学科理解视阈下对化肥若干问题的讨论及教学建议

Discussion on Several Issues of Chemical Fertilizers and Teaching Suggestions from Perspective of Subject Understanding

讨论了化学教学中关于化肥的若干问题:现行各版本初中教材对磷矿粉主要成分的表述不一,建议修改为Ca_(5)(PO_(4))_(3)F,与人体骨骼成分羟基磷酸钙相联系;植株缺失氮、磷、钾元素的外显症状有阶段性且与缺失某些微量元素在症状上有相似性,不可一概而论;化肥的特殊性质与其施用方式和肥效密切相关,磷肥的特殊性质使其施用方式有别于氮、钾肥,尿素在土壤中经过一系列转化最终以NH_(4)^(+)被作物吸收,同样不可与碱性物质混合施用。

This paper discusses several issues related to fertilizers in chemistry teaching:the current versions of junior high school textbooks have different descriptions of the main components of phosphate rock powder,it is recommended to change it to Ca_(5)(PO_(4))_(3)F,which is related to calcium hydroxyphosphate;The apparent symptoms of a plant lacking a certain nutrient element are staged and are similar in symptoms to the lack of trace elements,it can’t be generalized as a lack of any one element among nitrogen,phosphorus and potassium;The special properties of chemical fertilizers are closely related to the application method and fertilizer efficiency,the special properties of phosphate fertilizer make its application method different from that of nitrogen and potash fertilizer,urea undergoes a series of transformations in the soil and is eventually absorbed by crops as NH+4,and it cannot be mixed with alkaline substances for application.