High-Yield Cultivation Techniques for Agaricus bisporus in Rice Fields

Cultivating Agaricus bisporus in rice fields is a planting method that uses rice straw and other materials as the main raw materials, which are composted and fermented into growing substrate, and takes advantage of the temperature and light resources and idle seasons of autumn, winter and spring to cultivate Agaricus bisporus in the open field in rice fields after the rice harvest. This method makes full use of resources, can create a net profit of more than 5000 yuan per mu, with an input-output ratio of 1:3, and can improve the soil, delivering excellent economic and ecological benefits. The technical experience is introduced below:

1. Mushroom field selection Generally, a middle-season rice field or single-crop rice field should be selected that has higher terrain, fertile soil, convenient drainage and irrigation, is close to a water source, has good transport conditions, and has not grown Agaricus bisporus within 3 years. The rice stubble left at harvest must not be higher than 10 cm. After harvest, perimeter ditches and waist ditches should be opened in the mushroom field in advance for drainage, ready for use.

2. Preparation of growing substrate

1. Formula (calculated on the basis of an actual cultivation area of 400 sq m per mu of rice field). Formula One: 6000 kg dry rice straw, 400 kg rapeseed cake, 100 kg phosphate fertilizer, 60 kg urea, 200-250 kg lime, 150 kg gypsum and 150 kg special fertilizer for Agaricus bisporus. Formula Two: 5000 kg dry rice straw, 2000 kg dry cow dung, 40 kg urea, 200 kg lime, 150 kg gypsum and 100 kg special fertilizer for Agaricus bisporus.

2. Composting materials Livestock manure is rich in the nutrients needed by Agaricus bisporus and has a high heat output, making it a good composting material. Pig manure, cow manure and horse manure are all suitable; mixing several kinds of livestock manure gives even better results.

3. Pre-wetting and building the pile Dry rice straw should be pre-wetted 2-3 days before building the pile. When building the pile, mix livestock manure, rapeseed cake, special fertilizer for Agaricus bisporus, phosphate fertilizer, urea, etc. evenly and add them in layers; lime and gypsum are added at the first turning of the pile. The pile should be 2 m wide and 1.5 m high, with each layer 1.2 m, and the length is unlimited. The four sides of the pile should be vertical and neat, with an arc-shaped top. After the pile is built, cover it with plastic film, which both retains moisture and prevents rain (note that it must not be too tight, to prevent anaerobic fermentation).

4. Turning and fermentation About 7 days after building the pile, carry out the first turning. When turning, shake the straw loose, break it up and mix it evenly, and turn it thoroughly from top to bottom and from inside to outside. This time the pile should be 1.8 m wide and 1.5 m high. Sprinkle lime and gypsum evenly into the pile, and cover with plastic film after turning. After another 6 days, carry out the second turning. This time, note to make air holes in the pile to facilitate aerobic fermentation. This time the pile should be 1.5 m wide and 1.2 m high, and cover with plastic film after turning. After 5 more days, carry out the third turning. This time divide the pile into two, making the pile 0.8 m wide and 1.2 m high, and cover with plastic film after turning. At this point, uniformly spray the pile with 1000-fold phoxim or 1500-fold saomanjing or 300-fold 25% carbendazim solution to kill pests and diseases. After 4 days, carry out the fourth turning. At this point the straw has finished fermenting, is coffee-colored and full of elasticity, and can be transported to the field for spreading.

3. Spreading substrate and sowing Before spreading the substrate, disinfect and sterilize the mushroom field against insects and fungi with 100-fold phoxim, 1500-fold saomanjing and 300-fold 25% carbendazim, then divide it into beds with a bed surface width of 70-80 cm and a walkway width of 50 cm, with trenches between beds. Then spread the substrate; when spreading, shake it loose and spread it evenly, piling it into a "tile-back shape". The thickness is 30 cm. After spreading, cover with plastic film on rainy days; if the straw is rather dry on sunny days, spray lime water to adjust the humidity. One or two days after spreading the substrate, sowing can be done, choosing a cloudy day or the early morning or evening of a sunny day. First remove the cotton plug from the spawn bottle, stand it on its side in potassium permanganate for disinfection, and use a spawn hook to hook out the spawn into a sterilized basin, then evenly sow the spawn on the surface of the substrate as planned. For grain spawn, use 800 bags of spawn per mu of mushroom field for spot sowing. After sowing, scatter a thin layer of straw as a covering straw, and immediately cover the bed surface with plastic film to retain moisture and promote mycelial germination, while also covering the film with straw curtains.

