Fertilizer Made from Waste Sludge of a Bean Curd Factory Offered an Alternative to the Greening of Seashore with Chemical Fertilizer : Effects of the Fertilizer on Growth of Messerschmidia sibirica L. and Elymus mollis Trinius

古紙混合法および稲ワラ混合法を用いた特許法で、食品工場廃棄汚泥から約2週間で完熟汚泥肥料を作製した。国土交通省による新潟県日本海海浜緑化はハマニンニクを主体として、化成肥料を用いて行われているが、化成肥料に代わって我々の汚泥肥料を代替できるかを調査した。同時に、ハマニンニクの株間に植栽する海浜植物としてのスナビキソウの増殖に及ぼす当該肥料の影響を、新潟大学五十嵐キャンパス圃場に於いて調査した。ハマニンニクの生育に肥料は大きな影響を及ぼし、無肥料区では、最良生育株が見られず、平均生長指数は植栽4ヶ月後で1.04であったが、化成肥料区では2.0、古紙カップ区および稲ワラカップ区でもそれぞれ約2.0であった。スナビキソウの増殖には稲ワラ、紙カップ共に無肥料に比較して著しい増殖効果を示した。しかし冬季にスナビキソウの地上部は枯死し、春に新しい植物体を育てるのに時間がかかり、ハマニンニクの株間を埋めるパイオニア植物としては適していないと判定した。冬季の季節風によって静砂垣、堆砂垣を越えてきた砂によって、場所によっては、生育の優劣に拘わらずハマニンニクは埋もれてしまい、翌春の育成はその埋もれ具合に依存していた。従って、ハマニンニクをパイオニア植物として海浜の緑化をめざす国土交通省の現行の方法は、ハマニンニクが冬眠に入る秋までに、堆砂垣を越えて押し寄せる砂の堆積以上にハマニンニクの生長を促すか、あるいは、より強固な背の高い垣を設置してハマニンニクが砂へ埋没することを防ぐかいずれかの方法をとる必要があると思われた。我々は、ハマニンニクに代わる新しいパイオニア植物を選定することを提案した。Composting of waste sludge from a bean curd factory was performed using a patented paper-tip-mixing method and well matured compost (=PaperFertilizer) was resulted during two weeks. Ministry of Land, Infrastructure and Transport (MLIT) is trying greening of seashore of Niigata prefecture such as Ikarashi-hama beach and Kobari-hama beach using American dunegrass, Elymus mollis Trinius with chemical fertilizers. We surveyed if PaperFertilizer was alternative one in the greening of seashore. The effi cacy of the PaperFertilizer to enhance the growth of Messerschmidia sibirica L. was also checked in Niigata University agriculture field. The chemical fertilizer gave great affect on the growth of American dune grass. Without the fertilizer, well fl ourished plants were not observed and average growth index was 1.0 on four month after the planting. Contrarily to this, chemical fertilizer increased the index to 2.0 during the same period. PaperFertilizer showed the same average indices in the plants growth as chemical fertilizer. Above ground parts of Messerschmidia sibirica L. unfortunately withers away in winter season and furthermore, growth in height during summer time was not great compared to our expectation. Therefore, the plant has been excluded from the list of pioneer plants which were expected to fl ourish among the stem of American dunegrass. A seasonal wind in wintertime at Kobari-hama beach carried tons of sea sands across the fences which were made and designed by MLIT, and regardless of the flourish, in some places in the plot, American dune grasses were buried under the sand. The growth of the plants in next spring after the harsh winter depends on it that how much the plant was buried deep. Therefore, in the MLIT greening strategy in which American dunegrass is used as a main pioneer plant, it is necessary to grow the grass to greater height than that of the fences before winter comes. Alternatively, tall and durable fences must be set to prevent the grass from being buried alive. We proposed to search new pioneer plants alternate the current American dunegrass