Straw mushrooms take only 7-10 days from spawning to cultivation: cultivation techniques

I. Determining the cultivation period

Straw mushrooms (Volvariella volvacea) like high temperature and high humidity, so in northern regions they should be grown in summer. In central Hebei and southern Hebei, this is generally from late May to early September, when the temperature inside plastic greenhouses can be maintained at 22-31°C. When cultivated in this period, the mycelium generally germinates on the second day after spawning, the mycelium runs through the substrate on the third day, and the first flush of mushrooms can be harvested on days 7-9; growers in other regions can adjust the cultivation period flexibly according to local climatic conditions.

II. Selection and treatment of the growing substrate

The growing substrate is the nutritional medium for growth, and choosing a suitable substrate is the foundation for a high yield.

1. Types of growing substrate. Besides rice straw, materials rich in fibrous substrate such as wheat straw, waste cotton, cottonseed hulls, rapeseed, corn, millet straw, broomcorn millet straw, wheat bran, and spent mushroom substrate from oyster mushrooms and enoki mushrooms can all be used. Practice has shown that waste cotton and cottonseed hulls give relatively high yields.

① Cottonseed hulls. Cottonseed hulls are rich in nutrients, loose in texture, moisture-retaining and well aerated, making them an ideal growing substrate for straw mushrooms. The quality of cottonseed hulls directly affects the success or failure of straw mushroom cultivation; choose ones with plenty of fuzz, free of mold, free of clumps, not rained on, and preferably fresh hulls that have been stored only a short time after processing. Before cultivation, it is best to sun them for 2-3 days to kill contaminant spores and pests, then add 5-7 kg of lime per 100 kg, mix well with clean water, pile and cover for one night, and then pile them up for fermentation. Use about 130 kg of water per 100 kg.

The fermentation process for cottonseed hulls is: in a sunny place, spread a 10 cm thick layer of wheat straw on the ground, pile the cottonseed hulls that have been covered for one night on top of the wheat straw. If the amount is small, make a round pile 1 m high; if the amount is large, make a long pile 1 m high and 1 m wide and of unlimited length. Then compact the cottonseed hull pile slightly, insert ventilation holes from the top of the pile down to the bottom with wooden sticks 4-5 cm in diameter at intervals of 0.5 m, cover with a 5 cm thick layer of wheat straw, then cover with plastic film, and spray fly-prevention pesticide around and on the surface to prevent flies from laying eggs and producing maggots. When the pile temperature rises to 60°C, hold it for 24 hours, then turn the pile so that the top, bottom, inside and outside ferment evenly. When the material temperature again rises to 60°C and stays there for about 24 hours, fermentation is complete. The whole fermentation generally takes 3-5 days. Well-fermented substrate is reddish brown or dark brown, covered with white mycelial fuzz, has a fermented cottonseed-hull aroma, and has no musty or ammonia odor.

② Waste cotton. Waste cotton is the discarded offcuts from cotton gins, cotton mills and batting mills. It contains large amounts of cellulose and has good heat-retention and moisture-retention properties, but its aeration is relatively poor. Before use, soak the waste cotton overnight in lime water with a pH of 10-12, take it out, drain it, and pile it for fermentation. The fermentation method is the same as for cottonseed hulls, with a moisture content above 80%. Then loosen the waste cotton and it is ready for cultivating straw mushrooms. For good aeration, it can be mixed with wheat straw and wheat bran for cultivation or cultivated in layers.

③ Wheat straw and wheat bran. Choose fresh wheat straw from the current year that has not been rained on; old wheat straw from previous years is prone to contaminant organisms and gives low yields. Wheat straw is relatively hard in texture, high in wax, poor at absorbing water, and not easy to soften, so it should be flattened and crushed during threshing to make it soft and easy to absorb water.

Dig a rectangular pit in the ground with a flat bottom, line the pit with plastic film, put in crushed wheat straw in layers, keep pouring in lime water, and tread it with your feet until it is thoroughly soaked. Soak for one day and one night. Take the soaked wheat straw out of the pit, add 10-15 kg of decomposed chicken manure or pig manure and 0.5 kg of diammonium phosphate per 100 kg, and pile it into a heap 1 m high and 1 m wide and of unlimited length. After piling, cover with plastic film to retain heat and moisture. When the temperature at the center of the wheat straw pile rises to about 60°C, hold it for 24 hours, then turn the pile, turning the outer wheat straw into the center of the pile so that the inside and outside ferment evenly. Fermentation takes about 3-5 days. Well-fermented wheat straw is soft in texture, with the wax removed from the surface, feels springy when squeezed in the hand, is golden in color, has a wheat straw aroma with no off odor, and has a small amount of white mycelial fuzz. The physical properties of the wheat straw are improved; the straw is loose and well aerated. Fermentation treatment of wheat straw promotes the growth and reproduction of thermophilic actinomycetes and increases cellulose-decomposing bacteria, while the heat kills some harmful microorganisms that cannot tolerate high temperatures (such as various molds). If 4-5 per mille enzyme bacteria are added for fermentation, the effect is even better.

2. Growing substrate formulas. Based on straw mushroom cultivation practice in Hebei Province, the following formulas are considered good:

① Dry rice straw (or wheat straw) 53%, dry rice straw powder (or wheat straw) 30%, dry cow manure 15%, lime 1%, gypsum 1%, water as appropriate. pH 7.2. ② Dry straw (or wheat straw) 250 kg, human feces and urine 200 kg, burnt soil 310 kg, superphosphate 1.5 kg, water as appropriate, pH left to nature. ③ Cottonseed hulls 100 kg, lime 5 kg, water 180 kg. ④ Waste cotton 100 kg, dry straw powder 10 kg, bran 10 kg, cow manure powder 10 kg, water as appropriate, pH 8-8.5. ⑤ Various spent edible mushroom substrates 40%, wheat straw 40%, cottonseed hulls 12%, superphosphate 3%, lime 5%, with a water ratio of 1:1.7, pH left to nature.

3. Preparing the growing substrate. When mixing, first pile the main ingredients into a small heap, then scatter the auxiliary ingredients down from the top of the heap in several batches, mix repeatedly with a shovel, then add an appropriate amount of clean water and turn and mix repeatedly until evenly blended.

Note the following: ① The formula must be followed, and materials must be strictly inspected when taken. Moldy, deteriorated, or rain-soaked and clumped materials should not be used; ② mixing must be even; it is best to use a mixer or an old thresher and run it through two or three times; ③ control the moisture content, preferably 70%-75%; ④ the pH must be suitable. Straw mushrooms like a slightly alkaline environment, with an optimum pH of 8-9. Cottonseed hulls and waste cotton are fairly acidic, so lime needs to be added. To measure pH, precision test paper with a pH range of 5-14 is generally used. If conditions permit, a pH meter can be used for testing.