It is currently raining in different parts of the country and many people are busy on their farms.
David Kitubi, a soya bean farmer, says people planted way back in August through dry planting as a means of adapting to changing weather patterns.
By planting early, farmers are taking advantage of the first rain to help the crops grow up before onset of the next dry spell.
Kitubi adds that while such techniques are useful to seasonal crops like beans, perennial crops like banana, coffee need a different approach.
Farmers, therefore, have to think for better alternatives of water harvesting and conservation that can sustain their plants with enough water in a given period of time.
Kizza Charles, a roofer, says farmers can store water during the rainy season and use it productively during the dry spell in their gardens with ease and store it during the rainy season for later use in dry season.
“The main principle of water harvesting is to work with nature to harness the available water resources.
However, for a farmer to benefit from water harvesting, one must consider understanding the rain cycle, availability of water resources, storage options and harvesting equipment.
Water harvesting techniques
These are defined basing on the distance between the catchment area and the actual location where the water will be utilised from.
Kitubi says water conservation techniques like digging contours, ridges, deep tilling, mulching and adequate use of farm manure do improve the soils’ water retention capacity.
Such techniques include;
Pitting: These are small semi-circular pits dug to break the crusted soil surface. Farm yard manure is added into these pits to allow concertation of water and sol nutrients. incase of planting, the seeds are planted in the middle of the pits.
Contour bunds: Small trash, stone embankments, are constructed along contour lines. The embankment is used to trap the water flow which allows deep infiltration into the soil.
The amount of water stored in the soil entirely depends on the height of the bund and it is, therefore, recommended that counter bunds are used in gardens or places where the ground slope is not more than 5% of the soil depth that is one metre.
Mariam Nabiggo, a farmer at Kasangati in Wakiso district, adds that the most popular water harvesting techniques are the external or macro catchment systems.
These involve collecting water from runoff areas like rooftops which are located a distance away from where the water will be utilised from.
The catchment areas usually have slopes running ranging from 5-50% and the harvested water be used to cropped areas which are either flat or terraced.
However, when the catchment area is large and far from the dropped area, the runoff water is transported through the surrounding structures of diversion and distribution of networks.
Systems of water harvest
Hillside sheet runoff utilisation
Water usually runs off mostly in hill-top areas and collects naturally on low flat lying areas. Such run-offs can be diverted along into areas where the bunds have been constructed like a garden and allowed to form earth basins which do assist in holding water thus increasing the filtration levels into the soil.
The bunds play a vital role if the farming area is not at the bottom of the landscape.
Nabiggo advises that the water may also be directed through long deep canals that are made diagonally across the slope and placed with flat stones down both sides to ease water passage.
“The farmer can place more flat stones on top as well and cover them with soil, forming canals which deliver the water into the collection pits,” he advises.
The water storage pits can also be lined with sheets of polyethene bags to increase its retention.
Harvesting flood water
This particular method uses barriers like watertight stone dams to block the water flow and spread it to the adjacent plains available and enhances infiltration, thus using the watered area for crop production.
Stream diversion
Water from a stream can be diverted and directed into an arable piece of land for crop production while limiting water levels to prevent flooding.
This usually helps to create irrigation canals within the system as the water is constantly managed to prevent over flooding of such a place in a given area.
