It is advisable to choose sandy loam or light loam with flat terrain, good drainage, fertile soil and irrigation conditions. It is not suitable to choose the place where the soil is too sticky or low-lying and stagnant, and it is not suitable to choose the windward. Nursery land should be deeply plowed and raked, and base fertilizer should be applied. Generally, it is about 25cm deep in autumn and shallow in spring 15cm. Combined with deep ploughing in autumn, 2500-5000 kilograms of manure is applied per mu, which is turned into the soil and then raked flat.
germination
In order to make seeds germinate quickly and orderly before sowing, it is best to accelerate germination. There are many empty grains in the seeds of Platycladus orientalis. After the water is divided, the floating empty particles are fished out. Soak the seeds in 0.3% ~ 0.5% copper sulfate solution 1 ~ 2 hours, or soak the seeds in 0.5% potassium permanganate solution for 2 hours to disinfect the seeds. Then, accelerate seed germination. There are three methods commonly used to accelerate the germination of Sabina vulgaris seeds.
(1) Mixed snow burying method: choose a place with lee, shade, good drainage and convenient management. When the snow doesn't melt after winter, mix the seeds with 3 times of snow and put them in the cellar. Straw curtains and 10 cm thick snow should be put around the top, bottom and periphery of the barn, and seeds mixed with snow should be put in the middle. Bundles of straw are wrapped around the barn to prevent the snow in the barn from melting in early spring. Put it in the snow until it is taken out 3-5 days before sowing. After the snow is cleared, the seeds are screened out, scattered in the shade, and impurities are removed, so that the seeds can be planted. You can also mix the seeds into fine sand before sowing 1 week, after snow melting, dry in the sun, turn over, heat and moisturize, and when 1/3 seeds crack, sieve out or mix the sand and sow in time.
(2) Sand mixing to accelerate germination: When seeds are transferred too late to be preserved in snow or there is little snow in winter, sand mixing can be carried out to accelerate germination 15 ~ 20 days before sowing. Select the seeds to be disinfected and soak them in warm water for 24 hours. Then take out the seeds, mix them with fine sand twice the volume of the seeds, and stir them evenly. The humidity of the sand should be held by hand, and there can be no water. Put it in a wooden box and put it in a warm place indoors. The temperature of seed sand is always kept at 12 ~ 15℃, and it is turned over 2 ~ 3 times a day, and warm water is sprayed at any time to keep proper temperature and humidity to promote seed germination. When most seeds have germinated and there are 1/3 seed cracks, you can sow.
(3) Soaking the seeds in warm water to accelerate germination: soak the sterilized seeds in warm water at 45℃ for 24 hours, and take out the floating empty seeds in combination with seed selection. Then take out the seeds and spread them on the mat in the leeward and sunny place, often turn over the sun, keep a certain humidity, and wash them with warm water 1 ~ 2 times a day. After 5 ~ 6 days, when 1/3 seeds crack, sowing can be carried out.
sow seeds
Platycladus orientalis is suitable for spring sowing, but the sowing time is different due to the differences of climatic conditions in different places. Platycladus orientalis grows slowly. In order to prolong the growth period of seedlings, according to the local climatic conditions, it is advisable to sow early, such as in the middle and late March in North China, in the late March to early April in Northwest China and in the middle and late April in Northeast China. The seeds of Platycladus orientalis have many empty grains, which are usually germinated by water selection before sowing. In order to ensure the yield and quality of seedlings, the sowing amount should not be too small. When the seed purity is above 90% and the seed germination rate is above 85%, the sowing amount per mu is about 10 kg.
In northern China, Sabina vulgaris is raised on high beds or high ridges, and in some arid areas, it is also raised on low beds. Generally, the bottom water should be poured before sowing, and then the seeds should be pushed by hand or ditched by hand. When sowing, ridge sowing: the width of ridge bottom is 60 cm, the width of ridge surface is 30 cm, and the ridge height is 12 ~ 15 cm. Two rows or single rows can be sown in each ridge, with the width of double row drilling being 5cm and single row drilling being12 ~15cm. Bed sowing: general bed length 10 ~ 20m, bed width 1m, bed height 15cm, 3 ~ 5 rows vertically (along the bed) per bed, sowing width 5 ~ 10cm, horizontal drilling width 3 ~ 5cm and row spacing 65438. When sowing, the ditching depth should be consistent and the sowing should be uniform. After sowing, the soil should be covered 1 ~ 1.5 cm in time, and then the seeds should be suppressed to make them closely contact with the soil, which is beneficial to seed germination. In arid and windy areas, in order to keep soil moisture, grass can be used to cover the soil when conditions permit.
