Automation of Irrigation Methods – Next Frontier for Irrigation Management in India

Automation of Irrigation Methods – Next Frontier for Irrigation Management in India

India now has about 45 million ha area under irrigation. About 39%% of this area is irrigated by surface water and rest by ground water. The irrigation method adopted is invariably surface irrigation with only 3% area irrigated area under pressurized irrigation Surface systems are simple, have low energy consumption and require comparatively low initial capital. However, they are often associated with a high labour requirement and low water use efficiency The labour cost increases exorbitantly for night irrigation especially for winter crop. Night irrigation becomes necessary in surface water based sources as we can not waste water during night as well as with warabandi night irrigation is necessity. In tubewell irrigation, availability of electricity during night makes it a compulsion to do night irrigation.  Rising labour costs in rural areas is making night irrigation less monitored which further reduces already low irrigation efficiency. Over irrigation also leads to nitrogen leaching and poor productivity. Continuous reduction in per capita water availability and competition for scarce water resources have generated have further complicated situation. The per capita water availability of India is now just 1471 m³ ( as per new population estimates) which makes it a water stressed nation. It has been projected that population and income growth will boost the water demand in future to meet food production, domestic and industrial requirements. The projected total water demand of 1447 BCM in 2050 will outstrip the present level of utilizable water resources (1123 BCM) out of which 1074 BCM will be for agriculture alone. Since the total projected demand will be 324 BCM more than the present level of utilizable water resources, the challenge will be to produce more from less water by efficient use of utilizable water resources in irrigated areas. This means enhancing irrigation efficiency of our irrigation methods.

Automation is one means of ameliorating the problems of high labour requirement and low water use efficiency of surface systems. It refers to the operation of the system with no or just a minimum of manual intervention beside the surveillance. However, the spatial and temporal variability of the soil infiltration characteristics means that each irrigation behaves differently and are therefore difficult to standardize and automate. A lot of work has been and is being done in developed countries. In Australia they are trying integration of on-farm and channel control technologies which may become a real possibility in the near future. Typical bay and basin systems have head ditches at one edge of the field which are fed from open channels. Initial attempts to automate these systems appear to have focused on controlling the inlets or gates that supply water to the field. In California, automation of surface irrigation systems makes decisions on when to turn the water off based on a number of variables (flow rate, advance rate,

crop height, etc). This  decision is based on accurate and real‐time data (flow rate, advance rate, automated gates, ETc , and other variables). The system is optimized by considering  process of all flood irrigation variables to improve on-farm irrigation efficiency. It adjust irrigation time to allow for changing crop roughness (height and density of the crop) by adjusting border/set length to allow for variable soil type across the field adjusting flow rate to an irrigation set (one or more border/land) to improve efficiency. To achieve this computer simulation models are needed for accurate measurements during irrigation events (flow rate and advance rate).

Unfortunately very little work has been done under Indian conditions. The systems developed in European countries or USA or Australia cannot be used in Indian conditions as there is no commonality in field size. However the principle used will have to remain same. We will have to innovate to develop systems which are rugged, not much expensive, can run on batteries etc. To start with it can be used for dry season crops. The irrigation methods which can be automated  are furrow (potato, sugarcane, vegetables etc) and border irrigation (wheat, cotton). However automation can be done only on well laid furrows or borders (Plate 1 & 3). Very small furrows as shown in plate 2 cannot be automated. Actually it was discussion with these farmers who had very good irrigation systems laid in their fields to think further to increase efficiency and reduce labour woes.

Now question is how to proceed to design automation system for surface irrigation methods for our Indian conditions.  Presently four types of systems are being used for automation. (i) Time based systems; (ii) Volume based systems; (iii) Open loop system; (iv) Close loop system. Based on my experience, I think Time Based Systems will be best suitable for our conditions. We can design programmable solenoid valves to open and close after a specified time. The time period will be a function of size of stream,  length of furrow, number of furrows to be served by that feeder channel, soil infiltration rate and crop stage in case of borders. Thus an electronic device can be designed which can program a chip based card which can be fitted in solenoid valve. The pattern can be same as they program the swipe card keys used in hotels. It will also have to contain a clock to fix up both time and duration.

