In recent years, alfalfa breeding has developed rapidly in Haimen, Jiangsu Province. The method of relying solely on collecting and catching wild seedlings to obtain seedlings is far from meeting the needs of production. For this reason, Haimen City began to conduct research and trials on the technology of half-seedlings in 1996 and was successful. In 1998, 50 acres of mudflats produced 14.8 tons of seedlings, with an average yield of 0.29 tons per mu. In 1999, 250 acres of tidal flats produced 87.8 tons of seedlings, with an average yield of 0.35 tons per mu, which partially eased the contradiction of shortage of seedlings. The techniques for harvesting half-emitter seedlings in Haimen City are summarized below for reference.
I. Site Selection and Construction A high school tide area with a flat topography and a slight slope is selected. The surface of the soft mud is smooth, the mud content is about 80%, the mud depth is about 30cm, and the sand layer is underneath. The tide is smooth, the flow is slow, the water is calm and there is fresh water in the inner bay. The proportion of seawater is between 1.008-1.018 and the breeding season is 15-20°C. The selected nursery is divided into several rectangles arranged in rows to serve as seedlings. Banks and trenches are left between rows and rows. The size of the seedlings remains the same, and is specified as 3010m. The direction is perpendicular to the channel. The bank width is 0.6-0.8m, the channel width is 2-3m, and the depth is 0.1-0.15m. Tear the surface mud. A small trapezoidal embankment is built around the seedlings and the embankment is 0.3-0.5m high. The width of the embankment depends on the size of the storm. The waves are wide and narrow, but the width is generally 0.8-1.2m and the width is about 0.3m. A gap is left on each of the two embankments parallel to the channels on both sides for water intake and drainage. In places where wind and waves are relatively large, Miaowa is built into embankments on the outskirts. Its specifications are 1.4m in width, 0.4m in width, and 0.6m in height. The cross section of the embankment is slightly arcuate. Wrap around with black polyethylene paper or mix straw with mud and embankment. The gap between the embankment and the trench remains the same size as the trench. All embankments must be compacted, and it is advisable to build 1/3 of the height of each tide to filter the water and increase the strength of the embankment.
Second, the preparatory work 1? After the end of the construction of the extermination plant, use a 1:700 "triazophos" liquid 150gg/mu or 1:600 ​​"marathon" liquid 250g/mu for spraying. Kill fish, crabs, snails and other predators.
2? After the construction of the medicine, the soil is poured every other day, loosen the bottom, and the depth of soil is 0.2-0.3m. Then, the unevenly sized soil blocks are smashed to make the mud surface evenly and evenly. Water will be stored in a timely manner after the construction and the water depth will be maintained at about 0.3m.
3 畦 2-3 days before seedling emergence, drain the pool and use wood or mud horses to flatten and grind the soil on the entire area. Low bulge. The seedlings with more water content are often flattened and have better seedlings. Repeatedly, only after each batch of larvae is attached, it is sufficient to gently push and smooth the oil on the surface, and it is not advisable to use too much force, otherwise it is easy to damage the previously attached seedlings.
In order to correctly grasp the seedling-attaching time and timely correcting, we must do a good job in forecasting. The specific approach is: during the breeding season, daily inspection of intimal gonad development and sperm-egg emissions; examination of sea larvae development stages and the number of changes, when the sea larvae abruptly reduced, indicating that the larvae have been attached. It has been found through practice that the time from the fertilized egg to the larvae differs depending on the water temperature, as shown in the table below. As a result, it is possible to accurately make blunt predictions and carry out leveling in due course.
Water temperature (Celsius) 18-20 21-23 24-25 25-26
Time (days) 9-10 8-9 6-7 5-6
Third, training measures
1? Surface management: After the seedlings are attached, the water can be stored for 7-8 days, which can accelerate the growth of the seedlings. After 20 days with seedlings, ditches were excavated around the seedlings that had been overly thin and muddy to reduce the surface moisture. Keeping the soil soft and solid can stabilize the original seedlings and increase the amount of seedlings.
2? Maintenance of Miao Miao often check the sea, so that "three timely": found that the collapse of the dike collapsed and repaired; smashed the surface was rushed into the cavities filled in time to smooth the trowel; gutter clogging in a timely manner to clear.
3? Prevention of Natural Disasters The cold weather after entering winter should be stored to prevent freezing of seedlings; the weather is warmer, the embankment is drained, the flow is smooth, and the growth of seedlings is promoted; when the proportion of seawater exceeds 1.018, it is necessary Freshwater regulation.
