Precision farming yields many gains

The Chinese government's No 1 central document released in February attached great importance to high-tech agriculture, and it is a hot topic during this year's annual sessions of the National People's Congress and the Chinese People's Political Consultative Conference.

Everyone thinks high-tech farming means biotechnology, but it actually goes far beyond that. Biotech seeds are now being upstaged in the United States by a variety of "precision farming" technologies, such as drip irrigation and GPS guidance systems, that offer savings in the use of water and chemical inputs.

On big farms in the US four out of five tractors are now equipped with GPS systems that "auto-steer" the equipment in perfectly straight lines. With differential correction signals, these systems can tell a machine exactly where it is in a field, down to 1 square meter. This in turn allows on-board computers to access GIS mapping data and instruct the machine to apply fertilizer or lime at differential rates, location by location. This eliminates both under-application that can hold down yields and over-application that wastes money and pollutes the environment.