Background
The authors write that "attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to degradation of natural resources, whereas most technological innovations are not accessible [to] smallholders that represent the majority of farmers worldwide." As a solution to this dilemma, they suggest that co-cultures consisting of assemblages of plant and animal species "can support ecological processes of nutrient cycling and pest control, which may lead to increasing yields and declining susceptibility to extreme weather conditions with increasing complexity of the systems."

What was done
Based on this philosophy, Khumairoh et al. "conducted a field trial to investigate the attainable yields in complex agro-ecosystems by studying the combined effects of integration of compost application, ducks, fish, and azolla in a flooded rice system in a season with extremely adverse weather conditions of high rainfall on East Java, Indonesia."

What was learned
The three researchers report that the integrated system they studied "increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests," and that "in the most complex system comprising all components, the highest grain yield was obtained." In fact, they found that "the net revenues of this system from sales of rice grain, fish, and ducks, after correction for extra costs, were 114% higher than rice cultivation with only compost as fertilizer."

What it means
Khumairoh et al. feel that their results "provide more insight into agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate." And they say that "if smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically benign way."