Seedling management
After accelerating germination, seeds generally germinate and emerge in about 10 days after sowing, and the peak of emergence is about 20 days, and the germination rate in field garden can reach 70% ~ 80%. In order to facilitate the germination and excavation of seeds, the soil in the seed layer should always be moist, and the bottom layer must be watered thoroughly before sowing. If the soil is not too dry before the seedlings are unearthed, it is best not to pour plastic film water to avoid lowering the ground temperature and causing the surface soil to harden, which is not conducive to seedling emergence. After the seedlings are unearthed, someone should be assigned to look after these birds. Spraying 0.5% ~ 1% bordeaux solution immediately after emergence, and then spraying 1 time every 7 ~ 10 days for 3 ~ 4 times continuously can prevent the occurrence of damping-off disease.
Irrigation should be properly controlled during seedling growth period to promote root growth and development. The fast-growing period of seedlings is just in the high temperature and drought period after the middle and late June and before the rainy season. The temperature is high and the rainfall is low. It is necessary to irrigate in time and increase the irrigation times appropriately, and the irrigation amount will gradually increase. According to the soil moisture, irrigation should be done once every 10 ~ 15 days on the principle of one-time irrigation, and sprinkler irrigation or side irrigation is appropriate. After entering the rainy season, reduce irrigation, pay attention to drainage and flood control, so that internal water does not accumulate and external water does not invade.
Topdressing and irrigation are combined in the fast-growing stage of seedlings. Ammonium sulfate is usually topdressing 2-3 times a year, with 4-6 kilograms of ammonium sulfate per mu, at the early stage of fast-growing seedlings 1 time, and topdressing again after half a month. You can also use decomposed human feces for topdressing. After each topdressing, it must be watered and washed in time to prevent seedlings from burning.
Platycladus orientalis seedlings can be shaded to a certain extent and kept closed properly. When the seedlings get too close to affect the growth, it is time to remove the weak seedlings, the pests and diseases seedlings and the double seedlings. Generally, when the height of seedlings is 3 ~ 5 cm, the seedlings are thinned twice, and after the seedlings are fixed, about 150 seedlings are left on the bed surface per square meter, so the yield of seedlings per mu can reach 6.5438+0.5 million. Weed and loosen the soil in time during the seedling growth period to achieve "early weeding, small weeding and large weeding". Chemical agents are often used to weed, and 35% herbicide diethyl ether (EC) is used, the dosage is 2 ml per square meter, diluted with water and sprayed. Spraying 1 time after sowing or before emergence, spraying for the second time after 25 days and spraying continuously for 2 ~ 3 times can basically eliminate weeds. The dosage per mu is 0.8 kg each time. When the hardening of topsoil affects the growth of seedlings, loosen the soil in time, and the depth of loosening soil is about 1 ~ 2 cm, which should be carried out after rainfall or watering, and be careful not to touch the root system of seedlings.
The seedlings of Platycladus orientalis should be well protected against cold in winter. In cold and windy areas in winter, generally, frozen water is poured before the soil freezes, and then the soil is covered for cold protection or the wind wall is sandwiched for cold protection, or grass can be covered for cold protection. Production practice shows that covering soil has the best cold-proof effect, which is not only simple and labor-saving, but also beneficial to the safe overwintering of seedlings. However, it should be noted that the time of burying soil for cold protection should not be too early, and it is generally appropriate before and after beginning of winter before soil freezing; It is not too late to remove the cold-proof soil, and it is usually removed twice before and after Qingming after thawing; After moving the soil, make up the green water in time to prevent the seedlings from losing water and turning yellow due to the strong spring drought and wind.
Seedling transplantation
Platycladus orientalis seedlings leave the nursery for two years and are transplanted in the spring of the following year. Sometimes, in order to cultivate green seedlings, it is necessary to transplant them for 2 ~ 3 times to cultivate large seedlings with developed roots, strong growth and beautiful crown shape, and then plant them in the nursery. According to local experience, the survival rate of transplantation in March-April in early spring is relatively high, generally reaching more than 95%. The transplant density depends on the culture cycle. Seedling raising after transplanting 1 year, plant spacing10cm× 20cm; Cultivation for 2 years, row spacing of 20 cm× 40 cm; Cultivation for 3 years, row spacing of 30 cm× 40 cm; To cultivate large seedlings over 5 years old, the row spacing 1.5m× 2.0m ... generally, it takes many transplants to cultivate large seedlings, which is not only conducive to promoting the growth and development of seedling roots, but also to cultivate good crown and stem shapes and improve land utilization.
According to the size of seedlings, different transplanting methods are adopted, such as narrow slot transplanting, ditching transplanting and digging transplanting.
The management of seedlings after transplanting is mainly to irrigate them in time and thoroughly every time. When the soil moisture is suitable, timely adopt tending measures such as intertillage, weeding and topdressing. Except for shaping and pruning according to the requirements of landscaping, other measures are basically the same as those of general conifer seedling raising.