Climate-Smart Landscapes for Managing Water Resources in the Tea Growing Regions of Northeast India

Abstract:

Tea is an important global agricultural commodity, both commercially and culturally. Assam, an agrarian state in northeast India is the largest single tea growing region in the world and the productivity (both in terms of quantity and quality) requires a specific range of enviro-climatic conditions. Precipitation and temperature are two climate factors which highly influence productivity. Thus water plays a critical role in sustaining future tea production in Assam. Recently the region has been affected by heterogeneous spatiotemporal distributions of precipitation and rising temperatures. This has led to temporally varying drought-like conditions during the tea production season, reducing crop resilience and degrading yield quality. Quantifying regional climate-yield characteristics enables more effective decision-making regarding climate change mitigation, water resources management and adaptation to sustain (and enhance) future tea crop production. This research used a panel based regression model to statistically quantify the extent to which precipitation and temperature variables are associated with changes in tea yield. Monthly time-series climate and yield data were regressed for the period 2004 to 2014. Yield data were obtained from 80 tea estates across the four main tea growing regions of Assam, and 120 climate variables were selected for analysis. Results indicate that periods of drought (e.g. more than 10 consecutive days of zero precipitation) are significantly associated with reductions in yield, whereas periods of intense precipitation (e.g. number of days where the 95^th percentile was exceeded) are generally associated with increased yield. These results have provided an enhanced understanding of climate-yield characteristics, which will subsequently be used to deliver more climate-smart advisory decision-support services to tea producers in the region. Although water resources management practices, such as water harvesting structures, check dams and irrigation facilities, have been adopted by some tea producers, this research identifies a need for enhancing such climate mitigation measures, especially for minimising dry-spell induced crop failures.