PCRWR Research and Demonstration Farm for Rainfed Areas is located at Darkali Kalan, district Rawalpindi at 73.03O E and 33.30O N, 60 km away from Islamabad. It encompasses an area of 175 kanals typically representing the Potohar topography and livelihood. Here, integrated water management research is conducted to improve farm productivity under rainfed conditions. The R&D works trialed there are based upon the philosophy, "keep it simple and stupid". The interventions carried out at the farm are therefore simple and socially-acceptable and are yielding substantial economic returns. Salient management practices at the farm are: micro-catchments for orchard plants, solar-powered drip system for supplemental irrigation of orchards, solar-powered farmhouse electrification system, rooftop rainwater harvesting and drip bucket irrigation systems for kitchen gardening, slope transverse ploughings for erosion control and runoff entrapments, rainwater harvesting ponds etc.
Micro-catchment is a specially designed area with slope and dikes to increase runoff and concentrate it in planting basins. Maximum amount of runoff gathers near the root zone, infiltrate and stored in soil profile. Micro-catchments may enhance the water availability to the plant 3-4 times of the amount of annual rainfall. A number of fruit trees can be exclusively grown on rainfall, or it significantly reduces the supplemental irrigation requirement. Micro-catchments were developed around citrus, grapes, cactus, plum and other fruit trees at the farm to cut their irrigation requirements.
Solar-powered trickle system for supplemental irrigation
Trickle irrigation is a viable technology for the region, if designed and installed properly. Nevertheless, availability of power source in remote areas is a major hindrance for adoption of trickle system. Small solar-powered pumping unit can solve this problem. A 260 watt solar panel was connected to a 0.33HP submersible pump (DC, 5 GPM) at the farm. The pump was lowered in 40ft deep dugwell to pump water to 150 ft height. For this purpose, three overhead tanks (500 gallons each) have been placed at three different high locations. The system daily operates for 6 hours and is sufficient to fill 2 of the tanks, if required. These tanks are irrigating over 4 acres orchard through low pressure tickle system.
Rooftop rainwater harvesting
A technique in which rainwater is captured from the roof surface and stored in tanks for subsequent uses. Rainwater from the roofs is collected by connecting it's outlet to storage tanks (300-500 gallons) through pipe. A screen is attached to the outlet to prevent leaves and mud entry. The amount of harnessable water depends upon roof size, rainfall and the uses. The stored water can be used for domestic purposes and small scale gardening. The water harvested from office building is being used for the nursery. Besides, a number of plants are being irrigated from it.
Slope transverse ploughing
Pothwar's uneven topography leads to rapid drainage of water to the low-lying areas resulting in loss of water, soil and nutrients. Cultivation of crops with drill develops little furrows. Their orientation is kept transverse to natural flow direction. It reduces flow velocity, maximizes rainfall retention and thus reduced soil and nutrient losses. Yield of wheat and mung cultivated in this way was double than the neighboring farmers.
Plantation on Slopes
Soil erosion primarily originates from nude slopes. The slopes can be stabilized by plantation as roots act as binding agents for soil particles. Species having strong and intruding roots may be preferred for this. Cactus, beri (zizphus jujube), phalsa (Grewia asiatica), plum (Prunus salicina), etc. were planted on fragile slopes. It helped mitigate the primary soil erosion.
Stormwater management and harvesting
The waterways draining water collected from rills and gullies are the next category erosion source. Such waters may be katcha channelized and diverted to the adjacent depressions at regular intervals. This reduces erosion and the harvested pond water help recharge groundwater. The natural waterways of the entire farm were marked. Selected numbers of erosion-prone waterways were channelized. The intercepted water was diverted to the adjacent low-lying ponds, dug for storage. This helped in raising water table in the adjacent dugwell.