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Файл:Conducting work on the maintenance of landscape architecture objects. Textbook
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Seedlings are planting material grown from the seeds of tree and shrub plants
in the sowing department of the nursery. Seedlings are planting material transplanted
from seed to the nursery department of the seedling nursery.
Cuttings are plants formed from winter stem cuttings in the nursery department.
Cuttings are parts of plants intended for propagation (vegetative uterine specimens.
They are formed from 1–3 year old lignified shoots, their length is 20–30 cm, during
the period of autumn-winter dormancy on the mother plantation.
Green cuttings are parts of a shoot with leaves, harvested during the growing
season. They are formed with 2–3 internodes. Root cuttings are 5–10 cm root
cuttings. They are grown for 1–10 years.
Seedlings are grown from seeds of local origin. They are harvested in normal
and plus plantings, in forest seed plots and plantations. It is allowed to grow them
from seeds of other areas in accordance with zoning (forest seed).
Seedlings are grown for 1–5 years, the time depends on the plant species and
soil and climatic conditions.
The age of seedlings is determined from the time the plants emerge from seeds.
Seedlings and saplings should have straight stems, completely wooded shoot tips and
fully formed buds.
Planting material should have a well-branched root system and a sufficient
number of fibrous roots. If the length of the roots exceeds the dimensions required for
mechanized or manual planting, or if they are partially damaged, they must be cut off.
The length of the root system of seedlings should be at least 10 cm when
planted on soils with excessive moisture, 15 cm — with normal moisture, 20 cm —
with insufficient moisture.
Saplings have root lengths of at least 20–25 cm.
Seedlings are tied into bundles of 50 and 100 pieces, saplings — 50, 25 and
10 pieces, so that the mass of the bunch does not exceed 10 kg. Bunches are buried in
moist soil or placed in boxes, bags, etc. It is necessary to ensure that the weight of the
filled container does not exceed 30 kg.
You can store planting material for a short time in a shaded place in plastic
bags, with a storage temperature of no higher than 15 °C, with a protective layer of a
special substance that protects it against drying out.
Coniferous seedlings are stored in boxes or baskets, tightly placed in a creamy
peat-humus substrate and watered.
For short-term storage during work in a nursery or on a forestry plot, bunches
of seedlings must be buried in grooves, covering the roots and lower parts of the
stems with soil to 1/4 of the height.
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Without digging, the material can be stored for 1–2 days, treated with
preparations that prevent drying of the roots (calloid composition, naphthylacetic acid
(0.001 %), ethylene glycol ethyl crotyl ether (0.01 %), idyl lyoacetic acid (0.001 %).
For long-term, autumn-winter storage, seedlings and saplings are dug into the
grooves, the roots and lower parts of the stems are covered with soil to 1/3–1/2 of the
height.
The planting material is not tied into bunches.
The digging area should not be flooded with water, protected from wind and
direct sunlight.
During storage in the trench, certain conditions must be observed. The root
system must be in moist soil; when warm weather sets in, buds are delayed by
covering the digging area with straw, sawdust, etc.; when frost sets in, the planting
material is also insulated with snow, pine paws, and moss.
It is possible to store seedlings in refrigerators, glaciers, etc. at temperatures
from +1 to –5 degrees and high humidity.
Small seedlings with a closed root system are delivered from the nursery as
needed to the forest area. Their storage time does not exceed 2 weeks.
It is necessary to prevent the substrate from direct sunlight and drying out,
while ensuring access to diffused light.
Also, planting material with a closed root system can be stored in glaciers and
refrigerators, similar to seedlings with an open one.
At the onset of the growing season, boxes with open lids are placed in planting
areas in the shade, on mineralized soil in a ridge up to 1 m wide.
The ridges are covered with earth and substrate and watered 1–3 times a week.
Larger seedlings are stored outdoors, in a damp, illuminated place, preventing
the substrate from drying out.
1.3. CROP ROTATIONS AND OTHER MEASURES
THAT ENSURE NURSERY SOIL FERTILITY
Crop rotation refers to the process of growing main crops — planting
material, interrupted to increase fertility by various fallows and the cultivation of
other crops. Crop rotation preserves soil fertility, improves structure, and the
effectiveness of weed control.
