Soil Organic Matter Dynamics and Crop Productivity as Affected by Organic Resource Quality and Management Practices on Smallholder Farms

To my boys, I have done this for you. Thanks for the unwavering support and for believing in me. You are my inspiration. This is just the beginning of many more challenges to come. i Crop productivity in low-input agricultural systems is largely a function of the soil’s capacity to hold and release nutrients in soil organic matter (SOM). Although sandy soils on most Zimbabwean smallholder farms inherently contain a small amount of SOM, large variability in soil productivity (fertility gradients) exists between adjacent fields or field sections within the same farm. Farmer management of such variability remains a challenge and sustainable option for soil productivity are required. This study was based on the hypothesis that SOM, a renewable resource, is the driving force behind sustainable crop productivity on depleted sandy soils. Relationships between maize yields and SOM contents, nitrogen (N) release patterns, and their links with organic matter managemen