What is a nursery?

Baolong Huang

A place (garden) dedicated to cultivating young trees (seedlings). Its main task is to provide high-quality seedlings for afforestation. Nursery should implement scientific management, adopt advanced seedling raising technology as far as possible, pay attention to maintaining and improving soil fertility, prevent and control pests and diseases in time, shorten seedling raising period and improve seedling yield and quality.

Nursery variety

Nursery is divided into forest nursery, shelter forest nursery, garden nursery, fruit tree nursery, economic forest nursery, experimental nursery, etc. Nurseries with various business contents are called comprehensive nurseries. According to the length of service life, it can be divided into fixed nursery and temporary nursery. Fixed nurseries, also known as permanent nurseries or permanent nurseries, are generally large in scale, have a long operating life, have certain basic construction, cultivate more kinds of seedlings, have relatively perfect facilities, have a fixed labor force and intensive management, and can adopt advanced technology and implement mechanized operations. Temporary nursery is set up temporarily to accomplish certain afforestation or greening tasks, generally located near the afforestation site, occupying a small area, cultivating fewer kinds of seedlings and having a short service life. With the completion of the task, the seedling raising work will also end, such as forest nursery and mountain nursery. Temporary nursery not only saves the cost of packaging and transportation of seedlings, but also has strong adaptability to the environmental conditions of afforestation sites and high survival rate of afforestation. However, this kind of nursery is scattered, sometimes the water source is insufficient, the management is inconvenient, and the quality of seedlings is often poor.

When choosing a nursery, it is necessary to conduct a comprehensive investigation of natural and socio-economic conditions and make a comprehensive analysis according to the requirements of seedling tree species to determine whether it is suitable to choose as a nursery. When choosing a nursery, you should pay attention to the following conditions.

location

The establishment of nursery should be based on the principle of being close to the afforestation area, generally located in the center of the afforestation area, so that the cultivated seedlings can not only adapt to the environmental conditions of the afforestation area, but also avoid the influence of long-distance transportation of seedlings on the survival rate of afforestation. In order to facilitate management and reduce production costs, the nursery should be located in a place with convenient transportation.

zone

Generally speaking, it is best to locate a large fixed nursery on a flat or gentle slope with good drainage. It is rainy in the south of China, so it is best to choose a gentle slope of 3 ~ 5. When establishing a nursery in a place with a large slope, horizontal farming or horizontal terraces should be built. When establishing nurseries in mountainous areas, we should pay attention to choosing the appropriate slope direction. In southern hilly areas, if there are irrigation conditions, the southeast slope with good light is suitable; If the irrigation conditions are poor, it is best to use the northeast slope or the north slope with relatively shady and small evaporation. The southwest slope is exposed to direct sunlight and the soil is dry, so the seedlings are easily affected by drought. The west slope is scorching in summer and westerly in winter, which is not suitable for seedling raising. In mountainous areas, the air humidity is high, the temperature is low, and the soil moisture condition is good, so it is advisable to choose the sunny southeast slope or south slope. In the cold and arid areas in the north, the southeast slope is the best because of its high temperature, small temperature difference between day and night and light freezing damage. The selection of slope direction is also related to the characteristics of cultivated seedlings. For example, in the south of China, conifers such as Chinese fir, Cryptomeria fortunei and Fokienia hodginsii can choose the northeast slope or the north slope with short sunshine; The broad-leaved tree species that are drought-tolerant and like light, such as Robinia pseudoacacia, Ailanthus altissima, Oak, Schima superba, etc., are best in the southeast slope and east slope with sufficient sunshine and long sunshine time. Dongpo seedlings germinate earlier in spring, so it is not suitable to cultivate camphor trees, camptotheca acuminata, sassafras, eucalyptus and Casuarina which are sensitive to late frost. In addition, the nursery should avoid being located in low-lying areas where cold air gathers and water is easy to accumulate, valleys with weak light, tuyeres with severe wind disasters and hills that are too open and exposed. It is not advisable to choose places prone to mountain torrents and sediment accumulation or areas prone to floods in rainy season as nurseries.

land

Soil has a great influence on the quality of seedlings, among which soil moisture, soil texture and structure, soil pH value and so on are the most important. ① Soil moisture: Too dry soil will reduce the germination rate and seedling rate, and the seedlings will grow poorly, often with long main roots and short lateral roots. Excessive soil moisture will prolong the growth period of seedlings, and seedlings will not be completely lignified in autumn, which is easily affected by early frost and low temperature. At the same time, it will cause the overground part of seedlings to grow in vain and the root system to develop weakly, which will make the proportion of overground part and underground part unbalanced and reduce the quality of seedlings. Too wet soil is easy to cause seedling diseases such as root rot. ② Soil texture and structure: The physical properties of nursery land are often more important than fertility, because the latter can be easily improved by fertilization. Nursery must choose soil with loose structure and good permeability, and sandy loam, loam and light clay loam are generally suitable. Sandy loam is suitable for cultivating seedlings of most tree species, especially Pinus tabulaeformis, Robinia pseudoacacia and Betula platyphylla, which have low requirements on soil fertility. Some tree species such as Cunninghamia lanceolata, Phoebe bournei, Juglans regia and Fraxinus mandshurica have higher requirements on soil, so loam and light clay loam are more suitable. The groundwater level in the nursery should not be too high, otherwise the soil will be too wet. However, the groundwater level is too low, and the irrigation times increase in dry season, which correspondingly increases the cost of seedling raising. The suitable depth of groundwater level in nursery varies with soil texture. The groundwater level in sandy loam is generally 1.5 ~ 2m. ③ Soil pH: Different tree species have different adaptability to soil pH.. Most broad-leaved trees are suitable for neutral or slightly alkaline soil, while most conifers are suitable for slightly acidic soil. Generally, the soil with high salinity is not suitable for seedling raising. Only some salt-tolerant tree species, such as Melia azedarach, Ailanthus altissima, Ulmus pumila and Platycladus orientalis, can grow when the soil salt content is below 0. 1%.

