Table of Contents
An area upon which young seedlings trees are raised for planting. Or A nursery is an area in which seedlings are raised to be transplanted elsewhere. Or A Nursery is a place where plants are grown to a usable size.
An area upon which young seedling trees are raised for forest planting. Nursery is an area in which seedlings are raised to be transplanted elsewhere.
The Need for Forest Nursery Raising
- Direct seeding is seldom uniformly successful and artificial regeneration in most parts of Pakistan must be accomplished by planting.
- To make the seedlings available for planting outside the forest areas as e.g farmlands and areas under the control of the departments, nurseries are needed.
- Abandoned farmlands, prairies, and other denuded areas must, in most cases be forested by planting.
- Forest fires, by completely destroying the large areas of forest, often make regeneration by planting the only practicable method. (Katoch, C.D “Forest Nursery Handbook”)
Key task of Nursery Management
Key task of nursery management is to provide:
- The required number of
- Strong plants
- Of the right size
- At the right time
- Of the desired species
- Of the high grade
- At reasonable cost
Types and Classification of Nurseries
Nurseries are classified on the basis of:
1: Water availability as:
- Dry nursery
- Wet nursery
2: Time for working operations as:
- Permanent nursery
- Temporary nursery
3: Root covering as:
- Bare root nursery
- P-tube or covered or potted nursery
Temporary nurseries are used for a few years only, usually to grow stock for planting on a particular area. They are then abandoned and new ones are laid out where additional planting is necessary.
- Usually small and are increased or decreased in number with the demand for planting material.
- Wherever possible, they should be partially surrounded by high forest so as to break the force of the world.
- They are usually located on recently felled areas where there is an abundance of organic matter in the soil and are abandoned before the soil deteriorates under successive cropping. Manuring is not necessary.
- Temporary nurseries are often advantageously maintained in mountainous regions, as they afford an opportunity to:
- Grow each kind of stock in the same vegetative zone as the area to be planted.
- Cost of transportation is much reduced as plants are grown on or near the site where they are used. This is an important factor when large trees are used in planting.
- The time between lifting the stock in their nursery and set in the plantation is also reduced. (Sheikh, M.I Raising of nurseries.)
Disadvantages of Temporary Nursery
Some of the drawbacks are:
- As a rule, a single nursery that supplies all stock for planting in a given forest division is better than several small ones that are shifted about from place to place as circumstances require.
- A single nursery is more easily supervised, better cared for, and usually better located.
- Stock can be grown at a lower cost because a single large nursery with a given yearly output costs less to manage and maintain than several shifting ones of equal production.
- Temporary nurseries do not yield as good plants and the required output cannot be as effectively maintained.
Permanent nurseries are those where stock is grown continuously year after year on the same site.
- Permanent nurseries are usually large and intensively managed. Some forest nurseries in Europe have been in existence for more than 100 years. They are located near a superintendent’s residence.
- A large amount of labour is required in nursery work particularly for a period of 2 or 3 months in spring. It is highly important, therefore to locate a permanent nursery where labour is available and where minimum amount of time is consumed in going to and returning from work.
- It should also be located with reference to inexpensive and easy transportation.
- When stock is distributed by wagon or by pack animals, it is important that nursery should be located so that all parts of a forest can be reached directly by established roads and trails.
- Permanent nurseries require permanent staff, huts, sheds, fencing, permanent channels, machines and equipments.
There is no essential difference in management and treatment of temporary and permanent nurseries. In the latter, however the original outlay can be greater because cost can be spread over a long term of years. A large, centrally located, permanent nursery is generally preferable to several small ones because of greater economy in nursery supervision and operation. However, we may require nurseries scattered over to meet farmers demand.
Dry and Wet Nursery
A nursery in which water availability is not on the permanent basis is known as dry nursery. In this type of nursery the water is provided by artificial means e.g by making an artificial pond, or any other artificial means.
A nursery in which water availability is on the permanent basis is known as wet nursery. In this a permanent source of water is available e.g a river.
Open-rooted and Potted Nursery
Some species cannot be moved easily or transplanted safely from a nursery to a planting site unless they are grown and transported in pots, other species cannot grow well in pots. While the open-rooted stock method is cheaper to use, some species require the use of pots. If, however a species will grow either in pots or as open-rooted stock, each method has advantages and disadvantages that should be considered:
Advantages of Open-rooted stock
- There is less weight to transport from the nursery to the permanent site, pots are heavy.
- It takes less time to transplant open-rooted stock.
- Less care of open-rooted seedlings is required in the nursery.
- Seedlings are usually larger and so require less protection after transplanting.
Disadvantages of this nursery are
- Open-rooted seedlings need more space.
- They need more time in the nursery.
- The nursery location must have good soil conditions.
