The handbook offers a broad spectrum of rapid field tests covering the chemical
analysis of water, soil and plant samples. The presented tests focus on the
determination of parameters required to evaluate crop growth especially under
saline growth conditions. Experts involved practically in the management of
irrigated, salt-affected agriculture are aware of the fact that the chemical
analysis of salinity parameter usually does not cover all required information
for a satisfying evaluation. A professional evaluation of salt-affected sites
also needs reliable data on supplemental soil fertility factors. In order to
correspond to the complexity of fertility problems related to saline sites, the
HANDBOOK offers numerous approaches to determine fertility factors to complete
the picture. Table 1 gives an overview of the full measuring programme
presented in this HANDBOOK and feasible with the portable field laboratory
'SALINITY AND SOIL FERTILITY KIT'.
Full Test - Programme of the Field Laboratory
'SALINITY AND SOIL FERTILITY KIT'
EC and Total Salt conc.
pH and HCO³
NO³ and high K
Cl- and SO4
Ca and Mg
Osmot. Effect. Salinity
Na and SAR, ESP
RSC and adjR-Na
pH (H²O and CaCl²)
EC and %o salt
Cl- and diss. SO4
dissolved Ca, Mg, Na
Gypsum: dissolv., pecip.
SAR, ESP, Mg-adjESP
pH-KCl and CEC
Exchangeable Ca, Mg
Plant-available N, P, K
Carbonate and OM
those readers, who are experienced with field and laboratory work in
developing countries, the advantage of a compact and portable field lab
covering a wide range of determinations will be principally clear. The field
lab offers a significant potential to improve quality of field studies and to
increase working efficiency.
for those who may believe that the application of a 'low input technology' as
this field lab requires co-workers of lower qualification or formation, I must
warn from the beginning. From my own experience I want to stress, that the
practical execution of most methods is simple and will be no problem. However a
qualified evaluation of data often requires a specific experience formation in
order to avoid misuse or misinterpretation and to profit as soon as possible
from the potential of rapid field methods.
HANDBOOK covers a wide range analytical procedures and data evaluation, which
is required for extended studies at the start of a project, when little or
nothing is known on the resources and the project environment. In cases where
specific site factors were already identified as critical there is no need to
apply the full measuring programme. The measuring programme can focus on the
most critical site factors. This aspect will certainly encourage those, who are
confused from the large measuring programme offered in this HANDBOOK.
my recommendation for the efficient application of the rapid field tests
within projects is to progress in two steps:
In the first phase, when site conditions or project environment are still
unknown and there is no or little experience with application of rapid field
tests, an expert specialized in rapid chemical tests and their evaluation has
to be engaged. Part of his job will be to identify the most relevant plant
growth limiting site factors in close cooperation with local/national experts,
another part will be to train local experts in the application of rapid test
required under the special site conditions.
The second phase starts, when the most important critical factors are known.
The local experts are well experienced in the application of the identified
rapid field tests and their evaluation. Based on this progress of the first
phase and the identified need for analytical methods a small manual/report
focussing on local need is prepared. If required the composition of the
test-kits in the field lab can be adapted to the identified measuring
programme. There is no urgent need for a permanent cooperation with the
specialist, but it is recommended to stay in contact by reporting and
occasional visits and discussions.
to didactic reasons the HANDBOOK starts with the analysis and evaluation of
water samples. From experience we know that the beginner will have little
problems with the practical analysis and evaluation of water samples. The
experience gained with the analysis of water samples will facilitate the user
to analyse soil samples.
order to limit the volume of the HANDBOOK the description of the analytical
procedures will not repeat all technical details that are already presented in
the instructions of the specific test-kits. These technical details must be
taken from the directions found in the specific kits.
use all chemical flasks have to be closed carefully in order to avoid losses
by evaporation and leaking. It is recommanded to place all liquid filled
bottles in the direction of the handle of the set. The set should not be
exposed for a longer period to high sun irridation and high temperatures, as
the decay of some chemicals is accelerated.
all analytical procedures can be carried out directly at the site of the
sampling. But for routine analysis of greater series it is recommanded to
install the field lab in a cottage or simple house and to transport the samples
to this location.
HANDBOOK offers many tables and graphs recommended for a quantitative data
evaluation. Many critical ranges are considered as relatively 'safe', some may
be questionable or tentative. The limited reliability of some data and their
evaluation can be improved significantly, when a cross-check of different
approaches is carried out (e.g. comparison of soil and plant data, visual
I admit you may also meet situations, where the critical ranges offered in the
HANDBOOK appear unsatisfactory, which reflects the world-wide very different
site conditions. The critical ranges may only serve as a very first and rough
approximation, but even this is usually better than nothing. In such cases you
are cordially invited to coorperate with me and to adapt the recommended
classifications. For long-term monitoring programmes an adaptation to local
conditions is required anyhow.
the evaluation of water-soluble Magnesium in irrigation waters and soils I
propose a new approach. This appeared necessary to my own practical experience,
but also to the contradictory evaluation of Mg in classical evaluation
proposals for Mg in waters (SAR after USDA) and soils with respect to soil
physical properties. The classical SAR assumes positive Mg-effects on soils
physical properties, but many soil scientists have proved that high
exchangeable Mg-percentages may have a very unfavourable affect on soil
some respects the HANDBOOK exceeds its primary objective to support the
professional evaluation and management of salt-affected crop production:
Chapter 3.6.8 addresses to the controversially discussed problem of root water
uptake under saline soil conditions. I have severe doubts that root water
uptake can be evaluated from a simple function, where soil matric and osmotic
water potential are simply additive and equal in this respect.
Chapter 3.6.11 presents a concept for future research needed for further
progress in saline irrigation, where the horizontal distribution of salts in
the rhizosphere during irrigation cycles and the effect of root morphology play
a central role for crop salt tolerance.
not least I hope to receive your comments on this HANDBOOK, the proposed
methods and evaluations, especially when you have constructive proposals that
may contribute to an improvement. I am 100% sure that there are many things to
correct and to add. I will be very glad to learn from your experience.