防火树种木荷苗期营养DRIS诊断研究

采用回归最优饱和设计法对1年生木荷进行了施肥试验,运用DRIS诊断法对其叶片营养元素进行了研究。结果表明,以6～11月份木荷叶片N、P、K元素浓度测定值为依据,成功制定了DRIS指数法的营养诊断标准,经检验取得了较高的诊断正确率。木荷叶片N、P、K三元素浓度最佳比值范围为N/P=10.21±1.30,K/P=2.11±0.08,N/K=5.29±0.64;实验结果表明N、K肥对木荷苗影响较P肥更大。运用DRIS法诊断得到的木荷叶片养分浓度最佳比值范围将为木荷的合理施肥,提高苗木生长量提供科学依据。

Leaf Nutrient Diagnosis of Fire-resistant Tree-Schima superba with DRIS

Schima superba, widely planted as fire-resistant tree in the south of China. Fertilization experi- ments with an regression optimum saturation design were conducted in Xiangcheng District. The nutrients dynamics in the leaves of S. superba were studied with the application of diagnosis and recommendation integrated system （DRIS） method. Based on N, P and K concentrations in the leaves of S. superba from June to November, nutrition diagnosis standards of DRIS graphic and index methods were successfully established with high accuracy. The optimal N/P, K/P and N/K ratios were 10. 21 ± 1.30, 2. 11 ± 0.08, 5.29± 0. 64 respectively. Experimental results also showed that N and K fertilizer of S. superba seedlings impacts greater than the P fertilizer. The optimal nutrients ratios can provide scientific basis for rational fertilization and improving tree growth of S. superba.