福岡県農業総合試験場研究報告23 (2004) pp 93 - 98
煎茶園での点滴かん水施肥栽培が収量、品質及び土壌浸透水に及ぼす影響
堺田輝貴＊・森山弘信１）・中村晋一郎・吉岡哲也
煎茶園において，樹冠下の点滴かん水施肥（窒素50kg/10a）が，収量，品質および土壌浸透水に及ぼす影響について検討した。
１．窒素50kg/10aを点滴かん水施肥した場合，同程度の窒素を施用した慣行施肥法と比較して，一，二番茶ともに20％以上増収した。
２．点滴かん水施肥により，20％程度の増収条件下では官能評価や化学成分含有率等において，慣行施肥法より優れる傾向を示した。
３．ライシメータでの地下浸透水中の硝酸態窒素濃度は点滴かん水施肥を行うことで，慣行施肥法に対し早期に低下する傾向が認められた。また，点滴かん水施肥区の試験開始３年次の窒素溶脱量は，黒ボク土で1.9kg/10a，赤黄色土で3.6kg/10aと，各土壌でそれぞれ慣行施肥法の40〜36％となり，大幅に環境負荷が低減された。
［キ-ワ-ド：煎茶園，点滴かん水施肥，収量，品質，地下浸透水］
Effects of Drip Fertigation on Yield, Quality and Permeated Ground Water in Tea Field for Sencha. SAKAIDA Teruki, Hironobu MORIYAMA, Sinichirou NAKAMURA and Tetsuya YOSHIOKA (Fukuoka Agricultural Research Center, Chikushino, Fukuoka 818-8549, Japan)Bull. Fukuoka Agric. Res. Cent.,23: 93 -98 (2004)
We examined the effects of drip fertigation under the canopy on nitrogen application of 50kg/10a on yield, quality and permeated ground water in tea field for sencha.
1 When it was fertilized in drip fertigation on nitrogen application of 50kg/10a, the yield of first and second crop of tea was increased above 20%.
2 Under the increased yield of about 20% by drip fertigation, sensory quality test and chemical composition content rate of drip fertigation was superior than control.
3 The concentration of nitrate nitrogen in permeated ground water at the lysimeter was decreased by drip fertigation in early stage. Third year of examination starts, amount of leached nitrogen in andosol was 1.9kg/10a, and amount of leached nitrogen in red and yellow soil was 3.6kg/10a. It became 40〜36% of control in each soil, and the environmental loading was drastically reduced.
[Key words : tea field for sencha, drip fertigation, yield, quality, permeated ground water]
＊連絡責任者（八女分場） 1)現病害虫防除所