Comparison of N release from raw and composted hog and chicken manure, with and without inclusion of industrial, commercial and institutional organics

摘要

Composting is being considered by many hog and poultry farmers as a mechanism to reduce manure odours and bulk and produce a saleable end product. There may be cost-saving opportunities for municipalities to send their organics to farmer-run composting facilities. The purpose of this field trial was to compare the suitability, as a soil amendment, of composted hog and poultry manure with and without industrial, commercial and institutional (ICI) organics with non-composted hog and poultry manure and N fertilizer. An experiment consisting of hog manure (HM), poultry manure (PM), hog manure compost (HMC), poultry manure compost (PMC) and hog manure + ICI organics (HMC+ICI), poultry manure + ICI organics (PMC+ICI) and N fertilizer (F) applied at 50 percent, 100 percent and 150 percent plant-available N, plus non-fertilized controls (NF), replicated four times, was established on a loamy sand. The N availability of raw manures was assumed to be 50 percent of their total N content while the N availability of the composts was assumed to be 10 percent. Yield was determined at maturity and plant and grain samples, taken at boot stage and maturity, respectively, were analysed for N content. At boot stage, the order of N concentration was PMC+ICI > PMC >HMC+ICI > PM > HMC > F > NF, while in the grain it was PMC > PM > HMC+ICI > PMC+ICI > HMC > HM > F > NF. The N concentration at boot stage and in the grain increased with increased application of plant-available N. The N yield, although unaffected by N source, was higher in the amended plots than in the NF plots. Where high rates of compost had been applied, substantial quantities of NOs-N remained in the top 7.5 cm of soil in the fall of the year after harvest.