Water plays a crucial role as a fundamental input in ensuring the success of agriculture. Crops can receive water naturally through rainfall, or farmers can artificially provide water to agricultural fields through various human-engineered methods. Irrigation, the process of delivering water to crops through artificial means, involves utilizing infrastructure like canals, wells, tube-wells, tanks, sourced from water bodies such as rivers, ponds, or underground aquifers.

IRRIGATION SYSTEM

• Irrigation involves the artificial application of water to crops to fulfill their water requirements and can also serve to supply nutrients to the plants.
• It is commonly employed in regions with irregular rainfall, anticipated dry spells, or impending drought conditions. 
• Various irrigation systems exist to ensure uniform water distribution across the entire field.
• Sources of water for irrigation encompass groundwater from wells or springs, surface water from rivers, lakes, or reservoirs, and even treated wastewater or desalinated water. 
• The purpose of irrigation is to provide essential moisture for growth, development, germination, and other related physiological functions in crops.
• The frequency, rate, quantity, and timing of irrigation vary among different crops, influenced by factors such as soil type and prevailing season. 
• For instance, summer crops often demand more water compared to winter crops. 
• Farmers must safeguard their agricultural water sources to prevent contamination risks.
• Prudent water management is crucial to avoid over-extraction of groundwater from aquifers, emphasizing the importance of responsible water usage by irrigation practitioners. 
• Considered a fundamental infrastructure and an indispensable input for agricultural production, irrigation aims to sustain crop yields while optimizing water usage. 
• It also plays a role in maintaining landscapes and restoring disturbed soils. 
• The study of irrigation is often intertwined with drainage, which pertains to the natural or artificial removal of surface and subsurface water from a specific area.

TYPES OF DIFFERENT TYPE OF IRRIGATION

Well and Tube Well Irrigation:

• Well and Tube Well irrigation, extensively employed in India since the 1930s, involves the utilization of tube wells to supply water to crops. 
• With over 50 lakh tube wells operational across India, this method has significantly contributed to the success of India's Green Revolution. 
• Uttar Pradesh leads in the area under well irrigation, followed by Rajasthan, Madhya Pradesh, Punjab, Gujarat, Maharashtra, and Bihar. 
• Various well types, such as shallow wells, deep wells, tube wells, artesian wells, etc., cater to diverse agricultural needs.

Canal Irrigation:

• Canal irrigation, constituting a vital source, contributes to about 24% of total irrigation in India. 
• Effective in areas with low-level relief, deep fertile soil, and perennial river areas, canal systems are prevalent in the northern plains. 
• Two types, inundation canals and perennial canals, facilitate the gravity-driven transport of water from rivers, reservoirs, or tanks to farmlands. 
• The canals, typically trapezoidal in shape and made of reinforced concrete, brick masonry, or stone masonry, ensure proper water flow for cultivation.

Tank Irrigation:

• Tank irrigation employs reservoirs created by building small bunds across streams, serving as storage for irrigation.
• Rainwater collection supplements the water supply in these tank reservoirs. 
• Predominant in the peninsular plateau region, Andhra Pradesh and Tamil Nadu lead in tank irrigation, with significance in Karnataka, Madhya Pradesh, Maharashtra, Odisha, Kerala, the Bundelkhand region, Rajasthan, and Gujarat. Tanks, varying in size, are often constructed by individual farmers or groups.

Micro Irrigation:

• Micro-irrigation, a prudent technology promoted nationally and internationally, enhances cropping and irrigation intensity through focused water application. 
• It involves applying a small volume of water at low pressure and frequency, utilizing a network of pipes. 
• Drip irrigation, sprinkler irrigation, micro-sprinklers, porous pipe systems, and rain guns constitute various micro-irrigation methods. 
• Drip and sprinkler irrigation, known for efficiency, significantly reduce water, fertilizer, and labor requirements.

Drip Irrigation:

• Drip irrigation, also termed 'trickle irrigation,' precisely delivers required water amounts directly to plant root zones through drippers or emitters at regular intervals.
• Highly effective for various crops like vegetables, orchard crops, flowers, and plantations, drip irrigation ensures optimal soil moisture with low water application rates. 
• It stands out as an efficient method for conserving water and is suitable for a diverse range of crops.

Sprinkler Irrigation:

• Sprinkler irrigation involves spraying water into the air, simulating rainfall, and allowing it to fall on the ground surface. 
• Applicable to row, field, and tree crops, it is suitable for various soil types, excelling in sandy soil conditions. 
• While effective for most crops, it may not be ideal in consistently windy areas. 
• Sprinkler systems find use in watering lawns, gardens, and agricultural fields, excluding paddy and jute.

Furrow Irrigation:

• Furrow irrigation entails creating trenches or "furrows" between crop rows, directing water down the furrows using gravity, seeping vertically and horizontally to replenish the soil reservoir. 
• Ideal for broad-acre row crops like cotton, corn, and sugar cane, furrow irrigation remains popular due to its cost-effectiveness and simplicity.
•  It is especially preferred in developing countries or areas where mechanized spray irrigation is unavailable or impractical.

