|WORLD METEOROLOGICAL ORGANIZATION||
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IMPROVED IRRIGATION EFFICIENCY USING SOIL PHYSICAL TECHNIQUES
1. Purpose and objectives
To describe methods monitoring soil water under drip-irrigated crops, using soil physical techniques, with a view to improving irrigation
scheduling using only tensiometers.
This report describes experiments carried out in drip-irrigated sugar
cane in Mauritius directed at understanding all processes involved so that
the efficiency of irrigation could be increased. The emphasis was on
saving water without reducing crop yield. Details of the site, its climate
and soil are given together with a description of the instrumentation,
which included a neutron probe and arrays of tensiometers. The importance
of measurement in the soil as well as above ground in assessing an
An explanation of techniques developed for the analysis of data from irrigation schemes is given. These include diagrams showing the two- dimensional distribution of water potential in the plane at right angles to the drip line, and the concept of soil water Status - a method of summarizing large quantities of data from tensiometer arrays. There is detailed analysis from the sugar cane experiments of water movement under different irrigation regimes and hence of irrigation efficiency.
Situations are identified where inappropriate regimes might be used
on crops if determined solely by observation of the crop itself without
measurements in the soil. In order to prevent this, a method for
One of the Appendices gives an outline of soil physics theory and
terminology as it applies to this report.
5. Operational requirements and restrictions
Applicable to drip-irrigation schemes. Not restricted to sugar cane,
but possibly less appropriate for crops whose yield is significantly
affected by short periods of water shortage.
6. Form of presentation
Report in English. 67 pages, 31 figures, 7 tables.
7. Operational experience
Some knowledge and experience of soil physics are necessary in order
to appreciate fully the details of this report and make use of its
8. Originator and technical support
Institute of Hydrology, Wallingford, Oxon OX10 8BB, UK.
10. Conditions on use
Free of charge.
|(First entered: 07 OCT 94||
Last updated: 07 OCT 94)