Irrigation: Determinants of Agriculture – UPSC IAS

In this article, You will read Agricultural Infrastructure & Irrigation: Determinants of Agriculture (Infrastructural Factors) – for UPSC IAS.

Agricultural Infrastructure

  • If agriculture is the lifeblood of the Indian economy, then infrastructure is like the arteries and veins which are necessary for this sector’s and the economy’s sustenance and growth.
  • Infrastructure, mainly physical, in the agriculture sector implies those facilities that help farmers in the processes of sowing to selling; namely- irrigation, road connectivity, electrification, storage and telecommunication.
  • Investment in infrastructure leads to reduced costs per input, enhanced productivity, further income generation and capacity building. It has positive spill-over effects such as the development of rural areas, alleviating hunger and poverty and proper conservation and management of natural resources.
  • The ingredients of agricultural infrastructure is summarised in the chart below:
ingredients of agricultural infrastructure

Determinants of Agriculture

  • Determinants of agriculture decide the agricultural pattern, cropping pattern, and agricultural productivity of a region.
  • Various Determinants are shown in the chart below:

Irrigation

  • Water is an important input for successful agriculture. It may be available naturally through rainfall or artificially through irrigation.
  • The process of supplying water to crops by artificial means such as canal, wells, tubewells, tank etc. from the source of water such as resources, tanks, ponds or underground water is called irrigation.

Need for Irrigation

  • The main idea behind irrigation systems is to assist in the growth of agricultural crops and plants by maintaining with the minimum amount of water required, suppressing weed growth in grain fields, preventing soil consolidation.
  • In India the 2/3rd of total cropped area needs irrigation.
  • Nature of monsoon rainfall in India is uncertain, unreliable, irregular, variables, seasonal and unevenly distributed.
  • The features of Monsoon and its effect on Indian agriculture which makes irrigation a necessity is as under:
    • Uncertainty of arrival.
    • Variable especially in areas of low rainfall e.g.-Punjab, Haryana, W. Uttar Pradesh (High co-efficient of variability)
    • Variation in the spatial distributor of rainfall e.g. – Meghalaya has much more rainfall than that of Thar Desert.
    • Only 30% of cultivated land receives sufficient rainfall of more than 100cm. Also in area of high rainfall, irrigation is necessary to further increase farm productivity.
    • Monsoon gaps (no rain for 2 or more weeks during sunny season) may damage the crops in absence of irrigation facilities.
    • Monsoon is “seasonal”, 75% of rainfall happens in 3-4 months of the year and remaining in 8-9 months marked by dry season when irrigation is badly needed for growing crops (5 months dry in Kerala, 9 months dry in NW India).
    • Rainfall in most parts of India is torrential & therefore there is less opportunity for soil to absorb water & surface water goes waste. Also the rain water flows down very quickly along the hill slopes.
    • Irrigation is necessary to end Monoculture cropping practices in Indian Agriculture.
    • Irrigation is also necessary for socio economic transformation of rural India by making agricultural variable.
    • Certain crops like rice, sugarcane, jute, cotton require more water & need irrigation even in areas of heavy rainfall.
    • Introduction of HYV seeds & heavy doses of chemical fertilisers since green revolution has made irrigation necessary.
    • Sandy & loamy soil can’t retain water like Alluvial & Black soil.
    • The increasing population leads to more intensive agriculture which needs more irrigation facilities along with other inputs.
    • To supply essential moisture for plant growth which includes transport of essential materials irrigation is necessary.
    • Irrigation is required to leach or dilute the salts in soil.
    • To increase productivity, cropping intensity or gross cropped area the expansion of irrigation network is necessary.
  • It is estimated that yield of irrigated crops are 50% to 100% higher than that of non irrigated crops under similar geographical conditions.
irrigation map of india

The Benefits and ill Effects of Irrigation

  • The benefits and ill effects of irrigation is summarised in the table below:

