Analysis of the Efficient Integrated Farming Model of Fish Rearing in Lotus Root Fields

I. Field Construction

The area of the lotus root field should preferably be 1-2 mu, generally 1-1.2 m deep; around the field, culture trenches are dug, 1.5-2.0 m wide and 0.8-1.0 m deep, with the inlet and outlet opened at diagonal corners, so as to keep the field water clean and prevent the accumulation of toxic substances from harming the fish; apply 8-12 cubic meters of fermented and thoroughly decomposed manure per mu as base fertilizer.

II. Lotus Root Cultivation

In March and April each year, planting begins when the temperature reaches above 15 degrees C. When planting, bury the lotus root seed in the soil, with the lotus root head slightly deeper and the tail node slightly tilted up and exposed above the water surface, at an inclination of 20-30 degrees. The rows of lotus root seeds are arranged in alternating directions, one row facing east and one row facing west, with the second row opposite the first row between plants, so that the lotus roots and leaves are evenly distributed; the row spacing for planting is 2.0 m, the plant spacing is 1.5 m, and the planting depth is 10-15 cm.

III. Fish Fry Stocking

In mid-to-late May, when the water temperature is suitable, promptly stock the fish fry for integrated culture. The fish fry used are non-large herbivorous fish, such as rice field eel, loach, crucian carp, common carp, silver carp, etc., all of which are acceptable; the fish fry should preferably be diversified, so that fish in different water layers are matched with one another and the water space is fully utilized; common carp has the characteristic of eating ground maggots, so stocking some common carp can effectively prevent a large outbreak of ground maggots. The stocking size should be larger rather than smaller, and the density should preferably be 200-300 fish per mu.

IV. Field Management

1. Field inspection: attention should be paid to preventing drought and waterlogging. On rainy days, drain water promptly to prevent fish from escaping, and replenish water in time. If the water quality is too turbid, it can be improved by sprinkling in alum. During long periods of clear weather without rain, replenish water in time.

2. Water quality control: after planting the lotus roots, maintain a shallow water level for 10 days to help raise the water temperature and promote germination; during the period of vigorous growth, maintain the water level at 15-20 cm; during the lotus root formation period, a water depth of 5-10 cm is preferable. Every half month, use 40 g per cubic meter of quicklime to splash the entire field for disinfection.

3. Topdressing: when the field lotus roots grow 3-4 standing leaves and during lotus root formation, apply 300-500 kg per mu of human excrement or farmyard manure as topdressing. Fertilization should be carried out on a clear and windless morning. July to September is the peak feeding period for fish, so it is advisable to appropriately add rapeseed cake, which serves both as feed and fertilizer.

4. Field lotus root management: after the standing leaves cover the pond, promptly remove the shaded floating leaves and the aged early-standing leaves, so as to maintain ventilation and light penetration in the pond; promptly remove excessive aquatic plants in the field to prevent them from competing with the field lotus roots for nutrients; after budding, bend the flower stalk but do not break it, which can avoid nutrient consumption; prohibit the application of highly toxic and high-residue pesticides such as methamidophos, so as to protect the safety of the fish.

5. Installing black light lamps: on nights from May to October, hang several energy-saving black light lamps 15 cm above the fish trenches to trap moths and other insects in the field as food for the integrated culture fish; generally there are 3 peak insect-trapping stages, namely late May, late July, and late September, each lasting about 10 days.