The application of bio-based controlled-release fertilizers is one of the sustainable methods for improving fertilizer effectiveness and reducing agricultural non-point source pollution. In this study, liquefied tobacco (Nicotiana tabacum L.) stem (LTS) and castor oil were used as raw materials to prepare bio-based polyurethane coating (BPC). The BPC and biochar obtained through pyrolysis were coated on nitramine phosphorus to prepare bio-based double-coated controlled-release fertilizers (BDCRFs). The variables are the 3 %, 5 %, and 7 % BPC coating amounts and biochar from different sources (tobacco stem, fir wood and coconut shell were pyrolyzed at 500 ℃ under oxygen restriction) as components of BDCRFs. The results demonstrated that the excellent hydrophobicity (water contact angle = 138°) and lipophilicity (polyols contact angle = 30°) of tobacco stem biochar (TSB) was conducive to coupling with BPC to improve the controlled-release performance of BDCRFs. Column leaching test indicated the tobacco stem fertilizer (TSF) can achieve long-term controlled-release: with the coating rate of 3 %, 5 % and 7 %, TSF released 71 % ± 2 %, 66 % ± 2 % and 71 % ± 2 % of nutrients on 70, 84 and 124 days, respectively. Meanwhile, the kinetic analysis revealed that the nutrient release mechanism of BDCRFs followed the Ritger-Peppas model. Additionally, TSF with the excellent nutrient release performance were compared with conventional fertilizer (CF), nitramine phosphorus (NP), and no fertilizer (CK) in tobacco field experiments. The results indicated that the biomass, growth indexes and nutritional status of tobacco reached the highest under TSF-5 % treatment. Therefore, the nutrient release of BDCRFs matched the nutrient demand for tobacco growth, reducing the time and labor costs of topdressing and improving the nutrient utilization rate. Therefore, BDCRFs are considered as potential candidates for sustainable development of agriculture and the widespread development and application of controlled-release fertilizers.

中文翻译：

---

农业可持续性：生物炭和生物基聚氨酯偶联涂层制备新型控释肥料


生物基控释肥料的应用是提高肥料有效性和减少农业面源污染的可持续方法之一。本研究以液化烟草 （Nicotiana tabacum L.） 茎 （LTS） 和蓖麻油为原料制备生物基聚氨酯涂料 （BPC）。将热解得到的 BPC 和生物炭涂在亚硝胺磷上，制备生物基双涂层控释肥料 （BDCRFs）。变量是 3 %、5 % 和 7 % BPC 涂层量和来自不同来源的生物炭 （烟茎、冷杉木和椰子壳在氧气限制下在 500 °C 下热解） 作为 BDCRF 的成分。结果表明，烟茎生物炭（TSB）优异的疏水性（水接触角 = 138°）和亲脂性（多元醇接触角 = 30°）有利于与BPC偶联，提高BDCRFs的控释性能。柱浸试验表明，烟茎肥（TSF）可实现长效控释：涂布率分别为 3 %、5 % 和 7 %。 TSF 在 70、 84 ± 124 天分别释放了 71 % ± 2 %、66 % ± 2 % 和 71 % 2 % 的营养物质。同时，动力学分析表明 BDCRFs 的营养物质释放机制遵循 Ritger-Peppas 模型。此外，在烟草田间试验中，将具有优异养分释放性能的 TSF 与常规肥料 （CF） 、亚硝胺磷 （NP） 和无肥 （CK） 进行了比较。结果表明，在 TSF-5 % 处理下，烟草的生物量、生长指标和营养状况达到最高。 因此，BDCRFs 的养分释放与烟草生长的养分需求相匹配，减少了追肥的时间和人力成本，提高了养分利用率。因此，BDCRFs 被认为是农业可持续发展以及控释肥料广泛开发和应用的潜在候选者。