Detailed Explanation of the Key Technical Points of Rice-Duck Symbiotic Ecological Farming

Rice-duck symbiosis refers to placing ducklings about ten days after hatching into rice fields. The ducks eat the weeds and pests in the rice fields, and at the same time the movement of the ducks stimulates rice growth and increases the oxygen content in the water. Duck manure can also serve as fertilizer, while the rice fields provide the ducks with sufficient water and food, as well as a place for daily activities. This kind of system in which rice and ducks mutually promote each other is called rice-duck symbiosis. So what are the key points of rice-duck symbiosis technology? And what precautions are there? Today Qinnong Net will introduce to everyone how to realize this rice-duck symbiotic ecological farming technology.

I. Select and breed good duck varieties

First, the Ji'an red-feathered duck or the Shanma duck, which are suitable for free-range raising in rice fields, should be selected. Both of these 2 varieties are small to medium-sized individuals, move nimbly when raised among rice fields, and have a relatively large food intake, tolerate coarse feed, have lower costs, strong resistance to adversity when spending the night outdoors, and strong adaptability. Male ducks grow quickly and their meat is tender and fresh; female ducks have a high egg-laying rate. Second, ducklings must be well bred. Because the temperature in early spring is relatively low, attention should be paid to keeping them warm, and at the same time they should be fed a small amount of soaked broken rice, crushed corn and fine wheat bran, with an appropriate supplement of vitamins and protein. Generally, some shallow containers are placed in the rearing room (shed), filled with clean water to provide the ducklings with play and exercise and improve their adaptability to water. When raised to 20-25 days of age, when each one weighs about 150g, they can be released into the rice fields for rearing.

II. Timing of release

Control the timing according to the rice growth situation: generally ducks are released when the seedlings turn green and begin tillering. But it should be flexibly controlled according to the season. When the temperature is high in summer and autumn, the ducklings can be smaller; when the temperature is low in early spring or late autumn, the ducklings put out to pasture should be larger.

After the rice heads and flowers, stop releasing ducks to avoid damaging the rice. At this time, if the main wing feathers of the ducks are above 3cm, they can be sold on the market; if they have not reached the selling age, they can be transferred to rivers and lakes for grazing. From the actual local situation, in addition to fixed duck release in the rice fields during the rice growing period, duck release can also make full use of the stubble fields after the harvest of grass seed, spring flowers, and late rice.

III. Stocking density

The general stocking density of ducks among the rice clumps is 180-225 ducks/sq m, and it is best to have about 500 ducks as one flock. This not only helps avoid the duck flock being too dense and trampling and injuring the early-stage rice seedlings, but also allows them to spread to every corner among the rice within the enclosed range to look for food, achieving the purpose of uniformly controlling field pests and weeds. When releasing ducklings, it is best to raise 3-4 young ducks 1-2 weeks older than the other ducks in the flock, so as to play the role of warning when encountering external enemies and leading the way when returning to avoid wind and rain. In order to enhance the disease resistance of the ducklings, before release each duck needs to be injected with vaccines such as duck plague and duck viral hepatitis.

IV. Fertilizer and water management

Ducks are waterfowl. During the period when they forage and move among the rice, the field water layer should be shallow, so that the ducks' feet can step on the water layer of the surface soil, which helps the ducks' feet tread the mud and muddy the field water, playing the role of intertillage and loosening the soil and promoting the growth and development of rice roots and tillers. In addition, the need for draining the rice field to dry it can be solved by the method of draining in sections, that is, in one rice field, half of the rice field keeps a water layer, and the ducks are driven into it, while the other half is drained and left to dry until the requirement is reached. Or the ducks can be driven to the rivers and ponds at the edge of the field for a transition of 3-4 days. In order not to affect the ducks' foraging and growth among the rice, it is best to apply sufficient fertilizer at one time before transplanting the rice, mainly applying decomposed long-acting organic fertilizer (cake fertilizer 750 kg/ha) and compound fertilizer (225 kg/ha), while topdressing is replaced by duck excrement and decomposed azolla returned to the field to fertilize the soil.

