As organic agriculture is not practiced or studied by many people, knowledge on technical details is often scarce. Although it has been shown that organic agriculture is interesting in connection with the levels of returns to inputs and pollution, lack of formal research means that there are many questions remaining about why and how the system works. Lack of more information on organic agriculture in general, and on specific technical details in particular, is generally mentioned as the first obstacle to shifting to organic agriculture. Centers such as the Kenyan Institute of Organic Agriculture (located in Nairobi) and Gami Seva Sevana in Sri Lanka are established with the purpose of filling this gap. Sharing and enhancing traditional knowledge in developing countries is very important in organic agriculture.
For the developed world, insights in the topics of bio-physical and socio-economic characteristics of organic agriculture have been the focus of many studies, especially in the last decade. In contrast, relatively few studies of organic agriculture in developing countries have been undertaken. Many articles on this subject relate to practical experience, but have emited few scientific data. Perhaps the most extensive study, which greatly contributed to the development of this paper, is by the United Nations Development Programme (UNDP), which commissioned a 1992 study on organic agriculture in developing countries, to "...determine if organic agriculture systems can be an attractive alternative for current non-sustainable practices".4
Researching basic questions related to organic agriculture could, apart from increasing progress in organic agriculture, yield a high pay-back in terms of returns to applying the principles in areas of conventional farming. At the same time, progress in organic agriculture is, by its very nature of making use of local resources, dependent on knowledge of optimum local conditions. For example, a certain crop rotation in one place might prove excellent in keeping a particular weed within manageable limits, while in a different place (with a different climate) the threat of a potential insect pest requires a different rotation. In particular, soil fertilization varies between agro-ecosystems and even within production systems and parcels. There are, therefore, no ready-made solutions and extensive experimentation work and creativity are required.
Specific solutions are required, adapted to environmental conditions, level of organization and participation of farmers, and existence of qualified technical support. More often than not, related scientific information will be lacking in extension and research services. Besides the need to re-orient research agenda and train extension and development workers in organic agriculture, farmers play a crucial role in advancing research. In particular, the mobilization of traditional knowledge and dissemination of innovations introduced or known by farmers are an essential starting point for more responsive agricultural research. Technicians can greatly assist farmers in developing adapted technologies in a better position to respond to sustainability goals. Results of collective farmers' research can be documented in several countries of Latin America, Africa and Asia. Farmers knowledge of their agro-ecosystem, analytic capacities and willingness to experiment and innovate offer immense opportunities for research and hence, an improved information base.
Because of the public good properties of many inputs used in organic agriculture, unless a specific attempt is made by public policy bodies, a comparative lack of knowledge in organic agriculture will remain. Therefore, a first step in increasing the availability of knowledge on organic agriculture is to acknowledge that this form of agriculture could be an interesting option for agriculture both in developed and developing countries and that it has a role in improving food security and environmental sustainability, especially in poorly endowed environments. Extensive communication with those who have expertise in the area of organic agriculture is advisable. More active support could be given in the area of implementing projects for the collection of relevant data.
4 . The geographical distribution of the case studies indicates a wide distribution. In total, projects in 21 countries were included (i.e., Asia and Pacific: 4; Near East: 3; Sub-Saharan Africa: 6; Latin America: 8). Of the total, 6 projects were situated in marginal degraded areas, 12 were related to export-oriented organic agriculture, and 3 were oriented equally towards cash and food crops. This distribution was due mainly to the nature of the study (which was to be short), so that those projects were chosen for which data were reasonably easily accessible at the time. Most of the studies only considered aspects of one (main) crop, and many of the projects were still in the conversion stage (where yields can often be lower, and investments higher, than when the farm is an established organic farm). One of the cases described by UNDP was elaborated further in Werf (1993), where he studied 7 pairs of farms on a number of agronomic aspects in which the two systems differed, and then calculated the financial differences between the two systems, based on market prices (no premiums for organic products).