Application of Response Surface Methodology (RSM) to Cucumber Yield under Different Tillage Methods

Response surface methodology (RSM) was used in the modeling of cucumber (Cucumissativus) yield under different Nitrogen, phosphorus, potassium (NPK) fertilizer application rates and tillage methods at the experimental farm of the Department of Agricultural and Bio-Resources Engineering, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria. From the field experiment conducted, three tillage methods; conventional tillage (CT), manual tillage (MT) and no tillage (NT), were varied with three levels of NPK application; 0.04kg/m2, 0.05kg/m2 and 0.06kg/m2. All the cucumber plants for no tillage wilted and didn’t survive to maturity, while the highest cucumber yield of 3.29kg/m2 was obtained at conventional tillage/0.06kg/m2 NPK application rate. In optimizing the yield using optimal design of response surface methodology, it was observed that increasing NPK application rate beyond the maximum 0.06kg/m2 increased cucumber yield for the area. The optimized values obtained in the area were: the best tillage method; conventional tillage, NPK application rate of 0.064kg/m2 and cucumber yield of 3.376. The study revealed that no tillage at the chosen NPK application rates is not adequate for the study area. It was also evident that conventional tillage with increased NPK is the best management practice for the area, but care must be taken not to add excess NPK that will not be favourable to the crops and the soil of the area.