Nitrogen, phosphorus, and sulphur mineralization patterns of different animal manures applied on a sandy loam soil – an incubation study

A 16-week incubation experiment was conducted to determine the pattern of nitrogen (N), phosphorus (P), and sulphur (S) mineralization in soils treated with poultry manure slurry (PMS), poultry manure with bedding (PMB), cattle manure (CM), horse manure (HM), rabbit manure (RM), swine manure (SM), and goat and sheep manure (GSM) applied at 120 kg N ha⁻¹. The concentrations of nitrate–N (NO₃-N), ammonium-N (NH₄-N), total mineral nitrogen (TMN), available P, and S were determined fortnightly. Result showed that SM and HM had significantly (p ≤ 0.05) higher C:N, C:P, C:S, N:P and N:S than other manures. The percentage of TMN, P, and S mineralized was in the order of SM > CM > HM > GSM > RM > PMB > PMS. From 8 to 14 weeks, SM, CM, HM, GSM, and RM exhibited net negative ammonification, while net positive nitrification of NO₃-N occurred from 6 to 14 weeks of incubation in all manures. Soil treated with SM had a significantly higher proportion of total mineral N, available P, and S by 24, 54, and 45%, respectively. PMS had the highest mineralization and concentration of TMN, P and S; and peak at 10, 8, and 6 weeks, respectively. NO₃-N was the dominant form of total mineral N (R² = 0.99), and positive correlation occurred between TMN and cumulative P (R² = 0.82) and S (R² = 0.94). The study concluded that manure quality and properties are good predictors of N, P, and S mineralization.