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No.28 (1981/11) >

 
Title :沖縄におけるサトウキビに対するカンガイの必要性 (2)(農業工学科)
Title alternative :The necessity of irrigation for sugarcane produced in Okinawa (2) (Department of Agricultural Eegineering)
Authors :山城, 三郎
Authors alternative :Yamashiro, Saburo
Issue Date :30-Nov-1981
Abstract :1.本研究では, 宮古(島尻マージ地帯)と南風原(ジャーガル地帯)のサトウキビ栽培ホ場における水収支計算を行い, 不足水量と夏植サトウキビの10アール当り収量との関係から, カンガイの必要性について検討した。2.宮古では, 夏植サトウキビの全生育期間, 植付翌年の1年間, 植付翌年の7月∿9月の各生育期間における降雨量の平年値はそれぞれ3600mm, 2150mm, 590mmとなった。また, これらの各生育期間における有効雨量の平年値は950mm, 720mm, 230mmで, 不足水量の平年値は482mm, 467mm, 249mmとなった。3.南風原では, 各生育期間における降雨量の平年値は3450mm, 2100mm, 580mmで, 有効雨量の平年値は1020mm, 770mm, 245mm, 不足水量の平年値は421mm, 408mm, 220mmとなった。4.宮古では, どの生育期間においても, 不足水量と夏植サトウキビの10アール当り収量との間には負の勾配を持つ直線関係が認められた。すなわち, 島尻マージ地帯においては, サトウキビに対するカンガイが必要で, とくに植付け翌年の7月∿9月におけるカンガイの重要性が明らかになった。5.南風原では, どの生育期間においても, 不足水量と夏植サトウキビの10アール当り収量との間には確かな関係が認められなかった。すなわち, ジャーガル地帯においてはサトウキビに対するカンガイがあまり必要でないという結果が得られた。これは, 有効根群域より下の土層からの水分補給があるためだと推察される。
1. In this study, the necessity of irrigation for sugarcane was investigated by calculating incomings and outcomings of water in sugarcane field in Miyako (Shimajiri-maji area) and Haebaru (Jagal area), and examining the relationship between soil moisture deficiency and the yield of sugarcane. 2. In Miyako, rainfalls in the normal year for all the vegetation period, the period from January to December and the period from July to September in the year following the year when sugarcane was planted, were 3600mm, 2150mm, and 590mm respectively. For those periods, the available rainfalls in the normal year were 950mm, 720mm, 230mm and the soil moisture deficiencies in the normal year became 482mm, 467mm, 249mm respectively. 3. In Haebaru, rainfalls in the normal year for all the vegetation period, the period from January to December and the period from July to September in the year following the year when sugarcane was planted, were 3450mm, 2100mm, 580mm, respectively. For those periods, the available rainfalls in the normal year were 1020mm, 770mm, 245mm and the soil moisture dcficiencies in the normal year became 421mm, 408mm, 220mm respectively. 4. In Miyako, the relationship between soil moisture deficiency and the yield of sugarcane per 10 are was shown by linear equation with negative gradient in each period. It became clear that irrigation for sugarcane in the Shimajiri-maji area is necessary, especially for the period from July to September in the year following the year when sugarcane was planted. 5. In Haebaru, there are no precise trends in the relationship between soil moisture deficiency and the yield of sugarcane per 10 are in any period. It seems that irrigation for sugarcane in Jagal area is not so necessary. It is supposed that soil moisture may be supplied from soil zone under the effective root zone in Jagal area.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/4056
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.28 p.127 -137
Appears in Collections:No.28 (1981/11)

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