Geographical Factors Favouring Irrigation

  • Northern plains of India: Geographical factors favouring irrigation in Northern plains are:
    • Slope of land is gentle & canals can carry irrigation water to far off places.
    • Soft and friable soil makes it easy to dig canals and to link wells.
    • Deep clay in sub-soil acts as reservoir for rain water which percolates through porous aluminium. Hence, large quantity of ground water is available for irrigation through wells and tube wells.
    • A large number of perennial rivers provide water for irrigation throughout the year.
  • Peninsular plateau area: Irrigation in Peninsular plateau is not an easy task due to its difficult terrain and factors enumerated below:
    • Rocks are hard so digging canals & wells isn’t easy. That is why tank irrigation is mainly practiced here.
    • Surface is uneven so canals can’t carry water to far off places.
irrigation map upsc

Development of Irrigation

  • According to Rostov hypothesis, India was in second stage of economic development after independence where maximum population was dependent upon primary agricultural activity.
  • To boost this sector from 1st FYP onwards, agriculture planners advocated agricultural development as prime pre requisite behind agriculture growth and regional planning.
Development of Irrigation
  • In above chart the surface water irrigation is carried by canal, river linkages etc. In case of the harnessing of ground water, the availability of electricity plays a major role in extraction of water through wells and tube wells.
  • The availability of water and the type climate and terrain of an area plays a major role in deciding the irrigation practices of the area.
  • Thus it can be seen that important requirements for irrigation are:
    • Source of water
    • Distribution Channel
    • Field applications

Historical Developments in Irrigation

  • Since ancient times irrigation was practiced in India. Hindu Monarch, Mughal emperor and British rulers exhibited great engineering feats to develop irrigation at different times in history of India.
  • The pre-independent undivided India had some of the best irrigation system in the world. Much of the canal irrigated areas of Sutluj and Indus went to Pakistan.
  • Post- independence with advent of plan wing, sustained and systematic programmes for development of irrigation was taken up. This was done in order to ensure:
    • Balanced regional development
    • Rural development

Types of Irrigation Projects

  • The irrigation projects in India can be classified into three categories as mentioned in following table:
Types of Irrigation Projects
  • Major And Medium Projects Mostly Exploit Surface Water Sources Whereas Minor Projects Have Both Surface And Ground Water As Their Source.

Sources of Irrigation

  • There are different sources of irrigation in an area which are dependent upon the following factors:
    • Topography
    • Soil
    • Rainfall
    • Availability of surface or ground water.
    • Nature of river (perennial or non perennial)
    • Requirement of crops
  • Main types of irrigation include wells and tube wells, canals, tanks, traditional water harvesting techniques and micro irrigation.
Main types of irrigation
  • The traditional irrigation types include various irrigation practices of rural India which are being done from ages. Some of them are famous with names such as Johars, Baolis, Hundu, Suragam, Kuhls, Sprins and Doug.
  • Micro irrigation:
    • Micro-irrigation is considered as a prudent Irrigation technology promoted nationally and internationally to achieve higher cropping Intensity and irrigation Intensity through more focused application of water to crops.
    • Micro-irrigation involves two methods of irrigation system:
      • Drip Irrigation: In drip irrigation, water is applied near the plant root through emitters or drippers, on or below the soil surface, at a low rate varying from 2-20 litres per hour. The soil moisture is kept at an optimum level with frequent irrigations.
      • Sprinkle irrigation: In this method, water is sprayed into the air and allowed to fall on the ground surface somewhat resembling rainfall. The spray is developed by the flow of water under pressure through small orifices or nozzles. The sprinkler irrigation system is a very suitable method for irrigation on uneven lands and on shallow soils.
  • Other Types of Irrigation
    • Furrow Irrigation: Furrow irrigation is a type of surface irrigation in which trenches or “furrows” are dug between crop rows in a field. Farmers flow water down the furrows and it seeps vertically and horizontally to refill the soil reservoir. Flow to each furrow is individually controlled.
    • Surge Irrigation: Surge irrigation is a variant of furrow irrigation where the water supply is pulsed on and off in planned time periods. The wetting and drying cycles reduce infiltration rates resulting in faster advance rates and higher uniformities than continuous flow.
    • Ditch Irrigation: It is a rather traditional method, where ditches are dug out and seedlings are planted in rows. The plantings are watered by placing canals or furrows in between the rows of plants. Siphon tubes are used to move the water from the main ditch to the canals.
    • Sub Irrigation or Seepage Irrigation: It is a method of irrigation where water is delivered to the plant root zone from below the soil surface and absorbed upwards.
  • Any irrigation system requires three components viz.
    • Storage Component
    • Conveyance component
    • Field application
  • Irrigation Methods: Irrigation methods refer to the techniques adopted for carrying water from its source to crops. The characterises of efficient irrigation method is:
    • Uniform distribution of water.
    • Minimum transport and minimum loss of soil.
    • Storage of maximum water.
    • Crop growth not adversely affected.
    • Economically sound and adaptable.

