HARNESSING AND HARVESTING RAINWATER

Rain-fed areas measure about 22 percent of the total cultivated land in Pakistan

M.R. CHAUDHRY
Apr 16 - 22, 2007

The country received substantial amount of rainfalls during the months of January and February. Rainfalls are a great blessing of Allah Almighty, especially for the Barani (rain-fed) areas. It may be relevant to point out that out of the total area of NWFP i.e. 10 million hectares, 18 percent, which is equal to 1.8 million hectares, is cultivable and 60 percent thereof about one million hectares consists of rain-fed areas. Cultivation in the rain-fed areas depends mainly on rains. This is a vast tract of land, which should not be allowed to remain uncultivated.

In the Holy Qura'an Allah Almighty has ordained that life depends on water. Scientists are of the opinion that on whichever planet water is available, there is life.

Agriculture, rearing cattle, goats and sheep are the mainstay of people living in the rain-fed areas. Therefore, they pray for rainfalls but in most of the areas rainfalls are scant and scarce, which cast unfavourable effect on agriculture.

In rain-fed areas cereal crops like wheat, gram, rice and pulses are usually grown. Their yield per acre is very low. However, when rainfalls are adequate and in time, production is high. Every drop of water in these areas is dear to farmers and insufficient rainfall and moisture badly affects production.

The rain-fed areas of Pakistan measure about 22 percent of the total cultivated land in the country i.e. 22.1 Mha. Province-wise percentage is as under:

Balochistan

54.2 percent

N.W.F.P.

13.3 percent

Sindh

14.4 percent

Punjab

18.1 percent

As per estimates about 9 Mha is cultivable, which can be brought under cultivation if irrigation water and other resources could be made available. Classification of this area in accordance with the precipitation is given below:

CLASSIFICATION

ANNUAL PRECIPITATION

AREAS (INCHES)

Arid

Less than 10

Kohistan, Kachi, D.I. Khan, D.G. Khan, Cholistan, Nara

Semi Arid

10 20

Sahiwal, Faisalabad, Sheikhupura, Lahore, Bannu, Peshawar

Sub Humid

20-30

Sialkot, Gujrat, Potowar areas Humid More than 30

Humid

More than 30

Himalaya, Kashmir Valley, Chatral, Swat, Zob Loralai, Kohat, Waziristan.

In Punjab Barani zone, small farmers with less than five acres of land are in majority and their farm income is below the subsistence level. Development of water resources is, therefore, imperative for the Barani areas. So far 35 small dams with a total capacity of 105.32 million cubic meters have been constructed in the public sector. In addition, 416 mini dams and 739 water storage ponds have been constructed in collaboration with national and international development agencies. These water storage reservoirs have been found quite effective to re-charge the aquifers, facilitating utilization of ground water by constructing dug-wells and fractional tube-wells/turbines in the area.

Rain-water is a precious irrigation resource, particularly in the Barani areas.

The average annual rainfall is 180 million acres feet but its 50 percent is lost due to runoff, which is an overwhelming loss. Only 25 percent conservation of water is made while by using modern water harvesting technologies 90 percent of rain water is collected and conserved. Many countries using these technologies are getting almost similar yields in rain-fed areas as in irrigated areas.

If we could store this water and moisture, production can be equivalent to that in canal irrigated lands. The problem of shortage of water and moisture can be solved by observing the following simple, easy and economic measures:

DEEP PLOUGHING

It has been observed very often that a plenty of water run-off from the soil is lost for want of utilization and conservation. Therefore, it does not benefit the fields and crops. In order to save this wastage, deep ploughing should be carried out just after the first rainfall so that in between the first and the second rainfalls, the soil is in a position to absorb maximum amount of water and retain adequate moisture. For that purpose Mould Bold Plough fitted with tractor is most suitable. Deep ploughing makes the soil very soft and permeable 10-12 deep from the surface. Sufficient water gets absorbed and crops do not suffer from shortage of water and moisture. Cultivation becomes easy and successful. Deep ploughing also eradicates unnecessary weeds and herbs, which consume irrigation water, soil nutrients, fertilizers and affect the normal growth and yield of crops.

SOWING

Sowing should be done before sun-rise so that moisture of the soil is not wasted and sowing of seed is not affected.

LEVELLING OF THE FIELD

Levelling the land beautifies the fields. It has many benefits like:

- The field is ready for cultivation within the minimum possible time.
- Moisture of the soil is equal and simultaneous in all parts of the soil.
- Even a single drop of rain is not wasted.
- Weeding out, hoeing, spading and harvesting are easy to be carried out.
- Sowing of seed and growth and ripening of crops are harmonious.
- Every granule of fertilizer, which is an expensive input for the farmers has a favourable effect on plants and the crop.