4. Field management

1. Casing soil Three days after sowing, remove the plastic film and ventilate to promote mycelial growth. When the mycelium has grown to 1/2-2/3 of the substrate layer, begin casing soil. The casing soil thickness is about 5 cm, the soil particle diameter is within 2 cm, and the water content should be such that it can be formed into a ball when squeezed by hand and does not stick to the hand or sticks only slightly. The soil pH is 7.5-8. If the soil or straw is rather dry, adjust it with lime water.

2. Watering and supplementary fertilizing The principle of watering is mainly to keep the soil layer moist; in winter it is better to keep it dry than wet, and in spring it is better to keep it wet than dry. Generally, about 10 days after casing, when the fluffy mycelium about 1 cm below the soil surface forms threads and twisted small white knots appear, spray "mushroom-setting water", using 1 kg of water per sq m of mushroom bed, sprayed in 4 applications. Also spray Mushroom High-Yield Agent No. 1 once. After 3 days, when the small white knots in the soil layer become fleshy, round and hard small mushroom primordia and have generally grown to the size of mung beans or soybean grains, spray "mushroom-emergence water", using 0.5 kg of water per sq m of mushroom bed, sprayed in 4 applications, and spray Mushroom High-Yield Agent No. 2 once. At the stage when the mycelium knots and forms primordia, spray Mushroom High-Yield Agent No. 3 once; about 7 days after large-scale mushroom emergence, spray Mushroom High-Yield Agent No. 4 once. After each flush of mushrooms is harvested, spray "flush-transition water", using 0.5 kg of water per sq m of mushroom bed, sprayed in 4 applications. During the resting stage of the mushroom bed, spray Mushroom High-Yield Agent No. 5 once to adjust the pH of the bed surface and maintain the vitality of the mycelium.

3. Autumn mushroom management Autumn mushroom management is the key to a high yield. The focus of management is the casing soil layer and watering. Generally, spray less when there are many mushrooms and more when there are few mushrooms; spray more in the early stage and less in the later stage. It should also be handled flexibly according to weather conditions, mycelial strength, casing soil thickness, etc. At the end of each flush of mushrooms, remove the old roots and dead mushrooms from the bed surface, immediately replenish with moist wet soil, and then water. After harvesting 1-2 flushes of autumn mushrooms, the soil-layer mycelium on the bed surface sometimes becomes compacted; at this time, insert sticks promptly to loosen the soil layer, so that the compacted mycelium breaks and promotes a flush transition and mushroom emergence.

4. Winter management When the temperature drops below 5°C, Agaricus bisporus stops growing and enters the winter management stage. First, clean the bed surface and pry the substrate and replenish soil. Loosen the soil layer, pick out old roots and yellowed dead mycelium, and use bamboo sticks to pry the substrate layer to improve aeration; replenish soil where mycelium is exposed above the soil layer to maintain mycelial vitality. Second, water to preserve temperature, watering once every 10-15 days. Third, preserve temperature and ventilate, covering alternately with straw curtains and plastic film from top to bottom, so as to both preserve temperature and allow ventilation.

5. Spring mushroom management When the temperature stabilizes above 10°C, begin adjusting the water in the soil surface of the mushroom bed. Spray lightly and frequently, increasing the amount of water from little to much; as the temperature rises, large numbers of mushrooms emerge from the soil, and the amount of water sprayed should increase accordingly to accelerate mushroom emergence. After many flushes of mushrooms, apply an appropriate amount of supplementary fertilizer, carried out together with watering when the fruiting bodies have grown to the size of mung beans.

6. Pest and disease control Adhere to the principle of prevention first and prevention being more important than cure, persist in combining agricultural control, physical control, biological and ecological control with chemical control, eliminate highly toxic and high-residue pesticides, and eliminate the use of pesticides during mushroom harvesting. Do not apply pesticide in excess, and the application time should be chosen in the afternoon or evening.

5. Harvesting Harvest at the right time when the cap has grown to 2-4 cm. The cut surface is required to be flat, with no muddy base, and the stipe 1-1.5 cm. When harvesting, harvest by grade, handle gently, and keep the caps white and free of wounds. During harvesting, promptly dig out old roots and replenish with new soil, so as to keep the bed surface flat, keep the site clean and hygienic, and reduce the chance of contamination by foreign microorganisms.