Use Of Adsorption Isotherm Models To Determine Potassium Fertilizer Acreage Doses For Optimum Maize Growth And Yields In Nyamira County, Kenya

Abstract

The present work determined nutrients levels in farm soils of the intensive agriculturalregion of Nyamira County, Kenya and used Freundlich isotherm model to formulate potassium acreagedoses necessary for optimum maize growth and yields. Data obtained from equilibria concentrations ofpotassium in various soil solutions were fitted into Langmuir, Freundlich, Temkin and Van Hauy equations.The Freundlich isotherm model gave the best fit and was used to calculate acreage doses. Maize wasgrown under same doses of nitrogenous and phosphorus fertilizer and tendifferent doses of potassium inplots of 6m by 5m at two farm sites. The study found that maize growth parameters of plant height andstem girth and its yield parameters of ear weight, ear length, ear girth and grain yields increased steadilyas potassium doses were increased and reached their optimum values at potassium doses of 155.84 and144.76kgha -1 giving yields of 3315.27kgha -1 and 3340.50kgha -1 for farm sites 1 and 2 respectively.Externalpotassium concentration of 7.9mgL -1 associated with 95% relative yield was required for optimal maizeyield. The study also established that potassium doses significantly affected concentrations ofphosphorus and nitrogen in the tissues.