Irrigation Revolution: Micro Irrigation Systems

India is predominantly an agricultural country and even with current orientation towards services, still agriculture contributes ¼th of total GDP of the country, 15 percent of total export and 65 % of total population’s livelihood. After independence, India has made remarkable progress in increasing food production and productivity, credit goes to concerted efforts made under various Agri revolutions. For agriculture Land and Water are two most important resources. Of which, water (irrigation) becomes lifeline of agriculture. It is a truth in agriculture “if we fail in irrigation, we will fail in agriculture”. Water is required for agriculture as well as for other sectors (Domestic, Industries, etc) and the demand of water is increasing alarmingly. At present level, agriculture consumes over 80 per cent of total water consumption in India. The country is endowed with many perennial and seasonal rivers. The river system which constitute 71 per cent of water resources is concentrated in 36 % of geographic area. Most of agricultural fields are irrigated by use of underground water for assured irrigation, however, erratic, mansoon based rainfall is source for water for rainfed agriculture. Though water is a renewable resource, the recharge is ultimately limited to rain.

Drought like situation in Indian agriculture is more common and occurs frequently in some of the part of vast geography of the country almost every year. Excessive and unbalanced use of water became a common practice to grow more & more to earn more & more. In other words, the water resources are being depleted by current practice of farming and we will be devoid of sufficient irrigation water if the trend continues in years to come. All these factors are focusing the need of judicious and efficient use of water for agricultural use.

Various type of flood method of irrigation is commonly and traditionally followed in almost whole India. This system offers liable to loss of water conveyance, distribution and evaporation. Therefore, about 30-40 % of applied water is being utilized by the crop rest is leached out; evaporated, or lost through surface run off. Micro Irrigation System is panacea in irrigation related problems. In this technology, field is irrigated in the close vicinity of root zone of crop. It reduces water loss occurring through evaporation, conveyance and distribution. Therefore high water use efficiency can be achieved (Table 1). The unirrigated rainfed cropped area, could be irrigated with the water saved with this technology become a potential source of food production for the benefit of country’s food security.

Table 1: Irrigation efficiency under different methods of irrigation.

Irrigation efficiencies Methods of Irrigation - Surface Sprinkler - Drip Conveyance efficiency 40-50 (canal) 60-70 (well) 100 100 Application efficiency - 60-70 70-80 90 Surface water moisture evaporation - 30-40 30-40 20-25 Overall efficiency - 30-45 50-60 80-90

Table 2: Crop group wise advisable Micro Irrigation System Crop group wise advisable Micro Irrigation System Crop Crop Spacing Adjustable Micro Irrigation System Horticulture Crop 12 m to 3 m between crop raw. (wide spaced) Drip Irrigation System / Pours Pipe Crops fruit part under ground like Potato, Groundnut, Turmeric, Ginger, Vegetables, Medicinal Crops etc. Less then 1 m between crop raw. (Narrow) Drip Irrigation / Sprinkler Irrigation / Raingun Field Crops like Cotton, Castor, Tobacco, Pulses, Sugarcane, Banana, Vegetables etc. Less then 3 m between two crops Drip Irrigation Fodder Crops / Nursery Raising of Vegetables, Ornamental Crops etc. - Sprinkler Irrigation / Raingun

The advantages of drip irrigation are:

• Minimized fertilizer/nutrient loss due to localized application and reduced leaching. • High water application efficiency. • Leveling of the field not necessary. • Ability to irrigate irregular shaped fields. • Allows safe use of recycled water. • Moisture within the root zone can be maintained at field capacity.• Soil type plays less important role in frequency of irrigation. • Minimized soil erosion. • Highly uniform distribution of water i.e., controlled by output of each nozzle. • Lower labour cost. • Variation in supply can be regulated by regulating the valves and drippers. • Fertigation can easily be included with minimal waste of fertilizers. • Foliage remains dry thus reducing the risk of disease. • Usually operated at lower pressure than other types of pressurised irrigation, reducing energy costs. Crop-wise water saving over surface irrigation method and increase in yield is presented in table (Table 3).

Table 3: Crop-wise water saving and increase in yield Crop yield (q/ha) Irrigation Surface Drip % Increase Surface Drip % Saving Beet root 5.7 8.8 54 86 18 79 Bitter gourd 32 43 34 76 33 57 Brinjal 91 148 63 168 64 62 Brocolli 140 195 39 70 60 14 Chilli 171 274 60 27 18 33 Cucumber 42.3 60.9 44 109 41.7 62 Okra 155 225 45 54 24 56 Onion 284 342 20 52 26 50 Potato 172 291 69 60 27.5 54 Radish 10.5 11.9 13 46 11 76 Sweet potato 42.4 58.9 39 63 25 60 Tomato 61.8 88.7 44 49.8 10.7 79 Banana 575 875 52 176 97 45 Grapes 264 325 23 53 28 47 Papaya 130 230 77 228 73 68 Pomegranate 34 67 97 21 16 24 Watermelon 82.1 504 514 72 25 65

Even having many benefits the reach of MIS among the farmers restricted. Though, the government is trying to promote the technology through part financial support to offset its high initial cost syndrome. Few adoptions were observed in the decade of eighties and nineties (Table 4). Putting all together efforts of all machineries under one, total coverage of land under MIS is less than 1 per cent, which underlines the need of integrated efforts to be made by all stake holders. The rural electrification is another major constraint for the popularization of drip systems among farmers. The high care as well as meager crop and soil specific technology are few major constraints for deeper reach of the technology among farmers.

Table 4 : Decade wise development in the field of Micro-irrigation Decade Focus of Research/ extension Seventies Comparisons of micro irrigation system with conventional systems in terms of water savings and yield enhancements. Eighties Estimate water requirements, modifications of crop geometry and use of mulches in drip irrigated fields for realizing the potential benefits of the system Nineties Develop hardware and software for cost reduction, design modifications and fertigation and chemigation Twenty first century Precision farming, including the use and application of software and more efficient instruments in agriculture besides the use of simulation and modeling of moisture and nutrients movement under different soil and dripper characteristics

Promotion of adoption of Micro Irrigation System in India

1. Concerted efforts taken by the Government / NGO and the MIS companies for widespread awareness about the usefulness of the wonderful technology.

2. Efforts should be made to ensure the production and supply of good quality microirrigation system to the farmers by enforcing strict quality control measures.

3. Microirrigation should be made an integral part of all irrigation projects.

4. The microirrigation system manufacturers should also guide the farmers in adopting suitable agronomic practices along with microirrigation.

5. After sales service should be strengthen.

6. Technological intervention is required to cut down the cost of Micro-irrigation system.

Contributing Author: Dr Sarvesh Kumar Shah, engaged in improving crop productivity through emphasising judicious use of soil and water by the farmers since lase 10 years. I was did my Doctorate from GB Pant University of Agriculture and Technology, Pantnagar, India and was served in The Fertiliser Association of India as Agronomist and currently working with Parixit Industries Limited as Sr. Manager (Agronomy Services). sarveshshah@gmail.com