The publication of this Handbook was supported by the Russian Federation

S.A. Balyuk, M.I. Romashchenko, A.A. Nosonenko and M.A. Zakharova (Ukraine)
Systems for assessing the quality of  irrigation water were initially based on determining water 
salinity levels for evaluating the risks of  secondary salinization of  soils. Later, several attempts have 
been made at classifying the irrigation water quality in terms of  risks of  secondary alkalinization 
of  soils. In particular, in the USA [1], the sodium adsorption ratio (SAR, calculated as the amount 
of  sodium divided by the square root of  half  the sum of  the amounts of  calcium and magnesium) 
has been introduced as an irrigation water quality parameter. In more recent systems of  irrigation 
water  quality  assessment  developed  by  scientists  from  different  countries  [1-3,  8-10]  various 
combinations of  parameters have been used depending on the regional specifics of  soil properties, 
pollution by heavy metals, pesticides, silt, bacteria, etc.
A team from the Laboratory of  Fertility of  Irrigated and Solonetzized soils of  the Institute for Soil 
Science and Agrochemistry Research named after O.N. Sokolovsky (Kharkiv) directed by Prof. 
S.A. Balyuk developed a methodology for the experimental assessment of  soil and water quality 
on the basis of  their own long-term research data and existing publications by Ukrainian and 
international colleagues. This methodology involved the use of  parameters for the assessment of  
the risks of  soil salinization and solonetzization/alkalinization and salt toxicity to plants under the 
impact of  high salt concentrations in irrigation water in connection with the soil buffering capacity 
and thermodynamic parameters.
The methodology for the experimental assessment of  soil and water quality was based on the 
analysis of  the composition of  salt ions in soils and water. Three classes of  irrigation water quality 
(i.e., suitable, provisionally suitable and unsuitable) were assigned to different soils depending on 
the soil buffering capacity and calculated values of  total salt concentration in water. This system for 
irrigation water assessment has become mandatory for use in Ukraine, since it serves as a basis for 
development and ratification of  the State Standard of  Ukraine (DSTU 2730-94) “The irrigation 
quality of  natural water: agronomics criteria”[5]. This State Standard has been amended as a 
result of  its practical application and use by the State Water Agency and hydrology-amelioration 
expedition of  Ukraine for a period of  20 years [6].
This State Standard regulates the irrigation water quality on the basis of  chemical criteria and 
parameters of  the salt composition of  soil and irrigation water, which predetermine the risk of  
irrigation salinity, solonetzization/alkalinization of  soil and salt toxicity to agricultural crops.
The irrigation water quality in regard to alkalinization hazard should be assessed using the parameters 
of  pH, toxic alkalinity and carbonate hardness. Water quality class should be determined from the 
two most extreme values of  these three parameters.

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Soil salinity manаgement manual | Part II.Tutorial examples, guidelines and exercises 
Irrigation water quality in relation to the risks of  soil solonetzization should be assessed by the ratio 
(percentage) of  the sum of  alkali cations (sodium and potassium, meq/dm3) divided by the sum 
of  all cations (meq/dm
3
), together with soil type, buffering capacity and particle-size composition, 
the balance of  magnesium and calcium cations in irrigation water and the water quality class in 
relation to the risk of  alkalinization [56].
The system for water quality assessment in regard to the risk of  salt toxicity to agricultural crops is 
presented in Table 1. Toxic effects of  natural water can be caused by high alkalinity or acidity that 
can affect plants, especially, at early stages of  their development as well as ions of  Cl
-
, NO
2
-
, NO
3
-
, 
NH
4
+
 and CO
3
2-
 and hydrogen sulphide.