天津滨海盐碱土水盐动态及有机改良剂的改良效果研究

发布时间：2018-10-21 18:34

【摘要】：为了有针对性地对天津滨海地区的盐渍土进行改良,以天津大港地区刺槐(Robinia pseudoacacia L.)林土壤为研究对象,对不同土层的土壤水盐变化规律和盐分离子分布特征进行了研究。在此基础上有选择性地使用有机改良剂对该地区的土壤进行改良,并对改良结果进行评估分析,为该地区的土壤利用和林业工程建设提供合理的依据和技术支持。结果表明：试验地各土层年含水量变化范围在11.92%-28.78%；含盐量变化范围在4.19%～18.35%；不同土层的土壤含水量和含盐量随当地降雨量呈明显的季节性变化,春(3-5月)秋(9-11月)季节土壤含水量低,土壤盐分含量随土层深度增加逐渐降低：夏季(6-8月),土壤含水量高,土壤盐分含量随土层深度的增加逐渐升高。降水直接影响表层土壤中的水分含量和各层土壤中盐分离子分布,大大降低了土壤盐分含量,促进刺槐林的生长。试验地区土壤pH值偏高(7.37～8.39),属于碱性土壤,随季节变化不明显；土壤中,K+、Na+、Cl-、Ca2+和Mg2＋与含盐量年变化趋势保持一致,表层土壤随季节变化明显,春季表层土壤(0～10cm)含量明显高于其他土层；夏季(6-8月),各盐分离子含量在土壤中的分布随着土层深度的增加而增加。8042-和HC03-随季节变化没有明显的规律性。对各盐分离子特征性分析可得在表层土壤(0-10cm)中,Na+、Cl-、Ca2＋和Mg2＋与含盐量呈现显著的正相关性,为试验地的主要盐基离子。Na＋与Mg2＋、C1-显著相关,Mg2＋与Ca2＋呈显著相关,HC03-与其他盐基离子无显著的相关性。对各盐分离子不同时期在土壤剖面中的变异系数分析,除SO42-和HCO3-外,其他盐基离子在春季变异系数大(29.99～162.98),表现出强变异性,说明春季各盐分离子分布极为不均。使用草炭、糠醛渣、园林废弃物三种有机改良剂对土壤进行改良,结果表明三种有机改良剂均能有效地改善土壤的物理性质,增加土壤肥力,促进植物的生长。其中,使用草炭作为改良剂可以显著改善土壤的物理性质,增加土壤的全N和有机碳含量；使用糠醛渣作为改良剂可以有效降低土壤的pH,增加土壤有机碳、有效磷和速效钾含量,降低土壤含盐量,促进植物的生长；使用园林废弃物作为改良剂可以明显增加土壤氮和速效钾含量,提高土壤的阳离子交换量。总体来说,使用糠醛渣可以很好地改善土壤的酸碱环境,降低土壤的pH,持续有效的达到改良土壤的目的；使用园林废弃物可以最有效的增加土壤肥力,增加土壤的阳离子交换能力；使用草炭作为土壤的有机改良剂可以很好的改善土壤的物理性质,对土壤的肥力改良效果有限。
[Abstract]:In order to improve the saline soil in Tianjin coastal area, the (Robinia pseudoacacia L.) of Robinia pseudoacacia in Dagang area of Tianjin was used. The variation of soil water and salt and the distribution characteristics of salt ions in different soil layers were studied. On this basis, organic modifiers were selectively used to improve the soil in this area, and the results were evaluated and analyzed to provide reasonable basis and technical support for soil utilization and forestry engineering construction in this area. The results showed that the range of annual water content of each soil layer was 11.92-28.78, the variation range of salt content was 4.19 ~ 18.35, the soil moisture content and salt content of different soil layers showed obvious seasonal variation with local rainfall. The soil water content was low in spring (March to May) and autumn (September to November), and the soil salt content decreased gradually with the increase of soil depth: in summer (June to August), the soil water content was high, and the soil salt content gradually increased with the increase of soil depth. Precipitation directly affected the water content in the surface soil and the distribution of salt ions in each layer of soil, greatly reduced the soil salt content and promoted the growth of Robinia pseudoacacia forest. The pH value of soil in the experimental area is high (7.37 ~ 8.39), which belongs to alkaline soil and does not change obviously with the season, the annual variation trend of, K, Na, Cl-,Ca2 and Mg2+ in the soil is consistent with the salt content, and the surface soil changes obviously with the season. The content of surface soil (0~10cm) in spring was significantly higher than that in other soil layers, and in summer (June-August), the distribution of salt ions in soil increased with the increase of soil depth. 8042- and HC03- had no obvious regularity with seasonal variation. The characteristic analysis of salt ions showed that, Na, Cl-,Ca2+ and Mg2+ were positively correlated with salt content in surface soil (0-10cm). Na+ was significantly correlated with Mg2+,C1-, Mg2+ was significantly correlated with Ca2+, and HC03- had no significant correlation with other base-based ions. The coefficient of variation of salt ions in soil profile in different periods was analyzed. Except SO42- and HCO3-, the variation coefficients of other base ions in spring were large (29.99 ~ 162.98), showing strong variability, indicating that the distribution of salt ions in spring was extremely uneven. Three organic modifiers, namely, peat, furfural residue and garden waste, were used to improve the soil. The results showed that the three organic modifiers could effectively improve the physical properties of the soil, increase soil fertility and promote the growth of plants. The use of peat as a modifier can significantly improve the physical properties of the soil and increase the total N and organic carbon content of the soil, and the use of furfural residue as the modifier can effectively reduce the pH, of the soil and increase the soil organic carbon. The contents of available phosphorus and available potassium can reduce the salt content in soil and promote the growth of plants. The use of garden waste as a modifier can obviously increase the content of nitrogen and available potassium in soil and increase the cation exchange capacity of soil. In general, the use of furfural residue can improve the soil acid-base environment, reduce soil pH, to achieve the purpose of improving the soil effectively, the use of garden waste can increase soil fertility most effectively. The use of peat as soil organic modifier can improve the physical properties of soil and has limited effect on soil fertility improvement.
【学位授予单位】：北京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S156.42

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