Consequences of Organic-Mineral N Soil Fertility Amendments on Nitrogen Uptake and Maize Grain Yield in the Smallholder Farms of Meru South District, Kenya
Date
2012-11-06Author
Mutegi, Edwin Mwiti
Kung’u, James Biu
Muna, Mucheru
Mugendi, Daniel
Metadata
Show full item recordAbstract
The central highlands of Kenya is generally densely populated and declining land productivity with
reduced crop yields has been a major problem facing the smallholder farmers in the region. Land sizes
are small and this promotes continuous cropping with limited scope for crop rotation and inadequate
soil fertility replenishment. Efficient use of soil N amendments in maize (Zea mays L.) production is
necessary to maximize producer’s economic returns and maintain soil and water quality. An experiment
was carried out on the humic nitisols in Mucwa location, Meru South District, with the objective of
determining maize grain yields and N uptake under different soil N amendments. The experiment was
set in randomized complete block design (RCBD) with three replicates. The results reveal that maize
grain yields in the organics and/or mineral N soil amendments was higher than the yields obtained
where the recommended mineral fertilizers were used alone. The nitrogen (N) concentration in different
parts of the maize crop varied, with the grain having the highest, followed by the stover during the 2005
short rain season. Sole application of calliandra recorded the highest N uptake (170.8 kg N ha-1) while
the control gave the lowest (49.31 kg N ha-1). It is therefore concluded that differences in nutrient
release by the organic-mineral N soil amendments can alter net rate of nutrient uptake during crop
growth and therefore assist in synchronization of nutrient release and uptake by the growing crop.