Studies on an Improvement of Sugarcane Quality through Fertilizer Management Practices. : 2. Relationships between Ions in Sugarcane Juice and Pol in Cane and Use of Juice Analysis for Nutrient Diagnosis
| Autor: | Watanabe, Kenta, Taira, Eizo, Ueno, Masami, Kawamitsu, Yoshinobu |
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| Jazyk: | japonština |
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| Zdroj: | 沖縄農業. 48(1):35-44 |
| ISSN: | 1344-1477 |
| Popis: | 施肥管理はサトウキビの糖度に影響を与える要因の一つである．我々は搾汁液に含まれる養分のうち，特にこれまでの報告よりサトウキビ品質との関係が強いと考えられたK^+とCl^−を中心に甘蔗糖度との関係を調査し，施肥管理の面から糖度を改善する方法について検討した．また，搾汁液中K^+，Cl^−含有量の簡易推定法として搾汁液電気伝導度（EC）の測定が有効であるか調査した．2013年から2015年までの3年間，国内に存在する17の分蜜糖工場から収集した原料茎サンプルを分析した結果，搾汁液に最も多く含まれる陽イオンと陰イオンはK^+とCl^−であり，これらのイオンと甘蔗糖度の間には常に1%水準で有意な負の相関関係が認められた．K^+およびCl^−含有量は生産地により有意に異なり，K^+およびCl^−含有量の高い地域で糖度が低くなる傾向がみられ，このような地域ではこれらのイオンがサトウキビ圃場に過剰に蓄積されていると考えられた．ECはK^+，Cl^−含有量と高い正の相関を有することからECを測定することでこれらのイオンを簡易的に推定することが可能であると考えられた．基準糖度帯の下限13.1%となるECの予測値は817±283 mS m^であったことから，この値を指標とし，ECが一定の値を超えた翌年は一般的なカリ肥料でありK^+，Cl^−の両方を含む塩化カリの施肥量を低減させることで糖度を向上させることが可能と考えられた． Fertilizer management practice is one of the factors that influence sugarcane quality. We focused on nutrients present in sugarcane juice, especially K^+ and Cl^− which were thought to be harmful to sugarcane quality from previous reports, and investigated relationships with pol in cane (PIC) to achieve a quality improvement through fertilizer management practices. Moreover, we examined the effectiveness of measuring juice electrical conductivity (EC) to easily estimate K^+ and Cl^− concentrations. From 2013 to 2015, we collected sugarcane samples from all of the sugar mills in Japan. Juice analysis over the three years showed that K^+ and Cl^− were the most abundant cation and anion in the juice and that both negatively correlated with PIC. K^+ and Cl^− concentrations significantly varied depending on production areas and those with higher K^+ and Cl^− concentrations had a low sucrose concentration. This finding suggests that sugarcane in those areas may have been supplied with these two ions in excess. EC always positively correlated with K^+ and Cl^− concentrations and the mean EC of samples with lower PIC than the standard value (13.1 to 14.3%) was 900 mS m^. EC may thus be a reliable indicator of K^+ and Cl^− concentrations and could be used for nutrient diagnosis because of its ease of measurement. For improving sugarcane quality, we recommend that potassium chloride, which supplies both K^+ and Cl^− and is a commonly used potassium fertilizer for sugarcane production in Japan, should be used in lower quantities in a year following one in which the EC of sugarcane juice at harvest is higher than 900 mS m^ 論文 |
| Databáze: | OpenAIRE |
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