Crop rotation also involves alternating tree and shrub species crop rotation in
one place.
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When alternating main crops, subsequent ones should take advantage of their
predecessors; after legumes, for example, it is good to plant nitrogen-demanding
plants: lilac and others.
After rocks deplete the soil, plants are planted to restore fertility.
Crop rotation is also important for weed control.
When changing species in areas, lighting conditions, nutrition, methods and
amounts of cultivation change, which allows many weeds to die.
The inclusion of fallows — black, green manure and green — makes weed
control effective by clearing out rhizomatous weeds, especially on black fallow. In
fallow fields it is easier to control weeds with herbicides.
The need for different breeds in the amount of nutrients is different. The
removal of nitrogen and phosphorus substances by trees is 3–5 times greater than by
shrubs, and potassium is 3–6 times more. Trees and shrubs absorb minerals from the
soil, and after the leaves fall, they return some of the absorbed substances to the soil.
For the correct development of crop rotations, it is necessary to know the
impact exerted on the soil by the main crop, measures to increase the productivity of
the main crop, and know ways to restore soil fertility.
In forest nurseries, sowing is carried out in black, early, green manure and
green fallows. Soil cultivation technologies using these systems are available in
specialized literature on agricultural technology.
Soil cultivation in the nursery includes plowing, harrowing, cultivation,
peeling, and development of new lands.
Soil fertilization is of great importance to ensure high-quality planting material.
Correct use of fertilizers regulates soil acidity, increases the vital activity of soil
microorganisms, improves structural qualities, and creates the best ratio of nutrients
for the plant being grown. Organic, inorganic and bacterial fertilizers are used.
The bulk of fertilizers are applied when preparing the soil for planting. Types
of fertilizers, forms of their application and application rates are determined taking
into account soil fertility, as well as the properties of the plants themselves. Be sure to
enrich the soil with manure and other organic fertilizers. Application doses depend on
the plants and range from 40–300 t/ha. Manure is applied under pure or green manure
fallow, under previous crops.
Fertilizers containing calcium are also applied to previous crops. Half of the
annual norm of phosphorus and potassium fertilizers is applied before planting in the
fall, and half in the spring during cultivation. Nitrogen fertilizers are applied in the
form of dry fertilizers to the soil or foliar fertilizers during the growing season.
Microfertilizers are applied when there are signs of deficiency in the plant.
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Irrigation used in nurseries is sprinkling and furrow irrigation. Sprinkler
irrigation is carried out using special installations. Irrigation rates for sprinkling are
lower than for furrow irrigation (70–400 m3/ha). The disadvantage of sprinkling is the
compaction of the top layer of soil, which requires loosening.
When furrow irrigation is used, the soil must be well leveled. In this case, the
soil structure is not disturbed and a crust does not form. The furrows can be flowthrough or dead-end. The length of the furrow is 50–150 m, the depth is 12–18 cm,
the width at the top is 25 cm, the distance between the axes of the furrows is 0.5–0.8 m.
On large areas, furrows are made with a tractor furrow maker, on small ones with a
horse-drawn hiller. Before cutting, the soil must be leveled.
We will consider irrigation systems in more detail in paragraph 3.12.
1.4. ORGANIZATION, PLANNING AND ACCOUNTING
OF WORK IN THE NURSERY
Medium and large nurseries are usually divided into 4 departments:
reproduction, formation, uterine and economic.
Depending on the need (task) for growing certain breeds, corresponding
departments and nurseries are allocated. For example, in the propagation department,
1–2 year old planting material is grown. It has 3 divisions: sowing, cuttings, picking.
The formation department consists of 3 nurseries of ornamental forest species
and 1 fruit tree. In different nurseries of this department, seedlings transplanted from
the propagation department, rooted cuttings, and layerings are grown. This is where
the trunk and crowns are formed. In the formation department, seedlings are grown.
They also use grafting and grow decorative varieties and garden forms of trees
(variegated, beautifully flowering, etc.).
