What are the planting and fertilizing methods for garlic?
Garlic (Garlic), also called garlic bulb, garlic head, hu suan, hu, single garlic, single-clove garlic, is the collective name for garlic plants. A half-year herbaceous plant, in the lily family, genus Allium, with the bulb used as medicine. Harvested in spring and summer, tied in bundles, hung in a ventilated place, and dried in the shade for later use. The farming proverb says “plant garlic before the ninth (month), after the ninth it grows single cloves”. When the leaves wither in June, dig it up, remove the mud and sand, and dry it in a ventilated place or roast it until the outer skin is dry.
Garlic is oblate or short conical, with a grayish-white or pale brown membranous scale skin on the outside. After peeling off the scale leaves, there are 6 to 10 garlic cloves inside, growing in a ring around the flower stalk, with the base of the stem disc-shaped and bearing many fibrous roots. Each garlic clove is wrapped in a thin membrane; peel off the membrane and the white, thick, juicy scales are revealed. It has a strong garlic pungency and a spicy taste. It has a pungent odor, can be eaten or used for seasoning, and can also be used as medicine. The underground bulb is divided into cloves, and according to different skin colors it is divided into purple-skin varieties and white-skin varieties. Garlic was introduced to China from the Western Regions during the Qin and Han dynasties. Through artificial cultivation and breeding, it has anti-cancer effects and is deeply loved by the public as food.
1. Garlic's fertilizer requirements
Through experiments, autumn-sown garlic has a long growth period, and for every 100 kg of garlic bulbs produced, it needs to absorb 1.42 kg of nitrogen, 0.44 kg of phosphorus, and 0.99 kg of potassium. And at different growth and development stages, there are also great differences in the amount and proportion of nitrogen, phosphorus, and potassium nutrients absorbed.
1. Nitrogen: The absorption amount is relatively low during the overwintering period, then gradually rises, reaching a peak at the bulb expansion stage; before the differentiation stage, the absorption of nitrogen accounts for 30% of the total absorption. Therefore, meeting the need for nitrogen in the middle and late growth stages is a key measure to increase garlic yield and grade.
2. Phosphorus: Before overwintering, the absorption of phosphorus is very small, and it is even less after entering the overwintering period. From the greening stage onward, phosphorus absorption gradually increases. Garlic absorbs the largest amount of phosphorus during the differentiation and bolting stage. Because garlic's vegetative growth and reproductive growth proceed simultaneously, the demand for phosphorus absorption is relatively high and urgent. This is the intensive nutrient period for garlic's phosphorus nutrition absorption, with absorption accounting for 52.1% of total phosphorus.
3. Potassium: Garlic has two peak periods of potassium absorption. During the pre-winter seedling stage, potassium absorption accounts for 10.5% of total potassium; during the overwintering period it is less. Entering the greening stage, the first peak of potassium absorption appears, with absorption accounting for 26.7% of the total, nearly 4 times that of the seedling stage; the bulb expansion stage is the second potassium absorption peak, accounting for about 45% of the total potassium absorption during the whole growth period.
2. Garlic fertilization techniques
1. Basic principles of fertilization: Scientific and reasonable fertilization should be carried out according to the soil fertility level and the needs of garlic at different growth stages. Grasp the fertilization principle of “light early, heavy middle, supplementary late”, preventing both excessive vigorous growth in the early stage and premature aging due to fertilizer deficiency in the late stage.
2. Land preparation and fertilization: Garlic planting plots need deep plowing and fine harrowing to enhance soil permeability, which is conducive to soil microbial activity and soil nutrient transformation, improves the soil's storage capacity, and benefits root development and bulb expansion. After the previous crop is harvested, plow and sun the soil clods as early as possible, with a plowing depth of 20-25 cm.
Because it is covered with plastic film, topdressing is not suitable during the garlic growth period. Therefore, before sowing, sufficient base fertilizer should be applied at one time in combination with land preparation. Apply 2500-3000 kg of farmyard manure, 40-75 kg of chlorine-based compound fertilizer, and 1.5-2 kg each of ferrous sulfate, manganese sulfate, borax, zinc sulfate, and copper sulfate per mu, broadcast on the soil clods.
3. Heavy application of jointing fertilizer: Garlic is different from other crops. Under normal climate conditions, for garlic at the greening stage, field management is generally not carried out, to avoid bacterial soft rot breaking out on a large scale due to a sudden drop in ground temperature caused by watering too early, which would affect garlic growth. Therefore, the first topdressing should be carried out at the jointing stage, with 20-25 kg of nitro compound fertilizer applied per mu. After an interval of 15-20 days, apply the second fertilizer, at about 20 kg per mu.
4. Skillful application of differentiation and bolting fertilizer: When garlic enters the differentiation and bolting stage, vegetative growth and reproductive growth proceed simultaneously, and the demand for phosphorus is strong. This is also the most critical topdressing of garlic's whole life. Wait until the garlic scape shows its head (tail appears), then apply 15-20 kg of high-phosphorus high-potassium compound fertilizer per mu, dissolving it first and then applying it as a flush application.
5. Spraying time for foliar topdressing: It should be carried out before 11 a.m. or after 4 p.m. on sunny days. Types of spray fertilizer: choose 2 kg of ordinary calcium superphosphate or 1 kg of sulfur-based compound fertilizer and soak in 50 kg of water for 12 hours, then take the clear liquid and spray 1 mu; a 0.2%-0.4% potassium dihydrogen phosphate solution and 0.15% manganese sulfate, 0.5% borax, 0.2% zinc sulfate, and 0.15% copper sulfate solution can also be used. In the middle and late stages of garlic growth, according to the growth vigor and appearance, foliar spraying can be carried out 1-2 times, once every 7-10 days.