Polymer coating of water soluble fertilizers to curb excess solubilization of nutrients is well-acknowledged fact. Lack of information on phosphorus (P) release from controlled release nitrogen-phosphorus (NP) formulation and its impact on nutrient use indices has driven us to conduct this experiment. We developed NP formulations by reacting liquid ammonia and orthophosphoric acid in laboratory. Resulting NP formulations were characterized by solubility fractions, microscopy, spectroscopy, and X-ray diffraction. After coating with poly(vinyl alcohol) (PVA) and liquid paraffin (LP) at 2 and 3 w/w% concentration, P release kinetics and temperature sensitivity (Q 10 ) of the formulations were compared with diammonium phosphate (DAP) at 20 and 30 °C temperature in a P-deficient soil for 120 h of incubation. Finally, nutrient use efficiency and relative efficiency indices were determined from a greenhouse experiment in potted soil to assess the effect of polymer-coated formulations and of DAP at two application rates in comparison with a non-P amended control. Laboratory synthesized NP formulations were alkaline in reaction, definite cubical to hexagonal crystalline structure with smooth surface generating peaks related to P and N in fingerprinting region of Fourier transform infrared spectroscopy. Polymer coating of NP formulations delayed the P release compared with DAP, while LP-coated formulations showing slower P release than PVA-based coatings. Despite LP-coated formulations showed greater temperature sensitivity (Q 10 ), the PVA-based formulation significantly increased yield and biomass accumulation of wheat, with concomitant increase in crop P uptake and P use efficiency. Both LP and PVA-coated formulations showed a significant residual P accumulation in post-harvest soils. The findings underline the potential of polymer coating technology for enhancing P use efficiencies, thereby reducing environmental P footprints. Graphical Abstract

中文翻译：

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用于提高小麦磷利用率的聚（乙烯醇）和液体石蜡基控释氮磷制剂的合成

水溶性肥料的聚合物涂层以抑制营养物质的过度溶解是公认的事实。缺乏关于控释氮磷 (NP) 制剂中磷 (P) 释放及其对养分使用指数的影响的信息，促使我们进行此实验。我们通过在实验室中使液氨和正磷酸反应来开发 NP 制剂。通过溶解度分数、显微镜检查、光谱学和 X 射线衍射表征所得 NP 制剂。在用 2 和 3 w/w% 浓度的聚乙烯醇 (PVA) 和液体石蜡 (LP) 包衣后，将制剂的磷释放动力学和温度敏感性 (Q 10 ) 与磷酸二铵 (DAP) 在 20和 30 °C 温度在缺磷土壤中培养 120 小时。最后，养分利用效率和相对效率指数由盆栽土壤中的温室实验确定，以评估聚合物涂层制剂和 DAP 在两种施用率下与非 P 修正对照的效果。实验室合成的纳米颗粒反应呈碱性，具有明确的立方至六方晶体结构，表面光滑，在傅里叶变换红外光谱指纹区产生与 P 和 N 相关的峰。与 DAP 相比，NP 制剂的聚合物涂层延迟了 P 的释放，而 LP 涂层的制剂显示出比 PVA 基涂层更慢的 P 释放。尽管 LP 涂层配方表现出更高的温度敏感性 (Q 10 )，但基于 PVA 的配方显着提高了小麦的产量和生物量积累，伴随着作物磷吸收和磷利用效率的增加。LP 和 PVA 涂层配方在收获后的土壤中都显示出显着的残留磷积累。研究结果强调了聚合物涂层技术在提高磷利用效率方面的潜力，从而减少了环境磷足迹。图形概要