在新竹縣峨眉鄉18年生無子桶柑果園，以裂區設計進行試驗，探討有機肥施用量及草生對土壤酸鹼值、有機質及必要元素含量之影響。試驗以施肥量為主因子，包括全量有機肥、1/2量有機肥加1/2量化學肥、1/4量有機肥加3/4量化學肥及全量化學肥；雜草管理為副因子，包括草生及殺草劑處理，3重複。草生處理區之土壤中，有機質、有效磷、鉀、鈣、鎂的含量均明顯較殺草劑處理區高，經5年試驗結果得知，隨著草生年限之增加，土壤有機質及有效鈣含量會增加，有效磷及有效鎂含量則減少。有機肥施用量則明顯影響土壤酸鹼值，高有機肥施用區之土壤酸鹼值較高且穩定的維持在6.0～6.5間，而化肥處理區之酸鹼值會逐年下降而低於5.0，有機肥施用量對土壤養分含量之影響較不顯著。在台灣果園土壤中有效磷、鉀與鎂過高的狀態下，施用有機質肥料有助於改善此種缺失，同時可利用草生來穩定提高土壤有機質含量。
The experiment was conducted at Ear-mei to study the effect of organic fertilizer dosage and sod culture on soil reaction, organic matter and available nutrients content of Tankan (Citrus tankan Hayata) orchard. Split plot design with three replicates was used in this experiment. The main factors of the treatment included total, half, a quarter and zero amount of organic fertilizer. The sub factors included sod culture and weed control. The ability of sustainable management of tankan would be approached from this experiment. Sod culture plot had significantly higher soil organic matter, available P, K, Ca and Mg content than weed control plot. Results of five years experiment, it was also found that the soil pH and available Ca content increased and available P and Mg content decreased in sod culture plot. Organic fertilizer dosage also significantly influenced soil pH. The soil pH value maintained 6 to 6.5 in high organic fertilizer dosage plot. The soil pH value drop under 5.0 in chemical fertilizer plot. Most of soil in Taiwan orchard had excess P, K, Mg content, therefore, heavy dose of organic matter and sod culture were necessary.
