Select suitable for the cultivation of crab culture of the field:
The paddy field is preferred, the lake beach dry land for the second, barren grass reed beach for the next.
Soil soil bone should be yellow bone five flowers soil, for the best. Black green soil for the second, blackboard sand for the least.
PH value of the soil for 6.5-7.8 for the best, 6-7.5 for the second, 7.5-8.5 for the poor
Water:
Proximity to the natural water source is the main, large lakes, large rivers, upstream without factories for the best, along the water area of 15 kilometers of the population without living sewage, factory sewage, the most contraindicated source of water with chemical enterprises.
Opening pond:
The slope ratio of the surrounding ridge is 3:1, the height of the dam is 1.2 meters, to raise large-size crabs, mainly around the opening of the 50 centimeters, 3-meter-wide gently sloping back to the ditch. 50 acres of large blocks in the middle of the addition of the cross water ditch.
In and out of the water outlet for immobilization design.
Anti-escape wall fence design:
Pvc board-based, 55Cm-75Cm or so, half buried in the earth dam, 1 meter 5 intervals standing support bamboo poles, about 1 meter 8 high, 30cm buried under the soil, the top plus 5 mesh wire mesh, or nylon weaving mesh anti-theft.
Construction of the caretaker's house:
A feed storehouse, a feed work room, and a room for other tools and fishing gear should be guaranteed, and a living room, water and electricity lines, and testing equipment should be added if possible.
The first bottom change after opening a pond:
Open the pond, first put 80cm of water to soak the pond, check the infiltration point, make repairs, and then measure the water quality for 3 major items a week later. According to the water quality report, the calculation of lime, and other changes in the amount of low material, put the water to change the bottom
After completing the first change in the bottom, back to the water again, a week later to measure the water quality, to meet the standard of nutrient-quality water, with bleach or chlorine dioxide sterilization disinfection.
Three days after the release of dry water, organic fertilizer bottom, 200-300 pounds of homemade organic rotting fertilizer per acre buried. Then planted in the ditch Ile grass, planted, back to the water. 35-50Cm (on the board field)
| Step 2 | planting grass
After loaded with a good ring ditch Ile grass (mu 3 hundred pounds of fresh grass after the) began to put back to the water. And after three days, the first fertilization, fertilization using long-lasting organic fertilizer + a variety of bacterial sources at the same time cultivation. If necessary, add inorganic fertilizer to assist in obtaining a more satisfactory water phase and algae phase, the water body will be maintained in the board field about 50Cm, began to prepare for the first winter snail pond work.
The quality control of the screws and the water quality requirements of the pond, I have written about this separately and will not repeat it. This time, the number of screws it, each acre requires 60-80 sub-screws, 500-800 pounds, a one-time pond, the use of manual and boat, the screws into the ditch, pay attention to the avoid stacking into the avoidance of temperature into the, or snow and ice weather cast
Screws into the 3 days - a week, you should promptly observe the pond water quality and algae phase intersections. Found that the water quality is too clear, too thin phenomenon, the application of soybean milk + red pond water fermented by fungi, 5 kg per mu, sprinkle detailed 2 times, 2-3 days interval.
During the period, should be measured once the pH value and dissolved oxygen is abnormal.
In half a month after entering the snail (about ten days after New Year's Day, in the choice of sunny days), for the first time the green shrimp fry into the 5 pounds or so is appropriate.
And start to vegetable meal + soybean meal fermentation, every 3-4 days to follow the feed, per mu, 1 kg or so, the weather to the freezing point when the material is stopped.
Auxiliary fish: it is necessary to apply a certain amount of various fish in the pond for water quality balance. Because the natural water quality contains a variety of fish eggs will be with the water into the pond, the use of guppies to control the fish, to prevent after the application of feed bait is consumed is an effective means of recommending 5 per acre -18 or so appropriate, according to the amount of fish in the water body to determine the amount of fish. Also put in 3 chub (1 white ten 2 yellow) per acre 2 young fish per pound. And put in a catty of about 20 local crucian carp, about 2 catties, and banded crucian carp half a catty / strip, one per mu. You can put 2-3 grass carp in 30 mu pond.
|Step 3 |Into the seedling crab
Generally new ponds use winter seedlings + spring seedlings binary method into the seedling, old ponds, insert seedlings + spring seedlings into the seedling. Winter seedlings are generally 80 heads or less, the individual uniform seedling is good, spring seedlings, generally below 60 heads, uniform body is good, if the goal of raising large-size crabs: should be in the spring seedling specifications on the control: 40 heads of seedling is mainly). Winter seedlings about 400-500, spring seedlings about 800-1000.
