Methodologies to simulate soil litter decomposition in silvopastoral systems using soil and ruminal incubation

The decomposition of senescent leaf litter in silvopastoral systems (SPSs) is regulated by biotic and abiotic factors and plays a key role in nutrient cycling and soil carbon dynamics. The litter bag method is widely used to assess litter decomposition (LD), but it requires a long incubation period and a specific nylon mesh. Therefore, alternative approaches are needed. This study compared three methodologies for assessing LD of senescent leaves of Gliricidia sepium (gliricidia) and Urochloa decumbens (signalgrass) in an SPS. For two of the methods, soil was incubated in litter bags made of nylon or non-woven textile (NWT) for 256 days. In the third method, NWT bags were ruminally incubated for 144 h. The loss of organic matter, carbon, nitrogen, and lignin was evaluated. For gliricidia, no differences in the decomposition rate (k) of organic matter, carbon, or nitrogen were observed among methods. For signalgrass, ruminal incubation resulted in a higher k. Decomposition of senescent gliricidia litter can be reliably assessed using either nylon or NWT incubation methods, while signalgrass litter is more sensitive to textile type. Ruminal incubation with NWT is a viable alternative, and incubation times beyond 144 h are recommended to better capture late-stage decomposition, especially in grasses.