Key Points of Film-Mulched Cultivation Technology for Autumn Garlic

With film-mulched cultivation, the yield of garlic scapes increased from the original 100-150 kg to 200-300 kg, and the yield of garlic bulbs per mu rose from about 2000 kg to 2500-3000 kg.

1. Variety selection

The Puke garlic from Zhangqiu County, Shandong, is mostly used as the variety for autumn planting and film-mulched cultivation. Varieties suitable for local cultivation may be selected in each area.

2. Land preparation and fertilization

For garlic cultivation, base fertilizer is the main application, requiring more than 5000 kg of mixed farmyard manure per mu, plus 50 kg of superphosphate as base fertilizer. Do not plant on the same land in successive years. After plowing, make flat beds 1.67 m wide, and apply 2.5 kg of carbaryl powder per mu to control underground pests and garlic maggots. After the beds are leveled, spray herbicide. You may either cover with plastic film first and then plant the garlic, or plant the garlic first and then cover with plastic film.

3. Selecting garlic cloves

Before planting, the garlic cloves must be carefully selected. Remove moldy, shriveled, and overly small cloves. Trials have reported that using seed garlic cloves of 8-10 g yields more than 30% more garlic bulbs than using 4-6 g cloves.

4. Sowing

For the sowing period, in Northeast China it is mid-to-late September. By late November, before the soil freezes, the plants should have grown 4 leaves and 1 heart, with a plant height of 10-15 cm. Seedlings at this stage have relatively strong cold resistance, which is beneficial for overwintering and reduces seedling death.

The sowing density is 17 x 8.5 cm or 13 x 10 cm between rows and plants, planting 45,000-48,000 plants per mu, using 200-250 kg of seed garlic per mu.

When sowing first and then covering with plastic film, open furrows according to the row spacing, 3.3 cm deep, plant the garlic cloves according to the plant spacing, and cover with soil so that the tips of the garlic cloves are not exposed, then firm the soil. Use plastic film 1.4 m wide, which exactly covers a bed 1.5 m wide (excluding the 20-27 cm width of the ridges), and bury the edges of the film into the bed ridges. When covering with film first and then sowing, punch holes in the film according to the row spacing and plant the garlic cloves until the tips are not exposed above the film. Water immediately after planting.

5. Field management

When sowing first and then covering with plastic film, after emergence, promptly punch holes in the film directly above the seedling tips so the seedlings can grow naturally out of the film. From sowing to freezing, about 2 months pass, generally requiring 8-10 waterings; water less as appropriate on land with good moisture, but the freezing water must be applied sufficiently, and along with the freezing water apply 20-25 kg of ammonium bicarbonate per mu, or well-rotted diluted manure water. During the overwintering period, to prevent cold and protect the seedlings through the winter safely, after the Minor Snow solar term use wheat straw, rice straw, leaves, etc. as mulch, first covering thinly, then thickening the mulch in 2 stages as the temperature drops, up to a maximum thickness of 10 cm. After the Start of Spring solar term, as the weather gradually warms, remove the mulch in stages, and remove it entirely by the Awakening of Insects solar term. Around mid-March, regrowth begins; after 1 watering, practice seedling restraint. After the seedling restraint period ends, keep the soil moist regularly. After the "rotten line" (seed garlic) stage, apply 20-25 kg of ammonium bicarbonate per mu together with watering, then every other day apply a small amount of chemical fertilizer with clear water, until 3-4 days before extracting the garlic scapes, when watering stops. Garlic scapes should be extracted at noon on a sunny day when the garlic plants have less moisture, and they should be extracted as cleanly as possible. After scape extraction, the plants gradually age, so water and fertilizer should be applied together, with quick-acting nitrogen fertilizer to promote rapid growth of the garlic bulbs. Stop watering and fertilizing 20 days after extracting the garlic scapes, and about 5 days after that, when half of the lower leaves of the plants turn yellow, they can be harvested. In Northeast China, the harvest time is around June 20.