以我国东南沿海沙地主要造林树种短枝木麻黄(Casuarina equisetifolia)一年生苗木为研究对象,应用氮(N)、磷(P)、钾(K)三元二次旋转回归法,根据现实生物量的差异,划分为2种不同的产量类型,同时结合室内养分含量分析,以高产量类型为最适值,制定了诊断施肥综合法(Diagnosis and Recommendation Integrate Sys-tem,简称DRIS)及指数法的营养诊断标准,研究氮、磷、钾不同施肥配比条件下苗木体内氮、磷、钾的养分含量及其需求程度,对短枝木麻黄进行苗期综合营养诊断分析。结果表明:施肥配比对短枝木麻黄苗木生物量积累规律有较大影响,苗木生物量最优解为19.84 g/株,对应的最佳施肥方案为氮、磷、钾分别施肥0.329 g/株、2.298 g/株、0.154 g/株。短枝木麻黄苗期小枝3种元素浓度的最佳比值范围为P/N=0.3174±0.1302;K/N=1.1010±0.506;K/P=3.5564±0.5075,以生长末期12月份各处理苗木为例,列出各元素的DRIS诊断指数及相对需肥次序,证实了营养诊断的准确性。
Using one-year-old Casuarina equisetifolia seedlings, which are the main planting species along the sandy coast of southeast China,and ternary quadratic rotary recursive fertilizer design of N, P and K, two different output types were divided based on real differences in biomass. Further,by the data of N, P and K nutrient elements contents of the seedlings, nutri- tion diagnosis was analyzed for C. equisetifolia. There was an obvious impact of proportioning fertilization on biomass accumulation of C. equisetifolia. The optimal solution of seedling outputs was 19.84 g per tree,and the respective quantities of fertilization were 0. 329 g per tree for N, 2. 298 g per tree for P,and 0.154 g per tree for K. The rational scales of ratios among the nutrient elements were P/N=0. 3174±0.1302, K/N=1.1010±0. 506, K/P=3. 5564±0. 5075. Application of examples treated by ternary quadratic rotary recursive fertilizer design confirmed the diagno- sing accuracy and list sequence of nutrients demanded through DRIS( Diagnosis and Recom- mendation Integrate System).