How do the latest seeds grow?

Isatis root alias Daqing and indigo are plants of the genus Isatidis of the cruciferous family. It is cultivated all over the country. Banlangen likes the warm and sunny environment and is not strict with the soil. Drought resistance, cold resistance, avoid stagnant water. Radix Isatidis is propagated by seeds and can be used for direct seeding. Let's take a look at how to plant the seeds of Radix Isatidis.

Planting season

The sowing season of Radix Isatidis is different, the products harvested are also different. According to the sowing time of Radix Isatidis, it can be divided into four stages: autumn sowing, early spring sowing, spring sowing and summer sowing. Autumn sowing and early spring sowing are mostly for the purpose of harvesting seeds, the roots of Radix Isatidis planted in these two periods can not be used as medicinal materials; summer sowing is suitable to be used in the areas with long plum rain season in the south, this method can reduce diseases and insect pests, but the yield is low. Radix Isatidis sown in spring can harvest both leaves and roots, and the yield is higher, so it is the most commonly used method.

Prepare before sowing

Radix Isatidis is a deep-rooted plant, like the warm and cool environment, more resistant to cold, afraid of waterlogging, suitable for cultivation in North and Northwest China. Some preparatory work should be done before sowing Radix Isatidis, which mainly includes land selection, soil preparation and fertilization.

1. Site selection: Radix Isatidis is suitable for planting in sandy loam or river alluvial loam with low groundwater level, good drainage, loose and fertile loam. The Radix Isatidis planted on such land has the advantages of high yield, good quality, labor saving, low investment and high economic benefits. Here we should pay special attention to the selection of land must not choose clay and low-lying land prone to waterlogging, such land is easy to make Banlangen rotten root. In addition, the land is best chosen in the leeward to the sun, close to the water source, so as to facilitate the growth of Radix Isatidis in the process of lighting and watering. Bean stubble or corn stubble is better for the previous crop of the selected plot. If the selected land is sloping land, the slope should not exceed 15 °. Drainage facilities should be done well on the sloping land to prevent the loss of water, soil and manure and affect the growth and yield of Radix Isatidis.

2. Fertilization: base fertilizer should be applied before soil preparation. Base fertilizer to rotten pig manure, horse manure, sheep manure as the best, do not apply raw manure, otherwise it will produce high heat due to fermentation and burn the root system of Radix Isatidis. In order to control insect pests, it is best to spray 90% trichlorfon 800 times in the process of manure accumulation to kill eggs, pupae and larvae. These fertilizers contain high content of organic matter and complete contents of nitrogen, phosphorus, potassium and trace elements, which can not only meet the growth needs of Radix Isatidis, but also loosen soil structure and improve soil structure and physical and chemical properties. it can obviously promote the growth and development and yield increase of Radix Isatidis. Base fertilizer 2000-3000 kg per mu; if manure is sufficient, it can be added to 4000 kg per mu. When manure is insufficient, add 50 kg of diammonium phosphate or calcium superphosphate and 15 kg of potassium fertilizer such as potassium chloride or potassium sulfate per mu.

3. Soil preparation: because Radix Isatidis is a deep-rooted medicinal crop, the soil layer of the root must be loose. Therefore, it still needs to be turned deeply after fertilization. in order to ensure the growth conditions of the root system of Radix Isatidis, the depth of turning should be more than 30 cm, which is beneficial to the downward extension, straightness, smoothness and non-bifurcation of the root. In soil preparation, the sandy land can be turned slightly shallower, and the sticky land can be turned a little deeper. Finally, we have to break the clods and flatten the plots. ?

After the plot is completed, the bed will be made. In the north, the area with little precipitation can be used as a flat border, with a width of 1.5-1.8 meters. High beds should be made in the south to facilitate drainage. The border is 20-30 cm high, which is generally made lower in high-lying areas and higher in low-lying areas. The length of the border can be determined according to the topography, the flat land can be used as a long border, and the undulating land can be used as a short border. Leave a 30 cm wide operation lane between the two beds. Combined with the bed to further break the soil, make the soil fine and broken, prevent the border mixed with soil clods and sundries, affect the germination and root growth of Radix Isatidis, and ensure the quality of soil preparation. The standard for planting the border is that the surface of the border is smooth and the soil is fine. After the preparation of the land, it will be sown and planted.

Radix Isatidis sowing

1. Seed selection: the seeds of Radix Isatidis should be harvested the year before, with new black seeds on the seed coat. The maturity of such seeds is good, and the germination rate can be guaranteed to be more than 95%. And such seeds will not blossom in the same year after sowing; and if you choose seeds that have been stored for many years, not only the germination rate is low, but also easy to blossom in the same year, affecting the yield and quality of Radix Isatidis.

2. Seed treatment: after the seeds are selected, the seeds should be treated before sowing in order to improve the germination rate of Radix Isatidis seeds. Soak the seeds in clean water for 12-24 hours. On the one hand, it can remove the grass shavings and blighted seeds mixed in the seeds of Radix Isatidis, and on the other hand, it can soften the seed coat of Radix Isatidis, which is conducive to budding. Soak it out and dry it, and then you can sow the seeds.