Surge Irrigation:

• Surge irrigation involves intermittently applying water to improve distribution uniformity along a furrow. 
• It capitalizes on the varying water absorption rates of dry and wet soil, enhancing application uniformity while reducing deep percolation. 
• This method is known for faster field advancement and is effective in preventing soil surface sealing during wet conditions.

Sub Irrigation or Seepage Irrigation:

• Sub-irrigation, also known as seepage irrigation, delivers water to plants by controlling the water level below the root zone. 
• Effective for water conservation with low labor requirements, it involves controlling the water table to either rise or fall. 
• Unlike flood or furrow irrigation systems, sub-irrigation avoids flooding the field to ground level. 
• It is less common in arid regions and more prevalent in areas requiring drainage for farmability. 
• The same drainage network can be repurposed for water addition when needed for plant growth.

Problems Associated with Irrigation:

Expensive Micro Irrigation:

• Issue: Micro-irrigation systems are expensive, making them inaccessible to poor farmers.
• Addressing the Problem: Initiatives, such as those by International Development Enterprises (IDE), are working on developing low-cost micro-irrigation systems and creating awareness among impoverished farmers in states like Maharashtra and Gujarat.

Delay in Project Completion:

• Issue: Major and medium irrigation projects often face delays due to the continuous launch of new projects, resulting in underutilization of existing potential.
• Addressing the Problem: There is a need to streamline project management, ensuring timely completion of field channels, water courses, and land leveling, preventing unnecessary delays.

Inter-State Water Disputes:

• Issue: Water resource planning is conducted individually by states, leading to conflicts over interstate rivers, storage, and usage priorities.
• Addressing the Problem: A collaborative and coordinated approach, possibly through a national framework, is necessary to resolve inter-state disputes and ensure equitable water distribution.

Regional Disparities in Irrigation Development:

• Issue: There is a significant regional imbalance in irrigation facility development, with the North Eastern region lagging behind.
• Addressing the Problem: Special attention and focused investment are required in regions with lower irrigation development to bridge the regional gap and ensure equitable access to irrigation facilities.

Water Logging and Salinity:

• Issue: Introduction of irrigation has led to water logging and salinity problems in some states.
• Addressing the Problem: Implementing proper drainage systems and soil management practices to combat water logging and salinity issues, coupled with sustainable irrigation practices, can mitigate these problems.

Increasing Irrigation Cost:

• Issue: The cost of providing irrigation has been rising over the years.
• Addressing the Problem: There is a need for efficient management practices, adoption of cost-effective technologies, and transparent financial mechanisms to control and reduce irrigation costs.

Water Table Decline:

• Issue: Over-exploitation of groundwater and inadequate recharge from rainwater have resulted in a decline in the water table, particularly in the western dry region.
• Addressing the Problem: Sustainable water management practices, water conservation measures, and groundwater recharge initiatives are essential to prevent further decline in the water table.

Energy Crisis Caused by Power Outages:

• Issue: Power outages and unplanned interruptions contribute to an energy crisis in rural and urban areas.
• Addressing the Problem: Combining drip irrigation with solar panel systems can offer a sustainable solution, providing off-grid farmers with a reliable and uninterrupted power source for irrigation.
• Addressing these issues requires a comprehensive and integrated approach involving government agencies, NGOs, and the active participation of farmers to ensure sustainable and equitable irrigation practices.

Major Irrigation Projects in India:

In India, water's primary utilization is for irrigation. In essence, irrigation projects represent engineering endeavors designed to accumulate, convey, and supply water to agricultural lands for crop cultivation. 

• These projects span a spectrum from small-scale initiatives to major undertakings. 
• The classification of a project as major hinges on the Culturable Command Area (CCA), denoting the expanse where crops are grown within a specific season or timeframe. 
• When the CCA exceeds 10,000 hectares, the project attains the classification of a major irrigation project. 
• Such projects encompass extensive water reservoirs, flow diversion structures, and extensive canal networks that cover entire regions, complemented by sundry canals.

Highlighted Major Irrigation Projects:

Bhakra Nangal:

• Location: Sutlej River, Punjab, and Himachal Pradesh.
• Completion Year: 1963
• CCA: 40,00,000 ha

Beas Project:

• Location: Beas River, Punjab, Haryana, and Rajasthan.
• Completion Year: 1974
• CCA: 21,00,000 ha

Indira Gandhi Canal:

• Location: Harike River, Punjab.
• Completion Year: 1965
• CCA: 5,28,000 ha

Kosi Project:

• Location: Kosi River, Bihar, and Nepal.
• Completion Year: 1954
• CCA: 8,48,000 ha

Hirakud Project:

• Location: Mahanadi River, Orissa.
• CCA: 10,00,000 ha

Tungabhadra Project:

