research On Mechanism Of Saving Water And Preserving Fertility Using Biochar And Couple Effect Of Crop-Water-Biochar-Fertilizer

In this paper, with water saving and grain increasing, fixed carbon and reducing discharge and environmental remediation, biochar which is excellent resources was used to soil improvement, efficient use of water and fertilizer, improve crop yield and quality and so on. Sandy loam soil is a main soil in semi-arid regions of Inner Mongolia. In this paper, research was carried out on mechanism of water saving and fertilizer conservation, simultaneously to explore and construct coupling model on crop, water biochar and fertilizer. Research results have important theoretical and practical significance for large-scale application of biochar to improve sandy loam and Improve water and fertilizer utilization efficiency, select the appropriate biochar to improve crop yields, and so on. The main research results are as follows.(1) Soil column experiments showed that the effect of biochar on sandy loam on soil physicochemical properties was significant. The results show that biochar can eifectively reduce soil bulk density, the highest decrease was 9.4%, and increase soil porosity in 1.4%～8.9%. Compared with the control, soil moisture can be increased up to 1.67 times; vertical soil infiltration rate by 24% to 59%, horizontal diffusion can be decreased from 45% to 83.33%.(2) Biochar on tomato stem diameter, height, and root development has a positive role, improve the photosynthetic rate of tomato leaves, and increased yield of tomato. Compared with the control, the yield treatment of 40g biochar add into 1kg dry soil was the highest, and has an increase of 166.8%. Under the same treatment, biochar role in promoting the growth of pepper was not significant, high biochar content treatment reduced production of pepper. Compared with the control of total root length, the treatment of 60g biochar add into 1 kg dry reduced by more than 5%.(3) The results showed that biochar on soil temperature and soil three-phase has a positive role and significantly increased soil organic matter and nitrogen content. Biochar effectively improve water, fertilizer, heat, gas and other environmental factors of sandy loam soil, and a higher biochar treatment was significant to improve soil fertility.Compared with the control, daily average topsoil temperature of the treatment of 60t/hm2 and 40t/hm2 increase of more than 10%.soil moisture increase of more than 30%. and soil organic matter Increase in 53.2%-77.7%.The largest increase in soil nitrogen of the treatment of 40t/hm2 was more than 90%.Compared with the control, tomato yield of the treatment of 40t/hm2 was the highest. Tomato yields of fertilizer one level and fertilizer two level of the treatment of 40t/hm2 increase in 46.34% and 58.61% respectively, and yield of latter was the highest.(4) In this paper, numerical simulation equation was constructed on soil water, fertilizer and thermal under using biochar. Simulation accuracy was more than 0.85. The coupling model of crop-water-biochar-fertilizer was built innovatively for multiple linear regression models, multivariate non-linear regression model and the model based on BP neural network respectively.