Fertilization is crucial when growing garlic: which fertilizer is best?
Many farmer friends want to grow, or grow more, garlic to increase their income. But when growing garlic, you must pay attention to the fertilization issue, so which fertilizer is best for growing garlic?
1. What fertilizer is best for the base fertilizer of garlic?
1. The base fertilizer for garlic is best based mainly on organic fertilizer
Common organic fertilizers include barnyard manure, chicken manure, duck manure, stable manure, compost, and cake fertilizer. Whether the base fertilizer application rate is sufficient directly affects the marketability of the garlic bulbs and the overwintering performance of the plants, so sufficient base fertilizer should be applied in production.
2. Determining the application rate of garlic base fertilizer
The application rate of base fertilizer should be determined comprehensively by considering various factors such as the target yield of garlic and the fertilizer requirement per unit area for that yield. Where conditions permit, 50-100 kg of cake fertilizer such as cottonseed cake can be applied. Chemical fertilizers commonly used together with organic fertilizer as base fertilizer include superphosphate, nitrogen-phosphorus compound fertilizer, nitrogen-potassium compound fertilizer, or NPK compound fertilizer. Apply about 75 kg of standard nitrogen fertilizer per 667 sq m. Two-thirds of the nitrogen fertilizer should be applied as base fertilizer, and one-third as topdressing. The vast majority of phosphorus and potassium fertilizers should be applied as base fertilizer. For phosphorus fertilizer, use about 30 kg of superphosphate. When phosphorus fertilizer is applied as base fertilizer, whether it is superphosphate or calcium magnesium phosphate, it must be mixed with organic fertilizer and turned shallowly into the plow layer. For the amount of potassium fertilizer, generally apply about 30 kg of potassium sulfate per 667 sq m.
3. How should garlic base fertilizer be applied?
For base fertilizer application, generally half of the organic fertilizer is applied before plowing, spread evenly on the soil surface, and turned into the ground together with plowing; the other half is applied in a concentrated furrow application at sowing time, mixed with soil, and then sown. If ammonium bicarbonate or organic fertilizer is used as base fertilizer, it should be buried in furrows or applied with irrigation water, and after application it should be mixed evenly with the soil during land preparation. Phosphorus fertilizer is best applied shallowly, in a concentrated way, or in layers. Part can be applied before plowing, and the other part after plowing when planting garlic, or applied shallowly 6-10 cm underground after land preparation, to facilitate absorption and use by seedlings, cultivate strong seedlings, and improve the seasonal utilization rate of phosphorus fertilizer. Potassium fertilizer can be spread during plowing and turned into the ground.
2. What fertilizer is best for topdressing garlic?
From the seedling stage of garlic to each growth stage before bulb harvest, fertilizing in stages according to its growth and development and its fertilizer requirements and uptake characteristics is called topdressing.
1. Topdressing for garlic is generally based mainly on nitrogen fertilizer; when needed, nitrogen, phosphorus, and potassium fertilizers and various elements should be applied together, which is beneficial to the normal growth and development of garlic, promotes the absorption and use of nutrients, and improves quality. Nitrogen fertilizer has a significant yield-increasing effect on garlic.
When topdressing garlic with nitrogen fertilizer, attention should be paid to the possible adverse effects. According to experiments, the effect of nitrogen topdressing is closely related to the size of the seed garlic cloves; the smaller the seed garlic cloves, the greater the yield increase from nitrogen application. Therefore, when using small-clove garlic as seed garlic, the nitrogen fertilizer application rate should be appropriately increased.
2. Topdressing garlic with phosphorus and potassium fertilizers can improve the balanced absorption and use of nitrogen fertilizer, promote the growth and development of garlic, and increase the yield of garlic scapes and bulbs. In the later stage, garlic not only needs nitrogen topdressing but also phosphorus and potassium topdressing; nitrogen, phosphorus, and potassium fertilizers should be applied together in a 2:1:1 ratio, or a compound fertilizer should be applied. This is beneficial for preventing premature aging of leaves in the later stage of garlic and promoting the transport of leaf nutrients to the bulbs, and can significantly increase the yield of garlic scapes and bulbs.