3. Sowing time: in the planting process of Radix Isatidis, there are strict requirements on sowing time and sowing method. First of all, let's know the time of sowing. For the spring sowing of Radix Isatidis, the northern region generally sows in early April, while the southern region can advance appropriately, but it is required to sow only when the local temperature is stable above 12 ℃, which is beneficial to the deep root system and prolong the growth period.

4. Sowing: water should be watered once a week before sowing to ensure that the seeds of Radix Isatidis need water to germinate and take root. There are many sowing methods of Radix Isatidis, but there are two commonly used methods: strip sowing and hole sowing. ? The row spacing of 30 cm is adopted in strip sowing, and the sowing rate is about 3 kg per mu, while the row-plant spacing of 30 × 20 cm or 30 × 30 cm is used in hole sowing, and the amount of seed used is less, between 1.5 and 2 kg per mu. Sowing depth is 3 cm, after sowing, then cover a layer of fine soil, cover soil, the thickness is about 1 cm, and finally cover the border with plastic film to moisturize. Due to the strong wind in spring, in order to prevent the wind from blowing up the plastic film, after the plastic film is covered on the border, it should be pressed not only with soil around, but also in the center of the film. It should be noted here that due to the weak soil strength at the top of the seeds of Radix Isatidis, it is necessary to press the soil between the two sowing ditches so as not to affect the germination of the seeds.

Seedling stage management

The seeds of Radix Isatidis can generally emerge in 7 to 10 days after sowing, and all seedlings can emerge in 15 days.

1. Piercing ventilation: it is found that the film on the seedling should be broken in time after the emergence of the seed of Radix Isatidis, which is beneficial to the upward growth of the seedling and can avoid burning the seedling under the high temperature under the film. At this time, the temperature is still low at night, so the ventilation hole should not be opened too wide, otherwise the seedlings will stop growing. The size of the ventilation hole is slightly larger than that of the seedlings. The work of film mulching and ventilation should be carried out every day until all the seedlings on the border surface come out.

2. Weeding: during this period, due to the high temperature and humidity under the film, some weeds will grow rapidly and break the film. When weeds are found to break out of the film, they should be pulled out in time. In order to prevent weeds from continuing to grow here, hard clods should be pressed at this position after weeding.

3. Interseedling: with the growth of Radix Isatidis seedlings, in order to improve the ventilation and light transmission conditions of Radix Isatidis seedlings and ensure the normal supply of nutrition, interseedling should be carried out once when the seedlings grow to 5 to 6 true leaves. This time, the seedlings should be in line with the principle of removing the small and keeping the strong, and the distance between the seedlings should be kept at 5 to 8 cm. With the increase of the external temperature, the ground temperature is also increasing, some people think that the plastic film can be removed at this time, in fact, this is a wrong approach, because the ground temperature is high at this time, although the seedlings of Radix Isatidis can grow rapidly, but the growth rate of weeds is faster, when the film is opened, the weeds will soon cover the whole border, affecting the continued growth of seedlings. The purpose of not uncovering the film during this period is that the high temperature under the film can be used to kill weeds and conserve soil moisture. When the seedling of Radix Isatidis is 10 cm high, the second seedling should be carried out, and the seedling at this time is also the fixed seedling of Radix Isatidis. Before fixing the seedling, the covering film on the border should be removed, and then the border should be ploughed for one time.

4. Middle ploughing: on the one hand, mid-tillage can change the permeability of border soil, which is conducive to preserving soil moisture, and second, this mid-tillage is beneficial to the root system of seedlings, because the root system of Isatis root seedlings is not deep at this time. Therefore, the depth of mid-tillage should be shallow rather than deep, 2 to 3 cm is appropriate. The seedlings will be fixed after the intercropping is completed.

5. Fixed seedlings: the distance between the fixed seedlings is 20 to 25 centimeters, and the weeds should be removed while fixing the seedlings. In addition, if the broken ridges and lack of rows are found in the fixed seedlings, the seedlings should be replenished in time. The method of seedling supplement is to dig out the overdense Isatis root seedlings with soil, dig a small pit 5 cm deep in the missing seedling, and replant the seedlings in the pit. in order to facilitate the survival of the seedlings, slow seedling water should be irrigated in time after replenishing the seedlings. After the work of fixing seedlings is completed, 1000 times of carbendazim wettable powder should be sprayed once to prevent the occurrence of Sclerotinia sclerotiorum.

6. Topdressing: 3 days after uncovering the film, organic fertilizer should be applied once after the seedlings adapt to the environment. Isatis root from the seedling stage of nitrogen fertilizer, so this fertilization should be topdressing urea application rate of 3 to 5 kg per mu. At this time, the seedlings of Radix Isatidis are still small and the leaves are tender, so when chemical fertilizer falls on the leaves, it is easy to burn the leaves and affect the yield. This requires gently poking the seedlings of Radix Isatidis with twigs after fertilization to make the urea fall on the seedlings to the ground. Water should be watered once after fertilization, considering that the seedlings are still small at this time, the amount of watering this time should be smaller, and it is appropriate to soak through the surface. ?