Comparing water management in rice–wheat production systems in Haryana, India and Punjab, Pakistan

Abstract

The intensive irrigated rice–wheat systems in the northwest Indo-Gangetic Plains of South Asia are built on a long tradition of canal irrigation and the more recent advent of tubewells. Findings from farm surveys are used to examine water management and water productivity in the rice–wheat belt of India's Haryana State and Pakistan's Punjab province. Attributes of the irrigation sources help explain the widespread interest in groundwater use and the relative demise of canal water use. In each area groundwater now is the main irrigation source, used either solely or in conjunction with surface water. The ownership of tubewells is near universal among the surveyed farms, whereas conjunctive water use is more widespread during the monsoon season, among better endowed farmers and in the Pakistan Punjab. In Pakistan Punjab farmers primarily rely on diesel powered tubewells whereas Haryana farmers mainly use relatively cheaper electric power. Water productivity indicators for rice are markedly lower than those for wheat—largely reflecting significantly higher water inputs in paddy cultivation—but also vary between the study areas and by the prevailing water use, reflecting the limited incentives for farmers to use water wisely. A combination of technological, land use and market based approaches is likely to be most effective in achieving sustainable water management in these intensive cereal systems.

Introduction

South Asia's Green Revolution in the 20th century thrived on the adoption of semi-dwarf wheat and rice varieties and complementary technologies such as fertilizer and irrigation. This led to an impressive increase in cereal supply from 1965 to 1985 (Kataki et al., 2001, Murgai et al., 2001) and converted the northwest Indo-Gangetic Plains (NW IGP) and its irrigated rice–wheat systems into South Asia's strategic cereal basket. However, towards the turn of the century, productivity growth started to stagnate (Duxbury, 2001, Kataki et al., 2001, Prasad, 2005) and to lag population growth. This stagnation is associated with the prevailing soil and water management of an aerobic wheat crop and an anaerobic rice crop in a semi-arid environment. Water management thus played a pivotal role in both enabling the Green Revolution and undermining the past achievements, thereby raising questions about the future of the irrigated rice–wheat systems in the NW IGP.

The concern over water is not limited to the sustainability of intensive cropping systems. Per capita water availability in South Asia is less than the world average, and is extremely stressful in the Indus Basin and has more than halved over the last two decades in India (Babel and Wahid, 2008). Agricultural water use is estimated to consume almost 95% of the withdrawn water in South Asia, well above the global average (70%, Babel and Wahid, 2008). In the face of increasing competition for water from other sectors, concerns are being raised about agricultural water productivity (Hellegers et al., 2007, Kijne et al., 2003, Molden, 2007).

South Asia and particularly the IGP have a long irrigation tradition, but the latest two waves of irrigation development are of particular interest here. The first was characterized by massive public investments in large-scale canal irrigation schemes since the mid-19th century (Chambers, 1988, Jurriens et al., 1996). These schemes were primarily public sector led reflecting their capital intensive nature and need for collective action, but their management has proven problematic, including their inherent supply-led nature and cost recovery issues (Chambers, 1988, Gulati et al., 2005). A characteristic feature of these schemes is their scarcity by design: they were primarily intended to provide a protective form of irrigation in which a relatively large area would be served with irrigation water in an equitable manner. Preference was thus given to extending the irrigation reach and providing protection against crop failure and famine. The goal was to maximize returns per unit of scarce water (Bhatti et al., 1991, Jurriens et al., 1996). However, equitable sharing has proven difficult, typically leading to the lower reaches having a reduced canal water supply, more water deficits and lower yields (Latif, 2007).

The second wave of irrigation development was characterized by the rapid and ongoing spread of small-scale groundwater irrigation in rainfed and canal irrigated areas which started in the latter half of the 20th century (Qureshi et al., 2003b, Shah, 2007, Sharma et al., 2008). In both India and Pakistan, surface water long dominated irrigated agriculture, but has been overtaken by groundwater as the main irrigation source since the mid-1980s (Shah, 2007) with groundwater now serving 60% or more of irrigated lands (Shah et al., 2009). Concomitantly, the decline in South Asia's public irrigation system seems recent and rapid. Thus despite the massive prior investments in canal irrigation in NW IGP, irrigation is now primarily delivered by wells and tube wells (Murray-Rust and Velde, 1994, Shah, 2007). This means that groundwater is no longer supplemental to canal water, but is an integral and often the predominant part of irrigated agriculture.

Environmental concerns related to irrigation development in the semi-arid NW IGP are increasingly prominent. The first wave of irrigation development resulted in waterlogging and salinization (Ritzema et al., 2008), whereas the second wave led to groundwater overexploitation (Abrol, 1999, Ambast et al., 2006, Babel and Wahid, 2008). In the NW IGP the groundwater is primarily declining in areas with fresh and marginal quality groundwater and where the rice–wheat cropping system prevails. In India's rice–wheat belt the water table has fallen by 5–15 m over the last 20 years, often requiring lowering of centrifugal pumps in deeper pits or replacing them with submersible pumps (Ambast et al., 2006). In contrast, rising water tables are registered in areas where groundwater is of poor quality and where cropping systems other than rice–wheat prevail. Within the NW IGP there can thus be significant local variation in water management problems, with declining aquifers, water logging and salinization existing side by side (Abrol, 1999, Bhalla, 2007, Datta and Jong, 2002). Adding to the site specificity of water management are the diverging incentives farmers face.

The greater Punjab in the NW IGP is the Green Revolution heartland and shares a colonial heritage of investments in canal irrigation infrastructure. The greater Punjab was partitioned at Pakistan's and India's independence in 1947 and has subsequently been subjected to a diverging institutional environment. This likely contributed to differences in the way the second wave of groundwater development was implemented and in farmers’ water management practices. These differences may hold valuable insights for research and development in the quest for appropriate responses to the challenges facing rice–wheat systems. However, information on irrigation in South Asia is inadequate and often incomparable across sources, and despite their potential value, only a few studies have compared water management across borders (Shah et al., 2000, Shah et al., 2006, Shah et al., 2009), with Pakistan–India comparisons particularly problematic in view of political sensitivities.

We examine farmers’ water management practices in two rice–wheat areas in India and Pakistan using an empirical farm survey as our primary data source. We first present a typology of irrigation sources and characterize the water sources and tubewells in these rice–wheat systems. We then contrast water management and productivity in these systems in terms of the crops, the study areas, and the prevailing water use. We continue with a discussion of the implications for technological and institutional change.