Otherwise if fields are uneven, moisture level becomes irregular and uneven. Some places at higher level would have less moisture and soil at lower level would bear more moisture. Resultantly the entire field would not have equal and even moisture, and sowing and growth of the crop would not be smooth and equal.

BREAKING BIG CLODS IN THE FIELD

In case there are big clods of earth after ploughing, they should be broken into small pieces so that the soil could absorb rain-water easily. After breaking the clods, the land should be leveled by field land-leveler (Sohaga) to make the soil soft and permeable.

SLOPING LAND SHOULD HAVE A TERRACE

In sloping ground, stair-type terraces building helps a lot in capturing water for irrigation and preventing rainwater run-off. During the rainy season, seasonal streams and water drains take away the soil. For conserving the soil and saving it from erosion and land sliding, growing trees, plants and grass on the banks is useful. By constructing spurs and buds, soil becomes safe and is conserved from being damaged by the onslaughts of the streams. The fields should be ploughed in the opposite direction of the slope so that sufficient rainwater could be conserved in the field to facilitate maintaining the moisture.

CULTIVATION OF LEGUMINOUS CROPS

Growing junter, guar gum, ground nut and other leguminous crops add to the much needed organic matter in the soil. They also help nitrogen fixing in the soil, makes the soil porous, permeable and facilitates retention of water to safeguard the crops from drought and shortage of irrigation water.

SOIL CONSERVATION IN BARANI LAND

Conservation of soil in Barani lands is also a great problem. Conserving rain-water for irrigation is one problem but conserving the land to be eroded or soil run-off with the water is another. Farmers plough the soil to loosen the top soil to capture moisture. If the field does not have proper bunds on all sides of the field, then this loose soil is easily washed away along-with the rainwater during the monsoon or during irrigation and settle down elsewhere, which is an immense loss to farmers. Therefore, compact bunds should be constructed around the fields to safeguard the soil along with rainwater/irrigation water.

IMPROVED AND CERTIFIED SEEDS

After capturing water and retaining moisture in the Barani areas, ploughing and leveling the land, farmers should sow only certified, improved, pure and healthy seed as recommended by the Agriculture Department for Barani lands so as to get appropriate return of their labour and investment. Exercising this precaution would bring 10 to 20 percent increase in production.

USE OF FERTILIZERS

Farmers should provide suitable quantities of appropriate fertilizers and chemicals to their fields and crops to ensure necessary fertility to the land and crops, to increase the immunity of crops against pests, disease and drought, as recommended by the Agriculture Deptt Soil tests should be carried out periodically to determine which soil ingredients are deficient and then make up deficiency in consultation with Agriculture Extension Services Department.

FRUIT GARDENING AND ORCHARDS

Fruit trees should be grown in Barani lands, which require lesser water. These include almonds, apples, grapes, apricot, etc. Adequate water is available during the first year. These trees and plants maintain their growth thereafter even if there are fewer rainfalls after the first year. Potowar area has specifically been declared most suitable for growing almond plants.

AGRICULTURAL MACHINERY

In using agricultural machinery deep ploughing must be carried out. After 2/3 years, chisel ploughing should be arranged, which breaks the soil crust, which develops due to the normal ploughing. This improves the soil for better cultivation.

PRECAUTION

No cattle should be allowed to tread in the soil after ploughing the field as it hardens the surface, which affects the growth of crops grown therein. .

LAND AND ITS USE

Land should be used in accordance with its type, structure and ecological value. Rainwater should be conserved in tanks and ponds as near the field as possible to be subsequently used for irrigation. Fertility of land should be given due consideration. It can be supplemented by using fertilizers as recommended by the Agriculture Department. The better way is to use the organic matter in the form of green manure or cattle dung or both.

ORGANIC FERTILIZATION

If cattle dung or green manure is used in sufficient quantity in the fields, it is of great advantage for maintaining fertility of the soil. This organic manure enables the soil to retain moisture in sufficient quantity for sufficient time, which can be usefully used while cultivating the crops and during droughts. Its immediate advantage is that farmers get maximum yield and productivity of the field is maintained even for the next 2/3 years. Undesirable weeds and herbs grow scantly and possibility of attack by pests and insects is scarce. Mulching also helps preventing water from running into the ground. After ploughing the land, land levelers should be used to save the moisture. The solution lies in catching rain water and conserving the soil and fertility.