Improving modern agriculture through ‘intercropping’

We rely on modern agriculture to produce massive quantities of food and fiber, but the system is not without downsides. High crop yields are ensured through outsize applications of fertilizers and pesticides, which pose environmental hazards ranging from water contamination to the development of pesticide resistance in insects and weeds. Traditional forms of agriculture take a different approach, using relationships between different crops to increase crop yields and improve resilience against pests. A new paper studies the case for integrating these traditional agricultural techniques into modern agriculture.
 
Published in the journal Frontiers in Ecology and the Environment, the study was conducted by a team of researchers at Zhejiang University. Central to the research is the idea of intercropping — the planting of different crop species together. The researchers review the body of scientific literature surrounding the use of three traditional agriculture practices: legume-cereal intercropping, rice-fish co-cultures, and intercropped agroforestry. The team determines how traditional systems differ from monocropped agriculture in terms of crop yield.
 
The researchers find that under the right conditions, traditional systems with intercropping outperform modern systems. Legume-cereal intercrops generally outperform their monocropped equivalents, because the legumes help provide additional nitrogen and phosphorus to the cereal crop. Rice paddies with fish generally perform better than those without fish because the fish both fertilize the paddies and consume pest insects. While agroforestry receives the least discussion, the authors note that these types of systems can benefit from intercropping with the correct species selection.
 
A number of challenges must be overcome before intercropping becomes common in modern agriculture. Uniform plantings allows farmers to reduce the amount of work needed to manage a field, further assisted through a variety of mechanized tools. Intercrop systems run contrary to the status quo by increasing the complexity of fields, and the resulting field layouts — with different plant heights and varying row widths — negate the possibility of using today's most advanced farm machinery.
 
Intercropping results in additional labor costs, and a transition away from monocrops may be slow as a result. While the additional labor associated with intercrop fields could be justified by other benefits, such as improved habitat and water quality, the authors suspect these types of ecosystem services are valued little by farmers and consumers. New policies can help provide financial incentives for producers to switch to intercropping methods. Pesticide taxes, changes in farm subsidies, or payments for ecosystem services are all methods by which new systems could be encouraged.
 
There are many factors in the balance when attempting to feed a growing world population. Without improvements in yield per acre or a decrease in meat consumption, growing enough food to feed the world will lead to increased deforestation. However, increasing yields under modern agriculture often implies a greater number of resource inputs, including pesticides, fertilizers, and fossil fuels. Integrating the traditional methods of intercropping into modern agricultural systems can help to balance these risks by improving yields while decreasing fertilizer and pesticide inputs.