Qing Lan, commonly known as alfalfa, is mainly distributed on the north and south coasts of China, south of Japan's Honshu and on the coast of North Korea. It is loved by the masses for its delicious taste and high nutritional value. Breeding in China is basically based on natural seedlings, but due to the worsening of the ecological environment in recent years and the artificial indiscriminate harvesting, the natural seedling resources of the barley have dropped dramatically. In 2000, the author conducted an experimental study on the conservation of the barley of artificial barnyardgrass. The experimental process is now described as follows:
First, the choice of test sites
1. The location of the site test site was selected to be on the tidal flat on the edge of the shrimp pond in Shuangpu Township, the county's aquaculture farm. It was surrounded by mud and formed a rectangular paddy field with a height of 30 cm, an area of ​​300 cubic meters, muddy bottom, and annual seawater. The specific gravity is between 1.019 and 1.022, and the water temperature is 10-30 degrees.
2. Site trimming Before removing the seedlings, remove excess silt to make the entire site flat and smooth, and keep the mud thickness at about 3 to 5 cm. Because there are many predator pests in the farmland, kill the small crabs and other predator organisms before going to the seedlings.
Second, broadcast seedlings
1. Seeding time, density
On October 14, 2000, the young planting seedlings raised to 0.5-0.8 mm at the nursery were moved into the holding farm, with 18 million grains and a seedling density of 60,000 grains/m2. The water temperature at the time of sowing was 20°C, the specific gravity was 1.020, PU8.2.
2. Seedling method Before sowing seedlings, put 10 centimeters of seawater in Putian before putting the young seedlings in plastic buckets. Add half a bucket of seawater. Use a spoon to pick up the seedlings and the water together. Sprinkle them evenly. Tanaka.
Third, temporary management
1. Day-to-day management After daily ebb, check whether the dam has leaked or collapsed. Find the problem and repair it in time. At regular intervals, the seawater in the seawater was drained and the growth and reproduction of the enemy's predators were checked. When there were many predator-like creatures, they were sprayed with pesticides. Usually, some fertilizers are applied from time to time to cultivate benthic food organisms. Every month, select the day when the weather is fine and dry the seed once. As of December, due to the large number of oncomelania snails that affect the growth and feeding of young plants, the seedlings and oncomelania were scraped together with special mesh bags. After the oncomelania snails were removed, the seedlings were re-introduced.
2. Regularly check and measure the growth of the sample and check the seedlings every half a month. Measure the height of the shell and shell of the seed and record it.
IV. Results and Discussion
1. After more than five months of holding, on March 21, 2001, the seedlings were all scraped up for measurement. The maximum shell length measured was 8.0 mm and 8.0 mm, and the minimum shell length was 6.0 mm. 6.0 mm, with an average shell height of 7.0 mm and 7.0 mm, with a total population of 10.08 million, and a survival rate of 61%. In this experiment, due to the late nursery time, the temperature of the raising water was below the optimum growth temperature of 22-30 degrees C., so the cultivated young plants of the young seedlings grew at a slower rate, and the seedlings after the raising were of a smaller size. If the nursery is raised earlier in July and it is out of service in August, the size of the raised seedlings can reach 10 mm or more.
2. Due to the thin and brittle seedlings of barley, in the initial stage of holding, the seedlings and turning pools cannot be frequently carried out to prevent crushing of the outer shell of the seedlings during operation, resulting in unnecessary losses. During the holding process, proper dew-drying is beneficial to the growth of seedlings.
3. Before temporary maintenance, dredging, disinfection, and detoxification work are particularly important. Because the seedlings are removed from the interior of the room and the environmental conditions change greatly, it is necessary to create a good habitat, reduce the inadaptability of the seeds to the external environment, and improve the survival rate of the rearing. Moreover, the seedlings that have just been out of the pond have a small size and are vulnerable to attack by enemy animals. Therefore, after the construction of Putian, all the disasters in Putian should be removed and disinfection should be carried out regularly.
