Phase II Composting

Bacteria 100-170 °F. Different species of bacteria are active throughout this range so an optimum can not be given. At temperatures above 130 F. bacteria dominate and are responsible for the ammonification that occurs at these temperatures. The most common bacteria found by researchers are Pseudomonas species. 

Actinomycetes 1 15-140°F. with an optimum temperature range of 125-132°F. The most common species are found in the genera S/reptomyces and Thermomonospora. Nork done by Stanek (1971) has shown that actinomycetes and bacteria are mutually stimulatory, resulting in greater efficiency when working together. 

Fungi 110-130°F. with an optimum temperature of 118-122°F. Common genera are Humicola and Torula. Recent research indicates that these fungi are the most efficient de-ammoni-fiers, which has led to a more general use of their temperature range for Phase II conditioning. 

The basic function of these microorganisms is to utilize and thereby exhaust the readily available carbohydrates and the free ammonia. Ammonia in particular must be completely removed be- 

Many growers consider Phase II to be the most important stage in the growing cycle and rightly 

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Whereas in the shelf system all stages of the cultural cycle occur in the same room. The tray system utilizes a separate room for Phase II composting. On a commercial tray farm only the Phase II room is equipped for steaming and high velocity air movement. 

Phase II Compost will not heat up. Supplementation rates too low. Compost too mature. Ovcrsupply of fresh air. Air to bed ratio too great. Compost too wet. Check compost formula calculations. Shorten Phase 1. Reduce fresh air supply. Add more beds or trays and fill with more compost. Compost should be 70% at filling. 

Measures of Control Proper preparation and sufficient air during Phase II composting discourages this fungus. Atkins (1974) reported that excessive moisture and subsequent anaerobic pasteurization were the two main factors contributing to the spread of the White Plaster Mold. Before filling, the addition of gypsum to an overly wet compost will bind loose water, a condition favorable to this mold. 

Sharma et al. (2005) developed robust calibrations for some of the key parameters from the spectra or fresh phase I and II composts and found by the laboratory measurement that for phase I samples were greater than those of the phase II samples except for ash, due to a higher degree of heterogeneity in the substrate. 

HSS Sharma, M Kilpatrick, and L Bums. Determination of Phase II Mushroom (Agaricus bisporas) Compost Quahty Parameters by Near Infrared Spectroscopy. Near Infrared Spectrosc. 8 11-19, 2000. 

The composting process is divided into two stages, commonly called Phase I and Phase II. Each stage is designed to accomplish specific ends, these being ... 

Phase II Carried out indoors in speoially designed rooms, the compost is pasteurized and conditioned within strict temperature zones. 

Once finished, this compost is normally pasteurized at 1 35°F. for four hours. If pasteurization is impossible, discard the cool outer shell and utilize the areas showing strong actinomycete activity. Although these areas will not be free from all pests and competitors, they should provide a reasonably productive substrate. The aspect and characteristics of a properly prepared Long Compost should conform to the guidelines for compost after Phase II. (See Aspect of the Finished Compost on page 105 and Color Plate 8). 

The key to a successful Phase II, whether in trays, shelves or a bulk room, lies in the heat generating capabilities of the completed Phase I compost. To this end the compost should be biologically "active," a term that describes a compost with sufficient food reserves to sustain a high level of microbial activity. Whereas the Sinden Short Compost is a model of a vitally active compost, the Rasmussen Long Compost is considered biologically "dead" because these food reserves have been deliberately exhausted during Phase I. In this same sense, a compost having completed the Phase II is also considered a dead compost. 

Better compost ventilation—Heightened thermogenesis within the compost requires lower air temperatures within the Phase II room. The greater the compost to air temperature differential, the better the air movement through the compost. In this respect a dead compost requires a high room temperature and is difficult to condition because of its low microbial activity. 

Compost supplementation with soluble carbohydrates or vegetable oils is highly recommended, especially for those planning a Phase II without steam or with only limited supplemental heating. Hence, this type of supplementation is particularly appropriate for the home cultivator. 

