11.2014 Harvest and utilization of compost


Mushroom yield is dependent on mature mushroom harvest, i.e. method and organization of harvest under the conditions of fulfilling mushroom feeding requirements and the effective control of pinning and the growth of mushrooms. So then:

  • Mushrooms retain quality longer; therefore the harvesting is easier to organize. This requires the maintenance of an adequate rate of mushroom growth and high concentration of carbon dioxide throughout the harvesting season.
  • Harvesting mushrooms too early reduces the yield in accordance with the rule of 50% weight gain per day.
  • The role of thinning the fruiting bodies and the maintenance time between generations increases. The goal is to preserve the welfare of mushrooms and their dominance in reference to the principle that the stronger and older ones restrict the feeding of smaller and younger mushrooms. This significantly improves the quality.
  • It is very easy to loose the welfare in case of significant changes in microclimate, accelerating the growth of mushrooms caused by presence of collectors and the activities improving working conditions such as blowing cold air on the shoulders, dripping water from the humidification system, etc. The restoration of microclimate parameters is significant. Rapid changes usually cause excessive water evaporation; mushrooms are light and rust discolorations (rust spot) occur on mushroom caps due to water condensation after 2-3 days of storing in a cold room.
  • The first appearance of voids at the interface of the cap to the stipe is the beginning of the welfare loss. They can be seen when cut across mushroom cap. The second sign is a gradual loss of volume weight. The mushrooms are getting lighter and flat, and then a hollow in the middle is being formed.


At present yield sizes that can be achieved in each flush might be predicted.

  • First flush up to 23 kg/m2. It is assumed to be the maximum yield without quality loss.
  • Second flush up to 17 kg/m2. Further yield increase; yield similar to the first flush is planned to be obtained by increasing the dose of carbohydrate and water provided to the compost
  • Third flush up to 7 kg/m2 with prolonged duration up to 10 days. Solving problems with the transition to timely yielding and higher yields should allow further increase of the yields up to 10 kg/m2.

09.2014 Third flush problems

  • Fourth flush 5–7 kg/m2. It is necessary to improve feeding with easily digestible carbohydrates. Cultivation in the hall with a constant microclimate does not allow performing all activities required in the feeding cycle.

Presently an average weekly yield is about 40 kg/m2 and is higher on average by 5-10 kg/m2 than yields collected in the same production system (compost, casing) with protein supplements. Decreased yields during the spring season are due to difficulties of making good compost from very hard straw derived from the 2013 harvest. This situation is a very good time to test the technology based on the process of feeding mushrooms.

Compost utilization

A degree of compost utilization at obtained yield of 40 kg/m2 in three flushes and a load of 83-87 kg/m2 of compost, phase III is 46-48%. It did not exceed 50% but further conducted work should result in higher expected level.

Spent compost

Lack of diseases and pests, and very low sensitivity to further infection, and infestation by pests allows the completion of the production without disinfection. This practice has been carried out at the Chełkowski mushroom farm for years. This is due to the construction of cultivation halls. Non-steamed off used compost is a much better organic fertilizer than steamed off compost. The reuse of compost is a separate issue. The microbiological purity and the development of appropriate technology is the basic requirement for re-using it.