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高分子化学材料的保水剂 ,具有高倍吸水和保水能力 ,种类较多。该研究测定了钠类保水剂主要化学特性改土保土效应。通过田间试验 ,分析其对作物产量和肥料利用率的影响。研究表明 ,保水剂溶液钠离子和电导度随其浓度增加而增加 ,但增幅较小 ,对 p H值影响不大。钙、镁等二价离子对聚丙稀酸钠保水剂的吸水力拮抗作用明显 ,与尿素混用无不良效果。土壤加入保水剂后 ,其保水能力增加 ,改善结构 ,沙壤土较重壤土更显著。当土壤中保水剂含量在 0 .0 0 5 %～ 0 .0 1%范围时 ,土壤团聚体增加量明显。在 - 0 .5 MPa土壤水势压内 ,含保水剂 0 .5 %的土壤中 90 %水分可为植物根系利用。研究认为 ,保水剂保水作用主要表现 4方面 :自身保水、改良土壤结构增加土壤保水、促进植物生长提高肥料利用率、缓慢释水减少蒸发。田间试验发现 ,穴施 15 kg/hm2的保水剂的玉米和马铃薯分别增产 2 2 %和 16 % ,投产比为 1∶ 3.5和 1∶ 4 .2。保水剂与尿素或尿素磷肥混合使用于玉米 ,可分别提高尿素和磷肥利用效率 18.72 %和 2 7.0 6 %。
Polymer chemical materials, water retaining agent, with high water absorption and water retention capacity, more types. The study determined the main chemical properties of sodium aquasorb soil improvement effect. Field experiments were conducted to analyze the effects on crop yield and fertilizer use efficiency. The results show that the sodium ion and conductivity of SAP are increased with the increase of its concentration, but the increase is small, which has little effect on p H. Calcium, magnesium and other divalent ions of sodium polyacrylate water absorbent antagonistic effect was obvious, and urea mixed with no adverse effects. Soil water retention agent, its water retention capacity to improve the structure, sandy loam heavier loam more significant. When the content of soil water retention agent in the range of 0. 0 0% ~ 0 0 1%, soil aggregates increased significantly. At -0.5 MPa soil water pressure, 90% of the soil moisture at 0 .5% with retaining agent can be utilized by plant roots. The study shows that the water retention of water-retaining agent is mainly manifested in four aspects: self-retaining water, improving soil structure, increasing soil water retention, promoting plant growth, increasing fertilizer utilization rate, slow releasing water and reducing evaporation. Field experiments showed that corn and potato with 15 kg / hm2 of water-retaining agent were increased by 22% and 16%, respectively, with production ratios of 1: 3.5 and 1: 4 .2. The use of water-retaining agent with urea or urea-phosphate fertilizer in maize increased the utilization efficiency of urea and phosphate fertilizer by 18.72% and 2 7.06% respectively.