Agriculture and climate change in India
B. Venkateswarlu, Director of India’s Central Research Institute for Dryland Agriculture, writes about the measures needed to make Indian agriculture more climate-resilient.
India is a large country with a diverse climate. Diverse seasons mean diverse crops and farming systems. There is a high dependency of agriculture on the monsoon rains and a close link exists between climate and water resources. Two thirds of the area is rain dependent. Add to this picture the small land holdings, poor coping mechanisms and low penetration of risk management products.
With a 0.68 degrees Celsius increase in temperature so far in India, it is expected that there will be pronounced warming in future, particularly during the post monsoon period and winter. There will be increased frequency of floods during the monsoon and a decrease in winter precipitation with a lower number of rainy days.
Amongst the key impacts will be the faster retreat of Himalayan glaciers, frequent floods and decrease in crop yields. Yield reductions are predicted in wheat and rice due to temperature rise in key growing regions. Until last year, 2009 was the warmest year on record in India since 1901 (+0.913 degrees C above the normal of 24.64 degrees C) now the warmest year is 2010 (+0.93 degrees C).
In more detail, the potential impacts on Indian agriculture would look like this: the productivity of most cereals would decrease due to increase in temperature and CO2, and the decrease in water availability. There will be a projected loss of 10-40% in crop production by 2100 if no adaptation measures are taken. A one degree Celsius increase in temperature may reduce yields of major food crops by 3-7%. The length of the growing period in rainfed areas is likely to decrease, especially in peninsular regions. We are also going to see increased climatic extremes such as heat and cold waves, which are likely to increase production variability.
At the Central Research Institute for Dryland Agriculture, we have studied some of the impacts through modeling and experimentation and this is our summary: Kharif (autumn) crops will be impacted more by rainfall variability while Rabi (spring) crops by rise in minimum temperature. Wheat is likely to be negatively impacted in Rabi due to terminal heat stress. Rice will be affected both by temperature and water availability. Legume crops such as soybean and groundnut are likely to benefit due to increased temperature/CO2 if water availability is not limited. Milk yield in livestock will be impacted during heat waves. There will be changes in the breeding season in marine fisheries with a shift in seasonal catches. There will be a significant negative impact on commercial poultry due to heat stress. There will also be more opportunities for rainwater harvesting due to high intensity rainfall but greater loss of topsoil due to erosion.
So what are the adaptation and mitigation strategies? We need crops and varieties that fit into new cropping systems and seasons. We need to develop varieties with changed duration and varieties for high temperature, drought, inland salinity and submergence tolerance. We also need crops and varieties that tolerate coastal salinity and seawater inundation and varieties which respond to high CO2. Lastly, we need varieties with high fertiliser and radiation use efficiency.
We stress the importance of germplasm. Wild and extant varieties have traits tolerant to high temperature, elevated CO2 etc. These might have been discarded in the past due to low yield potential but can be made use of today as parents for the breeding of tolerant varieties to climate change. There is a need to revisit gene banks with a view to searching for unique traits required for climate change. In this search, indigenous knowledge and farmer’s wisdom have immense value.
Better management practices hold the key to adaptation and mitigation. For example, there is raised-bed planting of wheat in the Indo-gangetic plains which entails 20-25% saving in irrigation water and is suitable for mechanical weeding, and results in reduced herbicide use. We also need better water management and nutrient management of rice paddies.
The Indian Council of Agricultural Research has in fact started the “National Initiative on Climate Resilient Agriculture” (NICRA) towards this goal. This programme has three components: strategic research, technology demonstration and capacity building. The strategic research will focus on crops, natural resource management, horticulture, livestock and fisheries and aspects of climatic resilience in the production systems of the northeastern region. The demonstration will be of existing management practices for enhancing resilience of crops/livestock to current climate variability in 100 most vulnerable districts. The capacity building will be of scientists and other stakeholders in climate resilient agricultural research and its application.
The objectives of the programme are to enhance the resilience of Indian agriculture to climatic variability and climate change through the development and application of improved production and risk management technologies.
The challenge will be to see if the research and development and economic viability keep up with the pace of climatic change and enable food security in the decades to come.
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Image courtesy: flicker photo by World Bank