03.2014 Difficulties regarding high mushroom yield stability upon full supplement of nutrient requirements

In the past recent years it has been possible to balance the dose of a feeder in correlation to the water amount added into the substrate that would provide a full cover of nutrient requirements at a level of 35-37 kg/m2 in two flushes. However, it did not result in the stable and high yields.  Therefore a radical change in an approach to mushroom cultivation is in high demand. It means that there is a necessity to identify the causes of unstable yields in the current production practice and the findings that could help solve the existing issues. The substrate is not restricting a level and quality of mushroom yields but instead a production practice.

These are the identified problems that have been resolved so far.

  1. Irregular air movement in cultivation room and above each shelf.
  2. Significantly differentiated pH, calcium content and salinity of the casing layer.
  3. Unrepeatable structure of casing layer at a time of shock initiation.
  4. Simultaneous increase of large number of fruiting bodies in the second flush that resulted in the excessive harvest costs and worsening quality of collected mushroom caps.
  5. Water shortage during harvest time resulting in the decay of mycelium and fruiting bodies on the casing layer surface particularly at the end of second flush.
  6. Weakening of fruiting bodies in the second harvesting phase despite well-balanced nutrient requirements in both first and second flush.
  7. Lack of reproducibility of fixed and sufficient number of fruiting bodies in the third flush.  In this case a yield was dependent on number of fruiting bodies not their weight. Besides, a substantial increase in the yield of third flush still poses a significant challenge.
  8. Uncontrolled infections with Dactylium.

Despite unidentified problems, the final outcome was frequently affected by errors resulting from various quality of provided products, equipment failure etc. Currently one can introduce a concept of lost profits caused by sources within the company. Since it was determined that the substrate potential allows achieving high yields it has occurred that there is a necessity of defining second new definition regarding mushroom cultivation, which is a controlled feeding. The factors that can be controlled were already recognized. However, what procedure should be employed in regards of expected and sufficient nutrition effects is a new and difficult task.

The described difficulties have psychological nature as many rules of mushroom production have been recognized as inadequate in a new situation challenged by new issues. For instance, at present a producer needs to predict how fruiting bodies will perform within the next several hours and accordingly the microclimate parameters have to be adapted to meet the foreseen expectations. Generally this involves  “deterioration” and not “improving” a microclimate.

Human factor plays a significant role at expected increase of crops and currently used compost. This is due to the fact that at present the desirable results can be obtained without increases in costs and even with their reduction.  The elements that determine success are following: professional qualifications, ability to observe, correct conclusions regarding current happenings, commitment and time invest in production process.

Management of production with high yields will create a demand for an electronic control of mycelium conditions, fruiting bodies and primordia. This concept has been already developed. However, the potential producers are not convinced that the new technology and software would solve the existing problems. This production area is also looking to answer a question regarding if and how to introduce the robot operating systems.

At the end let me explain why it is so difficult to evaluate the quality of substrate and its production potential. Generally speaking, the producers own facilities, know technologies and have developed skills that would let them achieve yields at certain levels. Let’s consider a yield at the level of 30-32 kg/m2.  Usually the yield increases and improvement in compost efficiency become out of reach due to the lack of producer ability. In general, the high decrease in yields caused by worsening compost quality is observed than higher yields resulting from improved compost value. It explains the significant fluctuations in the yields noted for instance in the season of 2013/2014 due to the difficulties of adjustment of compost production technology to the variable quality of straw. Besides, investments in improving compost quality are ineffective if the water rate that would be required to utilize larger quantities of nutrition ingredients provided in better quality compost were not increased. There is a very strong resistance among mushroom producers against water application into the substrate and casing layer during harvesting. Thus, neither improvement of compost quality nor higher yields have been observed.