## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Horizon**} & \multirow{2}{*}{**Depth, cm**} & \multicolumn{3}{c}{**Bulk, mg/100 g**} & \multicolumn{3}{c}{**Labile, mg/100 g**} & \multicolumn{3}{c}{**Carbonates, \%**} \\ \cline{3-8}  & & **P\({}_{2}\)O\({}_{5}\)** & **K\({}_{2}\)O** & **P\({}_{2}\)O\({}_{5}\)** & **K\({}_{2}\)O** & **CaCO\({}_{3}\)** & **MgCO\({}_{3}\)** \\ \hline AU1 & 0–7 & 220 & 2450 & 3.7 & 40.4 & 1.7 & 0.8 \\ AU2 & 7–17 & 210 & 2350 & 2.1 & 40.1 & 1.3 & 0.7 \\ BCAnc & 17–43 & 170 & 2100 & 1.0 & 39.0 & 5.6 & 2.0 \\ BCAg & 43–73 & 170 & 2100 & 0.0 & 28.5 & 5.7 & 2.0 \\ Cag & 73–101 & 161 & 2050 & 0.0 & 22.0 & 6.1 & 2.1 \\ \hline \multicolumn{8}{c}{Dark Calcisol (irrigated)} \\ \hline AU & 0–30 & 230 & 2350 & 4.7 & 35.5 & 1.4 & 1.0 \\ BCAnc & 30–42 & 231 & 2100 & 3.2 & 34.0 & 1.8 & 1.0 \\ BCAg & 42–70 & 220 & 2000 & 2.0 & 20.1 & 3.1 & 1.0 \\ Cag & 70–100 & 180 & 2100 & 0.0 & 20.0 & 3.2 & 1.3 \\ D & 100–135 & 180 & 2100 & 0.0 & 25.0 & 6.2 & 2.1 \\ \hline \multicolumn{8}{c}{Typical Calcisol (reference)} \\ \hline AU1 & 0–6 & 201 & 2100 & 3.0 & 34.1 & 3.3 & 1.2 \\ AU2 & 6–23 & 210 & 2000 & 2.0 & 28.6 & 4.2 & 1.3 \\ BCAnc & 23–70 & 188 & 2000 & 0.6 & 31.5 & 6.3 & 2.3 \\ BCAg & 70–101 & 180 & 1950 & 0.0 & 8.8 & 7.3 & 2.4 \\ Cag & 101–131 & 205 & 2010 & 0.0 & 10.5 & 7.1 & 2.2 \\ \hline \multicolumn{8}{c}{Typical Calcisol (irrigated)} \\ \hline AU & 0–26 & 220 & 2200 & 4.2 & 33.5 & 3.6 & 1.5 \\ BCAnc & 26–40 & 220 & 2100 & 3.0 & 25.0 & 4.5 & 1.0 \\ BCAg & 40–67 & 195 & 2100 & 1.8 & 25.0 & 7.1 & 2.3 \\ Cag & 67–100 & 210 & 1800 & 0.0 & 20.0 & 7.8 & 2.1 \\ D & 101–120 & 210 & 2200 & 0.0 & 24.0 & 7.2 & 2.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Main nutrient and carbonate contents in different Calcisols. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Horizon**} & \multirow{2}{*}{**Depth, cm**} & \multicolumn{2}{c}{**Bulk, mg/100 g**} & \multicolumn{2}{c}{**Labile, mg/100 g**} & \multicolumn{2}{c}{**Carbonates, \%**} \\ \cline{2-7}  & & **P\({}_{2}\)O\({}_{5}\)** & **K\({}_{2}\)O** & **P\({}_{2}\)O\({}_{5}\)** & **K\({}_{2}\)O** & **CaCO\({}_{3}\)** & **MgCO\({}_{3}\)** \\ \hline \multicolumn{7}{c}{Light Calcisol (reference)} \\ \hline AJ1 & 0–5 & 141 & 1850 & 2.6 & 25.5 & 4.2 & 2.2 \\ AJ2 & 5–27 & 140 & 1650 & 1.2 & 30.3 & 4.3 & 1.2 \\ BCAnc & 27–43 & 121 & 1600 & 0.5 & 31.3 & 6.4 & 3.7 \\ BCAg & 44–89 & 120 & 1700 & 0.0 & 10.5 & 7.5 & 2.4 \\ Cag & 89–114 & 118 & 1600 & 0.0 & 11.5 & 8.1 & 2.2 \\ \hline \multicolumn{7}{c}{Light Calcisol (irrigated)} \\ \hline AJ & 0–36 & 181 & 2000 & 2.0 & 25.5 & 4.3 & 2.2 \\ BCAnc & 36–42 & 153 & 2100 & 2.1 & 20.0 & 4.5 & 1.9 \\ BCca & 42–86 & 131 & 2000 & 2.0 & 24.0 & 6.3 & 3.8 \\ Cag & 87–113 & 121 & 1800 & 0.0 & 0.0 & 7.6 & 3.4 \\ D & 113–120 & 123 & 1800 & 0.0 & 0.0 & 8.4 & 3.3 \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 8: Base cation (Ca\({}^{2+}\), Mg\({}^{2+}\), Na\({}^{+}\), K\({}^{+}\)) content (value on graph lines in meq/100 g of soil) and base saturation (%) on X axes. Rf—reference; Ir—irrigated. On the one hand, the soil cover of Central Asia is quite diverse due to geogenic and climatic conditions [32]; on the other hand, there is a long history of soil development and irrigation, which obviously leads to the convergence of their properties, in particular chemical ones. Therefore, soil profiles accumulate a huge number of results regarding previous stages of soil formation. That is why current irrigation does not always lead to strong shifts in soil formation. Land use, and in particular the utilization of soils in arid zones, faces many challenges, and the question arises whether we can achieve land degradation neutrality [37; 38]. Nevertheless, without detailed knowledge of irrigation processes of soil formation, the methodological apparatus of this assessment cannot be formed. In this regard, this study makes it possible to approach the formation of a holistic picture of arid subtropical irrigated soil formation in the densely populated valleys of Central Asia.