4. During the holding process, the amount of food organisms in seawater also affects the growth rate and survival rate of seedlings. The holding place is located near the edge of the shrimp pond. Compared to the natural sea area, the food organisms in the seawater are relatively abundant, and the fertilization of benthic food organisms is not regularly applied. Therefore, the bait factors for the whole holding process are basically the same for the seedlings. No effect.
First, the choice of test sites
1. The location of the site test site was selected to be on the tidal flat on the edge of the shrimp pond in Shuangpu Township, the county's aquaculture farm. It was surrounded by mud and formed a rectangular paddy field with a height of 30 cm, an area of ​​300 cubic meters, muddy bottom, and annual seawater. The specific gravity is between 1.019 and 1.022, and the water temperature is 10-30 degrees.
2. Site trimming Before removing the seedlings, remove excess silt to make the entire site flat and smooth, and keep the mud thickness at about 3 to 5 cm. Because there are many predator pests in the farmland, kill the small crabs and other predator organisms before going to the seedlings.
Second, broadcast seedlings
1. Seeding time, density
On October 14, 2000, the young planting seedlings raised to 0.5-0.8 mm at the nursery were moved into the holding farm, with 18 million grains and a seedling density of 60,000 grains/m2. The water temperature at the time of sowing was 20°C, the specific gravity was 1.020, PU8.2.
2. Seedling method Before sowing seedlings, put 10 centimeters of seawater in Putian before putting the young seedlings in plastic buckets. Add half a bucket of seawater. Use a spoon to pick up the seedlings and the water together. Sprinkle them evenly. Tanaka.
Third, temporary management
1. Day-to-day management After daily ebb, check whether the dam has leaked or collapsed. Find the problem and repair it in time. At regular intervals, the seawater in the seawater was drained and the growth and reproduction of the enemy's predators were checked. When there were many predator-like creatures, they were sprayed with pesticides. Usually, some fertilizers are applied from time to time to cultivate benthic food organisms. Every month, select the day when the weather is fine and dry the seed once. As of December, due to the large number of oncomelania snails that affect the growth and feeding of young plants, the seedlings and oncomelania were scraped together with special mesh bags. After the oncomelania snails were removed, the seedlings were re-introduced.
2. Regularly check and measure the growth of the sample and check the seedlings every half a month. Measure the height of the shell and shell of the seed and record it.
IV. Results and Discussion
1. After more than five months of holding, on March 21, 2001, the seedlings were all scraped up for measurement. The maximum shell length measured was 8.0 mm and 8.0 mm, and the minimum shell length was 6.0 mm. 6.0 mm, with an average shell height of 7.0 mm and 7.0 mm, with a total population of 10.08 million, and a survival rate of 61%. In this experiment, due to the late nursery time, the temperature of the raising water was below the optimum growth temperature of 22-30 degrees C., so the cultivated young plants of the young seedlings grew at a slower rate, and the seedlings after the raising were of a smaller size. If the nursery is raised earlier in July and it is out of service in August, the size of the raised seedlings can reach 10 mm or more.
2. Due to the thin and brittle seedlings of barley, in the initial stage of holding, the seedlings and turning pools cannot be frequently carried out to prevent crushing of the outer shell of the seedlings during operation, resulting in unnecessary losses. During the holding process, proper dew-drying is beneficial to the growth of seedlings.
3. Before temporary maintenance, dredging, disinfection, and detoxification work are particularly important. Because the seedlings are removed from the interior of the room and the environmental conditions change greatly, it is necessary to create a good habitat, reduce the inadaptability of the seeds to the external environment, and improve the survival rate of the rearing. Moreover, the seedlings that have just been out of the pond have a small size and are vulnerable to attack by enemy animals. Therefore, after the construction of Putian, all the disasters in Putian should be removed and disinfection should be carried out regularly.
4. During the holding process, the amount of food organisms in seawater also affects the growth rate and survival rate of seedlings. The holding place is located near the edge of the shrimp pond. Compared to the natural sea area, the food organisms in the seawater are relatively abundant, and the fertilization of benthic food organisms is not regularly applied. Therefore, the bait factors for the whole holding process are basically the same for the seedlings. No effect.