【作者】 杨浩；

【导师】 王百田；

【作者基本信息】 北京林业大学 ， 生态环境工程， 2011， 博士

【摘要】 本研究针对目前我国农林保水剂应用领域不同类型保水剂基本性能揭示还不够全面和清楚,保水剂与土壤结合后对土壤性能的影响研究还不够完善,特别是土壤水分-能量关系研究和土壤保水保肥能力改善作用研究还很缺乏,保水剂使用长效性研究不足等现状,选取了我国北方地区三种具有典型代表意义的土壤类型和国内外市场上常见的若干种保水剂类型,通过室内试验精准测定和野外试验长期观测的结合,对保水剂对土壤物理特性的影响作了初步研究。探索保水剂在不同质地土壤中的作用规律,以期为实践生产中的品种遴选、浓度制定、综合评价等提供理论支持。本研究主要分为室内试验和野外试验两个部分。室内试验又分为两部分,第一部分是保水剂常规性能及影响因子测定,具体包括品种筛选和低温对保水剂性能的影响；第二部分是保水剂对黄绵土、褐土、沙土三种土壤特性的影响,具体包括不同保水剂品种、浓度对三种土壤水分能态的影响、对土壤主要物理性质的影响、对土壤保水保肥能力的影响。通过对比分析三种土壤持水释水性能、土壤水分有效性能,土壤容重、孔隙度、团粒结构等物理性质的变化,和土壤在淋溶试验中保水剂对氮肥、钾肥和磷肥的保持能力,来揭示保水剂在土壤中的作用机理,同时对不同品种保水剂、保水剂浓度等方面进行评比和分析,以其筛选出适合于不同土壤类型的保水剂,探索合适的保水剂使用浓度等具有争议性的前沿问题。野外试验分为三部分,即对保水剂在黄绵土地区、褐土地区、沙质土壤地区野外造林中的应用,主要考虑保水剂对苗木、草本植物生长的影响,通过测定株高、地径、光和作用等生长生理指标,来揭示保水剂对植物作用机理。主要初步研究结果如下：(1)保水剂的吸水倍率受溶液pH值和溶液离子浓度的影响较大：溶液酸(碱)性越强,保水剂的吸水倍率降低的越快；溶液离子特别是阳离子浓度越大,保水剂吸.水倍率越小,并且对于金属阳离子而言,离子的价态越高对保水剂吸水倍率的抑制作用越明显。基于土壤保水剂在我国北方寒冷地区越冬是否对其长效性产生影响作了初步研究,结果表明：-20℃低温冷冻对钾基—聚丙烯酸脂—聚丙烯酰胺三聚体保水剂吸水倍率造成明显降低,-15℃低温冷冻对聚丙烯酸盐C类保水剂吸水倍率造成降低。(2)保水剂施入土壤中之后,土壤含水量和植物可利用水分含量都显著提高了,但是二者之间并不呈现线性相关。植物可利用水分含量的提高程度在不同的土壤水吸力范围内表现出差异性,这种提高作用在低吸力段(<0.8 MPa)明显高于高吸力段(0.8～1.5 MPa),且在0.05 MPa以下之间尤其显著。增加土壤中保水剂的浓度能明显提高土壤含水量和可利用水分含量,这种提高的趋势基本符合指数递减规律,即随着土壤水吸力的增大,土壤含水量增加的倍数逐渐减小。(3)保水剂能够有效改善土壤三相比例、增加总孔隙度和毛管孔隙度、降低土壤容重,促进土壤团粒结构的形成。对于黄绵土壤而言,保水剂对2-0.25mm粒径土壤团粒结构有明显的促进作用,且与浓度关系不大。对于北京褐土而言,保水剂在低浓度下(≤0.5%)主要促进了1-0.25mm粒径团聚体的形成,在高浓度段(≥0.75%)主要促进了2-0.5mm粒径段土壤团聚体的形成。(4)保水剂能够增加对肥料的吸附作用,减少肥料的淋失量,有利于植物营养元素的吸收和滞留。从保水剂对K肥的保持能力来看,对于试验的三种土壤基本都遵循丙烯酰胺与丙烯酸钾的共聚物(A)>钾基—聚丙烯酸酯—聚丙烯酰胺共聚物(B)>聚丙烯酸盐E类。从保水剂对土壤保持N肥能力来看,在偏粘性土壤中为丙烯酰胺与丙烯酸钾的共聚物(A)类>钾基—聚丙烯酸酯—聚丙烯酰胺共聚物(B)类>聚丙烯酸盐E类；而在偏粉粒性土壤中为聚丙烯酸盐E类保水剂>钾基—聚丙烯酸酯—聚丙烯酰胺共聚物(B)类>丙烯酰胺与丙烯酸钾的共聚物(A)类。从保水剂对土壤保持P肥能力来看,三者相差不大。(5)保水剂评价：对于三种土壤保水剂的适用性排序为：在晋西黄绵土中为,钾基—聚丙烯酸酯—聚丙烯酰胺共聚物类(B)>聚丙烯酸盐E类>聚丙烯酸盐C类>丙烯酰胺与丙烯酸钾的共聚物类(A)>聚丙烯酸盐D类；在北京褐土中为,丙烯酰胺与丙烯酸钾共聚物(A)类≈钾基—聚丙烯酸酯—聚丙烯酰胺共聚物(B)类>聚丙烯酸盐E类>聚丙烯酸盐C类>聚丙烯酸盐D类；在东胜沙土中为,丙烯酰胺与丙烯酸钾的共聚物(A)>钾基—聚丙烯酸酯—聚丙烯酰胺共聚物(B)>聚丙烯酸盐C类>聚丙烯酸盐E类>聚丙烯酸盐D类。(6)野外试验表明,保水剂处理对于林木幼苗、草坪草各生长指标和光和效率具有明显的促进作用,有利于生物量的积累,但是合理的使用方式和施用量是前提条件。更多还原

