Abstract
To reestablish agricultural production in the farmlands damaged by the Great East Japan Earthquake in the Sanriku region, we tested the effects of application of non-composted spent shiitake (Lentinula edodes) substrates (SSSs) as an organic soil conditioner. Sweet corn (Zea mays) was cultivated at Rikuzentakata as a test plant. As a result of SSSs application, chemical, physical, and biological properties of the soil were improved. Nitrogen deficiency and growth inhibition generally occur when non-composted organic matter with high C:N ratio is applied. SSSs had a high C:N ratio and were non-composted, but SSSs promoted plant growth even at early stages, suggesting that nitrogen nutrients from SSSs were immediately provided to plants without nitrogen deficiency and growth inhibition. The plants using SSSs grew slowly compared with those using chemical fertilizers; however, yields were similar. Thus, application of non-composted SSSs is an effective soil restoration treatment without decreasing yield in damaged farmlands.