In the nursery of large-sized seedlings, seedlings of 12–15 years old are grown
for planting in public gardens, parks, etc. At the fruit nursery, seedlings of fruit
species are grown. In the mother plants section, plantings that serve as a source of
seeds, cuttings, root shoots and layering are grown.
The economic department includes the nursery estate with an office, household
and economic-production premises, land, crops of agricultural herbs, crops, ponds, etc.
Some nurseries have dendrological departments where rare breeds are bred,
and an experimental department for conducting experiments on growing varieties and
hybrids.
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A special place is given to composting plants necessary for the production of
organic fertilizers. A special room is allocated for storing inorganic fertilizers and
drugs to combat diseases and pests.
Roads, sites and structures occupy about 10 % of the nursery area.
The most fertile areas with loose soils are allocated for sowing. Fertility is
maintained through crop rotation and fertilization.
The best site for a nursery will be a rectangular plot. The site for the nursery
should be located near transit roads and not far from the city.
The organization of the nursery territory is determined by the location of the
departments. The reproduction department is located on a permanent site with fertile
soils, protected from the wind and located close to a water source. Mother plants are
located near the propagation department. The department for the formation of trees
and shrubs (nurseries) occupy a permanent place in large nurseries. In small nurseries
they may not have a permanent place, because different nurseries are united in one
area to enlarge crop rotation fields and move nurseries within the common crop
rotation field.
The first nursery of trees and shrubs is placed on the best sites, the plants are
transplanted for the first time and they need good development conditions. In the
middle and southern regions, it is not necessary to allocate 1 nursery, it can be
combined with 2 and 3 nurseries, the rapid development of seedlings, plants are ready
for landscaping after 1 nursery.
The territory of the nursery is divided not only into nurseries and crop rotation
fields, but large crop rotation fields are divided into smaller areas, quarters, where
individual breeds are placed.
The blocks usually have the same size and shape; temporary roads are laid
between them, which do not interfere with soil cultivation and maintenance. The
administrative and economic center is located at the main entrance. Utility rooms are
available in each department. The machine and tractor park is located in garages.
The road network, drainage ditches and windbreaks also play an important
role. When designing, it is necessary to rationally place these elements.
It is necessary to place them along the boundaries of crop rotation fields.
The road network provides access to all areas. There are main roads, on-farm
roads and temporary roads. Main roads should be 6–10 m wide, covered with crushed
stone, asphalt or slabs.
On-farm roads of the second order are usually unpaved, their width is 4–5 m,
and are used for transporting goods to crop rotation fields. Temporary roads are
intended to serve the area under plantings. They should be 2 m wide.
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It is necessary to consider the correct placement of reclamation ditches. The
number of ditches, their width, location and depth depend on the degree of
swampiness and the nature of the soil.
Windbreaks are positioned perpendicular to the prevailing winds. The main
strip is organized along the border of the nursery, windbreaks inside the territory,
near the roads.
After determining the annual production of trees and shrubs, the so-called
production capacity, it is necessary to determine the ratio (in %) of produced plants:
fast and slow growing, beautiful flowering and decorative deciduous plants with
different growth rates.
Then the timing of their cultivation in nurseries is determined, and crop
rotations are determined. The establishment of each plant species is calculated by
nursery, taking into account plant mortality. Based on the calculations, the area of the
nursery is determined. The total sum of the areas gives the producing area of the
nursery, occupied by plantings and crop rotation fields.
The total area of the nursery consists of production and auxiliary areas
(20–25 % of production), occupied by roads, protective plantings and buildings, as
well as other areas not included in crop rotation.
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SECTION 2. CULTIVATION OF TREES
AND SHRUBS AND FLORICULTURE
2.1. STIMULATING SEEDS TO GERMINATE
The methods of stimulating seeds to germinate are different: physical, chemical
and physiological. Physical techniques involve complete removal or damage to the
seed cover (scarification, impaction), heat treatment and washing.
Chemical methods include treatment with acids, alkalis, microelements, and
stimulants. Physiological techniques affect the state of the embryo and involve
prolonged exposure to temperature, light, air composition, and sometimes treatment
with growth stimulants (gibberellin, auxin, kinetin). They are effective only if they
treat seeds that contain a sufficient amount of moisture.
