Study on the Application of pollution-free compound nutrient solution on Edible Fungi

Study on Application of Pollution-free Compound Nutrient Solution to Edible Fungi

Edible fungi are heterotrophic organisms without chlorophyll. Its growth and development depend on mycelium and microbial biodegradation to obtain nutrients, so the yield of edible fungi has a close relationship with the nutritional level of its cultivation substrate. General edible fungi production is prepared once before sowing, and only managed in terms of water regulation, ventilation and air humidity after sowing. There are two problems in such production management: one is that after inoculation, due to the lack of available nutrients in the base material, the mycelium cannot rapidly reproduce and grow; the other is that in the middle and late stages of growth, especially in the three-mushroom period, due to the lack of exogenous nutrients, it cannot meet the growth needs of the developing fruiting body and affect the yield of edible fungi [Jishan Huayao]. The experiment proves that there are few nutrients left in the substrate during the peak and middle stages of fruiting of fungi. Supplementing nutrients in time during these two important periods can significantly increase yield and improve quality. At present, most mushroom farmers often use nutrient solution with chemical fertilizer, yield-increasing agent and hormone as main components. Although it can obviously improve yield, there are some problems such as unstable yield-increasing effect and certain residue. A kind of pollution-free, low-cost and nutrition-enhanced compound nutrient solution for edible fungi was studied in this paper, which provided reference for mushroom farmers to produce edible fungi.

1 Materials and methods

1.1 test material

Biogas slurry was taken from No. 1 and No. 2 biogas digesters in Lijiazui Village, Neiguan Town, Anding District. The main raw material of biogas digester was pig manure. In the sampling process, strictly abide by relevant regulations, and store the plastic bottles washed with digestion solution for inspection. The test items include total nitrogen, total phosphorus and total potassium, as well as mineral elements such as phosphorus, potassium, sodium and magnesium in the marsh solution.

1.2 elemental determination

Biogas slurry samples were determined in this unit. Total nitrogen is determined by Kjeldahl method, total phosphorus by acid solution-molybdenum antimony anti-colorimetry, total potassium by flame photometry (Table 1), mineral trace elements (phosphorus, sodium, potassium, magnesium, copper, iron, manganese, zinc, calcium and sulfur) by wet ashing-atomic absorption spectrometry (Table 2).

Table 1 Variation range of main nutrient content in biogas slurry/%

Table 2 Contents of main mineral elements in biogas slurry

Although the nutrient content of biogas slurry is not high, these nutrients are mainly quick-acting. Due to the prolonged immersion of the fermentation product in water, some soluble components can be converted from solid phase to liquid phase, thus greatly increasing the content of available nutrients (Table 1). Among the main mineral elements contained in biogas slurry (Table 2), phosphorus, potassium and magnesium, which are most important for the growth and development of edible fungi, have high content, among which magnesium content is the highest. Therefore, as long as there is some biogas slurry or biogas residue, potassium dihydrogen phosphate and other fertilizers are not needed to produce strains. Other trace elements such as iron, cobalt, manganese, zinc and molybdenum need less, these elements exist in ordinary water, no longer add nutrients, biogas residue completely has the lack of elements in bacteria residue after fungus production.

1.3 Preparation of nutrient solution

Fresh biogas slurry is extracted from biogas digester by pump pipe and placed in shade, filtered by filter net, then a certain amount (small amount) of chemical fertilizer aqueous solution is added into it, and stirred repeatedly for later use. When the temperature is high, add a certain amount of quicklime clarification solution, such as bacteria bags or bacteria beds found in pests, can be mixed with some high-efficiency and low-toxicity pesticides.

