Evaluation of the potential of rotational tree fallows for sustaining maize production at Meatu, Shinyanga, Tanzania
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Date
1996
Authors
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Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
A study was undertaken on on-going agroforestry research at Meatu, Shinyanga, Tanzania to evaluate the potential of short tree fallows on maize yields and
soil fertility sustenance. The tree fallows involve three-, f our-
and five-year old fallows, respectively cropped thrice, twice and once.
In each of these tree fallows (experiments) the following three treatments were imposed: (a) maize + trees with prunings removed,
(b) maize + trees with prunings removed with 50 kg N kg'1 supplement, and (c) maize + trees with prunings returned back to soil.
Each treatment was replicated three times in a complete randomized design.
Results from this study have shown that maize yields were usually high at the opening of each
experiment, given sufficient rain. In 1993 maize yield was significantly higher (P<0.05) in the four-year fallow than in the three year
fallow.
In 1994 cropping season,
maize
yield was significantly higher
(P<0.05) in treatment with prunings than in treatment with N supplement. Results from routine soil
analysis showed that
soil parameters did not vary significantly between treatments within
experiments. However, P quantities in the top-soil were significantly different between experiments. Results from N- mineralization,
for the
first sampling, showed greater (P<0.05) nitrification rates under treatment with prunings than under treatment with N supplement in both three- and five-year
old
fallows. At the second sampling, nitrification rates were significantly lower (P<0.05)
in the three-year fallow than in the other two. Based on the results from this study no firm conclusion can be drawn on the suitability of the current treatments to maintain
maize productivity. Nevertheless, preliminary observations indicate
that the
treatment with prunings seemed to be the best. Comparing the three experiments with respect to maize yield and other soil parameters the four year old fallow seemed better than others.
Description
Dissertation
Keywords
Maize yield, Agroforestry, Tree prunnings