Improving SOC Modelling of Manure Amendments for Croplands

Abstract

In this thesis I analyse manure decay using a variety of methods, and use the results to inform the modification of a \ac{SOC} model with the goal of improving SOC prediction accuracy for manure-amended croplands.

The methods used in the first three chapters are: 1) qualitative literature review of manure \ac{C} mineralization experiments, 2) quantitative literature review of much the same papers with the goal of establishing relationships between manure decay rates and animal type, composting treatment, manure pH, and manure C/N, and 3) calculation of manure decay parameters and correlation analysis.

In the final chapter, the results from the preceding chapters are used to inform the modification of an SOC model: manure-C accounting and a rate-modifying factor for manure. The modifications increased SOC estimation accuracy for long-term field experiments, but not for a typical Ontario production farm. Manure composting treatment, storage type, and manure C/N are good predictors of manure decomposition dynamics in SOC models.