Dry farming: untapped potential in dry zone for field crops

Dr. P. M. Wijeratne Director, Field Crops Research and Development Institute, Mahailluppallama

Since the early stage of dry zone civilization, Sri Lanka has been strenuously endeavouring towards the attainment of economic prosperity through agriculture. These civilizations were basically founded on agricultural systems integrated with irrigated rice culture and chena or slash and burn cultivation.

The most fundamental feature of the dry zone civilization was the Tank Village System where the centre of the dry zone village is a tank; houses are grouped on one or both sides of the tank comparatively at a higher elevation, and rice is cultivated in the valley floor under irrigation from the tank. Both upland rice on unirrigable lower slopes and the dry crops on the unirrigable upper slopes are grown under the system of chena cultivation.

The dry crops grown on the upper slopes includes, Kurakkan (Eleusina corocana), Thanahal (Setaria italica), Cumbu (Pennistetum tpyhodeum), Menari (Panicum miliaceum), Maize (Zea mays), Cowpea (Vigna unguiculata) Greengram (Vigna radiata) Sesami (Sesamum orientale), Undu (Vigna mungo), Mustard (Brassica juncea), and chilli (Capsicun annum). What our forefathers referred to as dry crops during the era of dry zone civilization are now identified as Other Field Crops (OFCs) which constitute an important component in the Food Crop Sector in Sri Lanka. The system of refined chena cultivation or the growing of crops on unirrigable lands is known as Dry Farming in the modern agriculture.

Potential of dry farming in the dry zone

Dry farming is the profitable production of crops without irrigation on lands that receive annually a rainfall less than 20 inches. Presently about 55 percent of the total land surface of the earth receives an annual precipitation of less than 20 inches. The dry farming, therefore, has been a major focus of agricultural research because of the facts that the reclamation of these lands remains a key issue for increasing the agricultural production in the world. The central idea of dry farming is the conservation of natural water precipitation for crop production. The system of dry farming must therefore be constructed, on the basis of old principles, but with the establishment of right methods of conserving and using natural precipitation for optimum plant growth.

Vast potential exist for dry farming in the dry zone of Sri Lanka. The dry zone is a fascinating region which occupies about 70 percent of the total land area. Most of the dry zone receives a mean annual rainfall of 60-75 inches. The large proportion of the rainfall falls during the period of North-East monsoon which corresponds to October to January (maha season). The South-West monsoon which passes over the dry zone during the months of May, June and July (yala season) without dropping appreciable rain brings about high evaporation losses of soil moisture. In the two inter-monsoon periods there may be rains which are variable and unreliable.

Thus, there is a huge area of scrub jungles without adequate water resources for cultivation. The total extent of this land remained at 1.3 million hectares at the time of gaining independence. However, in early 1980s nearly 0 .14 million hectares of this land was brought under cultivation under the Mahaweli scheme. In recent years, more than 17 irrigation projects have been commissioned, under the dynamic concept of Mahinda Chinthana, to provide irrigation facilities for about 0.1 million hectares of this land.

Irrespective of all these attempts there is yet another area of seven million hectares of cultivable land that has no access to irrigation facilities. Dry farming remains the only pragmatic solution for the productive use of this land area during yala season mainly because the rainfall in yala does not exceed more than 20 inches. Since the agricultural expansion in the wet zone is limited, reclamation of this land is of vital importance for attaining self-sufficiency in OFCs.

Dry farming research at Mahailluppallama

From the sixth century onwards there was a gradual deterioration of the agricultural systems in the dry zone due to foreign invasions, internal dissensions and outbreak of diseases. The total collapse of the dry zone civilization set in when Sinhalese abandoned the area in 1200 AD. Sir Frank Stockdale, the Director of Agriculture (1916-1928) was of the view that the excessive chena cultivation is the major cause of the decline in Anuradhapura civilization. Many of such civilizations founded on upland agriculture involving shifting cultivations have vanished.

The notable examples are the Maya civilization in South America, Khmere civilization in Cambodia, and the Pagan Dynasty in Central Burma. It was in this backdrop that Stockdale took initiative to transform the uneconomic chena cultivation into a more viable and productive agricultural enterprise.

As the first step towards achieving this objective, Stockdale took over in 1926, a privately owned agricultural experimental station located at Maha Illuppallama in the North Central province, and initiated a dry farming research programme under the sponsorship of the Department of Agriculture.

But until 1938 dry farming research was entirely a matter of experiments, and there were no attempt to set up colonies devoted entirely to permanent cultivation under dry farming. However, these experiments were put into practice with the establishment of a dry farming scheme at Kurundankulama, four miles East of Anuradhapura, to determine if a farm family could support an independent livelihood from the income generated from dry farming. A fair measure of success was claimed for the scheme with the annual income of Rs 1,150.00 from a single allotment of five-acre block. In-depth studies were undertaken by the researchers at Mahailluppallama on the technical problems encountered by the allotees: A number of issues received high priority in research. They are: the behaviour of water table, the recognition of different categories of land which demanded separate agronomic treatments, and the maintenance of soil fertility for sustainable crop production, and development of appropriate cropping patterns to suit the environment were some of them. These findings formed a scientific base for carrying out the successful agricultural colonizations in the dry zone.

