Effect of microdose chemical fertilization method on soil chemical properties and productivity of maize (Zea mays L.) in West-Central Senegal

This study was conducted in West-Central Senegal (Thies region) during two cropping seasons (2018 and 2019) to evaluate the effect of different doses of chemical fertilizer on soil chemical properties and the productivity of maize. Four treatments consisted of T0 (absolute control), RD (Recommended dose= 200 kg ha-1 NPK and 150 kg ha-1 urea), M1 (microdose 1= 41.66 kg ha-1 NPK and 41.66 kg ha-1 urea i.e. 0.5 g hill-1 NPK and 0.5 g urea), M2 (microdose 2= 83.33 kg ha-1 NPK and 41.66 kg ha-1 urea i.e. 1g hill-1 NPK and 0.5 g urea) and four maize varieties Gwana and Soror (composite varieties), Pan12 and Pan53 (hybrid varieties) were arranged in a split plot design with four replications. On average height of ear insertion was significantly increased with fertilizer microdosing. In 2018, microdose M1 achieved 89% and 26% of the grain yields recorded from T0 and RD, respectively. In line with grain yields, the amounts of soil elements exported in 2018 were higher in microdose in comparaison with RD and T0. A progressive decrease in soil pH and potassium is observed. Soil nitrogen decreased in 2018 but it increased in 2019, while an opposite trend was observed for soil phosphorus. The microdose technique was economically profitable with value-to-cost ratio of 9 and 4.47 for M1 and M2, respectively. It is concluded that the positive effect of fertilizer micro-dosing in improving maiz production depend on year, and on the better exploitation of soil nutrients.