Efficiency Gains from Micro-Irrigation: a Case of Sprinkler Irrigation in Wheat
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Agricultural Economics Research Review 2019, 32 (2), 239-246 DOI: 10.5958/0974-0279.2019.00035.1 Efficiency gains from micro-irrigation: a case of sprinkler irrigation in wheat Prabhat Kishore ICAR-National Institute of Agricultural Economics and Policy Research, New Delhi 110012, India Email: [email protected] Abstract This paper assesses the efficiency gains from the adoption of sprinkler irrigation using data from a farm survey in the water-scarce, drought-prone Bundelkhand region of Uttar Pradesh. Our analysis goes beyond the conventional comparison of physical and economic parameters between micro-irrigation with flood irrigation. We estimate gains in crop yield, water productivity, and technical efficiency, correcting for omitted variable bias. Our findings show that sprinkler irrigation significantly improves yield (21%), water productivity (34%), and technical efficiency (20%); in other words, it saves water (15%) and diesel (8%). These findings are confirmed by our econometric estimates. Keywords Sprinkler irrigation, yield, water productivity, technical efficiency JEL classification Q12, Q15, Q25 Water is a critical input in agricultural production. Of in about 15% of blocks, mandals, or talukas. If this the total utilizable water in India (1,123 billion cubic trend continues, it will severely jeopardize physical metre), close to 80% is used for irrigation (Press and economic sustainability of agriculture (Gandhi and Information Bureau 2013). But water is also a scarce Bhamoriya 2011). Groundwater development in the resource, and with the intensification of agriculture over future should be linked with water conservation time, the demand for water has increased considerably measures. The Government of India realizes this, and and put severe pressure on groundwater resources. it has started emphasizing the importance of the Until the mid-1980s, surface water was the main source conservation and efficient utilization of water. In 2015, of irrigation; it accounted for 54% of the total irrigated it launched the Pradhan Mantri Krishi Sinchayee Yojna. area (Amarsinghe et al. 2007). The situation changed Pressurized irrigation technologies such as drip and gradually, and groundwater emerged as the main sprinkler systems can help to improve the sustainability source. In 2015–16, over 60% of the irrigated area of water resources and consequently agricultural relied on groundwater; since the mid-1980s, production systems. Several studies show that these groundwater has accounted for almost the entire technologies substantially reduce evaporation, and also increment in the irrigated area. There has been little conveyance and distribution losses, and improve investment in or maintenance of irrigation irrigation efficiency (Sivanappan, Rao, and Dikshit infrastructure, and the area irrigated by public irrigation 1994; Sivanappan 1994; Narayanamoorthy 1996, 1997, systems has almost stagnated (Amarsinghe et al. 2007; 2006; Dhawan 2002; Kumar et al. 2008; Saleth 2009; Shah 2009), leading to the over-exploitation of Narayanamoorthy and Deshpande 2005). These groundwater and a continual decline in the water table. technologies also lead to an improvement in the Several other factors, including subsidies for borewells efficiency of fertilizer and energy use (Kumar and and electricity, have contributed to the degradation of Palanisami 2010; Chandrakanth et al. 2013). Most of groundwater resources. Groundwater is over-exploited these studies prove the benefits of pressurized irrigation 240 Kishore P Table 1 Key characteristics of Bundelkhand region Particulars Bundelkhand Uttar Pradesh Geographical area (million hectares) 2.962 24.170 Net sown area (million hectares) 2.058 16.598 Gross cropped area (million hectares) 2.924 26.147 Gross irrigated area (million hectares) 1.464 20.965 Surface irrigation (%) 44.49 19.32 Groundwater irrigation (%) 55.51 80.68 Cropping intensity (%) 142.07 157.53 Average rainfall (mm) in past 15 years 707.09 717.47 Average groundwater table (m) in past 15 years 9.13 7.96 technologies by comparing their important parameters and rapeseed-mustard (3% of the cropped area). against those of flood irrigation, but such a comparison can lead to biased estimates, as the adoption of Sampling pressurized irrigation technologies involves a selection The data that we use in this paper come from a farm process that is influenced by several observable and survey conducted in 2017–18 primarily to assess the unobservable factors. This paper uses data from a field impact of the Direct Benefit Transfer scheme for micro- survey of over 400 farm households to assess the irrigation launched throughout the state in 2014. The benefits of sprinkler irrigation considering selection Bundelkhand region comprises seven districts: Jhansi, bias. Jalaun, Lalitpur, Hamirpur, Mahoba, Banda, and Chitrakut. For our survey we selected Jhansi and Data and descriptive statistics Mahoba because farmer registration there is higher for the Direct Benefit Transfer scheme for sprinklers. From Study area each