苎麻营养诊断最佳采样部位与采样时期

Optimum sampling position and sampling stage for nutrition diagnosis of ramie

对不同麻龄、麻季、生育期的苎麻茎、叶 （全株叶、新定型叶） 等部位取样测定 Ｎ、 Ｐ、 Ｋ含量及其在各时期变化， 结果表明， 叶片中 Ｎ、 Ｐ含量多数时期都显著或极显著高于茎， 其 Ｋ含量与茎的差异较小； 茎与叶片之间的 Ｐ、 Ｋ含量， 全株叶与新定型叶之间的 Ｎ、 Ｐ、 Ｋ 含量都呈极显著正相关； 植株前期 Ｎ、 Ｐ含量较高，中后期 Ｋ 含量较高。封行期至黑脚期是营养吸收高峰期， 对产量影响很大。在封行期至黑脚期 （快速生长期）， 采集新定型叶对 Ｎ、 Ｐ、 Ｋ等营养元素含量进行一次性营养诊断和调节施肥较为适宜。

The contents and variation of N,P and K in ramie's stems and leaves for different ramie ages,ramie season and growth stage were studied.The results showed that the contents of N,P in leaves was mostly higher than that in stems,while the content of K in stems was similar to that in leaves. There were higher contents of N and P in seedling stage and much higher content of K in middle and late growth stage.From the closing crop stage to the black foot stage the amount of nutrition absorbed by plants was the largest.The result indicated that it was more suitable for diagnosing the content of N,P and K in the newly grown leaves collected from the closing crop stage to the black foot stage and for regulating nutrition.