Management of major abiotic stresses in field crops

Abstract

The various abiotic stress such as drought, temperature extremes, high–light intensities, ultra–violet radiations, problematic soils (saline, alkaline, sodic and acidic) and flooding adversely affect the growth, development and yields of plants. The productivity of almost all the crops is limited by these environmental constraints. These impacts are further aggravated due to climate change and inter–and intra–seasonal weather aberrations. With the available knowledge and emerging tools and techniques, the impacts of droughts can largely be addressed, if not eliminated completely. Drought planning must be viewed as a dynamic process requiring a continued attention and can be tackled in a dual manner by: (i) drought coping practices in a season based on drought intensity, and (ii) drought amelioration on a permanent basis. Management of rainwater, soil, cropping systems, real–time contingency measures, land–use diversification and building resilience at agricultural landscape level are the major strategies for drought proofing. Agronomic management practices to control temperature extremes should be based on local territorial agroclimatic investigations. Adjusting sowing windows of field crops and other agronomic management practices are critical to mitigate heat stress and to realize optimal yields. Application of exogenous protectants and management practices like nutrient management are vital in improving the plant tolerance against cold stress. The practices such as soil management, crop management, and foliar application of nitrogen–containing compounds and suggested use of waterlogging–tolerant varieties reduced the impact of waterlogging/ flooding. Agronomic management of drought, thermal extremes and waterlogging/ flooding need future major long–term and short–term strategies such as micro–level climate–risk assessment in various crop–production systems, monitoring and forecasting of climatic extremes: creating virtual weather station at microlevel, use of geo–spatial, drought assessment and monitoring at different scales using advanced tools and techniques, and validation and dissemination of abiotic stress and crop–specific real–time contingency measures as 2–pronged approach, i.e. preparedness and real–time implementation.