Dynamics of pruning waste and spent horse litter co-composting as determined by chemical parameters.

The research article details the process and effects of co-composting pruning waste and horse manure, focusing on changes in organic matter, specific nutrient levels, and humification parameters.

Experimental Setup

• The researchers set up a composting system using a large heap (windrow) of pruning waste and horse manure, measuring 2.5 meters in height and 30 meters in length. The composting process was carefully monitored through various parameters.

Observations

• Over time, as the compost matured, there were distinct shifts in certain nutrients, specifically the concentrations of NH(4)(+)-N and NO(3)(-)-N. The concentration of NH(4)(+)-N decreased, while the concentration of NO(3)(-)-N increased.
• The water-soluble C (carbon) level also decreased with the maturation of compost, indicating a breakdown of raw materials.

Organic Matter Degradation

• They noticed that the content of Organic Matter (OM) dropped during the composting process, suggesting that the organic matter was being broken down. This transformation was monitored using a first-order kinetic equation.
• Microbiological activity, defined by the amount of CO(2) released through respiration, agreed with the observed decrease in organic matter. Higher levels of CO(2) respiration corresponded to a decrease in OM.
• They found a strong correlation between the loss of organic matter and the evolution of CO(2), indicating that these parameters can be used to gauge the maturity and stability phases of the composting process.

Humification parameters

• The parameters related to the humification process, which is an essential stage in composting where the organic material is converted into a stable humus, did not show any clear pattern over the composting period.
• From this observation, the researchers suggest that these parameters may not be suitable for evaluating the dynamics of the composting process.