Complex agro‐ecosystems for food security in a changing climate

Abstract

Attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to de-gradation of natural resources, whereas most technological innovations are not accessible for smallholders that represent the majority of farmers world wide. Alternatively, cocultures 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. Here we show that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks, and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. We found that azolla, duck, and fish increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests. In the most complex system comprising all components the highest grain yield was obtained. 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. These results provide more insight in the agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate. 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.

Ways forward for resilience research in agroecosystems

“…Increasing dependence on a small number of agricultural commodities (Khoury et al, 2014), unsustainable mining of water and soil resources (Foley et al, 2011), and the biological simplification of agricultural systems (Tilman et al, 2006) are potential sources of instability and vulnerability to climate change and unpredictability, endangering critical ecosystem services to and from agriculture. On the other hand, complex agroecosystems that rely on spatial, temporal, and or biological diversity to support self-regulating feedbacks and synergisms can lend resilience to adverse climate conditions while maintaining productivity and ecosystem service provision (di Falco and Chavas, 2008;Gaudin et al, 2015;Khumairoh et al, 2012). Recently, interest has turned to applying ecological resilience theory to agricultural systems to identify management practices and the underlying mechanisms that support agricultural production in the face of environmental stresses (Allen et al, 2014).…”

Thigmotropic responses of Oryza sativa L. to external rubbing stimulation

“…In Asia, farmers raised ducks in paddy fields, and the diverse activities of ducks directly stimulated the rice, and involved touching the stems, rubbing leaves, trampling the rhizosphere and shaking the aboveground [16,17]. These stimulating effects significantly changed the morphological traits of rice in paddy fields, including decreased plant height, thicker and harder rice stems, enhanced lodging resistance and improved tillering and leaf area expansion [18,19]. Thus, the anatomical structure of the rice culm internodes was significantly impacted by the ducks' activities [20].…”

Envisioning Present and Future Land-Use Change under Varying Ecological Regimes and Their Influence on Landscape Stability

“…This approach has been further developed for evaluation of ecological resilience by composing three indices investigating quality of soils, climate, and water [121]. Finally, other indicators such as pest pressure [122], weed pressure [87], frequency of landslides [10], and severity of soil erosion [123] have also been proposed as reliable indicators contributing to a better knowledge of agro-ecosystem resilience mechanisms.…”