Irrigation is defined as the science of artificial application of water to the land, in accordance with the crop requirement throughout the crop period for full-fledged nourishment of the crops.
The irrigation system is a manmade water management system, which is required to fulfil the water demands of the crop during less rainfall. Irrigation leads to increased efficiency and potentially higher incomes.
Necessity of irrigation in India
Non-irrigated (rain-fed) agriculture depends entirely on rainfall, stored in the soil profile. This form of agriculture is possible only in regions where rainfall distribution ensures continuing availability of soil moisture during the critical growing periods for the crops.
In irrigated agriculture, water taken up by crops is partly or totally provided through human intervention. Irrigation water is withdrawn from a water source and led to the field through an appropriate conveyance infrastructure.
The reasons why irrigation is a necessity in India
Seasonal Rainfall: Most of India’s rain falls during the monsoon season (June-September). The remaining eight months lack sufficient precipitation to meet crop water needs, making irrigation essential.
Unpredictable Monsoons: The monsoon’s erratic nature necessitates year-round irrigation facilities to safeguard against droughts and ensure crop survival.
Low Rainfall Regions: Areas like Rajasthan receive minimal rainfall, requiring irrigation to fulfill the water demands of crops.
Porous Soils: Sandy soils in some regions have high permeability, causing irrigation water to drain quickly, leaving crops thirsty. Irrigation becomes crucial in these areas to ensure adequate water reaches the plants.
Increased Crop Yields: Irrigation allows for optimal water supply, leading to increased agricultural output and improved profits for farmers. This fosters economic growth in India, where a significant portion of the population relies on agriculture.
Multiple Cropping: Without irrigation, areas may only support one crop during the rainy season. Irrigation enables farmers to cultivate additional crops (Rabi crops) in other seasons, maximizing land use.
Perennial Crops and Cash Crops: Perennial crops like
sugarcane require consistent water supply throughout the year, which irrigation provides. Additionally, irrigation allows for cultivating commercially valuable crops that might otherwise struggle with limited rainfall.
Controlled Water Delivery: Proper irrigation systems ensure controlled water distribution, optimizing water usage and maximizing crop yield. Additionally, proper irrigation practices can contribute to groundwater recharge, storing water reserves for drier periods.
Current Scenario
Of the total available agricultural land i.e. 1,80,888 thousand hectares. In several major states, including Maharashtra and Jharkhand, less than 20 percent of arable land is irrigated. Punjab is the only State which has nearly achieved 100 percent net irrigation followed by Haryana. Uttar Pradesh, Bihar, and West Bengal are among the five top States with more than 50 per cent net irrigated area. Interestingly, as per the government data 60 percent of the net irrigated area in the country is serviced through groundwater, which is under threat due to depleting water tables.
WATER BODIES AND STORAGES
Inland water resources of India are classified as rivers, canals, reservoirs, tanks and ponds, beels, oxbows,
lakes, derelict water and brackish water, and they cover an area of 7 mha excluding rivers and canals.
These are unevenly distributed in the country, and five states, i.e., Orissa, Tamil Nadu, Andhra Pradesh, Karnataka and West Bengal, account for more than 50 percent of the inland water bodies.
Uttar Pradesh has the highest total length of rivers and canals of 31,200 km, followed by Jammu & Kashmir and Madhya Pradesh.
Most of the lakes, beels and derelict water bodies lie in the states of Kerala and Tamil Nadu, whereas Orissa, West Bengal and Kerala have the largest areas of brackish water.
Irrigation Census
Minor irrigation schemes, utilizing groundwater or surface water and serving areas less than 2,000 hectares, play a vital role in expanding irrigation across India.
These schemes are categorized into six main types: 1. dug wells, 2. shallow tube wells, 3. medium tube wells, 4. deep tube wells, 5. surface flow schemes, and 6. surface lift schemes.
Recognizing the importance of minor irrigation for agriculture, several censuses have been conducted to create a comprehensive database for planning, development, and management of these schemes. The first census began in 1986-87, with subsequent censuses conducted periodically, with the latest one being the Sixth Minor Irrigation Census referencing the year 2017-18.
