Estimating the potential of rainfed agriculture in India: Prospects for water productivity improvements
Introduction
Rainfed agriculture is practiced on 80% of the world's agricultural land area, and generates about 70% of the world's staple foods, including most of the food in poor communities in developing and least-favoured areas (CA, 2007). The most recent estimates have put global rainfed croplands at 1.75 billion ha (Bha) at the end of the last millennium, or about 5.5 times the irrigated area in the world (GIAM, 2006). India ranks first among the countries that practice rainfed agriculture both in terms of extent (86 Mha) and value of production. Due to low land and labour productivity, poverty is concentrated in rainfed regions (Singh, 2001). While farmers in some high potential regions have increased yields by about 5% per annum in recent years, farmers in the semi-arid tropics of Asia (including India) have increased agricultural growth by less than 1%. Yield gap analyses for major rainfed crops find that farmers’ yields are about one-half to one-quarter of achievable yields (CA, 2007). Grain yields vary from 1 to 2 tons t ha−1 in many rainfed areas, compared to attainable yields of more than 4 t ha−1 (Falkenmark et al., 2001). The large yield gap suggests there is much to gain by improving productivity in rainfed agriculture.
Rainfed agriculture in India is practiced under a variety of soil type, agro-climatic and rainfall conditions ranging from 400 mm to 1600 mm per annum. Rainfall is a random input and its variation and intensity are high in areas of low rainfall. Rockstrom and Falkenmark (2000) note that a decrease of one standard deviation from the mean annual rainfall often leads to a complete loss of the crop. Dry spells (or monsoonal breaks), which generally involve 2–4 weeks of no rainfall during critical crop growth stages, causing partial or complete crop failures, often occur every cropping season. Kanwar (1999) has identified adverse meteorological conditions resulting in long dry spells and droughts, unseasonal rains and extended moisture stress periods, with no mechanisms for storing or conserving the surplus rain to use during the scarcity/deficit periods, which comprise the major cause of low yields and heightened distress in rainfed regions.
Supplemental irrigation is a key strategy, so far underutilized on a regional basis, to unlock rainfed yield potentials. The existing evidence indicates that supplemental irrigation ranging from 50 to 200 mm/season (500–2000 m3 ha−1) is sufficient to mediate yield reducing dry spells in most years and in rainfed systems (Wani et al., 2003). Since irrigation water productivity is much higher when used conjunctively (supplemental) with rainwater, it is logical that, under limited water resources, priority in water allocation may be given to supplementary irrigation (Agarwal, 2000, Joshi et al., 2005). On a regional basis, collecting small amounts of runoff using limited macro-catchments during the rainy season, using this resource for supplementary irrigation and adopting improved agronomic practices can improve agricultural production in rainfed areas (Pathak et al., 2009). The Consultative Group on International Agricultural Research (CGIAR) Challenge Program on Water and Food supported a study of the available runoff in the dominant rainfed regions of India, with the goal of examining the hydrologic and economic potential for improving agricultural productivity. That study, as a part of the ‘Strategic Analysis of India's National River Linking Project,’ had the following objectives:
- (i)
To identify the dominant rainfed districts for major rainfed crops in India.
- (ii)
To assess surplus runoff for water harvesting and supplemental irrigation and the irrigable area at the district level.
- (iii)
To estimate regional (district level) water use efficiency and the effect of supplemental irrigation on production of selected rainfed crops.
- (iv)
To conduct a preliminary economic analysis of water harvesting and supplemental irrigation in rainfed areas.
Section snippets
Methods of analysis
Districts are the primary administrative and planning units in India, and all data sets pertaining to agriculture, water resources, climate, human development and related parameters are available at the district level. There are 604 districts in India and the average size of a district is about 500,000 ha. We chose districts as the level of analysis for this research.