The second challenge will be to design a system which can be fitted in an open channel and pipeline. For open channel, it will two way: one to open towards feeder channel connecting to different furrows/border and another blocking flow forward in main channel. It can be a steel right angle system containing mechanism for opening and closing the valve. Although we think that pipeline cannot be used for conveyance in canal commands, but for slight undulating topography, a large diameter pipeline can be used for conveyance. During my work on designing canal based hybrid irrigation system, I designed a 140 mm diameter pipeline which had open channel flow on a slope of 0.9%, and it functioned very effectively for conveyance of water for rice irrigation during kharif season (plate 4).

A question may arise about the cost and affordability by the farmers, but the benefits will outweigh the cost.  Automation will lead to saving in labour cost (about 65%) and water use by 5-10%. With rising labour cost, cost of pumping and focus on increasing irrigation efficiency, automation is new frontier of irrigation management in India.

 Plate 1 Well laid furrows for potato (farmer’s field of Faizabad U.P.)

 Plate 2: Well laid small length furrows in a small farmer’s field (Faizabad, U.P.)

Plate 3: Well laid borders for wheat in farmer’s field (Faizabad, U.P.) 

Plate 4: Irrigation by pipe in Khaif rice in a canal command of Odisha (Overland slope 0.9%).

जाति सम्मेलन: राजनीति का एक काला अध्याय 

जाति व्यवस्था हिन्दू धर्म  की एक ऐसी कुरीति थी जिसे समाज ने पूरी कोशिश की मिटाने की। काफी हद तक यह खत्म भी हो गई है। केवल अभिभावकों द्वारा तय की गई शादियो में जात की कोई अहमियत रह गई है। पर हमारे राजनीतिज्ञ इसे छोडना नहीं चाहते हैं। हर इलैक्शन से पहले वे जातियों का जोड़ तोड़ शुरू कर देते हैं। बिहार इलैक्शन से पहले फिर वही प्रक्रिया शुरू हो गई है। पिछले महीने मैं पटना में था। हर तरफ विभिन्न जाति सम्मेलनों के पोस्टर लगे हुए थे। कल एक कायस्थ सम्मेलन भी हो गया। इसी तरह 2009 में लखनऊ विभिन्न जतियों के सम्मेलनों के पोस्टर देख कर बहुत क्षोभ हुआ था। उस क्षोभ को वयक्त करने के लिए मैं एक कविता लिख डाली थी। प्रस्तुत है:

कल शाम मैं एक बूढ़े वयक्ति से टकरा गया

चेहरे पर कुछ उदासी कुछ हैरानी के भाव लिए

एक किताब हाथ मे लिए कुछ खोज रहा था

मैंने पूछा

बाबा यह मोती किताब ले कर कहाँ घूम रहे हो

यह तो इंटरनेट का जमाना है

गूगल करो ढूंढ लो, क्यों इस कित्ब के पीछे पड़े हो

बाबा बोले

मैं खोज रहा हूँ इस किताब में अपनी गलतियाँ

किस सफे  पर लिख दिया था

जनतंत्र को जातितंत्र में बदलने का तरीका

मैंने तो आरक्षण की वकालत की थी

उस स्वप्निल समाज के लिए जहां कोई जात न हो

पर ये साथ साल बाद कोई भारत सम्मेलन नहीं करता

ये बड़े बड़े होर्डिंग बताते हैं

ब्राह्मण सम्मेलन, वैश्य सम्मेलन, यादव सभा जाट सभा

इसलिए मेरे भाई मुझे बख्शो

मुझे अपनी गलतियाँ ढूँढने दो

अपने सपनों की टूटी चिरकिया चुनने दो

जनतंत्र तो जातितंत्र में बदलने के खिलाफ

इस संविधान में लिखे सबदों को ढूँढने दो।

Combating Challenge of Declining Land and Water Resources –Few Out of Box Approaches for Small & Marginal Farmers

