福岡県農業総合試験場２４（2005）pp126-129
施肥量を削減した茶園におけるかん水の効果
堺田輝貴・中村晋一郎・久保田 朗・吉岡哲也
（八女分場）
施肥量を削減した茶園において，2月から10月までの少雨時にかん水を行い，土壌水分を適正に維持する管理が，茶樹の生育や荒茶品質および土壌中無機態窒素濃度に及ぼす影響について検討した。
かん水により，茶樹の生育に適正な土壌水分（pF2.3以下）を保つことで，施用した肥料からの窒素の供給が順調に進み，うね間土壌中の無機態窒素量は，施肥量を削減しても無かん水に比べ高い値で推移した。また，かん水により茶芽の生育が旺盛となり，荒茶の全窒素含有率や官能評価および生葉収量は，年間窒素施用量が35kg/10aでも，無かん水で年間窒素施用量が52kg/10aの場合と同等以上であった。
［キ-ワ-ド：施肥量，茶園，かん水，土壌中無機態窒素濃度，収量，荒茶品質］
Effects of Irrigation in Tea Field which Reduced Amount of Fertilizer.SAKAIDATeruki,Sinichirou NAKAMURA,Akira KUBOTA,and Tetsuya
YOSHIOKA (Fukuoka Agricultural
Research Center,Chikushino,Fukuoka 818-8549,Japan)Bull.Fukuoka Agric.Res.Cent.24：126-129（2005）
In tea field which reduced amount of fertilizer, the irrigation was carriedout
in order to maintain soil moisture in the aptitude, and the effect of tea planton growth, quality of crude tea and concentration of
inorganic nitrogen in the soilwas examined. The irrigation was carried out in a little rain from February
toOctober.
The supply of the nitrogen from used fertilizer smoothly advanced by maintaining the proper soil moisture by the irrigation for the growth of tea plant. And,concentration of inorganic nitrogen in the space between hedges soil changed atthe
value which was higher than non-irrigation, even if fertilizer level was reduced. In addition, the growth of the tea bud became the vigorousness by the irrigation. Total nitrogen of crude tea, sensory quality test, and yield of annual 35kg/10a nitrogen level of the irrigation were over the par in comparison with the casein which it was non-irrigation and in which the annual nitrogen level is 52kg/10a.
[key words: amount of fertilizer, tea field, irrigation, concentration of inorganic nitrogen in the soil, yield, quality of crude tea]
