Reed canary grass straw as a substrate in soilless cultivation of strawberry

• We evaluate the performance of ground reed canary grass straw as a growth substrate.
• Water holding capacity of reed canary grass is low in comparison to peat and coir.
• Buffering capacity of reed canary grass is similar to coir, but lower than in peat.
• Strawberry yield on reed canary grass is similar to that on peat or coir.
• Reed canary grass may be used as a substrate in soilless culture of strawberry.

The aim of this study was to evaluate whether ground reed canary grass (Phalaris arundinacea) straw (RC) could be used to replace peat for short production cycle greenhouse crops. Characteristics of RC, peat, mixture of RC + peat (50% + 50%), and coir were determined and the performance of strawberry (Fragaria × ananassa cv. Elsanta) on these substrates was evaluated. Water holding capacity of RC was low in comparison to peat and coir, but could probably be improved by decreasing its particle size in processing. The buffering capacity of RC was similar to coir, but clearly lower than in peat. Because of similar reactions to addition of base, liming recommendation of RC would probably be approximately the same as for peat. The C-to-N ratio was 60 in coir, 41 in peat, 23 in RC, and 29 in the mixture of RC + peat. High concentration of inorganic N in RC was rapidly consumed by the microbial activity in the incubation experiment. Vegetative growth of the strawberry plants was the most vigorous in peat, but the total yield, berry size, and sugar to acid ratio in berries were similar in all the substrates. In conclusion, ground reed canary grass may be used to replace peat or coir in soilless culture of strawberry. However, due to its low water holding capacity, irrigation regime has to be adjusted accordingly.