The DI system increased income of poor farmers by enabling more efficient use of water resources, improving yield, improving quality, and reducing labour costs. The DI system has a particular niche in monsoonal climates. The DI system allows farmers to plant the crops little early in the season so that the crop is already established at the onset of rainy season and can make efficient use of rainwater.
This helps to avert a crop loss, or a decline in yield that could arise from a dry spell or the early withdrawal of rain. Chandrakanth et al. (2013) estimated the economic benefits from MI in the eastern dry zone of Karnataka using primary data collected from a sample of 45 drip irrigation farmers (size of land holding =1.40 hectare) and 45 conventional irrigation farmers (size of land holding =1.11 hectare) meeting irrigation supplies from groundwater.
In order to cope with water shortage for the already planted perennial crops, drip irrigation was introduced. One of the key advantages of using such technologies is that it helps to extend the use of water during times of drought or water scarcity, and mitigates the risk of losing a crop. The MI can, thus, improve livelihood security to poor farmers vulnerable to rainfall variability.
Experiments conducted in dry region of Karnataka showed that the volume of water used to produce one tonne of mulberry, grapes and tomato was the lowest in drip irrigated farms (1.1 ha-cm, 0.9 ha-cm and 0.8 ha-cm, respectively) than conventional irrigated farms (2.6 ha-cm, 3.5 ha-cm and 1.9 ha-cm respectively). Output per ha-cm of water used in Drip Irrigated Farms (DIF) was 234% higher in mulberry, 368% higher in grapes and 248% higher in tomato as compared to conventional irrigated farms (CIF).
In DIF, 42, 26 and 42% of water has been saved as compared to CIF in mulberry, grapes and tomato respectively (Table 12.12). The economic efficiency of water use can be defined in terms of net return per ha-cm of water, net return per ha, and net return per rupee of water used for irrigation.
The net returns per ha-cm of water from mulberry, grapes and tomato were the higher in DIF (Rs.1,384, 4,723 and 2,696, respectively) as compared to CIF (Rs.525, 769 and 1,040, respectively) (Table 12.12). The results amply demonstrate the scarcity value of groundwater as reflected in motivating farmers to invest Rs.933 on drip irrigation for every one ha-cm of groundwater saved in the process of adoption of drip irrigation.
A survey performed during the year 2012-13 showed that switching to compulsory drip irrigation saved 48 million cubic metres (MCM) of water in a year in Rajasthan. This switching of the irrigation system resulted in saving of 2.4 × 106 litres of diesel, Rs.24 lakhs on diesel subsidy and Rs.48 lakhs in foreign exchange when solar system was combined with drip.
The beneficiary farmers saved about Rs.3,000 – 67,000 per annum by replacing electric or diesel pumps with solar pumps. These savings are likely to accrue over the life span of the solar pump, as electricity and diesel prices are expected to hike continuously. In this manner, the DI system is employed in about 34,338 ha irrigated land in Rajasthan with a total water-saving of 103 MCM in a year. Migrating from FIM to DI system saved about 3,000 m3 of water per ha per annum. The DI system has resulted in improved use of harvested rainwater for farmers, allowing them to irrigate two or three crops in a year.
3. Andhra Pradesh:
The success of MI is quite evident from the Andhra Pradesh Micro Irrigation Project launched in a big way in year 2003 to promote MI on large scale for sustainable development of agriculture. In this project, the major thrust was to bring three-million electrified pump sets in the State of Andhra Pradesh into MI systems.
The project covered more than 0.783 m ha area under the MI systems within 7-year period with capital investment of Rs.24,000 million, benefiting about 0.5 million farmers. The project helped in improving the crop productivity, saving in water and energy resources, and creating employment opportunities.
The project is contributing to an additional productivity of worth Rs.11,745 million per annum. On annual basis, the project is helping in saving of 144 TMC (thousand million cubic feet, 1 TMC = 2,700 ha m) of water, 388 million kWh of energy. Every Rs invest in a year towards the MI system pays Rs.2.4 through additional productivity.
The projected benefits due to the MI systems in sugarcane crop in 15,545 ha indicated a saving of 18,655 ha-m of precious groundwater, and 21.22 million units of electricity every year apart from 0.762 million tonnes of additional cane. These additional benefits converted into monetary terms are equivalent to Rs.841.45 million (Table 12.13). Every rupee spent on DI system for sugarcane resulted in additional benefit of Rs.4.05. Investment in MI also appears to be economically viable, even without availing State subsidy.
The northern portion of Gujarat is an absolutely water scarce region, although it contributes around 40% of total groundwater draft in the State. Excessive groundwater withdrawals for irrigation are leading to alarming decline of groundwater levels in many parts of the region. Hence, a study was initiated to analyze the impact of water-saving technologies on applied water productivity.
It was observed that the farmers were using different types of water-saving technologies for a variety of crops. Before adoption of water-saving technologies, on average blue water use for crop production was estimated to be 8397 m3 ha -1 which was reduced to 5175.5 m3 ha-1 after adoption of water-saving technology, showing a decline of 61.6%. Net income received by farmers before adoption of water-saving technology was Rs.54,615.5 ha-1 and it increased to Rs.95,759.4 ha -1 after adoption of water-saving technology.
The variation in physical water productivity for same crop under different types of water- saving technologies, suggested that government/promotional agencies should promote suitable water-saving technology for different crops, which would help in achieving water-saving and improvement in crop production and productivity.