Modern soil conservation, as we know it today, developed in the 1930s when concern with problems of soil erosion led to the creation of soil conservation services in the United States and, shortly after, in other countries. Since then a vast amount of money, time and effort has been expended on many different soil conservation projects and programmes.
It is not known how much has been spent on soil conservation but one estimate is that the United States Government alone has spent in excess of US$ 16 billion since the 1930s with present expenditure exceeding $ 1 billion a year.
Expenditure of this magnitude would be acceptable if the problem was being solved, but indications are that approximately 6 billion tons of top soil are still being lost annually in the United States, with off-site damage caused by erosion, estimated to be in the order of $ 3 billion a year.
In other parts of the world the picture is no better. Although extensive soil conservation work has been done in Australia over the last 40 years, the Australian Government recently claimed that the country was losing 90 million tons of soil annually and admitted the cost of land degradation to every Australian farmer to be around A$ 3600 a year. If soil erosion in the United States and Australia is bad, the situation over most of Africa is even worse. For example, terrible famines in Ethiopia in recent years are at least partly attributable to advance soil erosion. In fact, so bad has land degradation become in Africa that a new word - desertification - has been coined to describe the situation. This is in spite of many soil conservation programmes and projects which have been running in Africa for many years.
There have, of course, been some very good and effective conservation projects and programmes in a number of countries but, nevertheless, in spite of substantial efforts and the expenditure of large sums of money over the last half century, the results have frequently been disappointing.
With this problem in mind, this study was undertaken to try to identify the reasons for success and failure in soil conservation projects. Armed with the results of this study, it should now be possible to avoid repeating many of the mistakes of the past and developing new projects which have a far greater chance of success.
