The No. 1 Central Document once again highlights the importance of modernising agriculture. But many obstacles have to be overcome before agriculture can be truly modernised, according to Zheng Fengtian, professor at the School of Agriculture Economics and Rural Development at Renmin University of China.

Since the costs of many agricultural products are higher in China than in overseas markets, imports are preventing the optimum consumption of domestic products. Confounding this problem is the continuous rise in the costs of raw materials and labour.

Wasteful production methods are aggravating the problem of resource shortage, he said. Excessive use of pesticides and fertilizers is contaminating soil and water bodies, compromising the quality of arable land; and underground water tables are depleting fast because of unrestricted use of water.

Furthermore, with the continued migration of working age people from rural areas to cities, mostly elderly people have to do the strenuous farm work, which is harming agricultural production. And the imbalanced resource allocation has been increasing the cost of agricultural production. A large part of China's arable land is in the Yangtze and Pearl river delta regions with abundant water resources whereas the north and western regions are troubled with shortage of water. As the grain production base moves to the north, the transportation of the food to the south and the water to the north has become very costly.

These are major problems, and to tackle them, the authorities have to change the structure and production methods of agriculture, according to Professor Zheng.

To begin with, while evaluating agricultural products, the authorities should also take into account the environmental cost - as opposed to the current practice of deciding the price on the basis of input and output alone. Every fall, media outlets are full of news about bumper harvests. But the over-emphasis on output encourages higher outputs at the cost of the environment, and local agricultural departments go all out to achieve the production goals set by their governments.

For instance, the success of the pork industry in Jiaxing in Zhejiang province is measured mainly by the number of pigs without taking into account the water pollution it causes. This has to change, by, for example, shifting pig farms to sparsely populated areas and compelling them to follow high environmental standards.

Second, the way agricultural subsidies are provided has to change. There has been a substantial increase in agricultural subsidies over the past decade with a view to increasing production, which should not be the aim.

Subsidies for machinery, for example, should be given only to farmers who use machinery, since farming is still done mostly by households on a small scale in China. Hence, instead of giving every farming family a set of machines, the government could offer them prepaid vouchers to rent the machinery they need. This practice used by most of the developed countries is one China needs to adopt.

Another worrying development is that the use of fertilisers in China is increasing at a faster rate than that for grain output. The widespread use of antibiotics and fertilisers is endangering the environment and people's health. So, the authorities have to change the present agricultural development pattern and adopt one that conserves resources. The European Union uses a "seed coating technique" to limit the impact of pesticides and fertilizers on the soil and agricultural produce - to put it simply, a coating around the seeds prevents the spread of contamination to other areas.

The spray irrigation system, which aggravates the already serious water shortage, is another practice that China should abandon. It should adopt drip irrigation instead, because it uses only one-tenth of the water required for spray irrigation.

Moreover, sustainable technologies have to be developed to ensure sustainable growth. An article published in Nature magazine offers some useful advice. It says that though the output of organic farming is 50 to 80 per cent of fertiliser-and-pesticide-induced agriculture, it causes a lot less harm to water and soil.

If we consider factors such as output, investment, pollution and sustainability of the use of resources, organic farming is far more efficient and eco-friendly than the cultivation methods we follow.

In Denmark, for example, livestock farmers cannot use antibiotics. But they still breed and maintain healthy livestock and run profitable dairy and meat industries.

Incentives and support should be extended for technological innovation that will help realise sustainable agriculture in China, adds Professor Zheng.