photosynthesis, and therefore it will not create a greenhouse effect (a closed loop is
formed).
Miscanthus is a thermophilic, moisture-loving long-day plant that reacts the
change of the planting period and the depth of rhizomes' covering by changing its
morphology, physiology of growth and development as well as yielding capability. The
determination of an optimal planting time for Miscanthus plants has been a rather
controversial issue until present time.
According to scientists, the calendar time period of planting can vary considerably
from year to year depending on the state of the soil [2]. Therefore, the main criterion
for choosing optimal time for planting of Miscanthus rhizomes is the temperature
regime of the soil at the depth of their covering. Recently, there has been noticed a
tendency of weather conditions' change, in particular, the intense warming of the soil
in spring. The vegetative period of thermophilic crops is limited to the transition of the
average daily temperature of air to that of above +10 °С (as a rule, there are no frosts
at this time), and the period of the most active vegetation – with temperature transition
higher than +15 °С. Most researchers believe that the optimal time period for
Miscanthus rhizomes' planting occurs when the temperature of the soil at a depth of 5
cm reaches 10 ... 12 ºC and air temperature – 15 ºС, accompanied with the soil's
physical maturation. That is, starting from mid-April and to mid-May. Earlier planting
is risky due to the possibility of spring frost, and later – of drought [3, 4, 5, 6].
Although there are opposite literature data, according to which the optimal time
of planting is from March to April, and this is due to the use of spring moisture in the
soil, which provides better growth and development of plants. This is important,
because rapid growth and development leads to a greater accumulation of nutrients in
rhizomes, and also allows the culture to tolerate drought and frost better [7].
Another equally important factor, influencing the process of sprouts' emergence,
as well as growth and development of Giant Miscanthus plants is the depth of rhizomes'
covering. After all, the appearance of timely and uniform sprouts, normal development
and overwintering in the next year, and formation of high yields to a large extent
depend on the depth of rhizomes' covering. It is established that in case of sufficient
soil moisture, plants are developing better at a minimum depth of rhizomes' covering;
but due to the fact that during the planting the upper layer of soil in most cases is not
sufficiently moist, it is necessary to increase the covering depth.
The covering depth is substantiated by plant’s biology and depends on many
factors. The most important of these are: soil moisture, its granulometric (mechanical)
composition, climatic conditions, biological characteristics of the cultivar, and quality
of the planting material. On loamy and sandy soils, it is advisable to plant rhizomes at
a depth of 6 ... 8 cm, on sand – 10 ... 12 cm.
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