What technical details should be noted for raising ducks in rice fields?
1. Variety selection
Raising ducks in rice fields is an extensive rearing method and an auxiliary industry for green, high-quality rice production, mainly playing a role in biological control. Therefore, when selecting duck varieties, the key considerations should be small and medium-sized excellent varieties with strong vitality, broad adaptability, tolerance to rough feed, and strong stress resistance.
2. Time of entry into the field
1 week to 2 weeks after transplanting, once the seedlings have survived, put 1-week-old to 2-week-old ducklings into the rice field. Adult ducks should be put into the field a few days later as appropriate.
3. Field facilities
Before releasing the ducks, enclose and protect the surroundings of the rice field with plastic netting to prevent the ducks from running into neighboring rice fields. Also, in one corner of the field, build a duck house according to a size of one square meter per 10 ducks. The top of the house needs to be covered to avoid sun and rain. The duck house should be enclosed on three sides, but must be well ventilated, with the floor laid flat with wooden boards or bamboo boards, and a pond 2 times the size of the duck house and 50 cm to 60 cm deep dug beneath it. At the same time, dig several high-yield ditches 35 cm wide and 30 cm deep in the rice field, kept full of water throughout the duck-releasing period for the ducks to splash in.
4. Duck release standards
The stocking density for adult ducks is about 15 birds per mu, and for young ducks it can be appropriately increased according to circumstances. When releasing ducks, the ratio of male ducks to female ducks should be 1:4 to enhance activity in the field.
5. Water depth for release
The depth of water in the rice field should be just enough for the ducks' feet to touch the soil, so that the ducks fully stir the soil during their activities. As the ducks grow, the water depth gradually increases, and a water layer should be retained across the entire field surface.
6. Feeding in the field
Because ducks do not have the habit of grazing during the brooding period, feeding training is generally required before they are put into the field. First, train the ducks to learn to eat grain that has fallen on the ground, then scatter the grain into shallow water and let the ducks peck at it, gradually forming a conditioned reflex. After that, once the ducks are put into the rice field, they will actively seek food such as weeds, insects, and aquatic animals in the field. At the same time, pay attention to supplementary feeding; generally, each duck should be supplementarily fed 50 g to 100 g of feed such as rice grain, corn, and forage grass per day, with feeding at fixed times and fixed locations, and neither too much nor too little.
7. Grazing time
In principle, grazing time should be determined according to air temperature and water temperature. Because grazing is done in rice fields, ventilation is not as good as in rivers and ponds, and due to shallow water it is easily heated by the sun, so generally when the air temperature exceeds 30°C, it is not suitable to release ducks into the field. Especially in hot summer, it should be done before 9 a.m. and during the cooler afternoon. Rotation should be carried out appropriately. The same rice field should not be repeatedly used for release many times; it should be rested for a few days before release again.
8. Rice-duck symbiosis
Because ducks released in rice fields spend a long period in the hot summer, the duck house, on the basis of preventing rodent damage, should be kept ventilated, and some shade branches or small cool sheds should be set up. The high-yield ditches should be full of water so the ducks can splash more, which helps prevent heatstroke and lower temperature.
9. Using ducks to control insects
If rice seedlings are infested by insects, first find out the pest situation clearly. When the pest damage is relatively severe, reduce the feed so that the ducks are in a semi-starved state and consume large amounts of pests. If pesticide is to be sprayed on the rice seedlings, the ducks should be led into the duck house and penned up before spraying.
10. Later-stage management
At the early grain-filling stage after rice heading, the ducks should be brought back home or enclosed in field houses to prevent them from eating rice ears and affecting rice yield. After the ducks are collected, male ducks can be sold, and female ducks can be raised into laying ducks. To make collecting ducks convenient, during usual feeding the ducks should be trained to develop the habit of gathering when they hear a certain sound.
Weeding: The weeding effect of rice-duck integration is better than any chemical herbicide. When ducks are in the rice field, when young they eat small grasses in the field, and after growing they mainly eat broadleaf weeds. At the same time, the trampling of ducks can indirectly play a weeding role.
Pest control: The pest control effect is relatively obvious. Ducks can eat adult and larval rice water weevils and striped stem borers, reducing the harm to rice.
Increasing fertility: Because ducks live in the rice field, their excrement becomes a very good organic fertilizer, improves soil structure, raises soil fertility, and can increase soil fertility by about 15%.
Increasing yield: Ducks have the habit of rooting in the ground, which can play a role in intertillage and water activation, help loosen the soil, increase oxygen, promote rice root development, raise the thousand-grain weight and maturity of rice, and increase rice yield by about 7%.