Thousands of West African farmers have discovered the value of a three-finger pinch. The amount of fertilizer that you can pinch between three fingers is just enough to fertilize a single plant. A used bottle cap is another good measuring device for this new fertilizing technique, called micro-dosing.
As the price of chemical fertilizer continues to rise, many farmers are unable to afford large quantities of fertilizer. In drought-prone areas, farmers are often reluctant to invest in fertilizer because they don’t know if they will see a good return.
The International Crops Research Institute for the Semi-Arid Tropics, or ICRISAT, set out to determine the most efficient use of fertilizer, and thereby reduce the financial risk to farmers. Dr. Ramadjita Tabo is the regional coordinator of ICRISAT for west and central Africa. He explained that the organization could not recommend something that farmers would not be able to afford. So, he says, they had to find a way to get the right fertilizer in the right place at the right time, rather than simply blanketing fields with chemical fertilizer.
Initially, six grams of NPK (Nitrogen-Phosphorous-Potassium) fertilizer was tried in each seed hill. Then researchers realized that, since phosphorous is the major nutrient most lacking in Sahelian soils, just two grams of high-phosphorus fertilizer could do the trick. When this small dose is used, a 20 kilogram bag can cover an entire hectare.
While ICRISAT researchers determined the right amount of fertilizer, West African farmers discovered the best way to apply it. Two farmers work together to save time. The lead farmer digs a hole. The second farmer drops in seeds and a three-finger pinch of chemical fertilizer before covering it over.
Farmers in Burkina Faso, Mali, and Niger have tried the micro-dosing method on pearl millet and sorghum crops. On average, the micro-dosing method has led to yields 44 to 120 per cent higher than crops without fertilizer.
Micro-dosing techniques vary, depending on soil and climate conditions. For example, where soil is hard, farmers dig small holes before the rain starts, then fill them with manure. When the rains begin, they plant the seeds and apply a small amount of chemical fertilizer. This method not only provides nutrients, but also helps to ensure that the plant will receive sufficient water.
Field schools have been established in remote areas to teach farmers the micro-dosing method. Dr. Tabo says that farmers learn quickly, picking up the technique in less than a week. Farmers are encouraged to try fertilizer micro-dosing on a small part of their land at first, then, if they are pleased with the results, to expand the area next season.