Key Technical Points and Practical Methods of Earthworm Farming Explained
Earthworm Living Habits
1. Warmth-loving: 15°C-25°C is the optimal temperature. To create the optimal temperature, cover with a plastic greenhouse or plastic sheeting in winter, cover with rice straw in summer, sprinkle more water to cool down. They hibernate at 0°C-5°C, freeze to death below 0°C, die above 40°C, and stop growing above 32°C. In the Beijing area, put up the shelter and cover with plastic sheeting on October 25, and remove it on April 10 of the following year. In this way, the earthworms grow until December 20, and from then until February 10 of the following year, they are basically in dormancy. From February, to prevent escape due to excessively high temperatures, pay attention to uncovering in time. After the 10th, they gradually enter the optimal temperature range. At this time, special attention must be paid to the plastic sheeting on hot days. This is the most laborious period: uncover the plastic sheeting around the edges during the day, cover it well again promptly in the morning and evening, and water in time to maintain moisture. Thus, from March to June 10 is the spring peak egg-laying period for earthworm growth. During the high-temperature period, prevent heatstroke and cool down; it is best to water once a day. From June 10 to August 20 is summer, and after the 20th of August they gradually enter dormancy. Late September is the second peak egg-laying period for earthworms.
2. Moisture-loving, afraid of drying: Earthworms have a body water content of about 80%, and the feed is required to have a water content of 60%-80% (judged by squeezing the feed in the hand with water dripping between the fingers), so the water content of the breeding bed is required to be above 60%. Thus, water must be applied once a day or every 1-2 days. The water should not be too heavy, but it must soak through and connect with the lower layer of feed. Water in the middle of the day in winter, in the evening in summer, and during the day in spring and autumn.
3. Dark-loving, afraid of light: Earthworms hide by day and come out at night, and can be seen active and foraging in moonlight. The breeding bed should be covered with rice straw to maintain moisture and shade light.
4. Air-loving and quiet-loving: Loose feed is beneficial to earthworm growth. Our years of experience is to turn over the bed once (about 20 cm thick) before feeding to increase aeration. This point is very important. Over the years, we have found that in the bottom layer of the bed soil, the number of earthworms is very small, but feed is still present. The main reason is the lack of air, which is unfavorable to earthworm growth.
Farming Methods
1. Farming variety: Eisenia foetida. The "Daping No. 2" introduced from Japan is characterized by a high reproduction rate, multiplying more than 200 times per year, good settlement, heat tolerance and cold resistance, suitability for year-round production, and high output of worm bodies and worm castings.
2. Farming method: After ten years of building the site, we have always insisted on open-air compost farming. I believe this method is low-cost and the best method for large-scale production of earthworm products. It requires no investment in equipment and uses all idle land. Simply make unfermented cow dung, horse dung, and pig dung into beds 15-20 cm high and 1-1.5 m wide, with unlimited length, put in the worm seeds, cover well with rice straw, shade light and maintain moisture, and farming can begin. We started raising them from a few square meters, and up to now, more than 200 mu of land for expanded breeding all use this method. Its advantages are convenient operation, saving a whole series of work such as heap fermentation, keeping the nutrients of the feed from being lost, increasing the earthworm growth rate, and being easy to promote and apply in rural areas. This method also has its disadvantages: once the feed heats up, the earthworms die with no corpses left; in summer during continuous rainy days and after heavy rain, the bed is not ventilated and there is escape behavior. The way to avoid this is to ensure that each breeding bed has new feed. Make the feed into piles and blocks to create good conditions for the earthworms from bottom to top. The key to this method is to keep the feed moisture content at 60-70%. It must not be too dry or too wet, otherwise the feed will heat up and cause death.
Reproduction and Growth
1. Cocoon production: Each Daping No. 2 earthworm produces 56-58 cocoons per year, of which spring accounts for 40%, summer 25%, autumn 27%, and winter 8%.
2. Hatching rate: One earthworm cocoon hatches an average of 5-8 young worms, with a maximum of 12, but generally only 3-4 fully developed young worms. The time required for hatching and the hatching rate differ at different temperatures.
3. Growth period: The weight gain of young worms is slow. After entering the juvenile stage, growth is also slow. Only within about one month before and after sexual maturity do earthworms grow fastest. Taking action at this time can achieve high yields. In addition, the growth rate of earthworms is closely related to the state of the feed. Although the feed is the same, due to differences in fineness, the growth rate of young worms can differ by 1.5 times. Therefore, the feed should be kept in a finely broken state, avoiding large and small clumps in the feed (if clumps appear, they can be watered and mashed), to ensure rapid earthworm growth.
4. Farming density: The number of breeder earthworms should be controlled within 10,000 per square meter. The production worm population is 3 kg per square meter (20,000-31,000 worms), with 30,000 young worms per square meter in the early stage, dropping to 20,000 in the later stage.
5. Yield: The yield per square meter can reach 10 kg/year, generally 6-8 kg (because the north has only 8-10 months of production period each year). For every 25-30 kg of feed consumed, 1 kg of fresh worms can be produced, and 70% worm castings can be obtained. Our years of experience is that 5 cubic meters of cow dung produces one ton of worm castings and 50 kg of fresh worms.
Feeding and Management
1. Feed application: Promptly feeding earthworms sufficient feed is an important measure to ensure rapid earthworm growth. Use the method of placing feed in piles on top, with a thickness of 10 cm. Do not cover the entire bed surface and do not seek flatness, so as to facilitate separation of the earthworms.
2. Earthworm farming temperature: The optimal temperature is 15-25°C. In winter, thicken the breeding bed to 40-50 cm, cover the feed with rice straw, and add plastic sheeting to keep warm and moist. In summer, strive to water once a day to cool down. Staged farming: can be divided into seed population, breeding population, and production population; feed thinly and turn frequently, giving feed twice a month; before feeding, first turn the bed; each feeding thickness is 10 cm; always keep the feed fresh and breathable. Timely harvesting: harvest once a month in summer, once every 1.5 months in spring and autumn, and replenish feed promptly after harvesting. Rotation and renewal: breeder earthworms must be renewed once a year, and the breeding bed changed once a year, to maintain the vigor of the earthworm population and prevent population decline caused by natural development of the earthworms.
3. Feed: Best is cow dung, pig dung, horse dung, sheep dung, rabbit dung; pig, sheep, and rabbit dung plus stalks and rice straw.
Earthworm Harvesting
The best method is the natural light collection method. When earthworms are found in the breeding bed, the density reaches 20,000-30,000 per square meter, and 80% of individuals reach more than 0.3 g, it is the best harvest time. When harvesting, water thoroughly 24 hours before extraction; it must not be too dry or too wet. Then concentrate 70% of the 10 cm top layer of feed from the breeding bed onto a cement floor or plastic sheeting. Using the earthworm's light-avoiding characteristic, scrape layer by layer, scrape the feed clean, and finally make the earthworms concentrate in the bottom layer to achieve the purpose of collection.