炭化したナシ剪定枝の野菜栽培用土としての有効利用(土壌管理・施肥・灌水)  [in Japanese] The Availability of Carbonized Pruned Shoot of Japanese Pear as Vegetable Growing Media(Soil Management, Fertilization & Irrigation)  [in Japanese]

農業廃棄物の有効利用の一方法として, ナシ剪定枝を炭化し, 野菜栽培用土としての利用の可能性を検討した.市販栽培用土とナシ炭の混合試験では, ナシ炭はコマツナの生育にほとんど影響しなかった.栽培期間中にポットから流亡したNO_3-N量は, 粒径1cm以下の炭を容積比で20%混合すると減少した.ナシ炭には水溶性N成分がほとんど含まれず, 水溶性Kは高濃度であった.赤玉土との混合試験では, 粒径0.5cm以上のナシ炭の混合により, CECの増大が認められた.したがって, ナシ炭の土壌への混合は, 土壌改良資材, K肥料としての効果に加え, NO_3-N流亡の低減の可能性も指摘でき, ナシ剪定枝の有効利用が可能と考えられた.

The availability of charcoal as vegetable growing media was discussed from the perspective of recycling agricultural wastes. The charcoal was made from pruned shoot of Japanese pear (Pyrus pyrifolia var. culta Rehd.) which is the most abundant agricultural waste product from orchards at the Center for Environment, Health and Field Sciences, Chiba University. Charcoal mixed with commercial growing media, though the charcoal particle size and mixing proportion varied, hardly affected the growth of Brassica campestris var. peruviridis cv. Gokurakuten. Fine charcoal (0.1 to 1.0cm) mixed at a volume of 20% decreased the amount of NO_3-N in discharged water, especially during the early part of cultivation. At the end of cultivation, the cation exchange capacity (CEC) of the media tended to be increased by raising plant, not by mixing the charcoal. When charcoal was mixed with clay soil without fertilizer, coarse charcoal (0.5 to 2.0cm) improved the soil CEC, and fine charcoal (0.1 to 0.5cm) increased the soil potassium concentration. In conclusion, charcoal made from pruned shoots of Japanese pear can be used as vegetable growing media and will improve soil properties, while possibly decreasing NO_3-N discharge.