2 Results and analysis

2.1 Technique of Supplementing Nutrient Solution for Bagged Edible Fungi

2.1.1 The time to supplement nutrient solution depends on the mycelium growth in the bag first, that is, whether it is vigorous, the whiteness and density of the mycelium. Secondly, see whether the moisture content of the culture medium in the bacteria bag is lower than 50% ; in addition, the natural temperature has been continuously maintained above 9 ℃. If the above conditions are met, the compound nutrient solution can be continuously supplemented for 1 to 3 times during the fruiting period. can be supplemented for the first time at the end of picking the first two tide mushrooms,

4 When the mushroom picking is finished, it can be supplemented for the second time. If the following conditions occur: the hyphae in the bag are thin and yellow, the moisture in the culture medium is sufficient, the diseases and insect pests have appeared in the culture medium or the temperature drops below 4 ℃, it is not suitable to add supplementary compound nutrient solution.

2.1.2 Method of supplementing nutrient solution After picking the first 2 mushrooms of Pleurotus ostreatus, connect the switch on the special water replenisher and sprayer with a pipe, and connect the other end to the faucet. First insert the water replenishing device into the culture medium, then open the standby switch on the water pipe to replenish the water into the feed. When the quality of the bacteria bag reaches the quality of the bag or slightly higher, it is considered that the nutrient solution is supplemented properly. Generally, the mass of the bacteria cylinder loaded with 1kg dry material should reach 2.5 kg after hydration. After supplement of nutrient solution, it can produce 2~3 tides of high quality mushroom continuously, and the total yield is 50% higher than that of conventional mushroom production method. If nutrient solution is not supplemented in the early stage, as long as hyphae grow vigorously in the material, nutrient solution can still be supplemented when the temperature is above 10℃ after picking 3~4 tide mushrooms, but the amount of water supplement should be greatly reduced. In high temperature season mixed Clomid and high efficiency low toxicity pesticides, so as not to lead to overall pollution.

2.1.3 The biogas slurry nutrient solution is used for bag cultivation of edible fungi such as Pleurotus ostreatus, Lentinus edodes, Flammulina velutipes, Pleurotus nebrodensis and bag cultivation of Coprinus comatus. Pleurotus ostreatus is directly injected with water injector after 2~3 tides of each mushroom. The biogas slurry nutrient solution can be used in the whole cultivation cycle of Pleurotus ostreatus. The operation is simple, the investment is small, the pests are few, and the aftereffect is sufficient. The yield is increased by 30%~100% or more than that of the conventional aqueous nutrient solution, and the product has thick mushroom cover. Pleurotus ostreatus can be repeatedly applied by water injection after 2 tides of each mushroom, mushroom can be combined with water injection of mushroom stick, bag cultivation bags such as Pleurotus nebrodensis, Flammulina velutipes, Pleurotus eryngii and Coprinus comatus can be injected before mushroom emergence after full bag growth and maturity, or can be used after one tide of mushroom.

2.1.4 Formula of biogas slurry nutrient solution Add proper amount of lime, chlorpheniramine and some nutrients required by edible fungi to biogas slurry stock solution, which can increase the yield by more than double, the quality rate of products will also be greatly improved, the fruiting period will be prolonged, the fruiting aftereffect will be full, and the storage period of mushrooms will be significantly prolonged.

2.2 Application of Nutrient Solution in Bed Cultivation of Edible Fungi

Bed-grown soil-covered edible fungi (Agaricus bisporus, Coprinus comatus and Agaricus blazei) is fermented biogas slurry extracted from the discharge port of biogas digester with normal gas production and more than half a year of use. It is mixed with 1~2 times clean water to prepare nutrient solution. Biogas slurry can be used for topdressing from the beginning of mycelium growth to the end of production. The nutrient solution can be directly irrigated on the surface of the bacterial bed every time the mycelium is topdressed in the growth stage. The bed soil cannot be washed up, and then the water is sprinkled again. When the nutrient solution seeps down, After the mushroom body surface water is slightly dried, cover the agricultural film to keep warm and moisturize. In the future, depending on the humidity of the bacterial bed, biogas slurry should be applied once every 7~10 days, and fertilizer should be applied once after harvest in each tide mushroom in the production stage. Using biogas slurry as top dressing for edible fungi not only has simple technology, few diseases and insect pests, no residue, but also the mushroom body is especially fat, the number of fruiting tides increases by 1.5 tides on average, the yield is obviously improved, and the general yield increase range is more than 20%.

