A cropping system practice is the sequential cultivation of crops in different crop seasons of a year. Cropping system practices determine the land productivity and sustainability of agriculture in regions and, therefore, information on cropping systems of different regions in the form of maps and statistics form critical inputs in crop planning for optimal use of resources. Although satellite-based crop mapping is widely practiced, deriving cropping systems maps using satellites is less reported. Here, we developed moderate-resolution maps of the major cropping systems of South Asia for the year 2014–2015 using multi-temporal satellite data together with a spectral matching technique (SMT) developed with an extensive set of field observation data supplemented with expert-identified crops in high-resolution satellite images. We identified and mapped 27 major cropping systems of South Asia at 250 m spatial resolution. The rice-wheat cropping system is the dominant system, followed by millet-wheat and soybean-wheat. The map showing the cropping system practices of regions opens up many use cases related to the agriculture performance of the regions. Comparison of such maps of different time periods offers insights on sensitive regions and analysis of such maps in conjunction with resources maps such as climate, soil, etc., enables optimization of resources vis-à-vis enhancing land productivity. Thus, the current study offers new opportunities to revisit the cropping system practices and redesign the same to meet the challenges of food security and climate resilient agriculture.
Climate change is expected to increase the incidence and magnitudes of extreme weather events. To help farmers mitigate the expected impacts of extreme weather events, abiotic stress-tolerant crop varieties have been developed. The diffusions of the stress-tolerant crop varieties, however, have been limited. This chapter reviews recent studies on the adoption and impacts of the submergence-tolerant rice varieties in South Asia. Studies have identified significant benefits of those rice varieties in South Asia using various survey and analytical methods. However, farmers have problems identifying submergence-tolerant rice varieties in informal seed markets. Using DNA fingerprinting, a study found that many farmers in Bangladesh could not identify varietal names correctly. Effective public interventions are needed to help farmers in flood-prone areas adopt submergence-tolerant rice varieties.