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No.44 (1997/12) >

 
Title :草地による環境保全技術の確立 : 第 1 報 環境保全のための適草種の選定と草地造成時におけるリン酸施肥の効果
Title alternative :Establishment of technology in the environmental conservation by the grassland (1) Selection of appropriate grass species for the environmental conservation and effects of phosphate fertilizer for the establishment of the grassland
Authors :新城, 健
星野, 正生
Authors alternative :Shinjo, Takeshi
Hoshino, Masao
Issue Date :1-Dec-1997
Abstract :草地により環境保全を図るための適草種の選定と草地造成にあたってのリン酸施肥の効果を知る目的の試験を行って次のような結果を得た。(1)牧草の初期生育に及ぼすリン酸施肥の影響は明瞭に現れ, 無肥区の生育は少肥区, 多肥区に比べ著しく劣った。しかしこの初期生育の差は牧草が定着するに従い, 小さくなった。1年目には明瞭だった草丈の差は2年目には見られなくなった。(2)乾物収量に及ぼすリン酸施肥の効果は草丈と同様に1年目の初期に大きく, その後に小さくなったが, 年間を通じて多収となり多肥区>少肥区>無肥区の順であった。そしてこの効果は2年目にも残効として働き, 多肥区, 少肥区の収量が無肥区に優った。(3)ローズグラスは2年目を経過した時点で急激に草地の密度が低下し, 環境保全の目的には適さない草種と思われた。ギニアグラス, セタリアグラスは共に高い密度を維持し, この目的の適草種と思われた。リン酸施肥は草地の密度維持の上にも効果を示した。(4)リン酸の施肥水準は植物体内のリン酸含有率に明瞭に反映され, いずれの草種, 年次においても多肥区>少肥区>無肥区の順であった。2年目にはリン酸含有率のレベルの若干の低下があったが, 施肥の効果は明らかに残っており, いずれの施肥区も高いリン酸含有率を示し, 残効の存在を立証した。
Examinations for selection of appropriate grass species for attempting the environmental conservation by the grassland and for obtaining the knowledges of effects on the phosphate fertilizer for the establishment of grasslands were performed and following results were obtained. 1. Influences of the phosphate fertilizer on the early growth of the pasture grass were recognized clearly and remarkably poorer growth at areas of non-fertilizer showed than that compared with areas of the light fertilizer and of the heavy fertilizer. Differences, however, at the early growth among those examined areas became smaller when pasture grasses were established. Clear differences of plant heights at the first year were observed but no differences were seen at the second year. 2. High effect of the phosphate fertilizer on the yield of dry matters was found at the early state of the first year and then was becoming lower, but the high yield was recorded through the year with the orders at areas of high amount of fertilizer > of low amount of fertilizer > of non-fertilizer. This effect still worked at the second year as the residual effect, and a total yield at areas of the high and of the low fertilizers were better than an area of non-fertilizer. 3. Rhodes grass showed the decreased density of grassland rapidly when the second year had passed over and it was presumed that this grass species might not be suitable grass species for a purpose of the environmental conservation. Both grass species, Guinea grass and Setaria grass kept their high densities and were presumed as appropriate grass species. The phosphate fertilizer showed fine effects on the preservation of the grassland. 4. A standard for the fertilization with phosphate was clearly reflected on the content ratios of phosphate in plant. Every grass species showed the orders in areas of the high fertilizer > of the low fertilizer > of non-fertilizer in the contents, annually. Even a little decreased content ratios of phosphate in the second year were ovserved, the residual effect was clearly recognized and high content ratios were shown at every fertilized areas and the existence of residual effects were proved.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/3721
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.44 p.323 -329
Appears in Collections:No.44 (1997/12)

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