The publication of this Handbook was supported by the Russian Federation

Ameliorative deep ploughing. Ameliorative deep ploughing (ADP) is one of  the tillage methods 
applied to Solonetz and solonetzized soils including those with irrigation-induced alkalinity. The 
ADP level should be 10-15 cm deeper than the effervescence boundary (determined by testing with 
10% HCl), which allows the ameliorative mixing of  calcium compounds naturally present within 
a 35-60 cm layer of  soil. The ADP results in the mixing of  the solonetzic eluvial (E) and illuvial (B) 
horizons and a part of  the transient horizon (between the B and C horizons).
A correctly performed ADP is a one-off procedure that profoundly changes the soil profile structure, 
which does not restore to its original state for a period of  40-50 years following ADP. This period 
is characterized by significantly better hydrophysical, chemical, physicochemical and biological soil 
properties. Soils that underwent ADP treatment 50 years ago still support a higher productivity of  
agricultural crops than similar soils that were not subjected to ADP or that underwent chemical 
amelioration.
ADP is performed in summer and autumn, when soil conditions are optimal and allow for high- 
quality tillage. ADP is carried out on fields that are subsequently used as true fallow, occupied 
fallow or for row crops in the next year. In spring, these fields should be cultivated by a chisel 
plough to a depth of  20-25 cm for 2 or 3 times to ensure the best soil mixing and surface levelling.
ADP requires an obligatory application of  organic fertilizers. Farm-yard manure should be applied 
at rates of  40-60 t/ha within non-irrigated fields and 80-100 t/ha within irrigated fields. If  the 
availability of  farm-yard manure is scarce, then it can be replaced by local peat, sapropels, sludge 
and/or food production waste [7].