- Roots are exposed to air when the plants are lifted out of the nursery soil and again when they are planted at the permanent site. This can damage the plants.
Potted or P-tube nursery
The most commonly used container in Pakistan is usually referred to as plastic or polythene bags. They are also sometimes called sleeves or tubes. Other types of containers may be used, and if they are made from locally available materials, they may be more affordable.
Advantages of Potted nursery
- Good soil is not required at the nursery site.
- Seedlings can be placed closer together than in the open rooted method.
- The time in the nursery is shorter, and although pots require expense at the beginning, the shorter nursery cuts down on other expenses.
- Root growth is contained in a package that is easy to transport, and there is little or no exposure of hair roots to the air during transporting or transplanting.
- On difficult sites, potted plants may have better survival rates than open-rooted seedlings.
- Soil diseases may not be spread as rapidly to potted seedlings as in open-rooted beds.
Disadvantages of Potted Nursery
- The seedlings require root pruning while in nursery pots.
- Pots cannot be piled up for transport.
- They are heavier and more difficult to transport.
- Seedlings are normally smaller at the time of transplanting and require extra protection from grazing livestock until they are larger.
- Pots must usually be purchased, which may or may not be a problem (depending upon time saved in the nursery or on the expense of making certain soils ready for open-rooted planting). (Sahibzada M. Hafeez A Handbook on forest nursery)
[Video Tutorial] How to Raise a Polythene Tube Nursery?
Factors Determining Nursery Stock Production Success
Degree of success in the production of nursery stock for planting is largely dependent upon:
- Efficient administration and supervision
- Orderly and timely execution of nursery operations.
- Selection of suitable site.
- The economic and successful development of the site.
- Utilization of best cultural methods.
- Utilization of best lifting, storage, and packing methods.
- Elimination of losses in stock from preventable causes.
Administration and Supervision
The success of a nursery is intimately bound up with its administration and supervision.
- The administration must determine the species, number and various classes of stock required year after year for planting in a particular forest, state, or other administrative units. Superior judgment in these matters prevents heavy losses through raising of unwanted species and growing more than is needed at one time and too little at another.
- The administration provides plans for distribution of the output of a nursery by seasons, species, and classes of stock, often several years in advance, and initiates and acts upon all administrative features.
- A check and balance are done in the form of inventories of all stock in a nursery at least once each year. The inventory should show, for each species, number of plants, age, size, quality, and whether seedlings or transplants.
Selection of Nursery Site
Selection a site for a large nursery is a very difficult task, requiring mature judgment and careful study, especially in a mountainous region where all conditions favourable to nursery practice are seldom encountered on the same area. The most important factors influencing the selection of a nursery site are:
- Species of stock to be raised.
- Water supply.
- Slope, aspect and environment.
- Adequate labour supply.
- Readily accessible to main highways, railroads, electric power.
Species of Stock to be Raised
A little difficulty will be experienced in growing the particular species that are best adapted to the region to be served if a nursery site is located well within the planting region where climatic and soil conditions are quite similar to the region as a whole. The natural common occurrence of a species in a region is an unfailing indication that both soil and climate are well adapted to its growth.
The site must be favorable for growth of the particular species that are desired. If a nursery is well situated for growing the desired species, less watering and shading may be necessary and protection against the frosts and winter killing largely unnecessary, so that high grade stock will be produced at less cost.
When large number of plants is produced year after year it is often desirable to grow but a single species in a given nursery. A site can be chosen which is best adapted to the special requirements of the particular species. (Evans, R.W use of Polythene Bags as Seedling Containers)
When species of diverse requirements are grown, conditions are necessarily more or less unfavorable for at least a portion of them. By selecting a site of average conditions where the soil is neither too light nor too heavy, too wet nor too dry, too cold nor too warm, species of different requirements can be grown successfully.
In nearly all localities, because of the necessity for irrigation, a nursery site should be selected with reference to an adequate supply of water.
Soil that most fully meets the requirements for growing a diversity of species of varying requirements is one with:
A light sandy loam or loamy sand foundations
It should be deep fertile and fresh. A good soil is prerequisite to success and economy in plant production. An unfavorable soil can be artificially improved by manuring, or by the application of sand, clay, peat, leaf mold, or charcoal, as the case requires, but only at considerable cost. On the whole, physical characteristics of soil are more important than chemical composition, since fertility can be improved by application of fertilizers.
A heavy clay should be avoided even more than light sand. The former is lacking in porosity and permeability, distribution of soil water is uneven, and it is likely to be cold and too wet. It freezes more readily and plants grown upon it are in greater danger of being thieved by frost. It is much more difficult and expensive to work in all seasons, and in spring, when work is most pressing, it often can nit be worked at all.