In 1950, one of the most useful grants Sri Lanka received under the Colombo Plan has been from New Zealand to develop a full-fledged Dry Farming Research Station at Mahailluppalama. Presently the Field Crops Research and Development Institute (FCRDI) at Mahailluppallama (formerly the Dry Farming Research Station) has the mandate to carry out research and development activities on 14 OFCs which can be categorized into four groups as follows:

Condiments - Chilli, big onion, red onion.

Coarse Grains - Maize, finger millet.

Grain Legumes - Cowpea, green gram, soybean, black gram, kollu.

Oil Crops - Sesame, groundnut, sunflower, mustard.

Research conducted in 1950’s clearly identified various agro-ecological and soil factors that influence the productivity of OFCs. These findings helped to recognize the regional specificities of different environments and develop technologies to suit these environments. With the development of Mahaweli scheme the research agenda of the institute reflected bias towards irrigated agriculture because the development of new technologies to introduce OFCs into irrigated lands became a priority. Research has succeeded in developing more than 50 varieties with desirable traits which are widely grown in the dry zone.

Present status of OFCs and strategies

Presently about 119,000 hectares are cultivated annually under OFCs. Nevertheless, the annual production of these crops does not meet the domestic requirement. Therefore, about 42 percent of the annual requirement is imported to supplement the large shortfall of domestic production. Table-1 gives in details the cultivated extent, annual production, productivity and the importation of each crop.

Present government, under the concept of Mahinda Chinthana, seeks to implement a policy calculated to take the country forward towards self-sufficiency in all the food items. Thus, there is a sharp increase in the protection accorded to domestic agriculture. Therefore, the research and development strategies of FCRDI has been refocused to meet this challenge. Our annual per capita consumption of dry chilli is 2.23 kg and our annual requirement is about 42,000 mt.

The present productivity is 1.00 mt per hectare. However, with the presently available technologies the productivity of dry chilli can be increased up to 1.2 mt/ha. With the currently available technologies, we will need to cultivate annually about 20,000 ha to achieve self-sufficiency in dry chilli. The pathetic reflection is that during early 1980s the total annual extent under chilli was about 42,000 ha and this extent has now come down to 13,500 ha.

However, the productivity during that period was very low being about 0.8 mt/ha, and we used to import about 500 mt of dry chilli to meet the domestic requirement. Similarly the current annual production of finger millet is about 6,400 mt and the present productivity is about 1.1 mt/ha. The annual extent of cultivation of finger millet remains at 5,900 ha. We import annually about 3,200 mt of finger millet. FCRDI has released a high yielding variety of finger millet which could yield above 3.00 mt/ha under good management conditions.

If our farmers take little more efforts to practice proper management conditions, we will be able to achieve self-sufficiency with the existing cultivated extent of finger millet. Our annual requirement of onion is 250,000 mt and the annual cultivation extent is 10,000 ha.

We produce annually about 130,000 mt. The present productivity of big onion is 16.4 mt/ha which can be increased up to 20 mt/ha under good management conditions. In order to meet the domestic requirement we need about 6,500 ha of more land for cultivation.

Our annual extent under green gram is 8,570 ha, and the annual production is 9,250 mt. We import about 14,000 mt of green gram which accounts to 60 percent of our domestic requirement. In order to reach self-sufficiency in green gram we need to increase the cultivated extent by 6,000 ha. The scenario described above shows the importance of bringing more land under cultivation which is possible only with the reclamation of land area which has no access to irrigation facilities under dry farming.

FCRDI has already programmed out the agenda to make the country self-sufficient in OFCs. According to this agenda, by the year 2015, Sri Lanka will be self-sufficient in maize, red onion, finger millet, black gram, green gram, cowpea and soybean Importations of dry chilli, ground nut and red onion will be gradually phased out.

Development programmes of FCRDI will place more emphasis on the seed production programme of OFCs. It is assumed that by the year 2015 we will be able to produce locally all our seed requirements of onion, black gram, green gram, ground nut, sesame and soybean. Research agenda of FCRDI has been rearranged to address fundamental problems of dry farming. In the crop breeding programmes, more emphasis will be placed on the development of varieties suitable for moisture deficit environments.

Development technologies for the storage of a small annual rainfall; the retention in the soil of the moisture until it is needed by plants; the prevention of the direct evaporation of soil-moisturing during the growing season; the regulation of the amount of water drawn from soil by the plants. Let us hope that these efforts will go in the right direction to make a better Sri Lanka on sound agricultural economy.