三倍体毛白杨叶片营养DRIS诊断

Leaf nutrient diagnosis of triploid Populus tomentosa with DRIS

采用L1645正交设计法对造林后的三倍体毛白杨进行了施肥试验,运用DRIS诊断法对其叶片营养元素进行了研究。结果表明,以造林第3年7～10月份三倍体毛白杨叶片N、P、K元素浓度测定值为依据,成功制定了DRIS图解法及指数法的营养诊断标准,经检验取得了较高的诊断正确率。三倍体毛白杨叶片N、P、K三元素浓度最佳比值范围为N/P=19.116±1.270;N/K=3.054±0.289;K/P=6.356±0.651。DRIS诊断标准分别经各月份林木叶片养分元素浓度回代检验,林木N、P、K需肥次序与实际施肥量基本一致,其中以9月份林木各处理为例,诊断正确率达到了80%以上。3年生三倍体毛白杨林木对N、P、K需求次序为N>K>P,与DRIS诊断结果一致。运用DRIS法诊断得到的三倍体毛白杨叶片养分浓度最佳比值范围将为三倍体毛白杨的合理施肥,大面积推广提供科学依据。

Triploid Populus tomentos, widely planted in the north of Yellow River, is an ideal tree species for the pulpwood and plywood with the characteristics of short rotation, fast growth, excellent quality and anti-disease.Fertilization experiments with an orthogonal experimental design （L164^5） were conducted in Wei County, Xingtai City, Hebei Province. The nutrients dynamics in the leaves of Triploid Populus tomentosa were studied with the application of Diagnosis and Recommendation Integrated System （DRIS） method. Based on N, P and K concentrations in the leaves of Triploid Populus tomentosa from July to October in the 3^rd year after plantation, nutrition diagnosis standards of DRIS graphic and index methods were successfully established with high accuracy. The optimal N/P, N/K and K/P ratios were 19.116±1.270, 3.054±0.289 and 6.356±0.651, respectively. Diagnostic accuracy reached 80% with the analytical data in September for return test. The nutrients requirement by Triploid Populus tomentosa was in the order of N〉K〉P, which was in accord with the actual application rate of fertilizers. The optimal nutrients ratios can provide scientific basis for rational fertilization and spreading of Triploid Populus tomentosa.