Key techniques of Green cultivation of Asarum in farmland

Northeast Asarum is a perennial herb of Asarum of Aristolochia family. The whole herb was originally used as medicine, but it was modified by the Pharmacopoeia of the people's Republic of China (2005 edition) to be used as root. It mainly contains volatile oil, which has the effects of dispelling wind and dispelling cold, warming lung and resolving drink, dredging orifices and relieving pain. Most of them choose artificial cultivation under the forest or in mountainous areas. in recent years, many drug farmers use farmland for cultivation. The key techniques of green cultivation of Asarum in farmland are briefly introduced as follows, which can be used as a reference for drug farmers.

1 reasonable selection of land

1.1 surrounding environment

Pollution sources such as construction sites and hospitals are not allowed around Asarum. It should be 200m away from the main road and away from polluted rivers and ponds.

1.2 soil conditions

Asarum planting land should choose the valley at the foot of the mountain or between the two mountains, these plots are affected by the mountain forest, the air is moist, suitable for Asarum growth. It is better to loam or sandy loam with loose and fertile, moist and non-stagnant water, pH6~7. If the previous crop uses herbicides, it should be ploughed and fallow for 0.5 years and then reused. Planting Asarum in a large area of farmland should take soil samples at multiple points before planting, detect pesticide residues and heavy metal contents, and then plant them after qualified, so as to avoid significant economic losses.

(2) reasonable close planting

The farmland is exposed to light for a long time, the soil water evaporation is large, the air relative humidity and soil water content are low, and the temperature is relatively high, which is not conducive to the growth of Asarum. Therefore, we should appropriately increase the planting density to make the aboveground plants of Asarum seal ahead of time and reduce water evaporation and soil temperature. Generally speaking, row spacing 20cm and acupoint spacing 15~20cm are suitable. For example, 15cm, 4 2-year-old seedlings were planted in each hole, and 5-6 plants were planted in each hole in 20cm.

3 reasonable dimming

3.1 shading net dimming in seedling field

Asarum is planted in farmland, and different year-old Asarum should choose sunshade net with different light transmittance. In the field of raising seedlings in farmland, the shading net with 30% light transmittance can be selected for 1 ~ 2 years old, and the canopy density is 0.65% 0.7%. The 5 ~ 6-year-old seedlings can choose 40% light transmittance shading net, and the canopy density is 0.6.

3.2 planting corn and shading net to adjust light in transplanting field

The transplanting field uses 40% light transmittance shading net to shade the sun, and the 3-4-year-old Asarum also has to plant corn beside the border to adjust the light. Planting corn on the west side of the border in the north-south direction, and planting corn on the south side of the border in the east-west direction. The plant spacing is 20~30cm, and the planting period is the same as that in the field. 5-year-old 6-year-old Asarum plants closed ridges, in order to facilitate field management, corn can not be planted.

4 border cover

In order to reduce the soil temperature, improve the soil moisture, prevent grass famine and reduce the spread of disease, the transplanting field should cover the border between the rows with a thickness of about 2cm, and the covering material should be larch needle or rice straw. Cover the fallen leaves after the plant withered in autumn and before emergence in spring, and cover rice straw after emergence and before leaf expansion.

5 to prevent frost injury and drug injury

5.1 Prevention of frost injury

Asarum is an early spring plant, the emergence stage is in the late frost period, 1-year-old seedlings will suffer frost damage, more than 2-year-old plants are not afraid of frost. Preventive measures: after ① soil froze in late autumn, cover the border with leaves or straw above 10cm, and remove it later in the next spring, which can delay soil thawing, postpone seedling emergence and miss late frost emergence, so as to prevent frost injury. However, the emergence of seedlings should be checked frequently, and when more than 50% of seedlings emerge, the mulch should be removed in time to prevent Asarum seedlings from growing into "bean sprouts" under the mulch, and sunburn will occur after seeing the light. After ② emergence and removal of mulch, buckle the plastic arch shed, pay attention to ventilation during the day, cover strictly at night, and remove the shed after the final frost.

5.2 Prevention of drug damage

Asarum is planted in a small area of farmland, and Asarum is intermingled in the middle of other farmland. Asarum emergence is just when the corn field is hit with a closed herbicide; negotiate with the neighboring owner in advance and lower the sprinkler head when hitting the herbicide, so as to avoid drug damage caused by the liquid falling on Asarum plants in the wind.