Spent mushroom substrate as biofertilizer in agroecosystems of blueberry

Abstract

Blueberries (Vaccinium spp.) are one of the most commercially significant berry crops. Of all the fruit crops, blueberries are perhaps the most amenable to organic production: pest problems are fewer than with most other fruits, and they preferentially use ammonium nitrogen which is a direct breakdown product of organic nitrogen sources. Spent mushroom substrate (SMS) is a by-product of mushroom growing. It is often classified as waste despite that it is high in organic matter and mineral micronutrient and can be reused as a bioadditive or fertilizer. Spent mushroom substrate from Lentinula edodes was tested as a fertilizer in comparison with peat. Determination of the chemical composition, number of microorganisms and the content of total microbial biomass, direction of microbiological processes in soil fertilized by SMS and peat were conducted. The initial data for the analysis, calculations and mathematical analysis were the results of the first year studies of the multi-year experiment. The actual content of elements showed that SMS contains a high content of all nutrients except N ammonium. The salt content is within acceptable limits. High content of N nitrate indicates a possible risk of excessive vegetation. Analysis of the cationic-anionic composition of the aqueous extract from SMS showed, that the content of all salts is within the permissible norm, except for a slight excess of the norm by Na+. Toxic water-soluble salts do not exceed acceptable value. Microbiological studies of the structure of soil microbial communities showed positive effects of SMS on microbial activity. Basing on these results assumptions can be made that spent mushroom substrate from Lentinula edodes has all possibilities to be used as a biofertilizer in agricultural sector.