保水剂与肥料互作及保水缓/控释肥料研究展望

Interactions of Hydrogels with Fertilizers and Outlook on Slow/Controlled-Release Water-Storing Fertilizers Research

保水剂在农业上的作用日益重要,肥料与保水剂一体化使用是水肥调控的重要技术,是肥料研究的国际前沿。保水剂是吸水量超过自身重量数百倍以上的亲水性高聚物。保水剂一般分为天然的,合成的及半合成的。保水剂与肥料可以通过物理混合、包膜或化学合成三种方式结合为一体化的保水缓/控释肥料。保水剂具有吸水吸肥功能,保水剂可吸附大量中性分子,对阳离子养分也有较强吸附作用,对阴离子养分吸附弱。肥料种类与盐浓度影响保水剂的吸附作用与膨胀能力。保水缓/控释肥料在土壤中对肥料养分有延迟释放作用。保水缓/控释肥料可改善土壤持蓄水分和水肥交互作用,促进植物对养分的吸收和作物增产。保水缓/控释肥料发展方向是包膜和化成保水缓/控释肥料。保水缓/控释肥料湿润及养分控释机理研究也需要加强。

The application of hydrogels to agriculture is ever - increasing, and the incorporating use of fertilizer with hydrogels is the important technology to enhance the efficiency of fertilizer and soil water, which is the front in international fertilizer research. Hydrogels is hydrophilic high polymer which can hold water up to hundreds of times of their own weight . Hydrogels polymer is categorized into such three types as natural, synthesis and semi - synthesis. Hydrogels are incorporated with fertilizers into slow/controlled release water - storing fertilizers by such three ways as blending, coating and synthesizing. Hydrogels can absorb water and fertilizers, large amount of neutral molecule, and certain amount of cationic nutrients, but few anionic nutrients. The absorbing capacity and inflation capability of hydrogels in nutrient solution are influenced by sorts and concentrations of salts. Slow/controlled release water - storing i＇ertilizers can delay nutrient release of fertilizer in soils. Soil water - retaining capacity is improved by slow/controlled release water - storing fertilizers, interaction of water with fertilizers is enhanced, and also nutrient uptake of plant and crop yield is increased. Coated or synthesized slow/controlled release water - storing fertilizers is future trend to be developed, and much research work should be concentrated on wetting and nutrient- controlling release mechanism of slow/controlled release water- storing fertilizers.