3. Topdressing periods can generally be divided into pre-winter topdressing, green-up stage topdressing, garlic scape elongation stage topdressing, and garlic bulb growth stage topdressing.
(1) Topdressing garlic before winter: Pre-winter topdressing mainly promotes normal germination and emergence of garlic and cultivates strong seedlings. The appearance of strong seedlings before winter is: 5 leaves, plant height about 25 cm, fresh weight per plant about 10 g, uniform root system, about 30 roots. For autumn-sown garlic, seedlings generally emerge completely 7-9 days after sowing. To improve the safe overwintering performance of garlic, apply a seedling-promoting fertilizer. The seedling-promoting fertilizer generally accounts for about 25% of the total topdressing amount. For varieties prone to outer-layer cross growth, the seedling-promoting fertilizer should be applied less or not at all.
When garlic enters the overwintering period, overwintering fertilizer, namely winter manure, can be applied. Winter manure is commonly applied as a cover using compost, soil-and-miscellaneous manure, or horse manure, to thicken the protective layer for the root system during overwintering, improve the overwintering performance of seedlings, and ensure safe overwintering. At the same time, it also helps early green-up and rapid growth the following year.
(2) Topdressing garlic at the green-up stage: When the average daily temperature in spring reaches 7°C, garlic seedlings begin to turn green and grow. At this time, remove the covering promptly, expose the seedlings for 2-3 days, and before the plants start growing around the Spring Equinox, apply 1 green-up fertilizer. Generally, apply 1000-1500 kg of organic fertilizer per 667 sq m, or 10-15 kg of standard nitrogen chemical fertilizer. If seedling-promoting fertilizer and overwintering fertilizer have already been applied, no topdressing may be needed at the green-up stage, or the green-up fertilizer may be postponed and applied together with the scape-promoting fertilizer.
(3) Topdressing garlic during the garlic scape elongation stage: Topdressing during the garlic scape elongation stage refers to topdressing from the beginning of garlic clove differentiation to before scape extraction. This period is when garlic scapes and bulbs grow simultaneously. In Shandong, it is generally late March to early April, that is, before Qingming, when garlic enters the differentiation stage of garlic scapes and cloves, and May 20, that is, around Xiaoman, when it enters the scape extraction stage.
Because the elongation of garlic scapes overlaps with the early growth of garlic bulbs, it is in a period of vigorous growth. At this time all leaves have grown out, the aboveground growth of the plant reaches its maximum, the yield of underground garlic bulbs has formed nearly 50%, the root system actively expands laterally, and growth and absorption gradually reach a peak, so the topdressing amount should account for about 40% of the total topdressing amount. Increase the application of compound fertilizer and potassium fertilizer to promote garlic scape extraction and bulb expansion.
(4) Topdressing garlic during the garlic bulb growth stage: Because before garlic scape harvest, bulb growth is mainly increasing volume, and after garlic scape harvest, bulb growth is mainly increasing weight, with an average daily weight increase of about 1 g and a daily diameter increase of about 0.06 cm. During the garlic bulb growth stage, quick-acting nitrogen fertilizer should be the main fertilizer, combined with phosphorus and potassium fertilizers. The amount of this topdressing should account for 25%-30% of the total topdressing amount.
4. Garlic topdressing methods: generally strip application, application with irrigation water, or buried application. When applying soil-and-miscellaneous manure, open furrows along the rows and spread it in strips; when applying chemical fertilizer, generally open furrows and broadcast it or apply it in holes, then cover with soil and water, or apply it with irrigation water, or broadcast it during rain. Pay attention to strengthening intertillage and weed control, keeping the soil loose and preserving soil moisture, so as to speed up the absorption and use of nutrients by the root system.
Overall, garlic likes fertilizer, and when growing garlic, an appropriate amount of more fertilizer should be applied, but attention must be paid to the nutritional combination of base fertilizer and topdressing.