1.0 Status of Small and Marginal farmers

Although there has not been any significant reduction in overall net cultivated area, but the last four decades has witnessed a sharp decline in the average size of operational land holdings in India. This is reflective of the immense population pressure on the limited land resource available for cultivation. The average size of operational land holdings has reduced by half from 2.28 ha in 1970-71 to 1.16 ha in 2010-11. Consequently, the number of land holdings in the marginal and small categories have swelled by 56 million and 11 million respectively, during the same period. The size of the land holdings has implications for investments in agriculture, its productivity, farm mechanisation and sustaining farm incomes itself. Land holdings in the marginal category (less than1 ha.) constitute 67 per cent of the operational holdings in the country (2010-11). In terms of area operated, the share of marginal holdings has doubled to 22 per cent (2010-11) from a mere 9 per cent (1970-71). Similarly, the share of(operated area under) small farm holdings (1 to 2 ha) increased from 12 per cent to 22 per cent during the same period . Small and marginal holdings together, constitute 85 per cent in terms of number of operational holdings and 44 per cent of the operated area in the country. Thus, over the period, the marginal category has emerged as a distinct and dominant class by itself with its average size dwindling to a mere 0.38 ha. With whatever technological support to traditional agriculture, a small or marginal farmer will always remain poor and stressed. This fact has also been corroborated by recent socio economic survey.

 Similarly, there has been steady decline in per capita water availability. The annual water availability in the country is 4000 billion cubic meter (BCM). Out of this which 1869 BCM is available for use, also called as blue water and rest goes as green water. This 1869 BCM include 1537 BCM surface water and rest 432 BCM of ground water available for sustainable use every year.  Out of this utilizable water is only 690 BCM surface water and 432 BCM ground water making a total of 1122 BCM. The per capita water resources is 3305 m³  and availability at national average is about 1471 m³  (based on recnt population estimate of 1270 million) which is in  water stress zone. Again this value is not same for whole country with western part of the country coming under scarcity zone and eastern and north eastern parts being in above stress level zone. As per CWC figures the water availability situation is going to worsen in view of demand of increasing food production but also demand from other competing sectors. Table 1 depicts this scenario.

Table 1. Sector wise projected water demand in India

(billion cubic meters)

Sector/Year	2000	2010	2025	2050
Irrigation	541	688	910	1072
Domestic	42	56	73	102
Industry	8	12	23	63
Energy	2	5	15	130
Others	41	52	72	80
Total	634	813	1093	1447

(Source: Central Water Commission, 2008 & 2010)

The major factor deciding the water demand will be governed by changes in the socioeconomic status of the population and the extent of urbanization and industrialization. In recent years, there have been significant changes in the consumption pattern and the share of non food grain items in food consumption is increasing. Due to this, there is sharp increase in the demand of such items, i.e., milk, eggs, meat, vegetables and fruits. It is expected that this condition will continue and the gaps will further widen in the next 40 years unless corrective measures are taken to enhance production.

2. Strategies to combat

In view of above the future challenge to water management will be to produce more from less and lesser amount of water with smaller land resource. This will require searching of out of box solutions to enhance yield by using land and challenged ecosystems as well as using gray water. Few of such solutions can be following which need to discussed and researched by scientific community in coming periods.