Stony soil also is difficult to work but it can be improved to some extet by removing the larger stones when nursery beds are prepared. Root skin more readily when dug from clay than from sandy soil. Clay bakes and cracks upon drying, often exposing tender tools. At the time of seed germination this may be critical to tender embryos just breaking through seeds coats. Seedlings have difficulty in pushing through a heavy clay soil and weeds generally obtain a much firmer foothold in it. On the other hand, a heavy clay soil is preferred by some commercial nurserymen for propagating ornamental conifers because it adheres to the tools well enough so that each tree can be dug with a ball of soil around its roots and wrapped in burlap for shipment.
If the top soil is a fertile, porous, sandy loam 3 to 4 feet deep, underlaid by a more retentive subsoil, an infertile subsoil will not be disturbed by ploughing and by being mixed with the surface soil, and the soil, will be ideal for the production of excellent stock. Such a top soil, is sufficiently deep to provide ample drainage, and as surface soil moisture is depleted more is drawn by capillary from the subsoil.
A subsoil with a hardpan should be avoided because it prevents good drainage and excess moisture retained is favorable to souring of soil, excessive freezing and heaving, and development of nursery diseases.
It is mistakenly belief that when planting is to be done on a poor site with inferior soil, stock should be grown on a similar soil. Stock for planting on all sites should be grown on a similar soil. Stock for planting on all sites should be as well developed and vigorous as possible. It should be grown on the most favorable soil and under the best conditions.
A nursery should be situated near an adequate supply of water because of necessity for irrigation in almost all localities. Coniferous nurseries require abundant water well distributed throughout the growing season, especially during the first season after seed sowing.
The amount of water available during periods of low water and extreme drought should, if possible, be ascertained, since it is at such times that a nursery demands the greatest amount of water. This is extremely important in localities where the water supply from wells, springs, or streams tends to run short. Where the source of supply is a stream greatly in demand for irrigation purposes, it is essential to know whether there is, during dry seasons, sufficient un-appropriated water in the stream and whether its use is regulated by states laws.
In developing a water supply it is very desirable to consider possible future expansion of the nursery because an increased production will require an extension of the water system and enlarged supply.
Slope, Aspect, and Environment
A level site is usually undesirable if the soil is somewhat heavy. A level site is preferable on light, sandy soil. Level land is more easily cultivated and irrigated than sloping or rolling land.
Rough land should be avoided where top soil is shallow, because under-lying rock, gravel, or subsoil will be uncovered in leveling high places to fill depressions.
A gentle slope, just sufficient to permit satisfactory drainage, is best for an average site. If the slope is more than 5 degrees, erosion is likely to occur and terracing will be necessary to form seed beds.
Location of a nursery with reference to aspect depends chiefly upon latitude and altitude. Where provision is made for irrigation, southern aspects in northern latitudes and at high elevations are the best because of their greater warmth.
Nurseries should, not as a rule, be established in narrow valleys or deep canyons because lack of direct sunlight for a large part of the day seriously checks growth. Such sites are also subjected to frost damage because colder air seeks lower elevations in hilly and mountainous regions.
A nursery should not be fully exposed to the free sweep of the wind. It should be protected by a high forest or a well developed windbreak, at least on the windward side. It should not be entirely surrounded by high woods in regions where the soil is heavy or overly wet because movement of air is so completely checked that the soil is difficult to work, particularly during spring months. To what extent it is advantageous to protect a nursery by surrounding vegetation in the forest depends upon conditions affecting each particular site. In general some protection, at least on the windward side, is desirable.
The future development of a nursery can seldom be forecast. Extensions of nursery area may be necessitated by an expansion in nursery capacity or by changes in nursery practice, such as growing older stock, using wider spacing, longer rotations of fertilizing crop, or longer fallow periods. A location should therefore be chosen where a contiguous area of suitable land is so situated that it can easily be added to the nursery and water system extended to it at a reasonable cost.
The vegetation of a site is often a useful criterion of average moisture content, fertility, and acidity or alkalinity of the soil. It also has an important bearing on putting land into usable condition for nursery purposes. Land bearing down logs and old stumps or a large amount of rock are expensive to clear, and in the mountainous country, it often costs far more to put into suitable condition than the price of similarly situated land under cultivation.
The nursery should, if possible, be located where the climate is very similar to that of planting sites to be supplied. This will generally ensure the availability of suitable stock when sites are ready for planting. Localities of excessive rainfall, especially if the soil is generally cold, are not well suited for nursery purposes because under such conditions weeds are more numerous, moss and algae collect more easily on nursery beds, the stock is less sturdy, a number of species which can be successfully grown are smaller and nursery operations are hindered more than where the climate is drier, sites exposed to high winter winds and not protected by a snow cover are undesirable unless artificially mulched. This practice is expensive and mulch often harbours rodents which work under it and damage trees. (Hafeez M. Polythene tube size in Relation to seeding growth in the nursery.)