【Abstract】 Basic properties of Superabsorbent Polymers, effects on soil function after SAP mixed with soil, and long-term quality of SAP using were not revealed so comprehensively and exactly in the agriculture and forestry domain, especially soil moisture-energy relationship and soil capacity of keeping water and fertilizer.This research was focused on these points. Three typical significance soil and several common SAP on domestic and international market were selected for testing.Accurate determination indoor-test and long-term field-test were combined to test impacts of soil under the role of SAP. Searching the role of laws of SAP affecting on soil benefits for variety selection, concentration formulation, and evaluation.This research were divided into two parts, indoor-test and field-test. Indoor-test was also divided into two parts.First part were conventional properties and impact factors testing.The second part were variety selection and effect on SAP under low temperatures. The field-test, second part, were effect of loess soil, cinnamon soil and sandy soil under action of SAP, which Including actions on energy state of soil moisture, main physical properties, soil capacity of keeping water and fertilizer. Action mechanism of SAP in soil was revealed through comparing analysis of the index of releasing-water performance, soil-moisture characteristics, soil bulk density, porosity, granular structure,and capacity of keeping fertilizer of N, P,K. Appropriate SAP were chosen for different soil after appraisal and analysis.The field-test were divided into three parts, that is, applications of SAP in afforestation in loess soil, cinnamon soil and sandy soil Regions.Mechanism of SAP acting on plants were revealed through analyzing of effect on growing and physiological indicators,which including Height, DBH (Diameter), Capacity of Photosynthesis and so on.. Conclusion were drawn from above analysis:(1) Water absorbency of SAP was affected by PH value and ion concentration of solution. The more acidic (or alkaline),the smaller amount of the water absorbency.The higher metal ions concentration of solution,the lower water absorbency SAP had.High valence metal ions had a intensiver inhibition action than that low ones.A preliminary study was made to text whether the low temperature of northern China in winter influenced properties of Superabsorbent Polymers or not.The results shows that water absorbency of SAP obviously decreased when temperature reduced to -20℃according to Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B).Water absorbency of Polyacrylate with Macromolecule (Type C) decreased when temperature reduced to -15℃.(2) Superabsorbent Polymers obviously improved soil moisture and available moisture content for plants,but which were not similar to a linear related. The degree of improvement performanced on enormous diversity during to different soil water suction. The ameliorating effect in low soil water suctions (<0.8 MPa) significantly superior to the high soil water suctions (0.8～1.5 MPa), especially less than 0.05 MPa. It is that soil moisture and available moisture content strengthened obviously when the SAP concentration raiseed. The increasing trend basically consistented with the diminishing law of exponential relation.(3) Superabsorbent Polymers effectively improved soil three-phase proportion,increased total porosity and capillary porosity, reduced soil bulk density, and promoted the formation of soil granular structure.Superabsorbent Polymers obviously promoted granular structure of soil between 2-0.25mm and it does little mater to SAP concentration according to loess soil. For cinnamon soil, Superabsorbent Polymers mainly promoted soil granular structure between 1-0.25mm under lower SAP concentration,and fiercely promoted soil granular structure between 2-0.5mm under higher SAP concentration.(4) Superabsorbent Polymers enhanced soil adsorption of fertilizer,and reducing fertilizer leaching quantity,which conducive to assimilating of plant nutrients.According to ability of keeping potash fertilizer, Copolymer of Polyacrylamide and Potassium Acrylate (Type A)>Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B)> Polyacrylate with Macromolecule (Type E). For ability of keeping nitrogenous fertilizer, Copolymer of Polyacrylamide and Potassium Acrylate (Type A)> Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B)>Polyacrylate with Macromolecule (Type E) according to partial cohesive soil,and whicn in Partial Silt soil was the opposite. The ability of keeping phosphate fertilizer differed not quite amony the three soil.(5) Applicability of SAP in soil was that:According to loess soil,Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B)>Polyacrylate with Macromolecule (Type E)>Polyacrylate with Macromolecule (Type C)>Copolymer of Polyacrylamide and Potassium Acrylate (Type A)> Polyacrylate with Macromolecule (Type D). According to cinnamon soil, Copolymer of Polyacrylamide and Potassium Acrylate (Type A)>Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B)> Polyacrylate with Macromolecule (Type E)> Polyacrylate with Macromolecule (Type C)> Polyacrylate with Macromolecule (Type D). According to sandy soil,Copolymer of Polyacrylamide and Potassium Acrylate (Type A)>Copolymer of K-Polyacrylic Ester-Polyacrylamide (Type B)> Polyacrylate with Macromolecule (Type C)> Polyacrylate with Macromolecule (Type E)> Polyacrylate with Macromolecule (Type D).(6) Field tests showed that:SAP processing obviously promoted main growth indices and efficiency of photosynthesis, which accumulating biomass of plants.But reasonable usage mode and amount were the Prerequisites.更多还原