Peak miorobia activity normally occurs 24-48 hours after pasteurization. As Phase II progresses and the food supply diminishes, this activity begins to slow. Compost temperatures should begin to drop on their own, As they drop, the fresh air supply should be decreased, thus slowly raising the air temperature as the compost reaches the required temperature zones. If the fresh air minimum is reached and the compost temperatures are still dropping, a supplemental heat source must be installed. 

Fruiting Substrate Composted wheat straw enriched with horse and/or chicken manure, adjusted to 70% moisture content. Also, pasteurized chopped wheat straw supports fruitings of this species. Garcha et al. (1979) reported that composts having The distinct scent of ammonia after Phase II supported the greatest fruitings of Coprinus comatus. 

Compost Preparation raw materials, characteristics of composts at differents stages, Phase 1 and Phase II. 

Inky Caps (Coprinus sp.) occur during spawn run. Residual ammonia in compost. Prolong Phase II conditioning until litmus paper test shows no change. 

Actinomyces are commonly called Firefang for their ability to cause spontaneous combustion of decomposing materials. (Spontaneous combustion Is prevented by proper composting practices.) Many of these bacteria/fungi are true thermophiles and can live aerobically or anaerobically. Actinomyces is the major microorganism selected to colonize the compost during Phase II. When the finished compost is spawned, Actinomyces are consumed by the mushroom mycelia. See aiso Streptomyces. See Color Photo VIII. 

History, Use, and/or Medical Implications Streptomyces represents 80% of all actinomycetes which inhabit mushroom compost and is selected for its beneficial properties during Phase II. (See Chapter V). 

Medium Through Which Contamination Is Spread Air soil and dung. Measures of Control Concrete surface used for composting isolation of mushroom compost from areas where untreated soils and raw dung are being stored and filtration of air during Phase II If Chlysosporium occurs before or at the time of casing, salt or a similar alkaline buffer can be applied to limit the spread of infection. 

Both raw and prepared composts can become infected with this mold. It is thought that the spores are introduced with the fresh air during the cool down period of the Phase II orfrom thermo-tolerant spores from within the compost itself. Species in this genus can be found on media of poor nutritional quality. They are generally not seen in spawn culture. 

Meaures of Control Proper Phase I and Phase II management, especially full term pasteurization reduction of ammonia and water in finished compost and homogenous consistency of compost structure (avoidance of densely compacted zones). 

Microscopic Characteristics Conidia one celled, typically globose, brownish colored and often sculptured. Conidiophores are also darkly pigmented, simple, undeveloped and similar to the mycelium or at times having short lateral branches at whose swollen apices a single conidium is borne. Alternately, short chains of microconidia formed by flask shaped cells (phiatides) can occur. History, Use and/or Medical Implications Selected for use in compost nutrient conversion during Phase II of composting. 

Comments Scopulariopsisfimicolais the White Plaster Mold seen on compost beds. It is very detrimental to the growth of mushroom mycelia. Its presence is usually an indication of a short, wet and over-mature compost. This condition predisposes the compost to a difficult Phase II with dense anaerobic areas, ammonia-lock and consequently high pH levels. All these factors contribute to the growth and spread of Scopulariopsis fimicola, the species of White Plaster Mold most frequently seen in mushroom culture. 

In bulk substrates such as compost or plain straw, nematodes can be found in great numbers. The high temperatures of Phase I conditioning would normally destroy them if it were not for the fact they migrate to the cooler outer shell of the compost pile. Phase II can eliminate nematodes but only if the entire compost is subjected to pasteurization temperatures. In a properly prepared and thoroughly pasteurized substrate, the mushroom mycelium consumes all free water and then feeds on the bacterial population. This creates a "bacteriostatic environment", which effectively limits nematode growth capabilties. In an uneven substrate with overly wet and dry areas, however, the nematode s ability to breed increases. Wet areas are particularly suitable for... 

Phase II The pasteurization and final conditioning of a mushroom compost, phenotype The observable physical characteristics resulting from interaction between the host environment and the genotype, photosensitive Sensitive to light, phototropic Growing towards light, pileus The mushroom cap. pith The central cottony stuffing in the stems of some mushrooms. 

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