Adequate Labour Supply
Raising a forest nursery is a labor-intensive job. While selecting a site for nursery the availability of adequate labor should be kept in view.
Readily Accessible to Main Highways, Railroads, and Electric Power
A successful nursery needs constant and close supervision and inspection. Moreover, plants raised in the nursery have to be transported for planting in the field. It should, therefore, be readily accessible to highways and railroads for easy inspection and transportation of plants. Electric supply is a basic necessity and will add to available facilities at the nursery.
ALSO READ: Choice of Site for Nursery Management
Development of a Site for Nursery Raising
The manner of developing a site necessarily depends upon locality and permanency of nursery. In general, it relates to putting the site in good physical condition for the growth of desired stock and for construction of permanent improvements.
Although shape of a nursery must necessarily conform to topography and other features of a site, a square piece of land is more desirable than a long narrow strip. Nurseries of irregular shape present difficulties in arrangement and maintenance. Before work in a nursery is commenced a plan and map should be made showing all permanent features.
- Every large nursery should be permanently divided by roads and crossroads into blocks or compartments, square or rectangular in shape.
- The number of roads should be kept to a minimum and in each case adapted to the character of output and to methods of transportation and cultivation employed.
- Seeds beds, when not bordering on roads, should be surrounded by temporary paths at beast 2ft wide.
- Seeds beds are usually 3 to 4 feet wide and from 12 feet to the entire length of the compartment long.
- Transplants are most commonly set in rows in large blocks divided by paths.
- Long seeds and transplants beds are particularly desirable in nurseries in which implements are drawn by tractors in order to avoid the necessity for too frequent turning.
- Seeds beds should not, as a rule, be continued year after year in the same compartment. A rotation permits more economical methods of manuring and improving the soil by growing soiling crops.
At many large nurseries a map is prepared each spring showing blocks under cultivation and those lying idle, treatment given, the soil and species, age class, and density of stock in each block. These maps serve as a current office record of stock in the nursery and as a permanent record of soil management.
History should be preserved of all soil treatments, rest periods, and crops grown on the soil as an aid to intelligent soil management. Clearly defined blocks and orderly rotation are necessary to such record keeping. (sheikh, M.I Raising of Nurseries)
- Size of a nursery necessary to produce stock for a definite forest region bears no relation to the area of the forest but relates rather to number, size, species, and character of stock required yearly in its management. Where planting is used only to supplement direct seeding and natural regeneration is entirely by planting, particularly if large transplanted stock is used, the nursery must be extensive, embracing from ½ to 3 acres for every 1000 acres of forests.
- When the same species are transplanted at the expiration of 2 years in seedbeds and grown for an additional 2 years in transplant beds, the nursery should contain from 2 to 4 per cent of the area to be planted annually. Broad-leaved species, such as oaks, walnut, beech, ash, maple, and rapidly growing conifers like larch require much larger nursery space in proportion to area planted annually. Furthermore, the area required increases rapidly with the age of stock and the number of times transplanted.
- The actual area of a nursery is determined by output desired, species and age class of stock produced, the area occupied by paths and roads, spacing, and practice followed in crop rotation.
- For open-rooted stock, standard-sized beds contain five rows of trees and are approximately one meter wide. The length of the beds varies from 5 to 20 meters, depending partly on handling needs and the amount of labour and transportation available. Always follow room for extra beds.
- Beds are usually either sunken or raised, depending on species and site conditions. Sunken beds retain moisture much in the same way that micro-catchments work and thus are used where water availability is limited. Raised beds are prepared for open-rooted stock using the double-digging method. They provide seedling with a well-drained and aerated rooting zone for optimal growth.
- The number, character, and kind of buildings, depend largely upon size and permanency of the nursery.
- A superintendent or nursery foreman should reside on the grounds in order to be within reach at all times.
- The labour employed in nurseries is large of a temporary character. When the nursery is located near a town, workmen usually live in their own houses and are employed at a fixed rate per hour while actually engaged. When the nursery is inaccessible to an adequate supply of labour, temporary quarters must be provided at or near the nursery for the large number of labours required for a period of several weeks during autumn and spring months.
- One or more of the skilled labours, who are capable of handling men and taking charge of specific operations, are usually employed throughout the year. These men should also reside at or near the nursery; this contingency sometimes necessitates the erection of permanent quarters for them.
Aside from suitable quarters for the superintendent and for a part or all of the labour, necessary stable room and tool sheds must be provided. Packing and storage sheds should also be provided for the stock after lifting, while it is stored, sorted, and packed, and for storing packing boxes, seeds and other material used in nursery practice.