Seeds with very hard covers are scarified, scalded or treated with acid before
sowing. For scarification of seeds, there are mechanical scarifiers. After treatment in
it, the seeds easily absorb water and swell.
Impact — damage to the skin of seeds by striking each other or against a
vessel, while the skin is damaged without harming the seed. When shaking the
vessels, sand is sometimes added.
Instead of scarification, some seeds with a particularly strong shell (robinia
pseudoacacia (white acacia), gledicia (honey locust)) are soaked in hot water (60 °C)
until cool. Sometimes they are also scalded by immersing them in gauze for
1–2 seconds in boiling water, and then in cold water, repeating 2 or 3 times. Instead,
you can also apply treatment with concentrated sulfuric acid, then soaking in water
(white acacia — 30–50 minutes, honey locust — 60–120 minutes). The most
common way to influence seeds of tree species is stratification. With this method,
the seeds are interlayered with sand/peat and kept in winter at a temperature of
1–5 °C or under snow for 45–60 days.
When stratifying, the seeds are mixed with three parts of coarse sand, after
which the mixture is slightly moistened with water. The mixture must be moistened
and stirred every day until the seeds swell. After swelling, you should stop wetting it
and pour the mixture into a container placed in a cool room (+5 °C).
It is necessary to maintain the humidity and temperature of the mixture, and
also ensure that the seeds receive sufficient oxygen. When the roots appear, the
container is placed in the snow before sowing.
The shortest stratification period (1–2 months) is found in the seeds of beech,
Calligonum, Rhamnus, Tatarian honeysuckle, Pennsylvanian and downy ash.
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The stratification period for the seeds of apricot, privet, pomaceae, mackerel, and
golden currant is about three months.
A period of 6 to 8–10 months is required for the seeds of Manchurian aralia,
euonymus, hawthorn, hornbeam, dogwood, viburnum, linden, and rose hips.
The duration of preparation of seeds for germination is influenced by
environmental factors, collection time, storage conditions, etc.
Dried seeds require more preparation time than fresh ones.
Scarification is a damage to the hard shells of seeds to speed up germination.
In this process, the seeds are ground with coarse sand/metal filings, sandpaper, placed
in gauze and dipped three times alternately in boiling water and cold water. Then the
seeds are laid out and dried.
Scarification is used before stratification of oleaster seeds and other seeds with
a hard shell. The seeds of juniper virginiana and some other plants are subjected to
chemical treatment and treatment with concentrated sulfuric acid. Seeds are treated
with acid for 30–50 minutes, then washed with water and stratified for 90–120 days.
Stimulation of germination by hormones (gibberellic acid, kinetin,
benzolaminopyrine) and other substances (phenylurea, potassium nitrate, etc.) has
been used more and more recently and is considered a promising method. The
concentration of solutions and treatment time are established experimentally.
Hormones are used in concentrations of 0.001–0.1 %, other substances —
0.1–1 % and higher.
Gibberellin enhances the growth of embryos, but does not contribute to the
emergence of seeds from a state of deep dormancy. Cytokinins (kinin,
benzylaminopyrine) under certain conditions shorten the period of stratification
without affecting the course of further development of the embryo.
A new way of preparing seeds with a hard-to-permeable shell is forced
saturation in a vacuum, a mechanical process carried out immediately before sowing.
After this preparation, seed moisture increases by 1.5–3 times (compared to stratified
ones), and germination capacity by 16–21 %.
Other methods of preparing seeds with deep dormancy are being developed.
2.2. REPRODUCTION OF TREE AND SHRUB SPECIES
There are only three methods of reproduction: asexual, sexual, vegetative. The
main task of reproduction is to increase the population size while maintaining genetic
characteristics.
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The asexual method of reproduction is characteristic of lower plants: fungi,
algae. Higher plants (angiosperms and gymnosperms) are mainly characterized by
seed and vegetative methods of reproduction.
The seed method of reproduction (sexual) is a process in which, as a result of
the fusion of germ cells of two parents, a new organism is formed. With the seed
method, varietal characteristics are rarely preserved.