waterhead

Nursery should be located near rivers, lakes, ponds and reservoirs for irrigation. If there is no such water source, you should know whether there is groundwater available. However, the above-ground water source is superior to the underground water source, because the above-ground water temperature is high, the water quality is soft and contains a certain amount of nutrients, so it should be used as much as possible. The salt content of irrigation water should not exceed 0. 1 ~ 0. 15%. It is also necessary to know whether there is water pollution near factories and mines.

plant diseases and insect pests

We should know the species, spread degree and possibility of further expansion of pests and diseases in nursery and its vicinity in detail. If the pests and diseases are serious, it is not appropriate to choose nursery or take preventive measures as soon as possible.

Nursery area

The size of the conservation area should be suitable for its task. The total area of nursery includes production land and auxiliary production land. The land directly used for seedling raising is called production land. Its area is divided into net area and total area. Net area refers to the seedbed area or effective area. The total area includes the area of seedbed and path, also known as planting area. Usually, the seedling area refers to the hair area. The area required for seedling raising can be determined according to the type, age and quantity of seedlings needed each year and the output of seedlings per unit area. The seedling yield per unit area of each tree species can be determined according to the specified yield standard and with reference to the mature experience figures in local production. The total area required for raising seedlings of various tree species is the production land area of nursery. Because there will be some losses during tending, seedling raising and transportation, the production quantity of seedlings should be increased appropriately, generally about 3 ~ 5%. Auxiliary production land includes roads, fixed irrigation and drainage ditches, houses, courtyards and shelterbelts. Production land and auxiliary production land complement each other. Without these auxiliary facilities, production can not be carried out normally, but in order to improve the land utilization rate, the area of auxiliary production land should generally not exceed 20 ~ 25% of the total area of the nursery.

nursery

In order to make full use of land and facilitate production and management, it is necessary to divide nursery land. During zoning, the scope of each production area, the location of roads, irrigation and drainage ditches, construction land, etc. 1: 500 ~ 1: 2000 shall be marked on the plan. Production land is generally divided into production areas such as sowing, cutting (or asexual reproduction), transplanting and ear picking. The division should be based on local conditions, ensure that each production area has its necessary conditions, and try to maintain the integrity of each production area. Each production area can also be divided into several communities. The shape of a community is generally rectangular. The area of the plot depends on the scale of the nursery and the degree of mechanical operation in the production process. However, the plot of mountain nursery should be divided according to the terrain, and it can't be forced to be regular. Nursery road network is generally set with a main road running through the nursery, and several auxiliary roads perpendicular to the main road are set on both sides. When necessary, paths for people to work can be set between communities. The road network should be coordinated with the irrigation and drainage system as much as possible. It is best to set the water source at the height of the nursery for self-flow irrigation. At present, the nursery mainly adopts open channel irrigation. Open channel is easy to build and low in cost, but it wastes land, causes a lot of leakage, requires labor and is not convenient for farming, so it is best to implement pipeline irrigation. The purpose of setting the drainage system in the nursery is to remove the accumulated water in the nursery during the rainy season. Usually, a general drainage ditch is set at the lowest part of the nursery, a large or medium drainage ditch is set between the main road and several communities, and a small drainage ditch is set in each community to form a drainage ditch network to ensure that the accumulated water can be discharged from the nursery quickly and smoothly. Buildings needed for nursery management, such as offices, dormitories, warehouses, seed storerooms, machinery rooms and sites, should be located in areas with high terrain and poor soil quality, which are not suitable for nursery. A large nursery can be located at the center or entrance of the nursery. Shelterbelt can be set up in the nursery when necessary to prevent and reduce the harm of sandstorm, drought and cold.

Nursery technical archives

Long-term and systematic records were made on the land use of the nursery, the growth process of seedlings, the technical measures of seedling raising, the material consumption and labor consumption of various operations, etc. , as a file. By sorting out and analyzing these data, we can master the growth law of various seedlings, explore the rational use of land, labor, machinery and materials, and provide reliable basis for formulating the yield and quality standards of seedlings, summarizing the technical experience of seedling raising and implementing scientific management.