Nitrogen mineralization from cattle manure, filtermud, factory ash and nitrogen uptake by maize (zea mays) in a glasshouse experiment."
Abstract
To reduce over reliance on inorganic fertilizers due to high
prices, there is a need to increase utilization of organic input
sources such as filtermud, which is a by-product of white sugar
manufacture. Fresh filtermud(FM) is detrimental to crops and it
takes long ( > six months) to decompose under natural conditions.
Supply of decomposed filtermud is limiting due to its high demand
as its use is well established among farmers in the Kenyan sugar
belt. Consequently, a study was conducted to improve filtermud
quality through reduced curing time hence enhance nutrient release.
,The approach was: chemical characterization of filtermud, cattle
manure and factory ash followed by laboratory· incubation of
filtermud mixed with factory ash and or mineral nitrogen at
different ratios. Nitrogen uptake by maize was assessed through a
glasshouse pot experiment. The laboratory incubation experiment was
held for 12 weeks with sampling at 2 weeks interval; each time
mineral nitrogen (N03- and NH4+) forms were analysed. Miwani FM was
strongly acidic with a pH value of 4.93 and relatively lower lignin
content than that from Muhoroni and Chemelil. In terms of nitrogen
release it was superior to that from Chemelil and Muhoroni,
releasing 53% of nitrogen after 12 weeks. Regression analysis of
nitrogen release versus material quality showed that there was a
negative linear relationship between the % lignin content (r
0.99), lignin + polyphenol to nitrogen ratio (r= -0.93), lignin to
nitrogen ratio (r =-0.93) carbon to nitrogen ratio (r=-0.85) on
nitrogen release; hence % lignin was predominant factor controlling
the nitrogen release. A maize crop was grown for 9 weeks in pots
containing soils with FM from Miwani mixed with or without mineral
nitrogen at the following rates; 0, 7.5, IS, 30 and 45 tha -1 •, soil
mixed with 100 kq'Nha ? was included giving a total of six
treatments. FM at 45 tha-1 ammended with mineral nitrogen at 9 kg
N per ton of FM gave significantly (PsO. OS)) higher dry matter
(19g/pot) and nitrogen uptake (13%) than the rest of the
treatments. Therefore, for an inherently low fertile soil for
example, cambisol 45tha-1 FM amended with mineral nitrogen at 9 kg
N/ton of FM would be required to improve the fertility and hence
nutrient availability. The study should be continued under field
conditions for results to be conclusive.
Citation
Amolo, R. A(1996). Nitrogen mineralization from cattle manure, filtermud, factory ash and nitrogen uptake by maize (zea mays) in a glasshouse experiment."Sponsorhip
University of NairobiPublisher
Department of soil science, University of Nairobi
Description
Msc-Thesis