Hedges and Fences
It is always advantageous to fence a nursery. As the chief purpose of a fence is to protect the nursery from cattle and other animals, it may be of woven wire, wood, or stone or it may be of woven wire fence is efficient in protecting a nursery from animals. It can be made rabbit-proof by using a small-mesh netting for the lower portion of the fence, the under edge of which is inserted from 4 to 6 inches below the ground.
Gates or turnstiles should be constructed at advantageous points. Because of the large amount of labor required in nursery work and necessity for frequently passing in and out of nursery turnstiles are usually preferable to small gates. Large wind-swept nursery areas can be protected by means of movable woven lath fencing just as snow fence are used to protect highways.
Drainage and Irrigation
Surface drainage should be satisfactory. The slope of the land should be sufficient to carry off all surface water but not enough to cause erosion. The site should be brought to a uniform grade when it is relatively flat, but with minor unevenness, so that water will not stand in pools in depressions.
Springy slopes and low flats where water is near the surface should be drained by means of open ditches or covered drains. Such sites, however, should be avoided whenever possible.
Irrigation is necessary in the conduct of nursery operations except in the most favoured localities and under exceptional conditions. Although some species can be grown without irrigation in some regions.
Where precipitation is adequate for farm crops an ample supply of water very greatly reduces cost of stock, materially increases its size and makes success more certain, It is particularly important that coniferous seeds beds should be irrigated during the first year.
Water may be obtained from a nearby spring, stream, or pond or from a well. If water is drawn from a stream or pond and carries weed seeds, it may be necessary to provide for their removal by using charcoal or sand filtration beds at the intake of the water supply.
Whenever possible, the source of supply should be at a higher elevation than the nursery in order that water may be distributed by gravity. When the source is at a lower elevation, water is elevated to a reservoir or tank located on the highest ground in the nursery, from which it is distributed by gravity as required.
In small temporary nurseries no special provision is usually made for irrigation, but water is brought by hand from the nearby well or other source from time to time as required.
Distribution of water
The arrangement for the distribution of water is of considerable importance. Water is often applied artificially only to seedbeds, which may occupy one-tenth or less of an entire nursery, areas that are soiling crops or are fallow are seldom irrigated. Water is distributed to the beds in one of the following four ways:
d: Sub irrigation
Distribution of water over beds as a finely divided spray is admirable, as it is the nearest approach to rain. It should be uniformly distributed at a rate sufficiently slow to permit its complete absorption by the soil. Sprinkling should be sufficiently prolonged to wet the soil thoroughly to a feet or more in depth. Light sprinkling at frequent intervals, which only moistens the soil at a depth of 1 to 3 inches, is not as effective as a prolonged supplication at infrequent intervals. When installation is permanent, pipes vary in diameter according to length of line and manufacturer, with nozzles at 3 feet intervals. The pipes are raised on iron or wooden posts from 3 to 6 feet above beds. The pipes are commonly from 100 to as much 500 or 600 feet long and are usually arranged parallel to each other and about 50 feet apart. Under a water pressure of 30 pounds it is possible to irrigate for a distance of 25 feet on each side of the pipe. The main feed pipe through which water is brought to overhead pipes should be at least 2 inches in diameter and water should have a pressure of at least 2 inches in diameter and water should have a pressure of at least 25 or 30 pounds.
In the portable method of installation a single line of over head ¾ inch pipe 100 feet long with nozzles at 4 feet intervals is supported on iron stands about 1 feet above the ground. The spray reaches to a distance of about 25 feet on each side of the line. Water is brought to the system through an ordinary garden hose from near-by hydrants. The pipe can be quickly uncoupled into short length and transferred to a frame on a cart, after which it can be easily transported to any part of the nursery.
Special attention should be given to construction of beds in order to provide for effective application of water by flooding. Each bed should be as nearly level as possible, and the paths surrounding it should be from 4 to 6 inches above the general level. Water is permitted to flow over depressed beds as required, usually to a depth of 2 to 4 inches. Soil becomes thoroughly saturated by this method of irrigation. It is used chiefly in regions of scanty summer rains where for other reasons large quantities of water are required. The chief objection to flooding arises from the fine sediment that it leaves on the surface of bed after water is taken up by the soil. Where flooding is practiced, seed should be sown in drills, so that the soil between the rows can be worked after each irrigation.
By this method of irrigation water is made to flow in small furrows between rows of seedlings or transplants or between narrow beds when the seed is broadcast, the water reaching the plants by percolation through the soil. Water will readily percolate for a distance of 2 or more feet at either side of the furrow in loose, permeable soil when the nursery is graded and suitably arranged. This is an inexpensive and efficient method of irrigation. Its great advantage over flooding is in non-formation of a surface crust, and its advantage over sprinkling is in its reduced cost and decreased loss of water through evaporation. It is particularly acceptable for irrigating transplants and hardwood seedlings grown in rows a foot more apart or in narrow beds.
