Ever-degrading environment due to the application of a large amount of agrochemicals, like fertilizers into the soil, has raised the concern for implementing such measures which would not only reduce the chemical incorporation into the soil, but will also benefit the crops by shooting up the fertilizer utilization by the same. Henceforth, biodegradable formulations for phosphate are essentially required to undergird the evolution of modern day agriculture. Naturally occurring phosphate could not suffice the demands of global agriculture, and so, it has to be applied synthetically in the form of agrochemical. Taking the very facts into consideration, the preparation of a novel biodegradable formulation of nanocomposite hydrogel using PVA as polymeric matrix, kaolin clay as mechanical binder and DAhP as phosphate fertilizer is attempted in the present study. The analysis of final formulation was done using techniques like FT-IR, XRD and SEM. The synthesized compound is named PDK. It shows 66.6 g/g equilibrium swelling; shows 10 times swelling its own weight in 1 h of immersion and attained equilibrium after 3 h. Factors affecting swelling behavior like content of kaolin, temperature and pH have also been investigated which revealed that 1–3 wt% kaolin, 35–40 °C temperature and 6–7 pH are the best optimum conditions for PDK hydrogel to show best results in release and swelling. The release study for phosphate was done by volumetric ammonium phosphomolybdate method by dispersing the sample in water and soil and checking the release at an interval of 3 days for 30 days which revealed 88.8% release in water and 76.3% release in soil. The formulation shows considerable controlled release of DAhP and also presents a scope for the development of biodegradable phosphate-based controlled release fertilizer.

中文翻译：

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基于聚乙烯醇/高岭土/磷酸氢二铵（DAhP）的可生物降解肥料纳米复合水凝胶，用于磷酸盐的控制释放

由于土壤中大量施用化肥等农用化学品，环境不断恶化，人们对实施此类措施的关注提出了质疑，这些措施不仅会减少土壤中的化学品掺入，而且还会使农作物受益化肥利用率相同。从今以后，磷酸盐的可生物降解制剂基本上需要支持现代农业的发展。天然存在的磷酸盐无法满足全球农业的需求，因此必须以农用化学品的形式进行综合应用。考虑到实际情况，以 PVA 为聚合物基质制备新型可生物降解纳米复合水凝胶制剂，本研究尝试使用高岭土作为机械粘合剂和 DAhP 作为磷肥。使用 FT-IR、XRD 和 SEM 等技术对最终配方进行分析。合成的化合物命名为PDK。它显示出 66.6 g/g 的平衡溶胀；显示在浸泡 1 小时内膨胀 10 倍于自身重量，并在 3 小时后达到平衡。还研究了影响溶胀行为的因素，如高岭土含量、温度和 pH 值，结果表明 1-3 wt% 的高岭土、35-40 °C 的温度和 6-7 pH 值是 PDK 水凝胶显示最佳结果的最佳条件。释放和肿胀。磷酸盐的释放研究是通过体积磷钼酸铵法进行的，通过将样品分散在水和土壤中，并在 30 天内每隔 3 天检查一次释放，结果显示为 88。在水中释放 8%，在土壤中释放 76.3%。该配方显示出可观的 DAhP 控释，也为可生物降解的磷酸盐控释肥料的开发提供了空间。