The publication of this Handbook was supported by the Russian Federation

V.V. Medvedev and A.A. Nosonenko (Ukraine)
Precision  agriculture  is  a  site-specific  crop  management  system  that  takes  into  account  spatial 
heterogeneity, i.e., variability within a field.
Soil heterogeneity is an important management challenge. The heterogeneity predetermines 
differences in soil properties, plant nutrition and water and temperature regimes within a field. As 
a consequence of  heterogeneity, soils within a field will have different fertility levels. Because of  
differences in the moisture content of  soils at higher and lower parts of  the field, it is practically 
impossible to achieve high-quality soil preparation over an entire field to enable seed to be sown at 
the same depth. Consequently, seeds germinate at different times leading to differential phenological 
stages of  plant development up to the time of  harvest.
Among causal factors of  intra-field heterogeneity, the first and foremost is the heterogeneity of  
parent materials, i.e., their variability in particle-size composition, chemical and mineralogical 
composition and physical properties on both vertical and horizontal planes. The vertical 
differentiation is represented by layers of  different ages. Soils inherit the salinity characteristics 
of  parent materials (e.g., a specific mosaic pattern of  soil salinity distribution is known over salt 
domes in the area of  the Dnieper River). Soil gley features (excluding pseudo-gley) behave similarly, 
usually being predetermined by the degree of  waterlogging in parent materials.
The use of  hydrotechnical irrigation systems results in a significant increase in the heterogeneity 
of  soil cover because of  temporal and spatial factors. The soil cover is modified due to secondary 
salinization and alkalinization, compaction and loss of  structure as well as rising groundwater. 
Patches of  soils with excessive salt accumulations or waterlogging due to perched water or shallow 
groundwater table are very common within river floodplains in steppe regions. In some places, soil 
ares affected by karst and suffosion phenomena. Territories at higher hypsometric levels, especially 
those which are affected by saline groundwater, are characterized by localized deterioration of  the 
ecological and ameliorative state of  soils and the development of  slope processes. Closed-drainage 
lowlands are characterized by subsidence phenomena and the appearance of  mesodepressions 
known as ‘pods’ or ‘steppe saucers’.
According to F.I. Kozlovsky [6], irrigation for 20-25 years results in a complex spatial change in 
microtopography and soil properties. The initial microtopography becomes totally transformed, 
the  moisture  level  is  significantly  increased  and  processes  of   infiltration-induced  leaching  and 
subsidence-induced soil compaction develop.
The spatially differentiated transformation of  saline and alkaline soils is highly evident and must be 
taken into account in land use and management (with preference to precision agriculture) as well 
as soil protection and improvement. It is also necessary to further investigate the impacts of  some 
negative processes causing heterogeneity such as irrigation-induced erosion, subsidence as a result 
of  salt leaching, halogenation, consolidation (development of  vertic features and cementation) and 
waterlogging near irrigation channels. It is also necessary to verify the role of  surface levelling, which 
according to some studies [7] does not decrease, but increases the degree of  soil heterogeneity and 

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Soil salinity manаgement manual | Part I.Soil salinity management in the Eurasian Region 
favours soil striation (change in the soil surface structure with change in moisture level within a 
short distance from irrigation channels).
In general, irrigation has a significant impact on soil-forming factors and, therefore, results in the 
development of  new types of  man-made spatial structures of  the soil cover.
An increase in the structural complexity of  soil cover over the course of  long-term irrigation is 
associated with numerous and diverse manifestations of  heterogeneity that require the precise 
application of  both agrotechnical and ameliorative measures. According to [8], the practice of  
precisision agriculture on irrigated Common Chernozems of  the Donetzk Region (Ukraine) 
should focus on tasks of  reducing the high alkalinity of  soils and optimizing plant nutrition via 
nitrogen fertilizer application. That experimental research [8] aimed to identify which parameters 
of  soil fertility have significant effects on the productivity of  barley and cabbage. The coefficients 
of  correlation between the yields of  barley and cabbage (centner, i.e. 100 kg per hectare) and soil 
properties were tested at 40 points within the field.
The soil properties tested reflected the diagnostic criteria of  Chernozem degradation and included 
the following:
•  the content of  toxic soluble salts, in chlorine equivalents (0-50 cm);
•  the ration of  Ca: Na in water extract (0-50 cm);
•  pH in water (0-25 cm);
•  exchangeable sodium and potassium percentages (%) of  the sum of  cations (0-25 cm);
•  the total content of  humus,% (0-25 cm);
•  the total content of  nitrate and ammonium nitrogen, mg / 100 g of  soil (0-25 cm);
•  the content of  labile P
2
O
5
 by Chirikov method, mg / 100 g of  soil (0-25 cm);
•  the content of  labile K
2
O by Chirikov method, mg / 100 g of  soil (0-25 cm);
A strong correlation was detected between the following parameters:
a)  barley yield (2001) – total of  N-NH4 and N-NO3, mg / 100 g of  soil, with correlation 
coefficiant r = 0.71;
b)  cabbage yield (2002) – pH in water; r = -0,59;
c)  barley yield (2003) – total of  N-NH4 and N-NO3, mg / 100 g of  soil, r = 0.71
A medium degree of  correlation was found between the barley yield (2001) and pH in water (r = 
-0.36). The influence of  other testes parameters of  soil on crop yields were insignificant.
Therefore,  crop  productivity  on  Common  Chernozems  with  different  degrees  of   irrigation 
salinity depends on the spatial variability in the content of  mineral nitrogen and the pH (water) 
of  the plough layer. In a precision agriculture system (PAS) the attention should be focused on 
the optimization of  nitrogen supply to plants and the control of  alkalinity of  soil solution. The 
most satisfactory results can be obtained by a differentiated application of  nitrogen fertilizers and 
acidifying agents – physiologically and chemically acid mineral and organic substances. It should 
be taken into account that temporal variability in soil properties (especially the nitrogen content) 

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Chapter 5.Innovative methods and technologies for amelioration of salt-affected soils and agroforestry practices in marginal landscapes 
is quite strong and, therefore, soil properties need to be monitored during the growing season as a