preservation of water-physical properties of soils. Without their use, it is compacted,
its water absorption capacity deteriorates, the number of water-resistant units
decreases. According to our three years of research non-fertilized dark chestnut soil per
hour absorbs 14.72 mm of water at green manure in the year of effect and aftereffect,
the proportion rose to 16.3-20.6 per cent, and straw – 22.8-34.6 per cent.
Table 1 Humus content in 0-30 layer of dark chestnut soil under the influence of
long-term use of fertilizers in irrigated crop rotation
Experience option
Humus content, %
Loss or increase of humus
for the period
of experience
after the 4
th
rotation of the
crop rotation
in absolute
percentage
average
annual, kg /
ha
Without fertilizer
2.26
2.11
-0.15
-277.5
Р
2
О
5
2.26
2.19
-0.07
-129.5
N
2.26
2.23
-0.03
-55.5
NPK
2.26
2.25
-0.01
-13.5
NPK +80 т/ ha of manure
1 time per rotation of crop
rotation
2.26
2.35
+0.09
+166.5
We have determined that for the incorporation of straw into the soil, even in dry
years, moisture accumulates in the arable layer by 15-20% more than without it. This
should oblige producers of agricultural enterprises in any case not to burn straw, and
to use all post-harvest residues for soil enrichment with organic matter. In addition,
each ton of straw put in the soil is equivalent to 4-5 t / ha of manure by the amount of
dry organic matter introduced.
Many researchers determined that the amount of by-products, which can be used
as fertilizer after harvesting the main crop equals on average to 5-6-10 t/ha. All macro
- and micronutrients go with it to the soil. So, wheat straw on 1 hectare produces on
average 20 kg of nitrogen, 10 kg of phosphorus and 30-35 kg of potassium, with the
remains of corn 45; 18 and 100 kg, and sunflower – 40; 20 and 130 kg respectively. In
addition, by-products of agricultural crops contain calcium, magnesium, sulfur and all
trace elements. It is also known that the decomposition of crop residues depleted to
nitrogen is significantly accelerated by adding, for example, to straw 7-10 kg/t of the
active substance of nitrogen or modern biodestructors of stubble [7].
The calculations determined that the use of crop residues and straw, compared
with manure, can save on each hectare up to 170 kg of diesel fuel and 15-17% of cash
costs.
It is known that without the use of organic and mineral fertilizers to a greater
extent irrigated soils, which are formed significantly higher levels of crop yields would
deplete and, accordingly, the removal of nutrients will significantly increase. Our
studies have found that the use of organic fertilizers has a positive effect on the main
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