Impact of different co-composted poultry manures on the chemical and biological quality of the calcareous soil

Abstract

There is a gap knowledge regarding combined multiple chemical and biological parameters of the soil after using composted poultry manure. In this study, four types of co-composted poultry manure were added to a calcareous soil at two levels of 5 and 10% (w/w) and after one-month incubation, some chemical and biological properties were measured. The application of different composts led to a significant reduction in soil pH in the range of 0.3–0.5 units. On average, the increase in chemical parameters compared to those in the control was as follows at application levels of 5 and 10%, respectively: 0.61 and 1.19 dS m⁻¹ for electrical conductivity, 1.36 and 2.68% for organic carbon, 0.165 and 0.332% for total nitrogen, 3.1 and 7.2 cmol_c kg⁻¹ for cation exchange capacity, 101 and 314 mg kg⁻¹ for available ammonium, 1210 and 2251 mg kg⁻¹ for available nitrate, 177 and 408 mg kg⁻¹ for available phosphorus, and 940 and 1882 mg kg⁻¹ for available potassium. Control soil had the lowest microbial respiration, microbial biomass carbon (MBC), substrate-induced respiration, and the highest metabolic quotient. The mentioned indices were respectively in the ranges of 136–174 mg C kg⁻¹, 397–517 mg C kg⁻¹, 1354–1482 mg C kg⁻¹, and 0.048–0.050 mg C mg⁻¹ MBC day⁻¹ at the application level of 10%. Despite the favourable effects of composted poultry manure on the chemical quality of the soil, it is suggested that the level of application should be taken into account to prevent environmental pollution through excessive nitrogen and phosphorus.