Soil Properties and Nutrient Uptake of Coffee Seedlings as Influenced by NPK Fertilizer Formulations in Ibadan, Southwest, Nigeria

A greenhouse study was carried out at Cocoa Research Institute of Nigeria, Ibadan (Lat.7° 251N Long. 3° 251E) in 2010 to determine the effect of NPK fertilizer formulations on soil properties and nutrient uptake of coffee seedlings in Ibadan, Southwest Nigeria. The treatments consisted of NPK-liquid fertilizer (20: 2: 4 + TE-trace elements) applied at rates 0.33 and 0.66 mls/litre of water and NPK- solid fertilizer (15:15:15) applied at 1, 3 and 5 g/coffee seedling) and a control (no fertilizer application). The six treatments were arranged in a completely randomized design with three replications and data on coffee nutrient uptake and soil properties at six months after transplanting were determined. Results revealed that all the fertilizers irrespective of rates of application and types of NPK formulations enhanced the nutrient uptake of coffee seedlings relative to control. Leaf N-uptake was significantly (P=0.05) enhanced due to application of NPK liquid fertilizer applied at 0.33 mls/l of water compared to the control and NPK liquid fertilizer applied at 0.66 mls/l of water. Similarly, the leaf-P uptake was improved significantly (P=0.05) as a result of application of NPK solid applied at 5 g/coffee seedling compared to the control and other treatments. The leaf K-uptake also followed a similarly trend in which solid NPK fertilizer at 5 g/plant consistently promoted (P=0.05) the K-uptake of coffee seedlings compared to liquid NPK applied at 0.66 mls/litre of water. The pH of the soil was significantly (P=0.05) affected as a result of application of liquid NPK fertilizer at 0.33 mls and 0.66 mls/l of water compared to NPK solid fertilizer. The organic carbon was not significantly (P=0.05) influenced as a result of NPK fertilizer formulations. The organic carbon decreased in the order of 1g NPK solid< 3g NPK solid<control< 0.33 mls NPK liquid< 0.66 mls NPK liquid. The total N in the soil was not significantly affected as a result of NPK fertilizer types applied. However, the available P in the soil was significantly (P=0.05) increased as a result of NPK-solid applied at 3 and 5 g/plant compared to the control, at 0.33 and 0.66 mls/l of water. The improved growth and nutrient uptake of coffee seedlings through the use of NPK fertilizer formulations particularly liquid NPK provides alternative fertilizer options to farmers as a means of promoting crop growth.