National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Instrumentação, XV Novembro Street, CP: 741, São Carlos, SP, 13560-206, Brazil.
Department of Chemistry, Federal University of São Carlos, Washington Luiz Highway, km 235, São Carlos, SP, 13565-905, Brazil.
Sci Rep. 2021 Apr 7;11(1):7621. doi: 10.1038/s41598-021-87112-2.
Nitrogen fertilization has been a critical factor for high crop productivity, where urea is currently the most used N source due to its high concentration and affordability. Nevertheless, urea fast solubilization leads to frequent losses and lower agronomic efficiency. The modification of urea structure by condensation with formaldehyde has been proposed to improve nutrient uptake by plants and to reduce environmental losses. Herein we show that the co-formulation with Zn strongly modifies the N release (in lab conditions) and, more important, the Zn source-ZnSO or ZnO-has a critical role. Urea-formaldehyde (UF) served as a matrix for the zinc sources, and chemical characterizations revealed that Zn particles influenced the length of the polymeric chain formation. Release tests in an aqueous medium showed that the UF matrix favors ZnO release and, on the other hand, delays ZnSO delivery. Soil incubation with the fertilizer composites proved the slow-release of N from UF, is ideal for optimizing nutritional efficiency. Our results indicated that the ZnO-UF system has beneficial effects for both nutrients, i.e., reduces N volatilization and increases Zn release.
氮肥是提高作物生产力的关键因素，目前由于其高浓度和可负担性，尿素是最常用的氮源。然而，尿素的快速溶解导致频繁的损失和较低的农学效率。通过与甲醛缩合来修饰尿素结构，被提议用于提高植物对养分的吸收，并减少环境损失。在这里，我们表明与锌的共配方强烈改变了氮的释放（在实验室条件下），更重要的是，锌源 - ZnSO 或 ZnO - 起着关键作用。脲醛（UF）作为锌源的基质，化学特性表明 Zn 颗粒影响了聚合物链形成的长度。在水介质中的释放测试表明，UF 基质有利于 ZnO 的释放，另一方面，延迟了 ZnSO 的释放。与肥料复合材料的土壤孵育证明 UF 从 UF 中缓慢释放 N，是优化营养效率的理想选择。我们的结果表明，ZnO-UF 系统对两种养分都有有益的影响，即减少氮的挥发和增加锌的释放。