district we selected three developmental blocks This study was conducted in the Bundelkhand region randomly; from Jhansi we selected Bamaur, Chirgaon, of the state of Uttar Pradesh. The region occupies about and Gursarai and from Mahoba we selected Kabrai, 10% of the state’s geographical area and supports Jaitpur, and Panwari. For the next stage, six villages nearly 5% of the population. Of the total geographical from each block in Jhansi district and five villages from area, 69% is under cultivation. Agriculture is rain- each block in Mahoba district were randomly selected. dependent and rainfall is low (707 mm per annum) The key characteristics of the selected villages are given and erratic. Irrigation is limited to 50% of the gross in Table A1 in the appendix. cropped area, with groundwater accounting for 44% Most villages have basic amenities such as roads, (Table 1). electricity, and schools. Banking facilities are available The average depth of the groundwater table in the only in 27% of the villages, and about 33% of the Bundelkhand region is 9.13 metre, more than the state villages have some form of social organization average. The region is prone to frequent droughts that (cooperative society, gram panchayat, farmer producer affect agriculture and agriculture-based livelihoods. organization, etc.). Agricultural extension support is The cropping intensity is 142%, 16 percentage points available in about 67% of the villages. Finally, a sample less than the state average, and the cropping pattern is of 14–15 farm households was drawn randomly from dominated by pulses (black gram and green gram) and each village, thus yielding a sample of 480 farm oilseeds (sesame) in the rainy or kharif season. During households. All these households rely on groundwater this season, pulses occupy 19% of the cropped area for irrigation. and oilseeds 16% of the cropped area. In the post-rainy Our focus is on wheat, the main rabi crop in the region. or rabi season, the important crops are wheat (43% of Rainfall in this season is extremely low, only 11 % of the cropped area), chickpea (20% of the cropped area) the annual rainfall. In our sample, 84% of the Efficiency gains from micro-irrigation 241 households grew wheat. Groundwater is the main that of non-adopters. To consider this, we adopt source of irrigation for these households; only about treatment effects models from the programme 25% of them have adopted the sprinkler method of evaluation literature. In a regression framework, the irrigation and the rest follow the traditional flood treatment effects model is given by method. Ri = a + bCi + c′Xi + εi …(1) Descriptive statistics where, Ri is an outcome variable (yield, water productivity, technical efficiency) for farmer i, C is a To assess the efficiency gains from the application of i dummy variable taking value 1 for a farmer who has sprinkler irrigation, we compare the key production adopted sprinkler method of irrigation and otherwise parameters of its adopters with those following the 0. X is a vector of control variables, and is a zero flood method of irrigation (Table 2). The yield of wheat i εi mean random variable. under the sprinkler system is 21.9% more than the traditional method of irrigation, and the difference is An ordinary least squares (OLS) estimate of Equation statistically significant. This translates into significant 1 is likely to be biased if εi contains within it random income gains, gross and net. The level of the water unobservable factors such as ability that are not table on the farms of sprinkler adopters and non- uniformly distributed within the population of adopter adopters is similar, but adopters experience and non-adopters. In such a case, the error term is likely significantly better water productivity and technical to be correlated with Ci. Thus, for instance, if adopters efficiency.1 The differences in efficiency gains could are more productive than non-adopters because of be due to differences in input use or unobservable farm unobserved ability, then a simple comparison of the and farmer characteristics of adopters and non- means as well the OLS estimates of Equation 1 would adopters. yield an overestimate of the true measure of gains from adoption. Hence, we apply the two-stage Heckman Table 2 compares the means of some important procedure to correct for the bias from the endogeneity observables. There is no significant difference between of right hand side variables. Consider the following adopters and non-adopters in the use of critical inputs adoption equation: such as fertilizers, seeds, or machines. Sprinkler irrigation adopters use significantly less human labour, Ci = αi Zi + ui …(2) irrigation water, and diesel (to pump groundwater), and Where, Ci is a binary variable (1 for adopters and 0 for they save around 15% of irrigation water, 8% of diesel, non-adopters), Zi is a vector of variables that matters and 11% of labour. Adopters of sprinkler irrigation have for adoption, variables in Zi will overlap with variables larger landholdings, and a larger proportion have their in Xi. Identification requires that there be at least one own source of irrigation, i.e., tubewells.