January 08, 2007	Monday	Zilhaj 17, 1427

THE government is doing the right thing by encouraging farmers to try the efficient pressurised irrigation systems instead of the traditional gravity or flood irrigation. Among the pressurised systems, special emphasis remains on trickle / drip for point irrigation that cuts almost 50 per cent demand on existing water demand and increases crop yield significantly. In this context, just to create demand for the technique and to adapt the new water application systems, the current planning is to establish demonstration farms on 1500 acres in Punjab and 500 acres in each of the remaining three provinces.

In addition to short-term objectives, a strategic interest in such endeavour appears to be field testing for the sustainability of such pressurised systems under an environment of medium to heavy soils in arid and semi-arid region where gravity irrigation has been practised over centuries. As the current project is a second or third attempt in the introduction of pressurised systems, it is apparent that the new project is based on lessons learned from the not-so-successful similar attempts made in the recent past. This seems to be reason that private vendors and companies are being proposed to install such systems for demonstration in all four provinces.

However, such a paradigm shift in the modality of irrigation water application is not going to be an easy task. There will be many challenges of different nature that must be addressed properly for making this change irreversible.

If the establishment of demonstration sites is limited to a part of a farm, it may be difficult to fully know the adjustments required for fitting a pressurised system within a gravity water application environment. Demonstration sites based on entire farms are essential to learn about challenges that farmers will have to face in the existing environment of multiple cropping patterns, different land uses and related cultural practices.

When farms are fully dedicated to crops like vegetables, orchards or row crops like cotton; drip irrigation fits well. However, the same does not hold right when seasonal vegetables and row crops follow by say wheat or fodder. So, the second challenge would be that either new cropping patterns come into being or some innovative combination of pressurised systems has to be there to suit the new arising situation.

Even if we have row crops, vegetables or orchards, the nature of arid and semi-arid region is such that salinity will appear on the soil surface between rows in no time. To avoid shifting of the salts to adjacent plants, proper use of rain-water and occasional gravity / flood irrigation may become a necessity to maintain good soil health. It appears that a system that works well in sandier or tropical environment may need appropriate adjustments to fit a medium to heavy soils located in arid and semi-arid regions.

With proper adjustments, drip system should work well for orchards of mangoes, citrus, apple, guava, etc. However, when inter-cropping is opted, most citrus growers do, having a sprinkler system in place should help. In that case, however, challenge is to design a circular water application system that fits to rectangular fields.

For planners and managers, another issue concerns with use of tube-well and canal water. For tube-well water, drip systems will need either no or limited filtration arrangement whereas canal water must have to have silt-free clean water to avoid clogging of drip lines and emitters.

On the other hand, most of the tube-wells in the Indus valley pump sodic water having high amounts of carbonates and bicarbonates. Such groundwater creates sodic hazards in medium to heavy soils on one hand; the deposits of calcium carbonates (lime) could clog emitters on the other hand.

This implies that groundwater has to be treated in most cases and de-silting of canal water would be necessary for pressurised systems like sprinklers in general and drip irrigation in particular. Handling treatment with say sulphuric acid or tackling accumulated silt from different locations should be another aspect for serious consideration.

Canal irrigation system of the Indus Valley is marvel of engineering and uniquely tailored for surface/ gravity irrigation. Canals are conduits for rationing water as per weekly turn system. Both canals and tube-wells deliver water at very higher rates than any pressurised system can consume such flows. To address this challenge, a mushroom growth of on-site water storages becomes another necessity. Obviously, there will be a lot of work needed to make these options feasible and acceptable.

Of course, next challenge concerns with scenario when we all switch to pressurised systems to avoid excessive application of water using surface irrigation. In this case, what kind of remodelling will be needed for existing water supply systems as well as the new ones to fit efficient but slow-consumers of water at a farm or field level? Our researchers and planners must start thinking to devise adjustments to handle the upstream effects of pressurised irrigation systems. If proper plans are not thought through and implemented, canals will silt up fast.

Similarly; researchers, managers and planners have to come up with legal and physical flexibilities of making use of saved water by opting pressurized systems. Will the head-end farmers be able to sell their saved water to fellow farmers along the water supply system? This implies to structural adjustments of water supply systems and nature of water rights in future.

Another challenge relates to the proposed strategy versus an alternative one. In the latter context, pressurised systems have been encouraged in areas that are beyond the existing canal commands or generally termed as new areas. The approach seems more practical when compared with issues that are associated with canals and / tube-well commands as described above. Our planners and policy-makers should consider following the strategy by declaring deserts of Thal, Cholistan, Thar and others similar areas for pressurised irrigation systems only. This should encourage growing high-valued crops and orchard plants where surface irrigation will cause water-logging in these zones within no time. In the meantime, required conditions can be created to suit the adaptation of pressurised systems in canal and / tube-well irrigated areas.

In order to make the pressurised systems financially feasible, there is need to make marketing of agricultural products more producer-tilted instead of being heavily in favour of middle-men. How can farmers invest in this new technology when profitability in agriculture is restricted because of this odd marketing environment?

Once profitability is ensured, our policy-makers have to review the water rates like Abiana and free-access to groundwater as incentives to switch to efficient water application systems in agriculture. If seasonal irrigation charge per acre of a crop in canal commands is less than the rate being charged per hour of a tube-well in Punjab or free-access to groundwater with hardly paid power charges say in Balochistan, it would be very difficult to convince many to this paradigm shift in agriculture.

Asking farmers to leave practices passed on from one generation to other is tough challenge to be faced. As the farmers are only familiar with the old ways to apply irrigation, it is asking too much to happen unless we create conducive environment for the change as stated above and taking other most urgent steps that include:

• capacity building of farmers on regular basis;

• provision of technical support systems;

• availability of spare parts;

• regular maintenance; and

• un-interrupted power supply at farm / field levels.