• Location: Tungabhadra-Krishna River, Andhra Pradesh, and Karnataka.
• Completion Year: 1953
• CCA: 5,74,000 ha

Nagarjuna Sagar Project:

• Location: Krishna River, Andhra Pradesh.
• Completion Year: 1960
• CCA: 13,13,000 ha

Chambal Project:

• Location: Chambal River, Rajasthan, and Madhya Pradesh.
• Completion Year: 1960
• CCA: 5,15,000 ha

Damodar Valley Project:

• Location: Damodar River, Jharkhand, and West Bengal.
• Completion Year: 1948
• CCA: 8,23,700 ha

Gandak Project:

• Location: Gandak River, Bihar, and Uttar Pradesh.
• Implementation Year: 1970
• CCA: 16,51,700 ha

Kakrapara Project:

• Location: Tapti River, Gujarat.
• Completion Year: 1954
• CCA: 1,51,180 ha

Koyna Project:

• Location: Koyna-Krishna River, Maharashtra.
• Completion Year: 1964

Malprabha Project:

• Location: Malprabha River, Karnataka.
• Completion Year: 1972
• CCA: 2,18,191 ha

Mayurakshi Project:

• Location: Mayurakshi River, West Bengal.
• Completion Year: 1956
• CCA: 2,40,000 ha

Kangasabati Project:

• Location: Kangasabati River, West Bengal.
• Completion Year: 1956
• CCA: 3,48,477 ha

These major irrigation initiatives significantly contribute to the agricultural landscape, providing essential water resources for extensive cultivation across diverse regions of India.

FAQs on Irrigation in Agriculture:

1. What is irrigation, and why is it essential in agriculture?

Ans. Irrigation is the artificial application of water to crops, ensuring their water requirements are met. It is crucial in agriculture to supplement natural rainfall and provide crops with sufficient moisture for growth, development, germination, and physiological functions.

2. What are the different sources of water used in irrigation?

Ans. Various water sources include groundwater from wells or springs, surface water from rivers, lakes, or reservoirs, and even treated wastewater or desalinated water. These sources are vital for sustaining crops in regions with irregular rainfall.

3. Why is irrigation necessary in regions with irregular rainfall or impending drought conditions?

Ans. Irrigation becomes necessary in such regions to ensure a consistent water supply for crops, especially during dry spells or anticipated drought conditions. It helps maintain optimal soil moisture levels, supporting crop growth and preventing yield losses.

4. Are there different types of irrigation systems?

Ans. Yes, several irrigation systems exist to ensure uniform water distribution. These include well and tube well irrigation, canal irrigation, tank irrigation, micro-irrigation (such as drip and sprinkler irrigation), furrow irrigation, surge irrigation, and sub-irrigation.

5. How do farmers decide the frequency, rate, quantity, and timing of irrigation?

Ans. Farmers consider factors like soil type, prevailing season, and specific crop requirements when determining irrigation parameters. The water needs of crops vary, with summer crops often demanding more water compared to winter crops.

6. What is the role of prudent water management in irrigation?

Ans. Prudent water management is crucial to avoid over-extraction of groundwater, emphasizing responsible water usage. It ensures the sustainability of water sources, preventing contamination risks and contributing to efficient irrigation practices.

7. What are the problems associated with irrigation practices?

Ans. Some challenges include the expensive nature of micro-irrigation systems, delays in project completion, inter-state water disputes, regional disparities in irrigation development, water logging, salinity issues, increasing irrigation costs, water table decline, and an energy crisis caused by power outages.

8. How can expensive micro-irrigation systems be made accessible to poor farmers?

Ans. Initiatives, such as those by organizations like International Development Enterprises (IDE), are working on developing low-cost micro-irrigation systems and creating awareness among impoverished farmers.

9. What is the significance of major irrigation projects in India?

Ans. Major irrigation projects in India play a vital role in accumulating, conveying, and supplying water to extensive agricultural lands. These projects, often involving large reservoirs and canal networks, significantly contribute to the success of agriculture across different regions.

10. How can regional disparities in irrigation development be addressed?

Ans. To address regional disparities, there is a need for special attention and focused investment in underdeveloped regions. This ensures equitable access to irrigation facilities and promotes balanced agricultural growth.

11. What are some sustainable solutions to combat water table decline?

Ans. Sustainable solutions include adopting water conservation measures, efficient water management practices, and initiatives to recharge groundwater through mechanisms like rainwater harvesting.

12. How can the energy crisis caused by power outages be addressed in irrigation?

Ans. Combining drip irrigation with solar panel systems presents a sustainable solution, providing off-grid farmers with a reliable and uninterrupted power source for irrigation.

13. What role does irrigation play in addition to supporting crop yields?

Ans. Besides sustaining crop yields, irrigation also plays a crucial role in maintaining landscapes, restoring disturbed soils, and is often intertwined with drainage, which involves the removal of surface and subsurface water from specific areas.