elements of soil fertility in the link of irrigated grain-vegetable crop rotation (corn,
winter wheat + post-harvest, tomatoes). Under the influence of straw and green
fertilizer, and especially when using both types the content of organic matter, total and
water-soluble humus in the soil increases (Table 2).
Table 2 The content of humus and organic matter in the arable layer of dark
chestnut soil in the link of irrigated grain-vegetable crop rotation
(under tomatoes, average for 3 years)
Experience option
Term of
determination
Content
organic matter,
%
common
humus, %
water-soluble humus,
mg / 100g
N
120
P
90
K
60
-
background
1
6.64
2.00
17.99
2
7.21
2.04
25.81
Background+green
fertilizer
1
6.81
2.02
18.86
2
7.27
2.06
26.46
Background +
winter wheat straw
1
6.82
2.03
18.42
2
7.31
2.08
25.39
Background+green
manure+straw
1
6.91
2.04
19.02
2
7.38
2.09
27.16
HIP
05
0,22-0,27
0,01-0,03
1,12-2,47
Note:
*)
Term of determination: 1 – for the period of sowing-rising; 2 – when harvesting.
The latter, as it is known, characterizes the presence of organic substances in the
soil at the primary stages of mineralization. Over time, these organic substances in the
process of decomposition will turn directly into humus.
The use of straw of grain crops as an organic fertilizer was also studied on the
southern chernozem in various parts of the crop rotation in the cultivation of drought-
resistant crop without irrigation (Table 3).
It was established that in the conditions of rain – fed agriculture straw effectively
affects the main indicators of soil fertility-the content of humus, organic matter, mobile
forms of phosphorus and especially potassium, its structural indicators,
microbiological activity and the like. In addition, as it is shown in table 3, the grain
yield levels for the combined use of straw and N
60
P
40
are formed above the control, but
slightly inferior to mineral nutrition. This is due to the fact that for the decomposition
of straw, nitrogen fertilizer addition was not made, and due to increased mineralization
of organic substances cellulose-desructive microorganisms that use the nitrogen to
decompose organic matter.
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