A couple of years ago, fresh from college and struggling to venture into science writing, I attended a seminar on crop biotechnology in Nairobi, Kenya. I vividly recall one guy from a multinational biotech company extol participants who included resource poor farmers, agricultural extension officers, the media, members of parliament and representatives of non-profit organizations, to consider integrating conservation tillage (CT) into Kenya's agricultural policies.

Conservation tillage, he explained, preserves soil nutrients and reduces soil erosion. As soon as he mentioned this, one participant shot up, seeking to know how weed control would be done. 'Use herbicides,' the guy snapped.

This ignited a highly explosive debate about the pros and cons of conservation tillage that almost derailed the seminar. In a country where farmers are religiously allegiant to traditional farming methods, conservation tillage proved hard to sell.

Some in the seminar even dismissed conservation tillage as a ruse to promote the economic interests of multinational biotech companies. I, too, couldn't resist dismissing proponents of CT as apologists for the biotech industry.

Much water has passed under the bridge since then. I have come to appreciate that CT holds the key to sustainable agriculture, especially in developing countries. I must confess that I am not alone in this.

Last week, for example, Rockefeller Foundationa non profit that works with resource poor farmers in poor countriesreleased a report revealing that 75 percent of farmland in sub-Saharan Africa 'is severely degraded and is being depleted of basic soil nutrients at an ominous rate.'

The report, Agricultural Production and Soil Nutrient Mining in Africa, warns that unless farmers in sub-Saharan Africa fail to change their farming methods, food insecurity would worsen.

This report is an endorsement of conservation tillage and African farmers are better advised to embrace CT.

Conservation tillage is, certainly, the preferred farming method. Some would hasten to argue that conservation tillage promotes herbicide use whose impact on the environment can prove disastrous.

With the emergence of herbicide tolerant genetically modified crops, farmers no longer need herbicides for weed control. And since the jury is already out on the safety of genetically modified cropsthey yield high and are environment-friendlyfarmers in Africa must embrace them. They bond perfectly well with conservation tillage.