The old pond insertion of seedlings in mid-July or so, into the pond captive, bean seedlings (per pound (250 head of a 300 head), 1.5 pounds per acre or so, and starve the seedlings during October a December, to maintain the phenomenon of old man seedling of bean seedlings in the range of 10%, the weight of the individual can not exceed 50 head/catty. Reasonable control of nutritional intake is the key.
Spring seedlings, for 60 head of large seedlings 800 head per mu, about 15 days before the Qingming pond.
Note: Because of the spring seedlings in the pond, found that the first molt, the seedlings have the top shell, sticky fat phenomenon, must be replenished. And you have to add vitamin E in the feed to regulate it.
|Step 4 | Planting grass
Crab size, look at the watercress, watercress largely determines the specifications and production of river crabs, watercress plays a significant role in pond crab farming, is indispensable to the technical measures of the river crab culture, watercress planting area accounts for more than 50% of the area of the pond to be a few kinds of grasses mixed species, to prevent the watercress insect pests too many to be cut off, too few to be transplanted to the high-temperature season in a timely manner to fish out the decay of the The watercress.
Control the coverage of watercress according to different growing periods. Spring accounted for 20-30%, summer accounted for 55%, fall accounted for 30-40%, water plants too little, should be appropriate replanting or transplanting, too much water plants, should be taken in time to cut stubble removal, slowly deepen the pool water, increase the bottom of the pool dissolved oxygen and other technical measures. Water plants should be controlled in the water surface down 20-30 centimeters for the best. Watercress should pay attention to prevent withering, rotting stems, yellowing, rotten roots, sticky mud, crazy growth, etc., the specific situation should take appropriate technical measures to deal with in a timely manner.
|Step 5 | Do a good job of water quality control
Water quality control is the key, the high temperature season every 2-3 days to add water 1 time, sustained high temperatures side of the water change, while taking measures to increase oxygen in the whole process of aquaculture, the use of substrate modification and microbial agents to improve the quality of the substrate and the water to achieve ecological aquaculture purposes. Do a good job in May and August low, every three days to check the water quality of the work, timely detection of problems, prevention and control of water damage, more effective than the drug treatment of water damage.
When the spring seedlings in the pond, I was the first time in time to adjust the water level. To grasp the "spring shallow, summer full, autumn appropriate" principle, in three stages of water level adjustment. 3-5 months of the depth of water mastered in 0.5-0.6 meters, deep ditch to ensure that 1 meter, June-August control in 1.2-1.5 meters (high temperature season can be appropriate to deepen the water level), September-November stabilized in 1.0-1.2 meters, ditch water 1.5 meters. 1.m 5. Special attention should be paid to the crab moulting period should be maintained at a stable water level, do not easily into the water, out of the water, to prevent stress reaction.
When changing water, first exclude the old water at the bottom of the pool (the bottom water will generally flow in the deep ditch, so it is necessary to return to the ditch deep and wide, and then fill in the fresh water outside the river, divided into three or four times. Each time the amount of water change control in the pool water 1 / 5, add water should be selected in the early morning or morning, should not be added in the evening.
The dissolved oxygen of the water body should be kept above 7.5 mg/l all the year round, the pH is stable between 6.50-8.50, the molecular nitrogen is less than 0.02 mg/l, the nitrite is less than 0.2 mg/l, the hydrogen sulfide is less than 0.1 mg/l. If any of the following conditions exist, it is necessary to change the water or take other measures: daily fluctuations in pH are greater than 0.5, pH is less than 7 or pH is greater than 9; the transparency of the pond water is greater than 70 centimeters (white plate method) or too turbid and less than 20 centimeters (black plate method); the color of the pond water is significantly darker, the number of inorganic suspended solids is increased, there is a stable foam on the surface of the pond water, there is a lot of organic matter and the consumption of oxygen is increased; the floating head of the aquatic fish and animals, the pond The bottom is blackened.
Timely observation of water color and determination of water quality physical and chemical indicators. Learn from the old crab farmer's visual experience, water quality can usually be reflected through the water color, common good water color such as brown, yellowish green, light green, emerald green, etc., common bad water color such as white turbid water, clear color water, turbid water, oil stained foam water, dark green and dark green, dark brown and soy sauce color water. Poor water quality in addition to the visual reflection of the water color, but also through instrumentation in the water quality indicators such as ammonia nitrogen, hydrogen sulfide, nitrite, etc. reflected. If the water quality indicators change, appropriate adjustments should be made.