Effects of organic and mineral sources of nutrients on maize yields in three districts of central Kenya

2007 ◽  
pp. 353-358 ◽  
Author(s):  
S.K. Kimani ◽  
A.O. Esilaba ◽  
M.M. Odera ◽  
L. Kimenye ◽  
B. Vanlauwe ◽  
...  
Keyword(s):  
Maize Yields ◽  
Central Kenya ◽  
Mineral Sources

scholarly journals MAIZE YIELDS RESPONSE TO APPLICATION OF ORGANIC AND INORGANIC INPUT UNDER ON-STATION AND ON-FARM EXPERIMENTS IN CENTRAL KENYA

2009 ◽  
Vol 45 (1) ◽  
pp. 47-59 ◽  
Author(s):  
JAYNE MUGWE ◽  
DANIEL MUGENDI ◽  
JAMES KUNGU ◽  
MONICAH-MUCHERU MUNA
Keyword(s):  
Inorganic Fertilizer ◽  
Calliandra Calothyrsus ◽  
Yield Gap ◽  
Maize Production ◽  
Combined Application ◽  
Maize Yields ◽  
Maize Grain ◽  
On Farm ◽  
Organic Resources ◽  
Central Kenya

SUMMARYThis study investigated the feasibility of using sole organics or a combination of organics with inorganic fertilizer to improve maize production in on-station and on-farm experiments in central Kenya. In the on-station experiment, combined application of Calliandra calothyrsus, Leucaena trichandra and Tithonia diversifolia at 30 kg N ha−1 plus inorganic fertilizer (30 kg N ha−1) consistently gave significantly higher maize grain yields than the recommended rate of inorganic fertilizer (60 kg N ha−1). Sole application of calliandra, leucaena and tithonia also increased maize yields more than the recommended rate of inorganic fertilizer. In the on-farm experiment, calliandra, leucaena, tithonia and cattle manure either alone or combined with inorganic fertilizer increased maize yields with a similar magnitude to that of inorganic fertilizer. These organic resources could therefore be used to supplement inorganic fertilizer as a whole or in part. There was a yield gap between on-station and on-farm trials with on-station yields having, on average, 65% greater yields than the on-farm yields. There is therefore potential for increasing yields at the farm level by closing the yield gap.

Changes in the drought sensitivity of US maize yields

Nature Food ◽  
2020 ◽  
Vol 1 (11) ◽  
pp. 729-735 ◽  
Author(s):  
David B. Lobell ◽  
Jillian M. Deines ◽  
Stefania Di Tommaso
Keyword(s):  
Drought Sensitivity ◽  
Maize Yields

scholarly journals Mineral accretion in nursing piglets in relation to sow performance and mineral source

2009 ◽  
Vol 54 (No. 2) ◽  
pp. 41-46 ◽  
Author(s):  
G.A. Papadopoulos ◽  
D.G.D. Maes ◽  
G.P.J. Janssens
Keyword(s):  
Accretion Rate ◽  
Partial Substitution ◽  
Lactation Period ◽  
Mineral Analysis ◽  
Fe Content ◽  
P Content ◽  
Total Body ◽  
Inorganic Mineral ◽  
Mineral Concentrations ◽  
Mineral Sources

The present study investigated the effect of a moderate substitution of inorganic mineral sources with chelated mineral sources from four weeks prior to parturition throughout lactation on sow and litter performance. In addition, the aims were to determine whether the mineral source and litter performance affect mineral status and accretion in piglets at birth and at weaning. Forty gestating sows in a commercial pig herd were selected and randomly assigned to two experimental groups, with part of the Cu, Mn, Zn and Fe content of the feed added as either an inorganic mineral source or a chelated mineral source. From each sow, one piglet was randomly selected at birth and at weaning for total body mineral analysis. Neither the performance of the sows and the piglets nor the total body mineral concentrations of the piglets at birth and at weaning were significantly different between the two diet groups (<i>P</i> > 0.05). Fe, Na and P content of piglets at birth were inversely correlated with birth weight (<i>r</i> = –0.447, <i>P</i> = 0.004 for Fe; <i>r</i> = –0.431, <i>P</i> = 0.005 for Na; <i>r</i> = –0.340, <i>P</i> = 0.032 for P). Daily accretion rate of K and Ca of piglets was positively correlated with piglet growth performance during the entire lactation period (<i>r</i> = 0.469, <i>P</i> = 0.008 for K; <i>r</i> = 0.581, <i>P</i> < 0.001 for Ca), and negatively correlated with number of liveborn piglets (<i>r</i> = –0.424, <i>P</i> = 0.014 for K, and <i>r</i> = –0.405, <i>P</i> = 0.027 for Ca). In conclusion, the study documented that partial substitution of inorganic minerals with a chelated mineral source failed to exert significant effects on performance and total body mineral concentrations. The importance of the influence of sow milk production on mineral body stores in piglets warrants further investigation.

scholarly journals A serological evaluation of 1979–1982 Kenyan foot-and-mouth disease type SAT 2 viruses

1983 ◽  
Vol 91 (2) ◽  
pp. 335-341 ◽  
Author(s):  
C. G. Ndiritu ◽  
E. J. Ouldridge ◽  
M. Head ◽  
M. M. Rweyemamu
Keyword(s):  
Asymptomatic Carrier ◽  
Foot And Mouth Disease ◽  
Vaccine Virus ◽  
Disease Type ◽  
Mouth Disease ◽  
Two Dimensional ◽  
Foot And Mouth ◽  
Vaccine Virus Strain ◽  
Microneutralization Test ◽  
Central Kenya

SUMMARYSerological evaluations of foot-and-mouth disease type SAT 2 viruses isolated in Kenya between 1979 and 1982 were performed using the two-dimensional microneutralization test. Nine field isolates of epizootiological significance were compared with four vaccine viruses. The results obtained identified Tan 5/68 as the most appropriate reference vaccine virus strain since it had the broadest serological spectrum. Potent Tan 5/68 vaccines would be expected to provide adequate protection against the contemporary SAT 2 field viruses. In the case of K 83/74, which also was shown to have a broad spectrum with viruses isolated in Kenya, the results show that the 1982 isolate from central Kenya was significantly divergent (r < 1·00 at P = 0·01) and warranted tactical revaccination for its control. The study highlighted the fact that strain R1215 which had been isolated from the oesophageal-pharyngeal swabs of asymptomatic carrier cattle had a narrow serological spectrum suggesting that such viruses could be unsuitable as vaccine for the national campaign.

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