Study On Ameliorating Method Of Saline-sodic Soil In Western Jilin Province

Soil is an important carrier for the growth and development of plants and crops as well as an important natural resource for human agricultural production.In the long evolutionary process,due to natural or man-made factors,the soil will gradually degrade.Among them,saline-alkali land is an important form of soil degradation,which hinders the growth and development of crops and affects the normal agricultural production.The treatment of saline-alkali land,especially severe saline-alkali land,is a worldwide problem.But the existing practice shows that saline-alkali land can not only be controlled,but also have good economic output.Saline-alkali land treatment and ecological environment improvement is an important way to realize the sustainable development of agricultural and rural economy and an important barrier to national food security.In this paper,the arid and semi-arid area in the west of Jilin Province was selected as the research object to carry out the content analysis and characteristics of high-content water-soluble cations in saline-alkali soil.Furthermore,the technical scheme of using natural materials(straw,sediment and clay in irrigated area)to improve the saline-alkali soil was put forward,and the potted experiment was carried out to prove the effect of improving the saline-alkali soil.The field improvement experiment was carried out with the saline-alkali soil in Tongyu County as an example.The main results of the thesis are as follows:(1)The results of X-ray fluorescence spectroscopy and atomic absorption spectrometry show that the high contents of water-soluble salt cations(K⁺,Ca²⁺,Na⁺,Mg²⁺)in saline-alkali soil are almost completely dissolved after oscillating in the aqueous solution for about 1 hour;(2)By X-ray fluorescence spectrometer,the contents of K,Ca,Na and Mg in saline-alkali soil and the residue after oscillation were determined,and the water-soluble contents of K⁺,Ca²⁺,Na⁺and Mg²⁺can be obtained indirectly by calculating the difference value.The method is simple,fast,accurate,safe and environmentally friendly,and can effectively reduce the experimental error;(3)By adding mixed improver composed of fermented straw and sediment to saline-alkali soil,the results show that the mixed improver can improve the physical composition of saline-alkali soil,enhance the desalination efficiency,and significantly reduce the p H value and alkalization degree of the soil;(4)Through pot plants and field experiments to explore different proportions,when the ratio of fermented straw to sediment is about 2:1,the improvement effect is the best.In production practice,according to the principle of input-output benefit,mixing 1000?1500 g of amendments in 1m×1m×0.2m volume saline-alkali soil can basically meet the requirements of the improved saline-alkali soil;(5)The experimental results of in-situ improvement by mixing saline-alkali soil and clay show that clay in irrigated area can supplement N,P and other nutrient elements in saline-alkali soil,adjust the salt content of saline-alkali soil,and maintain the stability of trace elements such as heavy metals Cu and Zn in saline-alkali soil;(6)The results of the chemical and pot experiments show that the saline-alkali soil has the best improvement effect when the mass mixing ratio of saline-alkali soil and clay is 2:1.When the development of saline-alkali soil changes,sampling,analysis,experiment and simulation calculation can be carried out again to determine the optimal mixing ratio.