Detailed Explanation of Key Techniques for Integrated Lotus Root and Loach Culture
Is integrated lotus root and loach culture feasible? Lotus root grows in mud, and loach also lives in mud. Raising loach in a lotus root pond is a form of ecological aquaculture, mutually beneficial to both. So how do you raise lotus root and loach together? Let us walk you through it below.
Integrated Lotus Root and Loach Culture Techniques
1. Pond preparation.
The lotus pond used for raising loach should not be too large in area, and should have plenty of water, convenient drainage and irrigation, and fertile soil. Before stocking loach, the field ridges must be tamped solid and widened and reinforced. Escape-prevention nets must be installed at the inlet and outlet. Escape walls made of plastic sheeting or mesh netting must be set up around the field ridges, with the plastic sheeting or mesh netting standing 30 cm above the ridge surface and buried 20 cm into the ground. If an additional 20 cm wide step, 15 cm lower than the ridge, is built along the inner side of the ridge, the escape-prevention effect will be even better.
2. Loach stocking
Seedlings should be selected for uniform size and robust health. Stocking time is around Qingming Festival, when the lotus has grown 2 standing leaves and the water temperature has stabilized above 20 degrees, fish can be released, stocking 20,000 loach per mu. One week before stocking the loach, apply fermented organic fertilizer such as chicken, pig, or cow manure at 150-200 kg per mu, and superphosphate at 15-20 kg per mu, to fertilize the water quality, and at the same time add fresh water to bring the water level to 30 cm.
3. Feed feeding.
Although there is natural food for loach in the lotus pond, artificial feeding is necessary, otherwise the loach grows slowly and the benefits are poor. Loach is an omnivorous fish and can consume both animal and plant feed. Animal feed such as small trash fish, earthworms, snail and mussel meat, insects and their larvae, silkworm pupae, fish meal, blood meal, etc., and plant feed such as rice bran, wheat bran, soybean cake, tofu residue, vegetables, melons and fruits are all good feed for it. These two types of feed can be mixed in a certain proportion and made into balls for feeding. This is beneficial for concentrated feeding by the loach and also convenient for inspection and management.
4. Lotus pond management
Water quality regulation: As summer temperatures continue to rise, fresh water should be added as promptly as possible without affecting lotus growth, and 4 kg of quicklime per mu should be broadcast over the entire pond to regulate water quality and disinfect and prevent disease.
Harvesting: Starting in early October, begin harvesting the loach from the lotus pond. After several consecutive days, the harvest rate of loach in the pond can reach over 90%. After the loach are fully harvested, begin harvesting the lotus root, usually at the end of October. This ecological planting and breeding model achieves increased production of both lotus root and loach, obtaining relatively high economic benefits and relatively good social benefits.
5. Reasonable topdressing
In addition to applying base fertilizer, lotus root should also receive reasonable topdressing during the growing period. Topdressing should both meet the needs of lotus root growth and maintain a certain fertility level in the field water, while not harming the loach. Decomposed organic fertilizer or chemical fertilizer can be applied, and the amount applied at one topdressing should not be too large.
Loach Disease Prevention and Control
1. Parasitic diseases: Loach infested by trichodina, epistylis, or gyrodactylus often float on the water surface, spinning restlessly. The control method is to dissolve 0.7 mg/kg of a copper sulfate and ferrous sulfate (5:2) mixture in water and evenly broadcast it over the entire field, or broadcast fish insect net (deltamethrin solution) at 0.15-0.22 mg/kg evenly over the entire field.
2. Print disease: Loach print disease is caused by infection with Aeromonas punctata, with lesions generally appearing as oval or round swellings with red spots, mainly on both sides of the caudal peduncle, resembling a stamped seal. The control method is the same as for red fin disease.
3. Saprolegniasis: Saprolegniasis is not easily discovered in its early stages. By the time it can be seen with the naked eye, the hyphae have already invaded the loach's wounds and grown outward as external hyphae, clustering into a cotton-like appearance. The mold can secrete large amounts of proteolytic enzymes, which can degrade the diseased loach's body tissues and secrete large amounts of mucus, worsening the condition, causing greatly reduced appetite, weakness, and death. It often reproduces in spring, autumn, or winter, and can infect fish as long as there is a wound on the skin.
