Figure 2. Spearman correlation matrix between agrochemical characteristics: (A) 0–32 cm depths (n
= 12); (B) 32–50 cm depths (n = 12). Note: gf—gross form; mf—mobile form.
As for the ratio of carbon and nitrogen, i.e., enrichment with nitrogen, in the initial
state this indicator in all horizons of all variants of the experiment varied within the range
of 6.7–7.8. As expected, a slight enrichment in nitrogen corresponded to the upper arable
horizons. In connection with the changes in the content of humus, this ratio changed to a
certain extent. In the fall of 2016, in the variant with river irrigation (treatment 1), in the
arable layer it was 6.8 and in the subarable layer it was7.1, while in the second variant the
ratios were 7.1 and 6.4; that is, there was still a slight increase in the arable layer in the
ratio, while in the subarable layer it declined.
In the fall of 2018, there was an increase in the ratio in the second treatment compared
to the first one. In the remaining treatments (3 and 4), similar changes occurred as in the
second. According to the grouping of irrigated soils according to mobile forms of nutri-
ents, the soils studied by us before the field experiment (in the spring of 2016) were as-
sessed as very poorly supplied in terms of the content of nitrate–nitrogen (Table 3).
In the fall of 2018, according to the availability of Na-NO
3
, the arable horizons for all
treatments were assessed as poorly provided, with the N-NO
3
contents in the range of
28.1–28.6 mg/kg, while in the arable horizons they remained at the same level as in the
spring of 2016, whereby the contents in all subarable horizons of the studied soil variants
ranged from 9.2–11.2 mg/kg.
As for the variants treated with irrigation with river and mineralized water sources
in fall 2016 and fall 2018, there was no significant difference. However, in the second ver-
sion of the experiment, if the content range of N-NO
3
in the plow and subplow horizons
was 28.6–11.2 mg/kg, in the treatment 1 it is 28.5–11.10; therefore, there was a very small
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