Effects of soil properties on maize growth under increasing phosphorus fertilization in three contrasting acid soils in southern Cameroon

Abstract

Plant growth response to phosphorus (P) fertilizer in acid soils is affected by several soil properties. We conducted pot experiments with P using three contrasting acid soils from southern Cameroon (i) to study the main soil factors causing differences in growth responses of maize (Zea mays L.) to applied P, and (ii) to statistically model variation in soil qualities across soil types and their relationships to dry matter production. The soils studied were classified as Typic Kandiudox (TKO), Rhodic Kandiudult (RKU) and Typic Kandiudult (TKU). Shoot dry yield (DMY) was significantly affected by soil type (P = 0.000) and P rate (P = 0.000) but the interaction term was not significant. Predicted maximum attainable DMY was lowest in TKO (26.2 g pot–1) compared to 35.6 and 36.7 g pot–1 for RKU and TKU, respectively. Properties that enhanced DMY were the inorganic NaHCO3-P pool, individual basic cations (Ca, Mg and K) and pH, whereas exchangeable Al and C/N ratio significantly depressed DMY. Principal component analysis yielded similar results, identifying 4 orthogonal components which accounted for 84.68% of the total system variance (TSV). Principal component 1 identifying soil nutrient deficiency explained 35.9% of TSV. This soil quality varied significantly among the studied soils, emerging as the only soil quality which significantly (P<0.05) correlated with maize growth. The second component contrasted soil of different soil organic content while the third and fourth components identified to
soil texture and apatite-P pool respectively. These results show that acid soils could be used in maize production if they are amended with appropriate inorganic fertilizers.