Study On The Response Of Switchgrass To Saline-alkali Soil And The Improvement Effects Of Switchgrass On Saline-alkali Soil

In the context of the construction of ecological civilization, biological improvement become a hot saline ecological research governance. Energy plant switchgrass has a certain salinity, it can grow in marginal land salinization, but switchgrass for saline soil improvement and response to biological effects is unclear. Therefore, this paper Ningxia-Rossi Datan saline planting 1a,3a,5a of switchgrass as the research object, through field tests and laboratory test for a combination of methods to study the different cultivation years switchgrass for saline-alkali soil and biological response salt uptake and accumulation law and switchgrass on soil physical and chemical properties improving effect, aims to provide a new type of plant and the biological basis for the saline-alkali soil improvement, ecological environment and promote sustainable development of agriculture.The results showed that:(1) Switchgrass in Ningxia cracked earth saline conditions can grow, and with the increase of planting years, switchgrass plant growth by salinity influence gradually reduced,5 years old switchgrass plant height, tillering, yield, dry matter than 3 years old switchgrass and 1 born switchgrass.(2) Under saline conditions, different planting years switchgrass plant nutrients are three kinds of NPK with the advance stage of growth increased at first in a downward trend.1 year old switchgrass plant total nitrogen, total potassium content of more than 3 years old and 5 years old, but the total phosphorus content of less than perennial, switchgrass plants 5 years old the highest total phosphorus content.(3) Under saline conditions, different planting years switchgrass plants potassium and sodium ions with the advance stage of growth and a downward trend, switchgrass plants potassium content is higher than sodium ions. Switchgrass plants to absorb calcium is generally on the rise, magnesium ions showed a downward trend after the first rise, switchgrass plant absorption of magnesium ions is higher than the absorption of calcium. Switchgrass plants chlorine ion content showed a downward trend after the first rise, sulfate ions rise.(4) After saline planting switchgrass, Panicum virgatum, since the overriding greatly improved the condition of water and salt saline soils, soil environment conducive to plant growth direction. 5 years old switchgrass 0-20cm and 20-40cm soil layer soil bulk density compared with CK were decreased by 8.97% and 17.75%, the soil increased by 82.37% and 119.52%, soil moisture content increased by 96.78% and 27.67%, in the soil PH decreased 13.26% and 15.61%, total soil salt decreased 80.53% and 80.68%.(5) Growing switchgrass salinity energy plant to increase the nutrient content of soil salinity. Saline-alkali soil organic matter content increases switchgrass planting years is incremented, five years after planting switchgrass 0-20cm,20-40cm soil organic matter content than the saline-alkali wasteland improved 131.4% and 147.90%, total nitrogen promoted 71.6%,130.9%, nitrogen content raised 149.27%,167.73%. Full-scale saline soil, available phosphorus and potassium content of switchgrass planted after varying degrees of improvement.(6) The soil Mg2+, Ca2+ on the rise, and switchgrass planting; saline Growing switchgrass absorption and migration of soil salinity ions provides a good channel and carrier, and therefore with switchgrass planting years increased soil Na+, Cl- and SO42- were significantly reduced to life positively correlated.