Study Of Improvement Effects By Biological Measures In The Yellow River Delta Saline-Alkali Soil

In order to rational use saline-alkali soil resources of the Yellow River Delta, improve the ecological environment of saline-alkali land, in Yangxin County saline-alkali soil experiment area of the Yellow River Delta, we selected five kinds of salt-tolerant plants (Sesbania, Alfalfa, Chicory, Sweet Sorghum, White Sweetclover) to do biological improvement test of saline-alkali soil, explore different types of salt-tolerant plant improvement effects of saline-alkali soil. After two years (2012to2013) artificial planting test, the results showed that:(1) Planting five different types of salt-tolerant plants arable layer of soil bulk density are significantly lower, surface(0to20cm)bulk density decreased most significant. And contrast with basic data,the average bulk density reduction rate as follows:Alfalfa16.66%>White sweet cloverl5.23%>Sesbanial4.11%>Sweet sorghum11.02%>Chicory6.83%.(2) Compared with basic data, Sesbania, Alfalfa, Chicory, Sweet sorghum, White sweet clover’s initial soil infiltration rate are basic data’s2.53times,3.80times,2.30times and3.55times2.46times. Stable infiltration rates are basic data’s2.88times,4.76times,2.39times,2.42times and4.08times.(3) Salt-tolerant plants have obviously desalination effects, surface soil0to20cm of desalination is more than deep soil20to the60cm.They Were reduced average soil salinity: Alfalfa41.81%>Sesbania35.93%>White sweet clover30.82%>Chicory27.52%>Sweet sorghum24.21%.(4) Soil pH decreased slightly or no significant change, surface soil0to20cm reduction rate is more than deep soil20to the60cm. Plants growth regulate of the micro-climate, changing soil environment around the growth. Two years later, Sesbania, Alfalfa, White sweet clover were make soil organic matter increased by more than50%, which root have lots of nodulation, could fix atmospheric nitrogen and improve soil fertility;(5) Sweet sorghum and Chicory soil organic matter grow slower, two types of plants do not have the ability to fix nitrogen, only a small amount of leaves and roots remain in the soil, little influence on soil organic matter content. Meanwhile, the depth and level of development of plant roots were significantly different impact on soil organic matter. Dynamic changes of soil nutrients (Total nitrogen, Alkaline hydrolysis NPK) is owing to the following two main aspects:Salt-tolerant plants leaf litter and root into the soil;(6) During plant growth the selective absorption of nutrient ions. But its use rate of soil nutrients nutrient is less than accumulation rate, five kinds of treatment to maintain soil nutrient content overall increased levels.Seen by the changes in soil physical and chemical indicators, biological measures could make the test area’s saline soil environment has a significant improvement, besides different salt-tolerant plants have a certain different improvement..