4. Red fin disease: Loach red fin disease is caused by infection with short bacilli. Part of the epidermis near the dorsal fin peels off, appearing grayish white. In severe cases, fin rays become exposed, the fish stops feeding, and eventually dies. You can broadcast 1 mg/kg of bleaching powder or 0.3 mg/kg of strong chlorine essence over the entire field, repeat once after 24 hours, and thereafter broadcast once every half month for prevention.
5. Gas bubble disease: Caused by insufficient dissolved oxygen, supersaturated dissolved oxygen, or excessive content of other gases in the water. The loach floats on the water surface with its belly bulging like a bubble. Strengthen daily management to prevent water quality deterioration. When the disease occurs, immediately add fresh water and dissolve 4-6 kg of salt per mu in water and broadcast it over the entire pond.
Common Lotus Root Diseases
1. Lotus root rot, also known as black root disease or lotus root plague. It is the number one disease in lotus root production, generally prone to occurring in old lotus fields with shallow plow layers and shallow water and in continuous cropping fields, affecting lotus root formation and reducing yield. It is a lotus root disease caused by infection with the corm-like Fusarium fungus, mainly damaging underground stems, aboveground leaves, and leaf surfaces. Leaves sprouting from diseased stems are pale green in color, with brown drying starting from the leaf margins, and the petioles finally wither and die. The pathogen mostly invades through wounds, absorbing roots, or growing points, and spreads with flowing irrigation water.
2. Lotus root leaf blight is the second largest disease of lotus root, and the pathogen is a pathogenic fungus of the genus Sphaerotheca. It mainly damages lotus leaves. Pale yellow lesions first appear on the leaf margins, then gradually spread toward the middle of the leaf, turning yellowish brown, and finally spreading from the mesophyll to the veins until the entire leaf dies. High temperature and frequent rain favor disease occurrence, and insufficient fertility in the lotus field makes the disease severe.
3. Lotus root leaf spot mainly damages leaves and can sometimes also occur on petioles. It is caused by the pathogenic fungus of the genus Isaria.
Lotus Root Varieties
1. Elian No. 1. It is an early-maturing variety. Few flowers, shallow penetration into the mud, main lotus root with 6-7 nodes, 130 cm long, single root weighing about 5 kg, skin color yellow-white. In early July, 1000 kg of green lotus root can be harvested per mu, and after September-October, about 2000-2500 kg of mature lotus root can be harvested. Suitable for stir-frying.
2. Elian No. 4. It is a mid-maturing variety. Flowers white, main lotus root with 5-7 nodes, 120-150 cm long, single root weighing about 5-6 kg, tip nodes thick, skin pale yellow-white. Green lotus root can be harvested in mid-to-late July, with a yield of about 750-1000 kg per mu. Mature lotus root can begin to be harvested in September, with a yield of about 2500 kg per mu. It is relatively sweet when eaten raw, relatively mealy when stewed in soup, and also suitable for stir-frying.
3. Elian No. 5 (3735) early-mid maturing. Main lotus root with 5-6 nodes, 120 cm long, lotus root flesh thick and solid, air holes small, surface skin white. In mid-to-late July, 500-800 kg of green lotus root per mu, and in late August, 2500 kg of mature lotus root. Strong growth vigor, no premature aging, strong stress resistance, stable yield, good flavor whether stir-fried or stewed in soup, and highly popular in southern and export markets.
4. New No. 1 lotus root. Main lotus root with 5-6 nodes, 120 cm long. The lotus root is plump and large, with white skin and crisp flesh, and good commercial quality. After maturing in mid-to-late August, the yield is generally about 2500 kg per mu. Mealy when stewed in soup, sweet when served cold or stir-fried.
Integrated lotus root and loach culture not only leverages the mutually beneficial advantages of lotus root and loach growing together, but also can achieve a high-quality double harvest of products. This kind of polyculture method is the most economical and practical. Studying polyculture techniques well is conducive to increasing production and income. If you have the conditions, it is recommended that you try polyculture techniques.