GS-3生态固沙剂性能及其浓度对植物生长的影响

Effects of performance and concentration of GS-3 sand-fixing agent on plant growth

该文研究试验一种高效、环保、较低廉的生态固沙剂,为沙漠化防治和生态修复提供新材料与技术储备。该文对GS-3生态固沙剂理化性能及其对植物生长影响进行试验,结果表明:GS-3生态固沙剂固结层渗透性良好,抗压强度均高于2.0MPa,硬度大于40.0mm,质量变化较为小,抗风蚀性能良好;GS-3生态固沙剂对夏季地表高温有显著的抑制作用,并有效保持土壤水分,4.0%浓度乳液的固结层7月份0～5cm土壤温度比对照组降低8.1℃,降幅达31%,8月份0～5cm土壤含水量比对照组高2.8倍;GS-3生态固沙剂的保温、透气、保湿及隔离地表风沙流等特点,对提高植物出苗和促进植物生长作用显著;4.0%GS-3乳液试验区固沙效果最好,但3.0%浓度区植被盖度和生物量最大(是对照组的2.4倍和4.1倍)。综合成本和实际效果,3.0%浓度GS-3生态固沙剂具有较好的环境适应性,是库布齐沙漠及周边地区沙漠化防治如沙漠公路两侧防护、沙漠中基础设施周边沙害防护等的可选固沙材料之一。

China is one of the most serious desertification countries in the world, the desertification area covered 1.72×108 km2, involving 30 provinces (regions), which accounted for about 17.93% of the territory area by the end of 2014. Hobq Desert covering about 1.86×104 km2 is the seventh largest desert in China, which locates in the north of Ordos Plateau, and it is one of the important sandstorm source threatening the Beijing, Tianjin and Hebei urban regions where the linear distance from the Hobq Desert is about 800 km. Moreover, in the eastern part of the Hobq Desert, ten tributaries of the Yellow River cross the desert, and these are called the Ten Tributaries. According to the research results, the annual sediment by floods through the Ten Tributaries could reach as high as 2.37 × 108 t. The sediment causes serious silting in the Yellow River. Therefore, it very urgently needs to control the sandy desertification of Hobq Desert. Generally speaking, there are three kinds of sand-fixation techniques, engineering sand-fixation technique, biological sand-fixation technique and chemical sand-fixation technique. Chemical sand fixing technique sprays chemically bonded materials on the sand dunes to form a consolidation layer to prevent the wind erosion. In this research, we aimed to develop efficient, environmental and low-cost sand-fixing agent in order to provide new material and technical reserve for sandy desertification control and ecological restoration in Hobq Desert. GS-3 ecological sand-fixing agent is modified vinyl acetate polymer (cationic P (VAc-BA-DMC) emulsion), which is non-toxic, tasteless, safe, environment-friendly, good combination and cohesiveness. After spraying, it can form hard, water holding and breathable consolidation layer on the surface of sand. It is suitable for mechanized operation and can be combined with biological sand-fixation measures. Through studying the physical and chemical properties of GS-3 ecological sand-fixing agent, the results showed that: 1) The consolidation layer of GS-3 had great permeability, the compressive strength was over 2 MPa, the hardness reached more than 40 mm, the quality varied slightly, and the resistance to wind erosion was excellent. 2) The GS-3 had great inhibited effect on the high temperature surface in the summer, the soil moisture was maintained effectively. The soil temperature at 0-5 cm depth was decreased by 8.1 ℃ in July. The soil moisture at 0-5 cm depth was 2.8 times higher than the control group in August. 3) The thermal insulation, air permeability, moisture retention and resistance to wind erosion of the GS-3 was of great significance to the plant growth. 4) The 4% GS-3 was the best for sand fixation, but the vegetation coverage and biomass of the 3% GS-3 were the maximum (2.4 times and 4.1 times than the control group). The price of the 3% GS-3 ecological sand-fixing agent is about 2 RMB per square meter in the Hobq Desert, but the high-banded salix psammophila sand-barriers costs about 3 RMB per square meter. With the progress of production technology, the price of the GS-3 ecological sand-fixing agent will continue to decline, which is conducive to popularization and application in large areas. Considering the cost and the effect, the 3% GS-3 was the ideal sand fixation material.