de Lavôr Wellyda Keorle Barros, da Silva Eulene Francisco, de Almeida Ferreira Eveline, Gondim Joaquim Emanuel Fernandes, Portela Jeane Cruz, de Sousa Antunes Luiz Fernando, de Almeida Vasconcelos Aline, de Freitas Diana Ferreira, Mendonça Vander, Fernandes Bruno Caio Chaves
Center of Agrarian Sciences, Federal Rural University of the Semi-Arid, Mossoró, RN, 59625900, Brazil.
Center of Bioscience, Federal Rural University of the Semi-Arid, Mossoró, RN, 59625900, Brazil.
Environ Sci Pollut Res Int. 2024 May;31(23):33924-33941. doi: 10.1007/s11356-024-33446-z. Epub 2024 May 1.
With the expansion of organic agriculture, research is needed to indicate economically and ecologically viable fertilizer options, especially in semiarid regions, with low soil organic matter and nitrogen content. In the Brazilian semiarid region, vermicomposts are widely used by farmers and are scientifically investigated; however, there is no information for millicompost, a new type of organic compound that has shown very promising results in other regions. Thus, this study aimed to analyze the decomposition rate, nutrient release, and microstructure evaluation of vermicomposts from different sources and of millicompost produced from plant residues, with the application of mineral nitrogen-urea and organo-mineral fertilizer in the Brazilian semiarid region. The experimental design was a randomized block in a 4 × 3 factorial scheme, with four replicates; four organic composts (millicompost, commercial vermicompost, vermicompost from bovine manure, vermicompost from goat manure); and three types of fertilization (without fertilizer, with mineral-urea and organo-mineral fertilizer). The organic composts were decomposed using litterbags at the soil surface. The variable's decomposition rate and the nutrient release were evaluated at six-time intervals (0, 30, 60, 90, 120, and 150 days), and microstructure was evaluated at the beginning and the end of the experiment, with scanning electron microscopy (SEM). The highest decomposition was verified for commercial vermicompost rich in macro and micronutrients and with lower P contents. The lignin:N ratio and the initial P content were more important in the permanence of the organic compost in the field than the C:N ratio. Regardless of the organic composts, the use of urea as a mineral fertilizer stimulated decomposition more than the organo-mineral fertilizer. The initial composition of the nutrients was decisive in the dynamics of nutrient release, mass loss, and decomposition of C. There was no pattern in the release order of macronutrients. However, for the micronutrients, the release order was Cu > Fe > Mn, in all treatments. Microstructure analysis is a visual analysis where differences are detected through microphotographs and the biggest difference occurred with millicompost, which showed elongated fibers and fiber bundles, forming a relatively open structure characteristic of the presence of fulvic acid. However, the addition of organo-mineral fertilizer formed agglomerates in compacted micro-portions, helping the mineralization of C and N.
随着有机农业的发展，需要开展研究以指明经济和生态上可行的肥料选择，尤其是在半干旱地区，这些地区土壤有机质和氮含量较低。在巴西半干旱地区，蚯蚓堆肥被农民广泛使用且经过科学研究；然而，对于微堆肥这种在其他地区已显示出非常有前景结果的新型有机化合物，尚无相关信息。因此，本研究旨在分析巴西半干旱地区不同来源的蚯蚓堆肥以及由植物残体制备的微堆肥在施用矿物氮肥（尿素）和有机 - 矿物肥料情况下的分解速率、养分释放及微观结构评估。实验设计为4×3析因方案的随机区组设计，重复4次；四种有机堆肥（微堆肥、商业蚯蚓堆肥、牛粪蚯蚓堆肥、羊粪蚯蚓堆肥）；以及三种施肥类型（不施肥、施用矿物尿素和有机 - 矿物肥料）。有机堆肥在土壤表面使用垃圾袋进行分解。在六个时间间隔（0、30、60、90、120和150天）评估变量的分解速率和养分释放，并在实验开始和结束时使用扫描电子显微镜（SEM）评估微观结构。富含大量和微量养分且磷含量较低的商业蚯蚓堆肥分解程度最高。木质素与氮的比率以及初始磷含量在田间有机堆肥的留存方面比碳与氮的比率更为重要。无论哪种有机堆肥，使用尿素作为矿物肥料比有机 - 矿物肥料更能促进分解。养分的初始组成在养分释放动态、质量损失和碳分解方面起决定性作用。大量养分的释放顺序没有规律。然而，对于微量养分，在所有处理中释放顺序均为铜＞铁＞锰。微观结构分析是一种通过显微照片检测差异的视觉分析，微堆肥表现出的差异最大，其显示出细长的纤维和纤维束，形成了一种因富里酸存在而具有的相对开放的结构特征。然而，添加有机 - 矿物肥料在压实的微区形成团聚体，有助于碳和氮的矿化。
