Determining soil nutrient capacity to update fertilizer recommendations under soil and water conservation techniques in the zondoma watershed of Burkina Faso

Abstract

The use of the model Quantitative Evaluation of Fertility of Tropical Soils (QUEFTS) was combined with on-farm experiments to evaluate soil nutrient status under soil and water conservation (SWC) techniques such as stone barriers and Zaï to update fertilizer formulae used in sorghum production in the northern part of Burkina Faso. Results from nutrient omission trials (NOT) carried out in farmers' fields show clearly that phosphorus (P) and nitrogen (N) are the most limiting nutrients to sorghum production. SWC techniques affect soil nutrient status, nutrient exports and nutrient use efficiency. The average initial nitrogen fertility of these farms was 23.16 kg.ha-1 and 21.10 kg ha-1 under stone barriers and zaï respectively. Nitrogen exports reached an average of 28.05 kg ha-1 under stone barriers and 21.14 kg ha-1 under zaï. The average use efficiency for 1 kg of N was 40.11 kg of grain under stone barriers and 26.20 kg of grain under zaï. The results also show that the use of organic matter lowers the amount of mineral fertilizers needed for the same targeted yields. A basket of recommendations combined or not with organic matter was developed and evaluated for sorghum production. As a result, the formula (N29P11K13) was identified as the best option for sorghum grain production in this area under soil and water conservation (SWC) techniques.