Soil inorganic N and N uptake by Maize following application of legume biomass, tithonia,manure and mineral fertilizer in Central Kenya
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Date
2012
Authors
Mugwe, J.
Mugendi, D.N.
Muna, M. Mucheru
Kung’u, J.B.
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
In the smallholder farms of central Kenya
soils suffer from nitrogen (N) deficiency due to inability
to replenish it through application of chemical
fertilizers and/or manure. This study evaluated the
effect of some organic materials such as Mucuna
pruriens, Crotalaria ochroleuca, Calliandra calothyrsus,
Leucaena trichandra, cattle manure and Tithonia
diversifolia applied solely or combined with inorganic
fertilizer on soil mineral N dynamics and N uptake by
maize. Soils and maize samples were taken at 0, 2, 4,
6, 8, 12, 16 and 20 weeks after planting maize (WAP)
during 2002 long rain (LR) and 2004 LR seasons and
analysed. The study showed that amounts of soil inorganic
N and uptake of N by maize varied among the
different sampling dates, treatments and between seasons.
There was a general increase of mineral N after
the start of the season followed by a drastic reduction
during 6 and 4 WAP during 2002 and 2004 LR,
respectively. This trend was attributed to the decomposition
of organic materials at the beginning of the
season followed by leaching due to intense rainfall during
this period. Treatments that had tithonia, leucaena
and calliandra applied recorded the highest amounts
of soil inorganic N and also the highest N uptake by
maize. Poor rainfall in 2004 LR restricted N uptake
and was responsible for lower N uptake by maize in
2002 LR than in 2004 LR. At the end of the growing
season, there were high amounts of mineral N at 100–
150 cm soil depth that was probably due to leaching.
This mineral N is below the rooting zone of most maizeplants, consequently not available to maize crop and is therefore of concern.
Description
DOI 10.1007/978-90-481-2543-2_62,