do Valle Stella Fortuna, Giroto Amanda Soares, Reis Heitor Pontes Gestal, Guimarães Gelton G F, Ribeiro Caue
Department of Chemistry, Federal University of São Carlos, Washington Luiz Highway, km 235, 13565-905 São Carlos, SP, Brazil.
Embrapa Instrumentation, XV de Novembro Street, 1452, 13560-970 São Carlos, SP, Brazil.
J Agric Food Chem. 2021 Mar 3;69(8):2392-2402. doi: 10.1021/acs.jafc.0c07333. Epub 2021 Feb 18.
The development of smart and eco-friendly fertilizers is pivotal to guarantee food security sustainably. Phosphate rock and struvite are promising alternatives for P fertilization; nevertheless, the solubility of these sources is a challenge for consistent use efficiency. Here, we propose using a polysulfide obtained via inverse vulcanization as a novel controlled-release fertilizer matrix in a system containing either Bayóvar rock (Bay) or struvite (Str). The polysulfide provides S for plants after being biologically oxidized to sulfate in soil, generating local acidity for P solubilization. After 15 days of soil incubation, the composites with 75 wt % Str and 75 wt % Bay achieved, respectively, 3 and 2 times the S oxidation from the elemental sulfur reference. Results indicated that P content stimulates the soil microorganisms' activity for S oxidation. The matrix had a physical role in improving Bay dissolution and regulating the rapid release from Str. Moreover, the available P in soil was 25-30 mg/dm for Bay composites, while for pure Bay, it was 9 mg/dm.
智能和环保型肥料的开发对于可持续保障粮食安全至关重要。磷矿和鸟粪石是磷肥的有前景的替代品；然而，这些来源的溶解性对于持续的使用效率而言是一项挑战。在此，我们提议在包含巴约瓦尔岩石（Bay）或鸟粪石（Str）的体系中，使用通过逆硫化获得的多硫化物作为一种新型控释肥料基质。多硫化物在土壤中被生物氧化为硫酸盐后为植物提供硫，产生局部酸性以促进磷的溶解。土壤培养15天后，含75 wt% Str和75 wt% Bay的复合材料分别实现了元素硫参比材料硫氧化量的3倍和2倍。结果表明，磷含量刺激土壤微生物进行硫氧化的活性。该基质在改善Bay的溶解和调节Str的快速释放方面具有物理作用。此外，Bay复合材料的土壤有效磷为25 - 30 mg/dm³，而纯Bay的有效磷为9 mg/dm³。
