Enhanced efficiency fertilizer is a sustainable alternative to increase agricultural productivity. In this regard, the nutrient coating or encapsulation is one of the alternatives to improve the effectiveness of the fertilizer. Several matrices can be used, but predominantly the biodegradable ones, which have no environmental impacts. Chitosan has favorable characteristics, as biodegradation and harmless impacts on the soil, to use as a holder for fertilizers. In this work, microspheres of chitosan and sugarcane bagasse were prepared by the inversion phase method followed by potassium nitrate (KNO₃) fertilizer sorption. The structural, morphological and thermal properties were evaluated by Fourier transformed infrared, (FTIR), X-ray diffractometry (XDR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) before and after release evaluation. The release profile of fertilizer ions was assessed in water and soil. The matrices served only as support for KNO₃ and no chemical interaction was observed. KNO₃ releasing behavior reached a plateau after one hour of test for all samples. The release process generated cavities on the surface of microspheres since these spaces were previously fulfilled with fertilizer as observed by SEM. However, in the soil, the materials were dependent on the amount of water available and we observed a diffusion process for the nutrient release.

Graphic Abstract

中文翻译：

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壳聚糖-甘蔗渣微球作为肥料的输送：开/关水供应系统

增效肥料是提高农业生产力的可持续选择。在这方面，养分包衣或包囊是提高肥料效力的替代方法之一。可以使用几种基质，但主要是可生物降解的基质，对环境没有影响。壳聚糖具有生物降解和对土壤无害影响的良好特性，可用作肥料的保持剂。在这项工作中，壳聚糖和甘蔗渣微球的制备是通过反相法，然后用硝酸钾（KNO ₃）肥料的吸附。在释放评估之前和之后，通过傅立叶变换红外（FTIR），X射线衍射（XDR），扫描电子显微镜（SEM）和热重分析（TGA）对结构，形态和热性能进行了评估。评价了水和土壤中肥料离子的释放曲线。基质仅用作KNO _3的载体，未观察到化学相互作用。硝酸钾₃所有样品测试一小时后，释放行为达到平稳状态。释放过程在微球表面上产生了空穴，因为这些空间先前已用SEM观察到了肥料的填充。但是，在土壤中，材料取决于可用水的量，我们观察到了养分释放的扩散过程。

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