V. Prevention and control of diseases, pests and weeds

The control of pests among the rice mainly relies on ducks preying on them, but diseases such as rice blast, sheath blight, and rice leaf roller still need to be supplemented with efficient pesticide control. It is recommended to use low-toxicity, high-efficiency, low-residue pesticides to control rice diseases and pests. During spraying, attention should be paid to promptly collecting the ducks and taking them out of the field, and only release the ducks again after the safety interval. Where conditions permit, it is best to use biological pesticides for control. Biological pesticides are non-toxic to both rice and ducks, and also meet the production technical requirements of grade A green rice. In addition, about 1 insect-catching lamp can be set among about 4 ha of rice (it is better not to plant crops within about 5 m around the lamp) to trap and kill moth pests. Because the ducks continuously tread among the rice, weeds are significantly reduced.

VI. Duck feeding and management

In order to improve the survival rate of ducks, prevent the invasion of natural enemies at night, especially human theft, and facilitate management when the ducks are moved to another place for grazing, the ducks should be raised in a concentrated way in the hands of a small number of specialized households who understand duck-raising technology. Every morning the ducks are driven into the field on an empty stomach, and toward evening the ducks are collected back into the duck shed. When the ducks are collected and taken home in the evening, an appropriate amount of supplementary feed such as broken rice and rice bran should be added. Ducklings that have just been released for about 10 days have poor foraging ability, so some easily digestible and nutrient-rich supplementary feed should be added in the morning and evening to meet the needs of the ducks' early growth and development. The amount put in should be determined according to the number of weeds and small aquatic animals in the rice field. This management model can not only reduce the investment needed for netting, poles, and building simple duck sheds in the rice field, but also improve the safety of duck raising, especially increase the scale efficiency of duck-raising farmers.

VII. Precautions

1. It is recommended to use low-toxicity, high-efficiency, low-residue pesticides to control rice diseases and pests, and to avoid using pesticides as much as possible.

2. When building duck sheds in the field, consideration should be given to preventing damage by rodents.

3. During pesticide application in the rice field, the ducks should be promptly collected and removed from the field, and only released again after the safety interval. During the safety interval of pesticide application in the rice field, the ducks' drinking water and the rice field water should be separated to prevent duck poisoning and contamination of duck products.

4. Ducks cannot be released in places where duck plague has occurred or where ducks carrying infectious diseases have passed, as well as water surfaces and rice fields polluted by mineral oil.

VIII. Disease prevention and control

Raising ducks in rice fields is open raising, which is prone to infection and spread of diseases, so great attention should be paid to duck epidemic prevention work.

1. Duck plague

For meat ducks at 7 days of age, use chicken embryo attenuated vaccine 0.2-0.5 ml/duck for intramuscular injection. Antibodies can be produced after 7 days and protect the meat ducks until market.

2. Duck viral hepatitis

For ducklings at 1-3 days of age, use chicken embryo-adapted attenuated vaccine 0.5 ml/duck for subcutaneous injection at the neck. Antibodies are produced after 2 days and reach a high level at 5 days.

3. Duck cholera

The vaccine for duck cholera is avian Pasteurella vaccine, such as the 731 attenuated vaccine, which is used to inoculate duck flocks over 2 days of age, with an immunization period of 3 and a half months. Avian cholera aluminum hydroxide gel vaccine is used for ducks over 2 months of age, intramuscular injection 2 ml/duck, with another injection after an interval of 10 days, and an immunization period of 3 months. Avian cholera oil emulsion inactivated vaccine is used for ducks over 2 months of age, subcutaneous injection 1 ml/duck, with an immunization period of 6 months. It has been reported that a vaccine made with duck Pasteurella A, intramuscular injection 2 ml/duck, can produce immunity for 4—5 months.

The above is a relatively detailed introduction to rice-duck symbiosis technology brought to you by Qinnong Net. Rice-duck symbiosis solves to a certain extent the harm of weeds during direct-seeded rice, and can also prevent lodging of rice in the later stage to a certain extent. Therefore, this technology is currently developing rapidly in our country, but the technology is still not very mature, for example, research on soil physical and chemical properties and rice field biodiversity is still insufficient. Farmers can combine local characteristics, make full use of the rice field ecological structure, and on this basis add biological loops to expand income.