Furrows are run between rows or between beds and water is directed through them until the soil is adequately saturated, after which they are closed by cultivation. In order to prevent serious damage from soil washing, the surface should be even and ditches should have so slight a gradient that water barely flows. One disadvantage of furrow irrigation, not encountered with closed carriers, is the accumulation of weed seeds in irrigation ditches. This may materially increase the amount of weeding necessary.
Sub-irrigation requires less water than any method of surface irrigation. Water is distributed through a system of tiles open at the joints and laid a few inches under the surface. Water seeps into the soil and is distributed by capillary action.
ALSO READ: Layout of a Nursery
Each nursery has its own particular problem of soil management which must be solved before the nursery can be operated on a permanent basis. Even under the best and most economical methods of managing a large amount of hand labour are required in nursery operations. The amount of labour required to work the soil properly and keep it free from weeds depends not only upon its texture and compactness but also upon the thoroughness of its preparation when the nursery is laid out. For each nursery a definite plan of soil management should be worked out, involving the maintenance of soil fertility and the amendment of such other soil properties as may need improvement.
- Where it is the purpose to grow a variety of a species of various ages, it is usually preferable to prepare all parts of the nursery for the production of all kinds of plants. The best preparation is a deep working of the soil. The loosening and mixing of the soil should be done by hand trenching or by ploughing. Although hand working loosening the soil to a depth of 1 to 2 feet and throwing in ridges, gives the most thorough preparation, it is very costly and must usually give way to ploughing. It is often advantageous to use a subsoil plough in order to loosen the soil to a depth of from 12 to 14 inches.
- All stones and roots should be removed and the land is levelled or terraced where necessary.
- When land is worked in early autumn and allowed to lie fallow over winter, its physical condition is improved by its exposure to frost and winter rains.
- As soon as the land is in a condition to work in the spring it should be manured and harrowed. Ordinarily, it is preferable to apply manure preceding a soiling crop rather than immediately before seedbeds are prepared. Topsoil should be worked until it is finely divided condition, entirely free from lumps.
- On sites where the soil contains much weed seed or where there is an excess of undecomposed organic matter, it is advisable to cultivate a field crop for the first season. A crop, like potatoes, cabbage or corn that requires thorough and clean cultivation throughout the season is preferable. After the field crop is harvested in autumn, the soil is ploughed and left fallow over winter. The following spring it is in condition for the formation of seed and transplants beds.
- When nurseries are to be maintained for a long period of time on the same site, it is well worthwhile to give the most careful attention to thorough soil preparation. (Katoch, C.D Forest Nursery Handbook)
SEE ALSO: Soil Preparation for Nursery
Cultural and Tending Operations
Preparation of Seed Beds
The portions of a forest nursery that are not lying fallow or are not given over for the time being to soiling and agricultural crops are used for seeds beds or transplants beds. The relative proportion of each depends upon the kind and character of stock produced. In some cases only seedlings are grown, the stock is transferred directly from seedbed to plantation. In other cases, all seedlings are transferred to transplant beds for a period of 1 or 2 years before planting in the field. When transplants are grown the area of seedbeds varies from one-twentieth to one-sixth of the area of transplant beds, depending upon species and length of time that stock remains in seedbeds and transplant beds.
In most nurseries seedlings are grown in rotation with transplants and other crops. This is possible where nursery soil is light, free of rocks and other debris, and well-drained, otherwise, it is necessary to select the best soil for seedbeds. Seedling culture is more exacting in its soil requirements than the growth of transplants. Heavy, lumpy soils subject to sun-baking and surface cracking are less suited for seedlings than for transplants.
The size and form of seed beds depend upon locality and species and also upon the cultural methods employed, particularly the methods, of shading, watering, and working the soil. Assuming that the soil has been adequately enriched and prepared by previous cultivation and cleaned of all debris, such as sod weeds, roots, and stones, the beds are formed shortly before seed is sown.
Seed beds are usually made from 1 to 1.2 meter wide and 5 to 7m long for potted stock, and 5 to 20m long for open stock.
When beds are sown broadcast or in closely spaced drills, a width greater than 1.2m is objectionable as they cannot be cultivated and weeded readily from the paths. When drills are widely spaced so that a man can walk between them in weeding, beds are often 6 or more feet wide. Not infrequently a single bed occupies an entire compartment in the nursery.
Time of Seeding
The control of moisture in seed beds through irrigation and shading and their protection from birds and rodents make it possible to extend the time during which seeding can be done in a nursery much beyond that acceptable for direct seeding in the open, seed beds can be sown from late autumn to early summer when soil is ready for working. The best time within this period depends upon:
b: Local climate
c: Methods of nursery practice
All the species in which seed cannot be easily kept over winter without great loss in viability unless specially stored should generally be sown in autumn. Provision must be made to protect the beds from rodents and the sowing must be delayed until all danger of warm weather is past.
