3.柑桔栽培 (1)土壤:研究重点在土壤改良、土壤熟化指标、免耕生草法、杂草防除和盐害治理等方面。桔园土壤改良以美国、日本最为重视。美国建园时,用重型机械深翻土壤,业大量施有机肥改良土壤。日本还制定了土壤熟化指标。我国丘陵山地桔园采取挖深沟、大量施有机肥的办法进行 3. Citrus cultivation (1) Soil: The research focuses on soil improvement, soil ripening indicators, no-tillage grass lawn, weed control and salt damage control. Orange Garden soil improvement to the United States, Japan most attention. When the United States built a garden, it used deep-soled heavy machinery to soil the soil and used a large amount of organic fertilizer to improve the soil. Japan also developed soil ripening indicators. China’s hilly mountain orange grove to dig ditch, a large number of organic fertilizer approach