Comparison Of Soil Characteristics Of TuMoChuan Plain Before And After Salinization Amelioration Of The Soil And Salt Tolerance Of Maize Varieties

Soil salinization and secondary salinization is an important factor restricting agricultural production. Rationally developing and utilizing saline land resources play an importance role in sustainable development of agriculture in future. In the present study, the saline soil, amelioration and their micro-ecological features were investigated to explore effect of salt stress on corn seed germination, seedling growth, physiological and biochemical reaction. This research provided a theoretical basis for the early biological warning of secondary salinization, the effect of flue gas desulfurization gypsum improving saline soil, and the restoration of soil fertility and soil quality evolution.Firstly, the characteristics of soil microorganism and enzyme activity were investigated under different salinization conditions in the Tumochuan plain. Results showed that soil microbial quantity, microorganism quantity, enzyme activity decreased with the increase of salinization degree. The month variations of soil microbe amount and enzyme activity are different, and the time peak occurrence is also different.With the simulated experiment in the lab, we studied the influence of different saline types on soil biological activity. The results indicated that all different types of salt stress increased the content of soil available nutrients and soil metabolic quotient, significantly reduced the soil organic carbon content, microbial biomass carbon, microbial entropy and activity of soil enzyme. When salt content in chlorides, sulfates, chlorides plus sulfates and mixed sulfates were 8g·kg^-1, 24g·kg^-1,14g·kg^-1,10g·kg^-112g·kg^-1, soil respiration and soil metabolic quotient changed significantly, which could be used as critical value of salt stress. The response of soil urease, invertase, microbial biomass carbon, microbial quotient, soil respiration and metabolic quotient is more sensitive to salinity, which could be used as early warning indicators for the secondary salinization of soil organisms.Through the pot experiments, we investigated the effects of main salt type on seed germination and seedling growth of corn in the Tumochuan plain. The results suggested that different types of salt stress inhibits corn seed germinatio n, seedling growth and aboveground biomass, improving proline, SOD activity and malondialdehyde content in the young leaves, reducing the content of soluble protein. Different variety for each type of saline adaptability is different under mixed salt stress of NaC l and Na₂SO₄, NaCl and Na₂CO₃ The salt tolerances of jidan535 and nongfu No.9 were stronger. Under mixed salt stress of Na₂SO₄ and Na₂CO₃, the salt tolerance of yulong No.2, yulong No.8 and nanbei No.1 were stronger. Under mixed salt stress of Na₂SO₄、NaCl and Na₂CO₃, the salt tolerance of jidan535 and yulong No.2 were stronger compared to other cultivars.The field test showed that application of desulfurization gypsum increased the soil microbial quantity, enzymes activity, available nutrients and crop yield. Corn yield increased by 119% compared with control. Soil urease, fungi, alkali solution nitrogen, hydrogen peroxide enzyme and organic matter were the main factors affecting corn yield. Soil microbial biomass carbon, alkaline phosphatase, entropy, available potassium, microbial cellulose decomposing bacteria, nitrogen- fixing bacteria, actinomyces, based breathing, sucrase and urease play a crucial role on soil fertility properties due to the application of desulfurization gypsum. These factors can be used as the main evaluation indicators of soil fertility properties in the Tumochuan plain.