Effects of broiler litter age and application rate on nutrient mineralization under laboratory condition

Abstract

AbstractBroiler litter (BL), a byproduct of the broiler (Gallus gallus sp.) production cycle, can be regarded as a beneficial organic source to supply essential nutrients for crop growth. Understanding BL nutrient mineralization helps producers better manage nutrients on farms. However, the effects of BL age (length of time BL stays in poultry house before it is cleaned out, also known as the clean out frequency of BL) and application rate on the mineralization of BL nutrients are still poorly understood. Therefore, a 150‐day laboratory incubation study investigated the influence of BL age (6, 18, and 30 months) and application rate (5 and 10 Mg ha−1) on nutrient mineralization. The experimental design was a completely randomized design with three replications. Soil samples were collected at day 0, 10, 30, 60, 90, 120, and 150 and analyzed for nitrogen (N) species nitrate, ammonium, total N, and water‐extractable nutrients (water‐extractable phosphorus, potassium [WEK], calcium [WECa], magnesium [WEMg], iron [WEFe], copper [WECu], zinc (WEZn), boron [WEB], and manganese [WEMn]). Results showed that BL nutrient mineralization was affected by BL age or application rate, except WEFe. A greater amount of nitrate‐N was released during the first month, suggesting faster nitrification during the first 30 days after application. Mineral N (sum of nitrate‐ and ammonium‐N) release was more significant with the increasing age of BL and application rate. Greater availability of WEK, WECa, WEMg, and WEB was found in 18‐ and 30‐month BL from 10 Mg ha−1, and lowest in 6‐month BL from 5 Mg ha−1, whereas 6‐month BL with 10 Mg ha−1 has the greatest WECu. Our results suggested that older BL (30 months) with a greater application rate (10 Mg ha−1) had greater nutrient supply potential.