Influences of Heavy Application of Nitrogen on Soil Acidification and Root Growth in Tea Fields

Japanese Journal of Crop Science

Katsuhiko IKEDA¹  Shigehiko YOSHIKAWA¹  Naoaki TACHIBANA¹ 

关键词: Heavy application of nitrogen;    多肥栽培;    Root growth;    チャ;    Soil acidification;    土壌の酸性化;    Soil solution;    土壌溶液;    Tea plants;    根の生長;   

DOI  :  10.1626/jcs.64.516

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

We surveyed the actual levels of nitrogen application in the productive region of green tea in northern Mie prefecture and investigated the physico-chemical properties of the soils and root growth in the tea fields. The annual quantity of nitrogen supplied ranged from 5.8 to 28.3kg a-1, giving 14.7kg a-1 on average. The annual quantities of phosphoric acid and potassium were 5.7 and 4.6kg a-1 on average, respectively. More than 20kg a-1 of nitrogen had been applied annually for 11% of the surveyed tea fields. White roots in the topmost layer(0∼20cm) of inter-row soil were considerably reduced when nitrogen exceeding 14.0kg a-1 was applied and were not found when the amount of nitrogen exceeded 18.0kg a-1. The soil acidity (H2O) in the inter-row decreased from pH 5.9 to 2.9 with an increase in the amount of nitrogen applied. The topmost layer of inter-row soil was highly acidic lower than pH 4.5. Anions in the soil solution collected in the inter-row were mainly composed of NO3- and SO42- and the concentration of anions exceeded that of cations. The soil acidity was kept at pH 3 when alminium inos were available to compensate for the lack of cations.

【 授权许可】

Unknown