Dominant rainfed districts for different crops in India
Rainfed areas in India are highly diverse, ranging from resource-rich areas with good agricultural potential to resource-constrained areas with limited potential. At present, an estimated 60% of the 142.2 Mha net cultivated area is rainfed, which contributes to 44% of total food grain production. Rosegrant et al. (2002) have estimated that even by 2025, one-third of India's cereal production will be contributed by rainfed areas. Most of India's (coarse) cereals (91%), pulses (91%), oilseeds
Conclusions
Rainfed lands have substantial unexploited potential for growth, yet the risks of crop failures, low yields and the insecurity of livelihoods are high due to the random behaviour of the monsoonal rainfall. Rainfed agriculture is mainly and negatively influenced by intermittent dry spells during the cropping season and especially at critical growth stages. A district-level analysis of rainfed crops in India shows that total water availability may not be the major problem in rainfed areas. For
Acknowledgements
The support provided by CGIAR Challenge Program on Water and Food and International Water Management Institute, Colombo for implementation of “Strategic Analysis of National River Linking Project” is gratefully acknowledged. Sincere thanks to Dr. J S Samra, Chief Executive Officer, National Rainfed Area Authority of India, New Delhi, India.
References (32)
- Agarwal, A., 2000. Drought? Try Capturing the Rain: Briefing Paper for Members of Parliament and State Legislatures—an...
- et al.
India's water demand scenarios to 2025 and 2050: a fresh look
- et al.
Participatory watershed development in India: A sustainable approach
Water for Food, Water for Life: A Comprehensive Assessment of Water Management in Agriculture
(2007)- CRIDA (Central Research Institute for Dryland Agriculture), 1998. Base paper—National Agricultural Technology Project....
- CRIDA, 2001. Annual Progress Report. CRIDA, Hyderabad,...
- et al.
Water Harvesting for Upgrading Rainfed Agriculture: Problem Analysis and Research Needs
(2001) - FAO (Food and Agriculture Organisation of the United Nations), 1977. Guidelines for predicting crop water requirements....
- FAO, 1998. Crop-evapotranspiration: guidelines for computing crop water requirements. In: Allen, R.G., Pereira, L.S.,...
- FAO, 2002. World Agriculture: Towards 2015/2030: Summary Report. FAO, Rome,...
Satellite Sensor based Global Irrigated Area Mapping
Need for a future outlook and mandate for dryland agriculture in India
Accounting for Water Use Productivity
Cited by (102)
Developing a community based participatory model for efficient and sustainable use of groundwater – An exploratory research using system dynamics in a village in south India
2023, Groundwater for Sustainable DevelopmentAnalysis of crop water requirements and irrigation demands for rice: Implications for increasing effective rainfall
2022, Agricultural Water ManagementCitation Excerpt :Effective utilization of natural rainfall could be a promising strategy to design water saving measures in the southern rice growing region of China. Examples of this kind of rainfed rice cultivation systems are available in Sub-Saharan Africa (Raes et al., 2007), southeastern Tanzania (Biazin et al., 2012), and the Ganges Plain (Sharma et al., 2010). Currently, rainfed cultivation accounts for about 25% of global rice production.
Enhancing climate resilience of irrigated agriculture: A review
2022, Journal of Environmental ManagementImpact of natural resource management interventions on water resources and environmental services in different agroecological regions of India
2021, Groundwater for Sustainable DevelopmentSupplementary irrigation for managing the impact of terminal dry spells on the productivity of rainfed rice (Oryza sativa L.) in Fogera Plain, Ethiopia
2021, HeliyonCitation Excerpt :Moreover, PD1 with V4 treatment could be also recommended as an alternative technology for local farmers. In line with this result, Sharma et al. (2010) reported that water harvesting and supplementary irrigation are economically viable and possibly increase by 50% for crop production. ETB, Ethiopian Birr; AGY, adjusted grain yield; TVC, total variable cost; NB, net benefit; MRR, marginal rate of return; D, dominated treatments; FP, farmers practice; TWOI, transplanted but not irrigated; SAT, transplanted and irrigation to saturation; PD1, transplanted and ponding to 1 cm water; PD2, transplanted and ponding to 3 cm water; V1, X-Jigna; V2, Edget; V3, Hiber; V4, Fogera-1; V5, Nerica-4.