Irrigation Types

Tank irrigation

  • A tank consists of water storage which has been developed by constructing small bund of earth or stones built across the stream.
  • The water impounded by small bund of earth is used for irrigation and other purposes.
  • These are mostly of small size and are built by individual farmers and group of farmers.
  • Ratio of tank irrigated land and total area of country has been reduced from 14% in 1960-61 to 3% in 2010-11 due to increase in well and tube well irrigation and partly due to fall in tank irrigation.
  • Geographical distribution:
  • Andhra Pradesh, Telangana and Tamil Nadu are the leading states in tank irrigation.
  • Tamil Nadu accounts for 23% of tank irrigation in India whereas Andhra Pradesh and Telangana accounts for 28% of tank irrigation in India.
  • Drainage area of Godavari and its tributaries have large number of tanks. Nellore and Warangal are the main districts of tank irrigation.
  • Reasons for the presence of tank irrigation system in peninsular India are:
    • Undulating relief and hard rock make it difficult to dig canals and wells.
    • Little percolation of rain water due to hard rock structure and ground water is not available in large quantity.
    • Most rivers of this region are seasonal and dry up in summer. Therefore, rivers can’t supply water to canals throughout the year.
    • There are several streams which become torrential during rainy season. The only way to make best use of them is to impound it by constructing bunds and building tanks.
    • Scattered nature of population and agricultural fields necessitates the use of tank irrigation.
  • Merits and demerits of tank irrigation
tank irrigation map of india

Wells

  • A well is hole dug in the ground to obtain subsoil water.
  • An ordinary well is about 3 to 5 meters deep but deeper wells are about 15 meters deep.
  • Several methods like Persian wheel, Reht, Charas or mot, dhingly are used to lift ground water from wells.
  • Geographical distribution.
    • Well irrigation accounts for about 63% of net irrigated area in country. There has been a six fold increase in well irrigation since 1950.
    • Popular areas with sufficient sweet ground water are:
      • Northern Plains
      • Deltaic plains of Mahanadi, Godavari, Krishna, Cauvery,
      • Parts of Narmada and Tapi Valleys.
      • Weathered areas of Deccan trap
      • Crystalline and sedimentary zone of peninsular India.
  • Greater parts of peninsular India are not suitable for well irrigation because of uneven surface, rocky structure and lack of groundwater.
    • Large dry tract of Rajasthan, adjoining parts of Punjab, Haryana, Gujarat and some parts of UP have brackish underground water and is not fit for irrigation and human consumption as well as well irrigation.
    • Uttar Pradesh has the largest area under well irrigation which is 23% of county’s total.
    • Next to Uttar Pradesh are Rajasthan (10%), Punjab (8%), Madhya Pradesh (7.9%), Gujarat (7.3%) and Bihar (6.2%).
    • States, where well irrigation plays a significant role, are: Uttar Pradesh, Rajasthan, Punjab, Madhya Pradesh, Gujarat, Maharashtra, West Bengal, and Bihar.

Tube Wells

  • A tube well is a deeper well (>15 meters) from which water is lifted with the help of a pumping set operated by an electric motor or diesel engine.
  • Geographical conditions favourable for tube well installation is as follows:
    • Sufficient quantity of groundwater (a tube well irrigate 2 hectare per day against 0.2 hectare per day irrigated by ordinary well).
    • Sufficiently high groundwater table so that pumping is economical (water table should be <15 meters, greater than which it becomes uneconomical).
    • Regular supply of cheap electricity and diesel so that water can be taken out when needed.
    • Soil in the immediate neighborhood of tube well should be fertile so that the construction and operational cost of tube well is recovered by increased farm production.
  • Wells proliferated after Green Revolution in Punjab, Haryana and Western Uttar Pradesh.
  • Water application efficiency is 60% in well and tube well irrigation.
  • Merits and demerits of Well and Tube well irrigation
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