Evaluating the effect of plant population densities and nitrogen application on the leaf area index of maize in a reclaimed wetland in Kenya

Abstract

Abstract Maize is the main staple food in Kenya with over 90% of Kenyans relying on it. While the annual national consumption is increasing, the production of this crop has been on the decline in the last two decades. Maize production in Kenya fell by 33.4% in 2013 with Nyeri among the counties said to be grappling with the production of this crop. Land pressure is one of the major causes of decreased availability of food as well as soil depletion and encroachment upon fragile ecosystems such as wetlands. Nitrogen is a key nutrient in the production of maize, and its deficiency is a major factor limiting its production. This study investigated the effect of N application at 120 kg N/ha and maize density on the Leaf Area Index in reclaimed wetland soils in an experimental set-up comprising a randomized complete block design with three replications. The research was carried out in Nyeri County, Kenya. Leaf Area Index (LAI) was determined using the given SunScan formula. Measurements were done continuously until crop physiological maturity. Results indicated that the leaf area index increased with nitrogen application and reduced with spacing for most treatments. There were no significant differences between the two methods (Copy Method and SunScan). Leaf Area Index (LAI) was high in treatments containing nitrogen and high plant density. It was concluded that high plant density gives high LAI. 50 cm * 12.5 cm (-N) and 50 cm * 12.5 cm (+N) are the recommended plant densities for the site.