Detailed Explanation of High-Efficiency Double-Layer Mulch Cultivation Technology for Garlic

Qi Xinqiang, a garlic farmer in Qijiazhuang Village, Dingzhou City, Baoding, has grown mulched garlic for many years and, in the course of production, worked out a cultivation technique using double-layer plastic film mulch for garlic, achieving an earlier market launch for the garlic and relatively high yields, with a per-mu yield increase of more than 10%. It is worth the study and reference of vegetable growers in the major garlic-producing areas. The cultivation technique is introduced below:

1. Selection of excellent varieties. Select Shandong Guanxian garlic, an excellent garlic variety from Shandong Province and also an important export variety. Each garlic bulb has 7-8 cloves, the outer skin is slightly purplish-red, the skin is thin, the cloves are plump, the pungency is strong, and the quality is good; it is a bolting type. It grows vigorously, has strong cold resistance, a high bolting rate, and good storage tolerance, and is suitable for autumn planting.

2. Sowing at the appropriate time. Garlic must be sown at the appropriate time. If sown too early, the emergence rate is low and double-clove garlic is likely to appear; if sown too late, the growth period before winter is short, the seedlings are too small, and they are susceptible to freezing damage, which also affects garlic yield and quality. To ensure that the number of leaves on the garlic plants reaches 4-5 before overwintering, the suitable sowing period in the central region of our province is generally from late September to early October.

3. Land preparation and fertilization. Garlic has a relatively wide adaptability to soil; sandy loam, loam, and night-tide land are all acceptable, but slightly acidic sandy soil rich in organic matter, with a deep soil layer and good drainage, is best. When garlic is planted in such soil, the root system is well developed, greening-up is early, bolting is early, the bulbs are large, and the pungency is strong and aromatic, and harvesting the garlic is easy. Careful land preparation and increased application of organic fertilizer are of great significance for increasing garlic yield and improving quality. Careful land preparation: the plot for planting garlic needs deep plowing and fine harrowing to increase soil permeability, which is beneficial to the activity of soil microorganisms and the transformation of soil nutrients, and is beneficial to root development and bulb enlargement. The plowing depth for garlic land is generally 20-30 cm. After the previous crop is harvested, the land should be plowed and the ridges sunned as early as possible to activate the soil. Apply sufficient base fertilizer: because plastic film mulch is used, topdressing during the garlic growing period is not advisable; therefore, before sowing, sufficient base fertilizer should be applied all at once in combination with land preparation. Apply 6000 kg of high-quality barnyard manure, 80 kg of cake fertilizer, 50 kg of urea, 80 kg of calcium magnesium phosphate fertilizer, 25 kg of potassium sulfate compound fertilizer, and 1.5 kg of zinc sulfate per mu.

4. Sowing and film covering. Select garlic bulbs that are large in size, with large and uniform cloves, firm cloves, and white and fresh color, as seed. Generally, the 100-clove weight of garlic cloves is required to be more than 400 g. When the soil temperature stabilizes at 18-19°C, sowing can begin. In this way, by overwintering the garlic seedlings can reach a height of more than 25 cm, which is beneficial for safe overwintering. For sowing, the row spacing is required to be about 15 cm, the plant spacing should be kept at 6-8 cm, and the furrow depth is 10 cm. Place the seed cloves in the furrow and keep them upright, with a density of 40,000-50,000 plants per mu. Then cover with soil and cover with double-layer plastic film. When covering with film, the plastic film is required to be flat on the bed surface without wrinkles, with no gaps under the film, so that the film fits tightly against the bed surface to avoid the growth of weeds. When more than 50% of the garlic has emerged, puncture the film. Use sharp iron wire to make holes in the film, with the hole diameter kept at about 1 cm.

5. Field management. After sowing, immediately water once thoroughly; after the seedlings have emerged completely, water a second time; before the soil freezes, water once with antifreeze water. Several days later, cover with grass curtains or corn stalks to prevent cold and drought and ensure the garlic seedlings overwinter safely. Around the Spring Equinox, promptly remove the ground cover and choose clear, warm weather to water, promoting early greening-up and growth of the garlic seedlings. From early April to the end of April, according to soil moisture, water once every 5-7 days for plant growth, and apply topdressing 2-3 times with the water, generally applying 10-15 kg of ammonium sulfate or urea per mu. Stop watering 3-4 days before harvesting the bolts. After the garlic bolts are harvested, the soil should be kept moist frequently to promote rapid enlargement of the bulbs, until 2-3 days before harvest, when watering is stopped.

6. Pest and disease control. When the garlic seedlings reach the 2-leaf 1-heart stage, control garlic thrips and garlic flies, using high-efficiency and low-toxicity pesticides such as beta-cypermethrin. In mid-March, pay attention to controlling garlic maggots and garlic borers, using the same pesticides as above. To control garlic leaf blight, use a 1000-fold solution of 50% duomeiling or 65% jiameiling.

7. Timely harvest. In the central and southern regions of our province, garlic with single-layer plastic film is generally harvested in mid-to-late May. Garlic cultivated with double-layer plastic film can be harvested 7-10 days earlier, that is, it can be harvested at the end of April and the beginning of May. At this time, most of the plant leaves have already dried up and the false stem has softened. To seize the time and harvest and bring to market as early as possible, because the quantity of fresh garlic on the market is relatively small and the price is relatively high, only by seizing the favorable opportunity and selling promptly can relatively high returns be obtained.