Material Mixed Influence On Severe Coastal Saline Soil Physicochemical Properties And The Growth Of Plants

Caofeidian region belongs to the Bohai Economic Rim. Coastal urbanization and the development of industry and agricultural are rapid, which has become an important pole of China’s economic development. Soil salinization range further rapid expansion because of growing seawater intrusion, caused a significant deterioration of the ecological environmen, and restricted the development of regional economy. We need to carry out soil improvement work to protect the region’s economic and ecological environmente sustainable development. Against difficulties of this kind of soil, hard to improvement and utilization, high cost of green engineering, easy become salinization and poor soil fertility conditions, and proposed a method through mixing different materials, combine with fresh water drip leaching, straw mulch to reduce evaporation and drainage engineering construction to improve soil compaction and poor water permeability conditions. On this basis, plant plants, observation its growth status. Designed to reveal the nature of the impact of different materials mixed severe Coastal Saline Soil and growth of plants. The main research results were as follows:(1) Different materials mixed with heavy coastal saline soil in the leaching process showed a similar but different leaching effects. In the leaching out of the performance of high salinity and decreases sharply early in the leachates stabilized lower salinity reach about 500 ml. Ion content of the soil process is similar to salinity change, Cl- change and salinity changes in the highest degree of correlation. Leachate pH generally tended to increase, Doped gypsum treatment slight increase. In desalination rate, the best performance is coarse sand + gypsum processing, followed by coarse sand, gypsum, cow dung. Mixed materials in the presence of sufficient water leaching conditions can effectively reduce severe coastal saline soil soluble salt content, desalination rate reach 90% or even higher. Gypum can effectively prevent soil leaching alkaline desalination process.(2) Material mixes make severe coastal saline soil physical properties a certain degree of change. Mixed with straw let the 0-10 cm and 10-20 cm soil layer soil bulk density decreased by 16.36%, 13.33%. Straw and straw mixed with other materials also make the soil capillary porosity decreases, soil non-capillary porosity and total porosity increases, improved soil moisture conditions make capillary capacity, field capacity and saturated water holding capacity has increased. Straw + coarse sand + gypsum has a best performance at increasing soil non-capillary porosity and saturated hydraulic conductivity, the saturation at 0-10 cm and 10-20 cm soil hydraulic conductivity were 0.232 mm/min and 0.282 mm/min.(3) Material mixes make severe coastal saline soil chemical properties a certain degree of change. Compared with CK, after doping material, soil continue desalinization under natural rainfall and irrigation leaching, after 9 months and 12 months, CK is relatively stable soil salinity at 1 m depth. JSG and JS in 0-60 cm layer soil salinity less than 5 g/kg. Coastal Saline Soil pH will increase in the early desalination of salt leaching out of the soil, the more desalination, the more pH increases, when the soil desalinization becomes a certain extent, pH soil gradually stabilized. Gypsum was able to increase soil Ca2+ and lowering the pH. Mixed with straw increase the soil organic matter, total nitrogen, alkali hydrolyzable nitrogen phosphorus increase in the average content of 0-40 cm soil layer were 40.87%, 46.79%, 122.24% and 72.36%. Cow dung is a natural organic fertilizer, which make the soil organic matter and soil nutrient levels were significantly improved.(4) Material mixes had some impact on growth of plants. Soluble salt content of the soil largely determine the survival rate of plants, five kinds of plants have different survival rates in different materials mixed. JSG plants survive rates were 93.75%, 68%, 59.33%, 82.00%, 85.45%, the overall performance is better. Hibiscus moscheutos, Amorphafrut icosal have higher hight on JS and JSG treatment.(5) Through the main component analysis of 14 physical and chemical properties of soil, extracted four main ingredients, their cumulative contribution was 90.894%, basically reflect the full information indicators. By principal component composite score worthy of a mix of materials processed mixed effects on soil physical and chemical properties was JC>J>JG>JS>JSG>CK.