Chemistry Reference
In-Depth Information
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Figure 4
Agronomic efficiency of fertiliser N (N-AE) as affected by combination
with different classes of organic inputs (Classes I, II, III+IV, and
manure+compost) for organic N application rates #30 kg N ha
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(125
observations), #60 kg N ha
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(238 observations), #120 kg N ha
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(305
observations), or #240 kg N ha
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(352 observations). Error bars are
average Standard Errors of the Difference. The symbols *, **, and ***
indicate a significant difference with the sole fertiliser treatment at the 0.1,
1, and 5% level. In the legend, F, OI, FYM, and COM refer to fertiliser,
organic inputs, manure, and compost, respectively.
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residues that are needed to optimise the AE of fertiliser for a specific situation.
Data obtained in Niger support this proposition.
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Where fertiliser was applied
to millet, sufficient residue was produced to meet both farm household
demands for feed and food as well as the management needs of the soil in terms
of organic inputs and surface protection of the soil from wind erosion.
4.3 Organic Matter and Local Adaptation
The third component of ISFM addresses local constraints to improved
fertiliser AE. At this level, organic inputs have been shown to reduce P
sorption, at least in over one growing season,
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and alleviate soil acidity-
