Litter Decomposition Affected by Tree Species in an Alley-Cropping Site in Arkansas

Litter decomposition in an alley-cropping system is an important process contributing to soil carbon (C) and nitrogen (N) pools. An in-situ litter decomposition study was conducted using a litter bag method with four tree species, northern red oak (Quercus rubra L.), pecan (Carya illinoiensis Wangenh. K. Koch), pitch/loblolly pine (Pinus rigida Mill. × Pinus taedae L.), and American sycamore (Plantanus occidentalis L.). Litter bags were returned after 350 and 568 days and analyzed for remaining mass percentage and loss of C and N. A single exponential curve fit was used to determine the decomposition rate. Sycamore had the highest decomposition rate followed by pecan, oak, and pine. Initial litter C:N ratios followed a slightly different trend, with pecan lowest, followed by sycamore, oak, and pine. Litter quality, or C:N ratio, can help inform species selection and nutrient management in alley-cropping systems.