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What causes oxygen depletion in pond fish in winter?
This is because when the air temperature drops, in deep-water ponds, fertile-water ponds and high-density cage aquaculture waters, the water temperature at the surface is lower than that of the lower layer, and the specific gravity of the water is greater than that of the lower layer. Thus the cold surface water sinks and the warm lower-layer water rises, forming vertical convection of the water body. The water in the deep layer is low in oxygen or even anoxic, and the low-oxygen and anoxic water rises, causing severe oxygen depletion in the upper water body. On the other hand, this vertical movement of the water body accelerates the oxidative decomposition of organic matter such as leftover feed and feces deposited at the bottom of the pond, increasing the oxygen consumption within the water body. On yet another hand, in winter there is
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Key Technical Points for Planting Sichuan Pepper in Late Autumn and Early Winter
Compared with spring sowing, autumn sowing for raising Sichuan pepper seedlings gives better results. With autumn sowing of Sichuan pepper, there is no need for germination forcing; the seeds germinate naturally, and seedlings generally emerge completely from late March to early April of the following year, emerging 10-15 days earlier than with spring sowing. In this way, the seedling root system forms early, disease resistance and stress resistance are strong, and the rapid growth period arrives earlier. Land preparation and bed making. Choose a sandy loam plot that is sheltered from the wind and faces the sun, with deep and fertile soil and good drainage, as the seedbed. Apply 2000-3000 kg of barnyard manure per mu, and plow deeply and harrow finely. After land preparation, make beds 1 m wide
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Eight Key Points of Winter Management for Sichuan Pepper Trees Explained in Detail
The first is "pruning", which means shaping and pruning. Winter is a great season for pruning Sichuan pepper trees. When pruning, the "seven branches" must be removed, namely: water sprouts, dead branches, diseased and pest-infested branches, overly dense branches, crossing branches, overlapping branches, and weak slender branches. Then the removed branches should be gathered and burned, which can eliminate pests and pathogens overwintering on the branches and trunk. The second is "scraping", which means scraping off the rough bark. Many insect eggs overwinter in the cracks of the rough bark of pepper trees, and mulberry white scale insects parasitize the trunk. The scraped rough bark and gummosis spots should be gathered and burned, then apply Liujiaowei and Suolibaer pesticides, and
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Winter is the idle season, and it is the right time to plant scallions in the greenhouse
Using a fixed greenhouse to grow a crop of scallions during the winter idle season can improve the greenhouse's utilization rate and economic benefits, and also allows crop rotation, which not only creates a good preceding crop for the next crop but also does not affect the planting of early spring fruits and vegetables. Planting method: when the late autumn vegetable production in the greenhouse has ended, along with careful land preparation, apply 3000-4000 kg of high-quality organic fertilizer per mu, then open furrows and plant the scallions. Row spacing 25-30 cm, plant spacing no more than 1 cm, planting depth about 3 cm. The scallions to be planted can be selected from smaller plants among the autumn scallions.
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Detailed Explanation of Cold Protection and Warming Methods for Winter Piglets
The suitable temperature for piglet growth is: 34-30°C at 1-3 days of age, 30-28°C at 4-7 days of age, and 25-22°C at 15-30 days of age. Winter temperatures are low, so the following cold protection and warming measures should be taken for piglets. 1. The pen should be prepared for cold protection and insulation before winter, repair doors and windows in time, and fill in drafty holes and gaps. For open-style farmer pig pens, windbreak cloth curtains sewn from woven fabric or feed woven bags should be used to block the windward positions, minimizing ventilation as much as possible and preventing north wind and rain from directly penetrating from outside, so as to raise the temperature of the pig pen.
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Prevention and Treatment of Rheumatic Arthritis in Pigs in Winter
Rheumatic arthritis in pigs occurs mostly in the more mobile joints such as the shoulder, elbow, hip, and knee, and is often symmetrical, though it can also be migratory. The joints of the spine may also be affected. Acute articular rheumatism presents with symptoms of acute synovitis, with joint swelling, fluid accumulation in the joint cavity, and fluctuation on palpation. When standing, the affected limb is often flexed, and during movement the pig mainly shows lameness, often accompanied by systemic symptoms. When it becomes chronic, symptoms of chronic arthritis appear, with proliferation and thickening of the tissue surrounding the synovium, thickening of the joint, and restricted movement. The affected limb is difficult to lift, movement is slow, the stride is shortened, and the lameness lessens or disappears as the amount of exercise increases.
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Stomatitis is a common internal disease in dogs.
Stomatitis can be classified by the nature of the inflammation into catarrhal, vesicular and ulcerative stomatitis, with catarrhal stomatitis being the more commonly seen type. [Causes] The most common cause is direct injury to the oral mucosa by coarse hard bones, sharp teeth, nails, wire and the like, followed by secondary infection resulting in stomatitis; next is accidental ingestion of quicklime, ammonia water, moldy and spoiled feed, or irritating drugs at excessive concentration; and then cases secondary to tongue injury, pharyngeal fire or certain infectious diseases. [Key points of diagnosis] The sick dog refuses coarse hard feed and prefers liquid feed and
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Wintersweet is an excellent tree species for winter flower viewing
Ecological habits Wintersweet is also known as huangmei and huangmeihua. It belongs to the genus Chimonanthus in the family Calycanthaceae. It is a deciduous shrub, about 3 m tall, with simple opposite leaves. The leaf blades are elliptic-ovate or ovate-lanceolate, acuminate at the apex, rounded or wedge-shaped at the base, 7-15 cm long, entire, with a rough surface; the flowers are bisexual, solitary in the leaf axils of one-year-old branches, with very short pedicels, yellow, waxy, and fragrant, blooming from December to March. Cultivated varieties include Qingkou wintersweet; Chaiyouxin wintersweet; and Gousheng wintersweet. Wintersweet originated in central China. It prefers sunlight but is also slightly shade-tolerant, relatively cold-tolerant, and drought-tolerant, hence the saying "wintersweet that cannot die of drought"
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Planting Techniques for Intercropping Shrubs in Southern Magnolia Fields
In the first 3 years of southern magnolia seedling growth, to offset the drawbacks of large initial investment and no profitable output from field-planted trees in the early stage, small shrubs such as littleleaf boxwood, golden-leaf privet, and red-leaf barberry can be intercropped. During the first 3 years of intercropping small seedlings, 6000-7000 plants per mu at an average of 0.5 yuan per plant can yield more than 3000 yuan in income. After the 4th year, the southern magnolia has grown to 5-6 cm, and can then be sold selectively at about 80 yuan per plant. From then on, annual sales all generate income. Cultivation points: southern magnolia 1-year
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Methods and Technical Key Points for Trunk-Cutting Planting of Black Locust in Autumn and Winter
Late autumn and early winter is the best time for trunk-cutting planting of black locust (Robinia pseudoacacia). Its characteristics are as follows: First, it avoids the spring tree-planting peak period and the busy farming season, makes full use of the winter slack period, and fully guarantees the timing and quality of planting. Second, according to the physiological characteristics of black locust, the daily average temperature required for root growth is relatively low; after leaf fall in autumn the aboveground part stops growing while the underground part still grows for a period, and when the leaves fall the mobile nutrients in the branches and leaves return to the trunk and roots, so the roots are rich in stored nutrients at that time, which exactly gives the root system a growth stage. Third, the planting
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