4? In addition to killing the enemy, the creature can cover the seedlings with a net, and can also use the nets or jaws to capture, shoot, etc. to expel fish, snails, crabs, ducks and other predators. Fourth, from the beginning of December to the third of the following year, the seedlings can receive seedlings as long as 1.5 cm. The seedlings were stored on the day before the seedlings were collected. The next day, with the six-tooth rake on the seedling lice, even with the mud belt muddy repeatedly, the water will be stirred into mud, a little precipitation, the seedlings will float on the water, and then use the net to pick up, after cleaning
I. Site Selection and Construction A high school tide area with a flat topography and a slight slope is selected. The surface of the soft mud is smooth, the mud content is about 80%, the mud depth is about 30cm, and the sand layer is underneath. The tide is smooth, the flow is slow, the water is calm and there is fresh water in the inner bay. The proportion of seawater is between 1.008-1.018 and the breeding season is 15-20°C. The selected nursery is divided into several rectangles arranged in rows to serve as seedlings. Banks and trenches are left between rows and rows. The size of the seedlings remains the same, and is specified as 3010m. The direction is perpendicular to the channel. The bank width is 0.6-0.8m, the channel width is 2-3m, and the depth is 0.1-0.15m. Tear the surface mud. A small trapezoidal embankment is built around the seedlings and the embankment is 0.3-0.5m high. The width of the embankment depends on the size of the storm. The waves are wide and narrow, but the width is generally 0.8-1.2m and the width is about 0.3m. A gap is left on each of the two embankments parallel to the channels on both sides for water intake and drainage. In places where wind and waves are relatively large, Miaowa is built into embankments on the outskirts. Its specifications are 1.4m in width, 0.4m in width, and 0.6m in height. The cross section of the embankment is slightly arcuate. Wrap around with black polyethylene paper or mix straw with mud and embankment. The gap between the embankment and the trench remains the same size as the trench. All embankments must be compacted, and it is advisable to build 1/3 of the height of each tide to filter the water and increase the strength of the embankment.
Second, the preparatory work 1? After the end of the construction of the extermination plant, use a 1:700 "triazophos" liquid 150gg/mu or 1:600 ​​"marathon" liquid 250g/mu for spraying. Kill fish, crabs, snails and other predators.
2? After the construction of the medicine, the soil is poured every other day, loosen the bottom, and the depth of soil is 0.2-0.3m. Then, the unevenly sized soil blocks are smashed to make the mud surface evenly and evenly. Water will be stored in a timely manner after the construction and the water depth will be maintained at about 0.3m.
3 畦 2-3 days before seedling emergence, drain the pool and use wood or mud horses to flatten and grind the soil on the entire area. Low bulge. The seedlings with more water content are often flattened and have better seedlings. Repeatedly, only after each batch of larvae is attached, it is sufficient to gently push and smooth the oil on the surface, and it is not advisable to use too much force, otherwise it is easy to damage the previously attached seedlings.
In order to correctly grasp the seedling-attaching time and timely correcting, we must do a good job in forecasting. The specific approach is: during the breeding season, daily inspection of intimal gonad development and sperm-egg emissions; examination of sea larvae development stages and the number of changes, when the sea larvae abruptly reduced, indicating that the larvae have been attached. It has been found through practice that the time from the fertilized egg to the larvae differs depending on the water temperature, as shown in the table below. As a result, it is possible to accurately make blunt predictions and carry out leveling in due course.
Water temperature (Celsius) 18-20 21-23 24-25 25-26
Time (days) 9-10 8-9 6-7 5-6
Third, training measures
1? Surface management: After the seedlings are attached, the water can be stored for 7-8 days, which can accelerate the growth of the seedlings. After 20 days with seedlings, ditches were excavated around the seedlings that had been overly thin and muddy to reduce the surface moisture. Keeping the soil soft and solid can stabilize the original seedlings and increase the amount of seedlings.
2? Maintenance of Miao Miao often check the sea, so that "three timely": found that the collapse of the dike collapsed and repaired; smashed the surface was rushed into the cavities filled in time to smooth the trowel; gutter clogging in a timely manner to clear.
3? Prevention of Natural Disasters The cold weather after entering winter should be stored to prevent freezing of seedlings; the weather is warmer, the embankment is drained, the flow is smooth, and the growth of seedlings is promoted; when the proportion of seawater exceeds 1.018, it is necessary Freshwater regulation.
4? In addition to killing the enemy, the creature can cover the seedlings with a net, and can also use the nets or jaws to capture, shoot, etc. to expel fish, snails, crabs, ducks and other predators. Fourth, from the beginning of December to the third of the following year, the seedlings can receive seedlings as long as 1.5 cm. The seedlings were stored on the day before the seedlings were collected. The next day, with the six-tooth rake on the seedling lice, even with the mud belt muddy repeatedly, the water will be stirred into mud, a little precipitation, the seedlings will float on the water, and then use the net to pick up, after cleaning