Detailed Explanation of the Key Points of Standardized Cultivation Techniques for Bracken Fern
Bracken fern (Pteridium aquilinum var. latiusculum), also called fist vegetable, cat's claw, and dragon-head vegetable, prefers to grow on sunny plots in low mountain areas. It is found in most parts of China, mostly distributed in sparse coniferous and broad-leaved mixed forests; its edible part is the unexpanded young leaf bud. After processing, bracken fern has a delicate, smooth taste and a light fragrance. Mixed with seasonings, it is cool and refreshing, a rare top-grade dish to go with wine. It can also be stir-fried, processed into dried vegetables, used as filling, or pickled into canned goods. It is widely distributed in mainland China and Southeast Asia, and is also welcomed on dining tables in these regions.
Morphological characteristics of bracken fern
Root: The underground rhizome of bracken fern is dark brown, long and extending horizontally, with a diameter of 0.6-0.8 cm and a length of more than 10 cm, up to a maximum of 30 cm.
Leaf: The leaves of bracken fern grow from the underground stem, with fine veins and pinnate branching. The leaf margin curls inward. The leaf stalk has fine down when young and tender; after becoming herbaceous, the stem is smooth and the down disappears. In early summer, reproductive organs, namely sori, form on the inside of the leaves and are ochre-brown.
Key points of standardized cultivation of bracken fern
Land preparation and bed making
It is advisable to choose soil rich in humus. During land preparation, apply leaf litter compost and barnyard manure, and make flat beds or raised beds 1 m wide. Planting can be done after the soil thaws.
Propagation methods
Bracken fern has two propagation methods, namely sexual propagation (spore propagation) and asexual propagation (rhizome division propagation). In production, asexual propagation is mostly used. For asexual propagation, dig out the underground rhizomes, select robust ones for division and planting, with a row spacing of 70-80 cm and a plant spacing of 50-60 cm. Transplant when the seedlings are 10-15 cm tall.
Root stock cultivation
The root stocks (underground stems) of wild bracken fern are relatively thin and weak, with low yield. Therefore, the root stocks must be fertilized and cultivated. This measure is the key to increasing yield. In order to dig more root stocks, the growth community of bracken fern must be investigated in advance. When the soil thaws but before sprouting, dig as early as possible and try to damage the roots as little as possible when collecting root stocks. The amount dug per person is generally 10-15 kg.
Bracken fern does not have strict requirements for soil quality. In order to facilitate protected production, choose a fertile, well-drained loam site sheltered from the wind and facing the sun for cultivation. Apply base fertilizer 10 days before planting (decomposed chicken manure, farmyard compost, and optionally additional phosphorus and potassium chemical fertilizers) and make beds (flat beds, 1.2-1.5 m wide). The planting method is to open shallow furrows about 10 cm deep in the beds at a row spacing of 50-60 cm, first water the bottom of the furrows, and then place the dug root stocks. Generally, 140-200 kg are planted per 667 sq m. After planting, not only should soil be covered, but rice straw should also be spread on the bed surface.
Topdressing is mainly carried out in May-June. To prevent excessive vegetative growth, nitrogen fertilizer must not be excessive; calculated as pure nitrogen, it should not exceed 15 kg per 667 sq m. At the same time, attention should also be paid to the coordination of phosphorus and potassium fertilizers. During the rainy season, pay attention to preventing waterlogging to avoid lodging. After September, the aboveground part is required to be lush, and the underground root system is required to be developed and interlaced into a net. When early frost arrives and the aboveground part withers, more than 1 month of dormancy is needed before protected production can be carried out.
Field management
During the growth period, frequent intertillage, weeding, and irrigation should be carried out. During the rainy season, strengthen drainage to avoid root rot; apply thin fertilizer multiple times, and fertilize once after each harvest. Fertilization should be carried out 2-3 days after harvest; in winter, cover with dry grass to preserve moisture and prevent cold; before sprouting in early spring, water and topdress in time to promote stem and leaf germination.
Harvesting
Bracken fern can be harvested for more than 10 years after one planting. Each year in spring and early summer, when the young stems grow to 20-25 cm, the leaf stalks are tender and the leaflets have not yet unfolded and are in a fist-hook shape, they can be harvested. If too late, the edible value will be affected and the next year's harvest will be adversely affected; if too early, the yield will be reduced. When harvesting, cut with a knife or pinch with the hand, as close to the ground as possible. After one harvest, the second harvest can be carried out in 10-15 days, and 2-3 consecutive harvests can be made in one year.