Climate change with an increase in temperature can seriously affect the agriculture sector in Assam, while the shortage of water in the fields can also lead to serious consequences. According to a State Government report, an increase in both frequency and intensity of high temperature, along with its large variability, is emerging as a potential threat to the sustainability of rice production.
This is because rice is a C3 plant and such plants grow in hot tropical conditions like in the valleys of Assam and photosynthesis becomes inefficient when the temperature rises above long-term mean temperatures and deteriorates further when temperature increases beyond this threshold, which is likely to be the case due to global warming.
The second major impact of climate change on agriculture is that the farmers may face the problem of a shortage of water for cultivation. The report said that the emerging trends of rainfall indicate that the number of rainy days is decreasing and the number and extreme rainfall days are increasing and so has their intensity. With total rainfall increasing in most of the areas in Assam in the future, it is likely that runoff will be high.
Due to high runoff, the seepage of water for groundwater recharge will go down. The report pointed out that exploitation of groundwater continuously at higher degrees would lead to soil health problems like acidity, alkalinity, elemental toxicity, etc. Iron and Arsenic toxicities have already been reported in the state.
This would ultimately constrain groundwater exploitation. Therefore, the use of surface water and a solar electric pump operated drip or sprinkler irrigation of harvested rainwater would remain as the last resort for assured irrigation. The state would have to tackle untimely flood and drought conditions. Such incidents have been reported since 2003 in Assam.
Not only do floods wreak annual havoc, but the accompanying uncertainty prevents farmers from taking risks and making investments in land improvement. Moreover, changes in climate would normally shift the host pattern and life cycles of various insects, pests, and pathogens. Many non-pest insects of cultivars might turn to be normal pests while many existing ones might perish forever.
These would lead to the exploring of new resistant varieties and pest control methods, the report said. Making agriculture climate resilient has the potential of uplifting rural poverty and enhance the adaptive capacity of the sector as a whole. Concerted efforts are required to realize the untapped potential of this sector. Therefore, an integrated adaptation approach is suggested as a way forward for ensuring the sustainability of agricultural crops and horticulture in the State.