| Songnen Plain which western plains are concentrated saline-alkali soil in China is one of the regions. It has become the third of world's Sodium regions. The severe alkali amelioration has been a difficult point. In this paper, through appling the the ecological amelioration of severe saline and alkali soil, we studied soil characteristics, photosynthesis, plant growth, ecological effects and mechanism of "water-carbon-salt". The conclusions are followed:1 The effect of saline and alkaline soil ecological amelioration on soil properties:soil total porosity increased by 5%-20% than the control (saline bare land 55.08%), with deep groove treatment the soil total porosity of up to 75.35%. Saline control area of bare land and soil bulk density as high as 1.4 g cm3. Soil electrical conductivity as an important indicator of soil salinity, four different measures have improved significantly reduced electrical conductivity of soil, the average reduced 1288 us cm-1, the same time, soil pH decreased about 1.5 units. Improvement measures to improve soil nutrients, such as the nitrogen tank in the deep grooves and shallow compared with the control untreated Improvement increased by 50% and 100%. Ecological control measures significantly improved the soil physical and chemical properties, the soil are conducive to further improvement.2. Ecological Governance severe alkali plant photosynthesis and growth:the improved cultivation of the plants have different photosynthetic capacity increase, which licorice, sweet corn and Yan Bo, etc. The deep groove treatment was increased 2.5-12 umol.m-2s-1. Processed in different plants obviously increased in biomass, including sweet corn, cabbage, radish, and Yan Bo, etc. groove processing is much higher than its coverage, it is proved the demand of these plants to high soil organic matter, and alfalfa, licorice, sugar beet and false cocklebur and other biomass in the different treatment because of the gap caused by strong adaptability is not obvious.3. For the improvement of severe saline soil, with the increase in soil depth, soil water-soluble sodium, exchangeable sodium, ESP changes and decreased pH value, sodium ions from the surface of 0.2m (2.25 g kg-1) down to 4.4m (0.2688 g kg-1). Soil exchangeable sodium was from the 0.8m (6.67 cmol kg-1) down to 4.4m (0.34 cmol kg-1). Soil alkalization degree (ESP) from the surface 0.2m layer (16.54%) decreased to 4.2m layer (1.10%). Soil water-soluble calcium, magnesium, sodium, potassium and calcium showed a positive correlation, r> 0.5, p <0.05. pH value from 0.4m (9.84) down to 4.4m (9.07). Different cover heights and different soil depths and different media coverage on the degree of soil salinization and soil fertility impact. Which cover thickness 25cm, maximum biomass, the sum of water and no water 1.1 kg 0.9 kg. Cover 10cm, biological diversity index and Margalef index of the largest Gleason. Downward trend in nitrogen, which covers treatment values were higher cover 10cm (92.9 mg kg-1) and cover 20cm (94.5 mg kg-1); damage to deal with similar coverage, with the highest value of damage 10cm (78.8 mg kg-1). Artificial substrate for the higher organic matter content, so the maximum nitrogen (106.9 mg kg-1). pH value and conductivity, the thickness of the increase and decrease coverage, down from 0.11 down to 3.52, the average conductivity is also lower 15μs cm-1 to 2500μs cm-1. The average pH value of different mulch materials reduce 0.04-3.68, the average conductivity decreased 24μs cm-1 to 2062μs cm-1, between the most obvious coverage of artificial substrate, pH, and conductivity decreased by 3.61 and 2062μs cm-1. |
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