A LARGE-SCALE investigation into the plight of farmers and problems in the countryside is to be held by the Chinese Ministry of Agriculture. About 550 officials will form 49 groups to spend 21/2 months looking into the problems in villages. The newly-elected Minister of Agriculture, Mr Liu Jiang, warned in a New China News Agency report that China's reform and modernisation drive ''will be hindered if the rural problems are not solved properly''. He said groups would go to villages and farms in 26 provinces and regions from Thursday to gather information about problems in rural China and the prospects for this year's grain and cotton production. The groups will also check on the implementation of the central government's policies, issued during the past few months, on reducing farmers' financial burdens and measures to boost production. Alarmed by farmers' grievances, Chinese leaders have vowed to take prompt and effective measures to boost agricultural development. The Executive Vice-Prime Minister, Mr Zhu Rongji, has been given the task of overseeing agriculture at the State Council. He is expected to be assisted by Mr Chen Junsheng, one of the eight state councillors. According to a Chinese newspaper report, agriculture expert Mr Du Runsheng argued that the major problem was the low income of farmers. The income gap between farming and the other sectors has been widened again since 1989, he said. Mr Du, 80, a former director of the Rural Development Research Centre of the State Council, was quoted as saying recently that the way to reform agriculture was to lift all price controls on farm produce. The marketisation of grain prices will not only reduce over-consumption but facilitate the free circulation of commodities, he said. Mr Du proposed that the period of utilisation of land for farmers should be extended to at least 50 years.