Let’s take a closer look (1) Selection of sea area for cultivation. As a sea area for cultivation, the following conditions must be met: Substrate: Flat mud bottom and mud sand bottom are better, and harder sand bottom is better. In short, soft mud bottom is the worst. The rocky bottom is fine. The former hits the pegs, and the latter lowers the weight. Water depth: It is determined based on the length of the seedling rope and the way of raising it. Generally, raft culture can be developed in sea areas with a water depth of more than 5 meters during the dry tide in winter. Water flow, wind and waves, the better breeding area is one with large currents and small waves. Offshore areas with deep water, strong currents and strong winds and waves are also good breeding areas as long as safety is guaranteed. Sea areas with upwellings and cold water masses are especially good. Transparency: The breeding sea area must have good transparency to promote the growth of kelp. The key to the requirement for transparency in sea areas is the relative stability of transparency. Nutrient salt: The breeding sea area must have a good nutrient salt content, and the nitrogen content is generally required to be above 100mg/m3. Sewage situation: Sewage includes domestic sewage and industrial and agricultural production sewage. Breeding sea areas should avoid polluted sea areas. (2) Structure and setting of breeding rafts There are two main types of breeding rafts: single rafts (also known as large single rafts) and double rafts (also known as large double rafts). Single rafts are superior and are the main type of kelp culture in my country. Single raft frame structure: It is mainly composed of floating rafts, prong cables, prongs (or stone weights), floats, hanging ropes, etc. Floating boat: It floats on the sea surface through the buoyancy of the float, and the seedling rope is hung on it. Its length is the length of the raft, about 50-60 meters. Its material is plant fiber or chemical fiber rope. Prong cable and prong (or stone mass): used to fix the raft body. One end of the prong cable is connected to the floating raft, and the other end is tied to the prong on the seabed. The cable material is the same as the floating raft. Prongs include wooden prongs and bamboo prongs. The stone mass can be made of stone or reinforced concrete components. Float: Provides buoyancy for the cable. Types include moso bamboo tubes, glass balls, plastic balls and polyethylene foam. The layout of sea areas should be planned uniformly and laid out rationally. Consideration must be given to flow, safety, and ease of operation. Define the rankings and form intervals. Generally, 30-40 rafts are in one ranking (one zone). The distance between zones is 30-40 meters, and the spacing between rafts (equal) is 6-8 meters. When setting the direction of the raft, the relationship between wind and current and the light receiving condition of the kelp should be considered. There are two categories: downstream rafting and cross-current rafting. Be careful to prevent diseases in kelp farming Edit this paragraph 1. Method of dipping fertilizer to prevent insects. Water bugs are characterized by strong activity during the day and weak activity at night. At night, when the water temperature drops to 8°C, it dives to the bottom of the sea and does not pose a threat to the kelp. During the day, when the water temperature rises, you can mix seawater and urea at a ratio of 300:1. Put the kelp seedlings into the fertilizer water and dip them for a short time. All the water lice will fall off the seedling rope, and then put the kelp seedlings out. Put back into the sea. This method is easy to operate and highly efficient. Two people can dip more than ten seedlings per hour. Kelp seedlings should be dipped in fertilizer twice a day; the best times are 4 to 5 a.m. and 6 to 7 p.m. And you need to keep applying fertilizer every day. When the first-stage seedlings grow to more than 66 cm, you can clip the seedlings. The clamped seedlings have thicker roots and grow quickly, so pests do not pose a threat to them. 2. Deepen the water layer method. When the kelp grows from mid-March to early April, the weather becomes clearer and the transparency of the seawater increases dramatically. Due to the short growth period and weak seedlings in the middle and late stages, kelp seedlings are difficult to adapt to the rapidly changing external environment. Farmers should go to sea frequently during this period and observe frequently. Once a few kelp seedlings are found to have both sides curled inward, it is a precursor to white rot. During this period, if immediate measures are not taken, the disease will be unstoppable when the kelp curls over a large area. The water layer of mid- and late-stage kelp should be deepened by about 50 to 82 centimeters (the first-stage seedlings can be relatively shallow), usually in about 10 days, so that the curly kelp can return to straightness and grow well. By mid-to-late April, the kelp enters the thickening stage, and the demand for light increases sharply. At this time, the kelp must be raised to about 33 cm above the water surface. This method is particularly effective. Issues that should be paid attention to when processing kelp. Edit this paragraph. After the kelp is harvested and landed, it is directly dried in the sun and is called light-drying. Light-drying kelp has a wide range of uses without loss of nutrients. It is the raw material for extracting iodine, glue and alcohol. Regular consumption of kelp can prevent and treat goiter. In addition, a large number of products are exported every year. The country has stipulated the kelp processing standards (revised and issued on April 1, 1979). In addition to strict implementation in accordance with national regulations, some frequent problems must be paid great attention to.
(1) As kelp used in seaweed chemical industry, it should be dried carefully to ensure that the moisture content does not exceed the specified 22%; impurities should be carefully removed to ensure that it does not exceed the specified 2%. As a chemical raw material, it must not be adulterated and must be for the country and the country. The user is responsible. (2) As an export product, we must strive to dry it thoroughly on the same day; impurities, sporangia, stems, yellow and white edges, etc. are not allowed; the color must be dark brown, and shoddy products are not allowed to damage the country's honor. ① Substrate: The seabed is preferably a flat and undulating rock reef surface or has a certain slope; followed by a large rock substrate; in addition, gravel or gravel substrate can also be multiplied by throwing stones. ②Water quality: The water quality is clean, and the natural nitrogen content can always be maintained at about 10 mg per cubic meter. There are many suspended solids in the sea water, the water is mixed, and there are sediments and floating mud on the rocks. It cannot be used. ③Water depth: generally from the low tide line to 2.5 meters. ④ Biology: There are a large number of miscellaneous algae growing on the reef surface, which is not suitable for use. Although it can be removed, it is too labor-intensive and the gain outweighs the loss. ⑤Flow velocity: According to the survey, the flow velocity does not exceed 60 cm/second, and spores on the reef surface can adhere and grow. ⑥Water temperature: Pay attention to sea areas where the water temperature does not exceed 27°C in summer, so that megasporophytes can reproduce over the summer. (3) Kelp multiplication method: ① Spore-collecting and stone-throwing multiplication method: that is, manually attaching spores to stones and then throwing them into the selected sea area. The size of the rocks depends on the size of the wind and waves. Throw stones per acre. ②Seed kelp method: Save the kelp seeds over the summer, transport them to the selected sea area after the sporangia mature in autumn, dry and stimulate the seeds for 2-3 hours, and then tie the two ends of the ropes to stone anchors and pull them Tightly plunged into the seabed. 1,000 trees per acre are planted in the seed belt. ③Suspended rope tied seedling propagation method: This method is adopted in Japan, that is, seabed floating rafts are first set up in the selected sea area. Hang seedling ropes from the floating raft frame to allow the spores to disperse naturally. Attached to the rocks.