It should be noted that in natural agro-ecosystems, in particular on virgin lands,
the phosphate mode is located in certain equilibrium: the phosphates that plants absorb
from the soil for the production of biomass, return to the soil in the form of organic
compounds and again mineralizing, this is a small biological cycle. Plowing of the soil
leads to the shift in the balance of the phosphate condition. This process is associated
with changes in the physico-chemical, water-physical and other soil traits, as well as
the balance of phosphorus that forming in the soil.
According to our research (Table 6), sod-podzolic soils have low content of
mobile phosphates. Noted that on the average during the years of our research, stocks
of mobile phosphorus during the vegetation period of cereal grasses have increased.
Known, that phosphorus in soil is the most stable, among the other agrochemical
indicators. Inasmuch as liming of the area with perennial grasses allows the suspension
of erosion processes, the content of mobile phosphorus in the soil, increases from 81.5
mg/kg in the variant with Phleum pratense L. to 108.4 mg/kg in variant with Dactylis
glomerata.
Established that investigated factors, namely cereal grasses, different soil
tillage’s, influenced on stock formation of mobile phosphorus in the soil. The highest
rates of mobile phosphorus noted that during the cultivation of Dactylis glomerata,
which accounted to 106.9 mg/kg in control and 108.4 mg/kg with small plowing.
Results of our research established that during the cultivation of cereal grasses on
sod-podzolic soils happens improving of the phosphate mode as result of content
increasing the mobile phosphorus in the arable layer.
Potassium plays an important role in the life of plants and microorganisms. To
obtain high harvest required significant amount of this element. It affects the synthesis
of monosaccharides, cellulose, pectin substances and the processes of motion products
of photosynthesis.
Established, that potassium is one of the essential vital elements of plant mineral
nutrition. The genetic type, state of cultivation, mineralogical and granulometric
composition, determines the content of this element in the soil. In the same time,
proved that the lowest content of potassium are in sod-podzolic soils, especially on
sand and sandy loam types, in which potassium washed away more, than accumulate.
Before the start of experiment, was made the soil surveys aimed on determining
of potassium content in sod-podzolic surface gleyed soils of the experimental field and
it amounted to: in the arable layer (0-20 cm) - 97.0 mg/kg of soil.
During the research (2011-2013), we established the following changes of
potassium reserves in the soil: in variant with Dactylis glomerata, it increased by 6.4
mg/kg of soil, in variant with Lolium perenne - by 3.8 mg/kg of soil (Table 6).
The change of physico-chemical indicators of the soil under the cereal grasses is
attributable to the influence of root system to penetration into the thickness of the soil
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