2.1 Protected cultivation with solar energy and rain water harvesting system

Protected cultivation has potential of increasing productivity manifold both by controlling environment as well as vertical cultivation. To meet increasing demand of vegetables and flowers, this technology can be a boon. It can also be used to enhance the productivity of arid zones and dry semi arid zones where production of vegetables and flowers is quite low which entails its import from other ecosystems. We need to evaluate the potential of protected cultivation in such harsh climate to enhance the productivity as well as profitability from a smaller patch of land. As sunshine is available in plenty, solar energy can be harnessed to meet the energy requirement for maintaining the temperature and humidity as well as supplying good quality water. This will require fusion of technologies from three sectors: horticulturists, designers of protected cultivation structures, and solar energy experts. Both rain water and ground water can be used for irrigation with solar energy for pumping ground water. For areas having poor quality water, solar energy can be used to improve the quality as the required amount will be low. Rain water harvesting from roof of controlled structure with collection on side of structure will facilitate easy availability of water.  With proper designing the whole system can be converted in a self sufficient one in terms of energy, water.  Such a system will enhance the profitability of farmers, higher water use efficiency and higher land productivity. This will have potential of retiring land for other uses as well as diverting saved water competing users.

2.2 Use of gray water for oil palm cultivation

As stated earlier, there will be shortage of about 325 BCM of water by 2050.  This shortfall can either be met by enhancing water use efficiency or using gray water. Municipal waste water is being used for peri-urban horticulture but it has its own perils. Untreated waste water is being used for vegetable cultivation in peri-urban areas creating a health hazard for unsuspecting consumers. Total amount available is 38,254 million litres per day (mld) of waste water equivalent to 14 BCM out of which only 11,787 mld, (31 per cent) get treated. This will cross  170,000 mld (62 BCM) by 2051. Unfortunately not much  information on effect of irrigation by contaminated water on vegetable quality is available but this aspect will be very critical for our future vegetable production strategies. National Green Tribunal (NGT) has ordered MP Pollution Control Board to inspect nullahs used by vegetable farms in  state and submit a report on heavy metals present in water and vegetable samples. Tribunal took a serious exception to vegetable farming being done using sewage water in the city. Indore administration has banned cultivation of vegetables on the side of nullahs. The collector has empowered municipal authorities, the food and the health departments to destroy all vegetables grown along the side of the nullahs. Uprooted vegetables from around five acres of land in the Bhagirathpura area of Indore. Six acres out of 35 acres of farm land irrigated by sewage water in Bhopal district has been destroyed by the district administration.

However such steps are not solution as peri urban horticulture irrigated by municipal waste water is a reality spread over in all ecosystems. Thus it is essential that this problem is tackled with two pronged strategies: first develop decentralized system to reduce contamination level within tolerable limit, and develop protocol for utilizing waste water with different contaminant level for different crops. Under first strategy, work has been initiated to develop an on line filter which can be fitted in the delivery pipe. The initial results have shown significant promise. Work is in progress to enhance the filtration efficiency and study hydraulics of the system. If this device is successful, it will be very effective in reducing growth of contaminated vegetables in peri urban horticulture.

Oil palm is a major growth area which can reduce our dependence upon import of oil from south east Asian countries. This import beside taking toll on out balance of trade, is also facing problem from an unexpected quarter of environmentalists who are opposing cultivation of oil palm in Indonesia and its import by us. Oil palm can be grown on in challenged ecosystem, if proper irrigation is provided. The annual irrigation requirement is about 1300 mm. There is need to evaluate if municipal waste water can be used for irrigating oil palm in semi arid regions in terms of uptake of contaminants in final products of oil and if there can be a refining method to extract contaminants from oil at processing stage. Since the harvest index of oil palm is quite low and in terms of oil it is further small, this is achievable. If this technological breakthrough can be made, we can utilize land in our challenged ecosystems alongwith gray water for meeting a vital demand of our economy beside improving profitability of land in challenged ecosystems.

2.3 Use of floating islands in wetlands for flower cultivation

A huge area under wetlands especially in high rainfall regions is unproductive. Further a good number of them are being used as sink of waste water. A technique of floating islands is being used for cleaning of these waters. The challenge before horticulturists is to identify flowers which can be cultivated in such conditions fulfilling  both purposes, i.e.,  economic utilization of wetlands and treating the waste water by removing contaminants.

3. Conclusion

Declining land and water resources is posing a major challenge to maintain as well as enhancing production of horticultural products. New approaches have to be explored to meet this challenge.