Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental (CIMYSA), Scientific and Technological Bioresources Nucleus-BIOREN, Universidad de La Frontera, Temuco, Chile; Instituto de Ciencias Agronómicas y Veterinarias, Universidad de O'Higgins, Campus Colchagua, San Fernando, Chile.
Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Center, Ottawa, Ontario, Canada.
J Environ Manage. 2020 Apr 15;260:110137. doi: 10.1016/j.jenvman.2020.110137. Epub 2020 Jan 25.
Metallic oxides and clay minerals have gained increasing interest as additives of composting due to their influence in greenhouse gas emissions reduction and their effectivity in the stabilization of carbon both in compost and soils, leading to a cleaner compost production and potentially C sequestrant amendments. In this study, wheat straw (WS) was co-composted with iron oxide and allophanic soil and their influence on WS composting and composition of the end-products was evaluated. WS compost and their humic like-substances (HS) fraction were characterized by chemical and spectroscopic analyzes. After 126 days of process, the elemental composition showed slight differences of the N content for compost and HS, where the C/N atomic ratio tended to decrease relative to the initial material (WS; 130). This trend was more pronounced in the HS from co-composted treatments (<30). The addition of inorganic materials increased the total acidity and phenolic-OH group contents (15 and 14 mEq g respectively, iron oxide treatment) relative to the treatment without inorganic additives. Nevertheless, the FTIR and solid-state CNMR spectroscopy barely support the wet chemical analysis and revealed a similar final composition between all the studied compost treatments. These results suggest that the incorporation of these materials as compost additives had no major effect on the spectroscopic features of the end-products, however, critical changes of the properties such as the extractability, functionality and composition of HS were revealed by traditional methods. In conclusion, the supply of metal oxides and clays could impact the aerobic composting of WS favorizing the stabilization of certain C pools and adsorptive properties of the end-products, that is of importance in production of amendments suitable for being used in degraded and contaminated soils. Nevertheless, under the experimental conditions of our research C stabilization apparently depends of other mechanisms that still need to be elucidate.
金属氧化物和粘土矿物作为堆肥的添加剂越来越受到关注，因为它们可以影响温室气体排放的减少，并且可以有效地稳定堆肥和土壤中的碳，从而生产更清洁的堆肥，并可能成为碳封存的改良剂。在这项研究中，将小麦秸秆 (WS) 与氧化铁和类沸石土壤一起进行共堆肥，并评估它们对 WS 堆肥和最终产物组成的影响。通过化学和光谱分析对 WS 堆肥及其腐殖质类似物 (HS) 部分进行了表征。经过 126 天的处理，元素组成显示出堆肥和 HS 中 N 含量的细微差异，其中 C/N 原子比相对于初始物料 (WS；~130) 趋于降低。这种趋势在共堆肥处理的 HS 中更为明显 (<30)。与没有无机添加剂的处理相比，无机材料的添加增加了总酸度和酚羟基含量（分别约为 15 和 14 mEq g，氧化铁处理）。然而，FTIR 和固态 13C NMR 光谱几乎不支持湿法化学分析，并显示出所有研究堆肥处理之间最终组成的相似性。这些结果表明，将这些材料作为堆肥添加剂加入堆肥中对最终产物的光谱特征没有重大影响，但是传统方法揭示了 HS 的一些重要性质的变化，例如提取性、功能性和组成。总之，金属氧化物和粘土的供应可能会影响 WS 的好氧堆肥，有利于某些 C 库的稳定和最终产物的吸附性能，这对于生产适合用于退化和污染土壤的改良剂非常重要。然而，在我们研究的实验条件下，C 的稳定显然取决于其他仍需阐明的机制。