The results showed that biogas slurry treatment could double the biological efficiency of wall-type cultivation of edible fungi, the yield increased by 90.3%~124.4%, the mushroom shape was plump, large and shiny, and the commodity quality was significantly improved, which was obviously better than that of common nutrients and aqueous nutrient solution. In addition, the quantity of high-quality "mud seam mushroom" in the middle of bacteria bag increased obviously after treated with biogas slurry and biogas residue. Biogas slurry residue has the properties of increasing yield, increasing efficiency and improving quality in edible fungi production, and is a pollution-free and low-cost edible fungi high-quality yield-increasing nutrient.

2.3 nutrient solution immersion method

After the yield of all bag cultivation edible fungi, mushroom blocks, logs and the like decreases or does not produce mushrooms for a period of time during fruiting production, the cultivation materials are in a serious water shortage state, and can be soaked in biogas slurry with a certain concentration, and then taken out after absorbing enough water in biogas slurry nutrient solution until they are recovered to the original weight. Biogas liquid soaking technology is especially suitable for bag cultivation of edible fungi such as Flammulina velutipes, Pleurotus eryngii and Pleurotus nebrodensis, etc., which have less mushroom tide. When the yield of these fungi decreases obviously or even does not produce mushrooms, biogas liquid soaking can make them produce a tide of mushrooms with higher yield again, which plays an important role in the production of some rare fungi. In order to prevent the soaked matter from floating, the soaked matter to be soaked can be put into the nutrient solution pool and then pressed with heavy objects. The soaking time should not be too long. The bacteria bags with excessive water loss can be soaked in several times. Visual bag

The amount of water content determines whether it is necessary to supplement biogas slurry nutrient solution. Pleurotus ostreatus and pleurotus eryngii bags can be soaked in biogas slurry solution. Pleurotus nebrodensis, Flammulina velutipes and shiitake mushrooms can be soaked in 1∶1 or 1∶2 concentration to supplement nutrition after harvesting, and continue to produce mushrooms.

3 Conclusions

Biogas slurry with certain concentration as nutrient solution (basal fertilizer and topdressing) of edible fungi has significant yield increase effect, and can improve the quality and advance the fruiting time. Compared with the conventional nutrient solution containing chemical fertilizer, yield-increasing agent and hormone as main components, the cost of nutrient solution mainly containing biogas slurry was reduced by more than 80%, the yield-increasing rate was increased by 20%~50%, and the high-quality product rate was increased by more than 10%. When applied concretely, compared with the general aqueous nutrient solution, the yield increase rate of Pleurotus ostreatus can be increased by 50%~60%, the yield increase rate of Pleurotus nebrodensis, Pleurotus eryngii and Flammulina velutipes can be increased by 20%~25%, the yield increase rate of Agaricus bisporus and Coprinus comatus can reach more than 50%, and the high quality rate of various edible fungi products is obviously improved, generally above 15%. After applying nutrient solution with biogas slurry as main component, edible fungi have sufficient aftereffect in late fruiting period, the number of fruiting tides increases by 2~3 tides, pollution and diseases and insect pests are significantly reduced, the production cost is reduced (the total cost can be reduced by 15%~20%), and the sustainable development of edible fungi production can be realized.

Practice has proved that the biogas slurry contains the components of organic fertilizer needed for edible fungi cultivation, because biogas slurry is fermented by anaerobic bacteria in biogas digester, and the liquid nutrients are comprehensive and rich, which is a low-cost, pollution-free and high-quality edible fungi production nutrient solution. Biogas slurry is used as the main component to make nutrient solution, which is lower in cost and simpler to operate than common aqueous nutrient solution; the dosage is less, water and fertilizer are saved, and the environment is not polluted. The edible mushroom product can meet the requirements of organic food standards.