Local climatic conditions may be favorable for autumn seeding in one locality and less favorable in another. Regions subject to heavy winter precipitation and prolonged summer drought are usually favorable for autumn seeding; regions subject to dry, cold winters with little snow are much less favorable. Regions with short growing season and late spring are usually favorable for autumn seeding regions with an early spring and long growing season are more favorable for spring season.
Method of Seeding
Seed beds are sown broadcast or in dills. Broadcast seeding is chiefly practiced in sowing conifers and small seeded broad-leaved species in seed beds that are covered prior to germination and young seedlings protected by shading. Drill seeding is the general practice in sowing in the large seeded broad-leaved species.
Inspite of the theoretical advantages to be derived from broadcast seeding, such as greater uniformity of stock and better use of all available plant nutrients, soil moisture, growing space and light, drill sowing has a slight advantage in economy of operation and quality of stock, because of rapid growth and early removal seedlings, class of labor frequently employed for nursery work, and the greater ease of weeding and thinning drill sown seedlings.
The chief advantage in broadcast seeding is the much larger number of plants that it is possible to produce per given area of seed bed and the resulting decreased cost of production. For this reason broadcast seeding is preferable on ordinary nursery soils, such as sand and loam, that have adequate water supply when the stock remains in the seed bed only 1 or 2 years. When it is necessary to hold stock over for an additional year after it has reached the most suitable size for lifting, drill seeding makes the checking of growth by root pruning easier without the use special equipment. Drill seeding is usually preferable on heavy soils as it renders cultivation possible, thus facilitating the entrance into the soil of both air and water.
Covering the Seed
Immediately after the seed is broadcasted it is presented into the soil with rollers or hoe or other tool with a smooth surface. The covering soil may be shifted over the seed beds with a strong ¼ inch mesh sieve. The covering soil should be but slightly moist. A covering of fine loam induces better germination than sand, the latter is preferable because of its freedom from crusting when wet. The depth of soil covering should be from 1 to 4 times the average diameter of the seed, depending upon the locality and the character of the soil. Deep covering is more acceptable in regions having a dry atmosphere.
Quantity of Seed per given Area of Seed Bed
The quantity of seed to sow on a given area of seed bed depends upon a number of factors, of which the more important are:
1: The species. It is of the highest importance in determining quantity of seed as it determines the size of seed. The number of seeds per pound is a rough index of the quantity to be sown. Rapid-growing species are less densely sown and so less quantity of seed.
2: The tree percentage of utilization value of the seed. The utilization value of the seed determined from germination tests, or better yet the tree percentage of seedlings to be expected under the particular nursery practice, should be used always in determining the most desirable amount of seed for a given area.
3: The length of time that the seedlings remain in the seed beds. Most species can safely stand 2 to 3 times as close in the seed beds the first year as they can the second year. When they remain through the third year they should have from 2 to 4 times the space of 2 year seedlings. In general, when the seedlings are transferred direct to the plantation they should have twice the space in the seed bed as when grown for transplanting; thence but one-half the quantity of seed should be used.
4: The quality of stock required: Quantity should be secondary to quality. Too dense seedlings cause the resulting seedlings to be tall, slender, and weak. (Sahibzada M. Hafeez A Handbook on Forest Nursery)
Formula for Seed Quantity
The following formula shows the method of determining the amount of seed required for any given area of seedbeds and is applicable to the broadcast or to the drill method of sowing:
Pound of seed required = No of plants desired on an area ➗ No of seeds per pound that will germinate and grow
There are five attributes of the seed of direct importance and each one must be evaluated for any given seed lot.
The definition of a pure seed is one that appears normal in all respects regardless of whether or not it contains a kernel. All dwarfed, malformed, broken, cracked and insect-damaged seeds are included with trash as impurities. Take the working sample and determines its weight in grams to 2 decimal places. Pour the sample on to a glass plate or formica sheet and separate the impurities from the pure seed. Weigh both portions separately and calculate the purity to the nearest whole per cent as follows:
Pp% = (Weight of Pure Seed ➗ Weight of Sample) x 100
Count out 1000 pure seeds taken from the purity test and determine the total weight in grams to the nearest first decimal place. The approximately number of seeds per 1lb is obtained as follows:
No./lb = (453.6 x 1000) ➗ Wt. of 1000 seed
Full Seed Percent
Using the pure seed from the seed weight test count out 500 seeds. Cut each one with a knife or crush it with a small hammer. Record the number of seeds which are full, i.e contain a kernel and calculate the percentage as follows:
Full seed Percent = (No. of full seeds x 100) ➗ 500
MC% = [ ( Original Wt. – Oven Dry Wt. ) ➗ Original Wt. ] x 100
The object of testing the germinative quality of seed is that it provides an indication of the percentage of seeds in a given lot that may be expected to produce seedlings. It also provides a quality index by which one seed lot may be compared with another. Similarly it can be used to compare one nursery with another using the same seed lot. Equally, it can be used as a yardstick in the evaluation of different sowing techniques. It is also a measure of the treatment the seed has received between harvesting and sowing. Before proceeding further it is necessary to give the definitions of some commonly used terms.