The vegetative method of propagation determines the well-developed ability of
plants to regenerate — to restore an entire organism from its individual parts or organs
(buds, cuttings, roots, leaves, etc.). With the vegetative method, all the characteristics
of the mother plant from which parts for propagation were taken are preserved.
Let us list the methods of vegetative propagation of woody plants: cuttings,
layering, root suckers, dividing bushes and grafting. In nurseries, propagation by
cuttings and grafting is most often used. Advantages of the vegetative method
compared to the seed method: obtaining new plants, the propagation of which by
seeds is impossible due to the small number/absence of seeds, due to the difficulty of
growing, higher growth rate of planting material.
A cutting is a part of a stem, root or leaf that is separated from a plant and,
with proper care, develops into an independent plant. Cuttings can be stem or shoot,
root and leaf.
Woody plants are propagated mainly by stem and sometimes root cuttings.
Stem cuttings are:
- with leaves — green (summer) non-lignified;
- without leaves (winter), woody.
Almost all shrubs are propagated by green cuttings: climbing roses, lilac,
forsythia, hydrangea, wisteria, mock orange, buxus, tamarix, actinidia, privet,
honeysuckle, Buldenezh, yellow acacia; from trees — garden forms of willow,
catalpa, honey locust, poplar, ash, ash maple, silver maple, etc.
To propagate woody plants by cuttings, it is necessary to select the most
valuable forms and varieties, and the material for it must certainly be unaffected by
diseases and pests and absolutely healthy. Plants selected for propagation must have
large flowers, pure color, and correct shape. As a rule, young plants form best roots.
It is necessary to carefully select and prepare tools and equipment for work, the
workplace must be clean, the tools must be convenient.
For cuttings, the following tools are needed: a sharp knife, pruning shears,
pegs, mixtures for growing plants, pots, containers. After work, tools are cleaned and
stored in special places. The disadvantage of seed propagation is later flowering, but
its undoubted advantage is that it makes it possible to obtain new varieties.
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2.3. GROWING SEEDLINGS
When cutting to harvest green cuttings, shoots of the current year with green
bark are cut off, their lower ends are lowered into water and transferred to the place
where the cuttings are cut. Shoots are cut in the morning or on cloudy days; if it is hot
outside, cuttings are best done in the shade, in a cool place.
Be sure to pay attention to the length and thickness of the cutting. These
parameters are very important for good root formation. For shoots with short nodes,
cuttings should be taken with 3–4 internodes, for shoots with long nodes — with 2.
The total length of green cuttings should be 4–12 cm (on average 8–10 cm).
Green cuttings longer than the declared size take root poorly, can easily dry
out, and the process of root formation occurs more slowly. You should also not take
very thin cuttings, as well as those that are inflexible or brittle, those with flowers or
flower buds. Rules for green cuttings:
- the cuttings are cut while hanging, with a sharp knife, the cut is made
obliquely;
- the upper part of the cut passes above the bud, close to it, the lower part — 3 mm
below its base, under the leaf cushion;
- the upper and lower leaves are left; for very large leaves, 1/2–1/3 of the leaf
blade is removed;
- the cuttings are placed in a container with a small amount of water, sprinkled
with water, and covered with a wet cloth. Plants that cannot stand a long stay in water
are stored in damp peat, moss or under film;
- on cuttings of coniferous plants, a longitudinal split is made at the base to
a depth of 1 cm.
When planting cuttings, you will need cold greenhouses 30–35 cm deep or
shelving in a greenhouse. A layer of good turf soil mixed with sand to a level of
10–15 cm is poured into the bottom of the greenhouse, and a layer of coarse washed
sand is placed on top of it to a level of 3–5 cm. Also, sometimes cuttings are planted
in warm greenhouses. Be sure to fit the frames tightly to the greenhouse boxes and
lay hot resin felt along the sides.
Rules for planting cuttings:
- planted in rows to a depth of 1–1.5 cm under a wooden peg;
- leave 6–10 cm between rows, 2–4 cm between cuttings;
- press the soil tightly around the cuttings, and leave the bottom leaf on the
surface;
- water through a fine sieve, cover with a frame, shade with mats;
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