| Under the premise of the analysis about aeolian sandy soil has the impoverishment characteristics of "water leakage fertilizer leakage" in sandy or desert area, the study used sawdust as the main raw material and through a series of biological decomposition processes, synthesizing a new biomass soil improver for improving sandy soil. In the study, the improver was applied in aeolian sandy soil accordance with different ratios (0%,15%,25%,35%, and45%) to form matrix soil, and by testing physical and chemical properties, the ability of retaining water of matrix soil and seeding plants, probed the improvement effect of the improver on aeolian sandy soil. The main conclusions as follows:1. Biomass soil improver had a very significant improvement to the physical properties of aeolian sandy soil. With improver ratio increasing, the bulk density decreased by2.50%-18.59%, while the total porosity increased by11.05%-28.34%, capillary porosity increased by14.28%-27.83%, saturated water content increased by13.90%-57.68%, field capacity increased by17.24%-57%. Compared with the control (0%), the bulk density of15%ratio reached a significant difference (p<0.05), the other indicators all reached extremely significant difference (p<0.01). The total of more than0.25mm diameter aggregates increased by3.13-8.90times, all reached extremely significant difference (p<0.01).2. Evaporation capacity of the matrix soil with improver dropped, and had a positive correlation with the improver ratios. At the end of the evaporation test, cumulative evaporation rate of the control was maximum, reached91.02%of the initial water content, while improver ratios were15%,25%,35%and45%, they were90.90%,88.00%,84.39%and80.19% respectively, and the cumulative evaporation rate of25%,35%and45%ratios all reached significant difference (p<0.05).3. The different ratios of improver had impact of varying degrees on aeolian sand soil condensation water. The improver ratios were15%,25%and35%, the total condensation water and average daily condensation water of11days were20.66g、21.96g、20.43g and2.08g、2.11g、2.06g, respectively; compared with the control (18.26g,1.82g), the increase rates were13.14%,14.79%,11.88%and14.36%,16.12%,13.37%, all reached significant difference (p<0.05), and25%ratio reached extremely significant difference (p<0.01).4. Improver could slow down the speed of the water infiltration of aeolian sandy soil, increase soil water storage capacity. Compared with the control, water stable infiltration rate, the average infiltration rate, and precipitation water amounts of25%,35%,45%ratios all reduced significantly (p<0.05).5. Improver had significant regulatory role to chemical properties of aeolian sandy soil. With the increasing of improver ratio, available nitrogen improved by57.98%-227.91%, available phosphorus raised1485.18%～4895.27%, available potassium improved by74.31%-261.03%, total nitrogen improved by628.48%～1134.68%, total phosphorus improved by46.12%～74.67%, organic matter improved by742.76%～2044.26%, all increased extremely significantly (p<0.01). And the soil pH value varied from9.04of the control to8.82of25%,8.59of35%and8.52of45%, respectively, all reduced extremely significantly (p<0.01).6. Improver had improvement role of varing degrees to the emergence and preservation of four kinds of shrub species. The emergence rates and the preservation rates of Zygothyllum xanthoxylum and the emergence rates of Hedysarum mongolicum in the matrix soil, compared with the control, all had no significant difference (p>0.05); preservation rates of Hedysarum mongolicum in matrix soil of each ratio were significantly higher than the control (p<0.05); The emergence rates and preservation rates of Caragana microphylla at the ratios of25%and35%were48%46%and67.71%,54.67%, respectively, were significantly higher than the control (28%and11.67%)(p<0.05); The emergence rate and preservation rate of Amygdalus mongolica at the ratio of25%was72.5%and72.67%, respectively, were significantly higher than the control (50%and0%)(p<0.05).7. Improver had a significant promoting role to the growth of four kinds of shrubs. At the end of the growing season, the height of Zygothyllum xanthoxylum, Caragana microphylla, Hedysarum mongolicum, Amygdalus mongolica all increased by21.5%～52.3%,10.3%～42.8%,7.5%～19.4%,17.4%～43.2%respectively, compared with controls; the diameter increased by8.9%～19.8%,0.5%～31.4%,45.7%～62.9%,22.1%～27.0%, respectively; the number of leaves increased by49.8%～126.7%,11.4%～71.5%,113.5%～202.2%,16.0%～22.9%, respectively. Consolidated the difference test results of three indicators on plant height, diameter and the number of leaves showed that, when improver ratio was25%, the improvement effect of Zygothyllum xanthoxylum growth was better, while was45%, was significant (p<0.05); when improver ratio was15%, the growth effect of Caragana microphylla was better, while was45%, was significant (p<0.05); when Hedysarum mongolicum were at15%,25%and35%ratios, Amygdalus mongolica were at25%,35%and45%ratios, compared with the control, the improvement effects were all better. Meanwhile, the biomass of four kinds of shrubs had obvious improvement; compared with the control, when improver ratio in the matrix soil was25%, the dry weight of the total biomass and fresh weight of aboveground biomass of Zygothyllum xanthoxylum increased significantly (p<0.05), when the ratio was45%, Caragana microphylla increased significantly (p<0.05), when the ratios were15%,25%,35%and45%, Hedysarum mongolicum and Amygdalus mongolica all increased significantly (p<0.05). In addition, the fresh shoot ratios of four kinds of shrubs decreased significantly by applying improver (p<0.05).The results show that:biomass soil improver can improve the ability of "retain water and fertilizer" of aeolian sandy soil effectively, improve physical and chemical properties of aeolian sandy soil, promot the growth of test shrubs obviously, so it can be used as a improver for improving aeolian sandy soil. |
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