Certain tracts in the country are better suited for growing particular types of rice and the pilot project aims to capitalise on this information to help lower farmers' costs and lift revenues.

The Agriculture Ministry has chosen four areas for a rice zoning pilot project that aims to improve yields and planting efficiency.

The areas cover Buri Ram, Chiang Rai and Suphan Buri provinces and the vast Thung Kula Rong Hai plain, the locations of the best fields for producing premium-grade rice including Hom Mali fragrant jasmine rice.

It is expected the ministry will spend several billion baht through its departments of Irrigation, Agricultural Economics and others to support the scheme. They will work co-operatively to carry out the zoning plans, different from the past where each would handle zoning separately, resulting in slow progress.

``The zoning system would tell farmers where the proper areas are to grow rice with higher profits,'' said Chakun Saengruksawong, director-general of the Agriculture Department.

The areas have proved to be ideal for cultivating premium-grade rice _ Buri Ram and Thung Kula Rong Hai for Hom Mali rice, Suphan Buri for white rice in the rainy season, and Chiang Rai for glutinous rice.

``As well, we can learn which fields could be developed as commercial areas,'' he said, adding that although Thailand grew 23 million tonnes of paddy a year on about 63 million rai of plantations nationwide, there was no classification of commercial areas for rice.

Mr Chakun said that the zoning system would help the authorities to monitor output development more effectively and improve farm earnings by about 400-500 baht per rai.

Normally, farmers receive about six to eight baht a kilogramme for fragrant rice. Given current low yields averaging 300 kg per rai, farmers earn about 1,800 baht per rai, Mr Chakun said.

``The zoning would aim at improving productivity to 450 kilogrammes a rai, eventually it will raise their incomes,'' he added.

Mr Chakun said under the plan, the selected areas would be surveyed and classified as plantations for growing rice for different yields, depending on irrigation and soil fertility.

They would be classified as plantations growing less than 350 kg of paddy per rai per year, between 351 and 450 kg per rai per year, between 451 and 550 kg per rai per year, and above 551 kg per rai per year.

Mr Chakun said some rice fields could produce an average of only 303-320 kg of rice because of insufficient rain and inadequate irrigation systems but it could give higher yields if the government increased investment in technology and irrigation systems.

Zoning for Hom Mali rice plantations will be announced to enable authorities to help farmers increase product and maintain quality of the country's prestige rice, following standards set by the Commerce Ministry.

He said the Thung Kula Rong Hai plain was one of the best areas for cultivation of Hom Mali rice.

The government has invested heavily in the area since 1981 to turn the two-million-rai Thung Kula Rong Hai, one of the country's driest areas spanning Roi Et, Maha Sarakham, Surin, Si Sa Ket and Yasothon provinces, into productive rice fields.

But it was reported that only 700,000 rai had met state productivity targets due to severe soil salinity and insufficient irrigation.

The inclusion of Thung Kula Rong Hai in the zoning scheme is in line with the plan of the Agriculture Ministry to inject 3.9 billion baht to increase production of Hom Mali fragrant rice in the plains from 2004-06.

The project is aimed at doubling the area's rice yield from the current 250 kg/rai.

Rice productivity in Thung Kula Rong Hai varies depending mainly on the amount of rainfall as well as the efficiency of fertiliser applications.

The rice zoning scheme is being supported by exporters.

Vichai Sriprasert, president of the Rice Exporters Association, said it was better for the government to improve yields and reduce production costs of farmers by applying technology rather than putting a large budget into rice price-support schemes.

The investment in irrigation systems is crucial, and is as important as the investment in the electricity grid, especially in the Northeast, he said.

The ministry also plans to implement a zoning system for rubber, palm oil, soybeans, pineapples, durians, longans, coffee, sugarcane and tapioca.