Is the total number of seeds that germinate in the test plus the number of sound seeds remaining ungerminated at the end of the test, expressed as a percentage, e.g. Out of a total of 400 seeds, 220 germinated and after cutting open the remaining 180 seeds it was found that 60 were sound.
Germinative Capacity = ( 220+60 ) ➗ 400
Is the percentage of seeds in a sample that have germinated in a test up to the time when the rate of germination ( the number of seed germinating per day) reaches its peak. The number of days required to reach this peak is the Energy period. E.g Out of a total of 400 seeds of pine the daily rates of germination from the 7th to the 11th day after sowing were 20, 60, 80, 70, 55 with a continuing decrease thereafter.
GE = [ ( 20+60+80 ) ➗ 400 ] x 100
40% and the EP is 9 days.
Watering Seed Beds
As soon as the seed is sown the beds should be watered thoroughly and thereafter kept in a moist condition. When germination once begins it should be watered only often enough to prevent them from drying out. The frequency of watering varies widely with the weather, soil and kind of covering material and no specific rules can be formulated for watering. The general rule for watering is simple: adequate amounts of water are needed at regular intervals. Excessive watering is costly and may result in loss of nutrients through leaching. Reduction or cessation of irrigation in late summer accelerates the hardening of the seedlings before frost.
Watering should take place in the early morning and late afternoon or evening. The plants should receive about 5mm of water each time. The top 20cm of soil in the pot or bed must be kept moist. Checking the pots or beds regularly will show whether the soil is sufficiently moist. Moisture levels should never be allowed to drop near the wilting point.
Weeding and Cultivation
Source of supply of weed seed that is brought to the nursery by water, wind, in mulch, manures should be reduced as much as possible. Seed beds should be kept free from weeds. This necessitates from 3 to 6 weeding or cultivation the first season. Frequency depends upon condition of the soil, season. Young plants may need weeding about once every ten days. One of the largest source of expense in nurseries is the weeding, which is necessary several times a season.
All stocks that has been definitely allocated for removal from the nursery in the spring should, if possible be dug well in advance of the beginning of growth. When seedlings and transplants are prepared for sale or packing they may be brought to the packing shed as soon as they are lifted and spaced out on long tables where culls and other discards are thrown out after which they are counted, in bundles of 50 or 100 and healed in until dispatched for shipment. The culls and discards represents the poorer and weaker individuals in which may of the defects are inherited.
Storage of the Nursery Stock
The stock is lifted in late autumn or early spring and stored until ready for shipment or transport to the plantation. Weeks or months may intervene between lifting and final resetting in the field. Methods of storage:
1: Healed in the open.
2: Healed in under cover. The term healing is applied to the temporary setting of the plants in the moist soil in order to prevent the roots becoming dry.
3: Nursery stocks can be stored for long periods in cold storage when properly packed.
4: In snow or ice pits- stock can be held back by storing it in snow or ice pits on the planting site.
CHECK ALSO: Protection of Nursery
Transport of Nursery Stock
In pacing nursery stock for transport the weather condition, distance and time in transit must be considered. When distance is short, plants may be packed in a wagon for transportation and taken to planting site. They may be placed in the wagon for transportation and taken to planting site. They may be placed in the wagon box, in planting baskets or in larger packing cases or boxes. Transport may be by motor, trucks. It may be by mail or express or rail. Careful handling during transport is required. Bundles of seedlings should be covered with damp moss or moist grass.
When nursery stock is received after shipment, it should be unpacked immediately and planted at once or else healed in until required. Roots should be thoroughly moistened but pudding is not necessary. The plants can be laid in a temporary ditch and covered over with moist earth until they are planted out.
?? Free Download: Manual of Nursery Practices by Keats C. Hall
- Evans, R.W “Use of polythene Bags as Seedling Containers in plantation Establishment in the Tropics”
- Hafeez M. “Polythene tube size in relation to seedling growth in the nursery.”
- Katoch, C.D “Forest Nursery Handbook”
- Ken, McNabb “Nursery Manual Pakistan Forestry Planning and Development Project.”
- Sahibzada M. Hafeez “A HandBook on Forest Nursery”
- Sheikh, M.I “Raising of Nurseries.”
Cover Photo – Patfeeder Nursery Dera Murad Jamali Nasirabad Balochistan
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