Because of alkaline calcareous nature of soils, availability of micronutrient is a problem, particularly Zn in rice soils, Cu and Zn in citrus and Fe in apples.

• 因碱性石灰性土壤的特性，微量养分有效性不高，特别是水稻土中缺锌，柑桔园中缺铜缺锌和苹果园中缺铁。