保水缓释钙肥的特征与性能

采用化学聚合反应将保水剂与硝酸钙聚合为一体化物质,并以吸水倍率、p H值、土壤水分特征曲线、元素分析、红外光谱、电子显微镜及7 d溶出率法表征保水钙肥的吸水持水能力、化学性质、形貌结构及养分释放性能。结果表明:保水缓释吸水倍率约为165 g·g-1,含钙量为103 g·kg-1,p H值近中性;保水剂通过化学键结合,基质包埋负载钙盐;网络孔隙及基质是保水钙肥吸水保水的物理结构;与对照相比,保水钙肥添加量为1%时,在测试吸力段可增加土壤容积含水量平均14.0%。此外,保水钙肥显示较好的钙素养分延缓释放性能,可将钙素较长时间保持在水凝胶基质内而延长水溶性钙有效期。

Characteristics and performance of water-absorbent slow-release calcium fertilizer

Incorporating super absorbent polymer (SAP)and calcium nitrate into one body by chemical polymeriza-tion,and then water-absorbent/-retaining capability,some chemical properties,morphology and nutrient release perfor-mance of water-absorbent calcium fertilizer (WACF )were characterized by water absorbency,soil water characteristic curve,ultimate analysis,IR,SEM and 7-day dissolution rate .The results show that the WACF has water-absorbency of approximately 165 g·g-1,103 g·kg-1 of calcium content,nearly neutral pH.The SAP incorporated with calcium fertilizer by chemical bond and substrate occlusion .The pores of cross-linked network of WACF are space to storing water .In com-parison with the check treatment,WACF can increase volumetric water content of soil by average 14 .0%between tested suction when the ratio of WACF to soil is 1%wt .Also,WACF show better slow-release performance of calcium nutrient which retain calcium nutrient in hydrogel substrate much more time that increase available duration of soluble calcium .