Effects of Broiler Litter Application on Crop Yield, Soil Fertility, and Organic Carbon Dynamics in No-Till Corn-Soybean Rotations

Southeastern United States, with its significant poultry production, experiences challenges in sustainable management of poultry waste. One potential solution is utilizing poultry litter (PL) as a soil amendment, which not only provides nutrients to crops but also increases soil organic carbon (SOC) accretion. However, the effect of continuous application of different rates of PL on SOC dynamics is not well studied. This study leveraged an ongoing field experiment at west Tennessee started in 2019 in a corn-soybean rotation system. Treatments include four rates of PL: (0.448 Mg ha^-1, 0.673 Mg ha^-1, 0.896 Mg ha^-1 and 1.569 Mg ha^-1 PL application rates) applied every year along with a positive control (conventional nitrogen fertilizer) and negative control (no fertilizer). Soil samples collected from four depths (0-5 cm, 5-15 cm, 15-30 cm, and 30-60 cm) in October 2023 were analyzed for soil bulk density, soil organic carbon (SOC), microbial biomass carbon (MBC), SOC fractions (mineral associated organic matter and particulate organic matter), and wet aggregate stability (WAS). At 0-5 cm depth, bulk density was the highest (1.34 g cm^-3) for 0.673 Mg ha^-1 of PL and the lowest (1.16 g cm^-3) for 1.569 Mg ha^-1. Additionally, MBC was the highest (470 mg kg^-1) with 1.569 Mg ha^-1 at 0-5 cm, while inorganic nitrogen application showed the least MBC in all depths (112 mg kg^-1 - 301 mg kg^-1). Further laboratory and statistical analyses are currently undergoing. This research aids in the in-depth understanding of SOC storage and climate resilience implications of PL application in soil