粤西8年生加勒比松施肥效果研究

【目的】研究阳江8年生古巴加勒比松Pinus caribaea var.caribaea人工林对氮磷钾不同配比及与微量元素混施的肥效反应。【方法】设定17个氮磷钾不同配比及与微量元素混施的追肥处理,15个月后监测古巴加勒比松的生长量和养分。【结果】协方差分析结果表明,N(21.5 g·株~(-1))、P_2O_5(30 g·株~(-1))的配比处理效果最好。单株施用50 g尿素+250 g钙镁磷肥+25 g氯化钾处理15个月后,单株材积增量比空白对照平均可提高23.6%。加磷(N_2P_1K_2、N_2P_2K_2)比无磷处理(N_2P_0K_2)的生长量显著增大。另外,在氮磷钾相同情况下,添加硼对材积也有显著促进作用。【结论】磷与硼是影响郁闭后加勒比松生长的重要元素。氮磷配比对肥效反应有重要调控作用。

Effects of fertilization on growth of eight-year-old Caribbean pine in West Guangdong

Objective] In order to study the fertilizer response in an eight-year-old Pinus caribaea var. caribaea plantation in Yangjiang to the application of different proportions of nitrogen ( N ) , phosphorus (P) and potassium(K) fertilizers mixed with microelements. Method]There were 17 top application treatments of different proportions of N, P and K fertilizers mixed with microelements. The growth and fo-liar nutrient concentrations of P. caribaea var. caribaea were determined after 15 months.Result]The covariance analysis showed that the optimum proportion of fertilizers was N (21. 5 g·plant-1 ) and P2 O5 (30 g·plant-1). The individual stem volume of plants fertilized with 50 g urea+250 g calcium magne-sium phosphate fertilizer+25 g KCl for 15 months was increased by 23. 6% on average compared to the blank control. The treatments with P ( N2 P1 K2 , N2 P2 K2 ) had significantly more growth compared to the P deficiency treatment (N2P0K2). In addition, boron(B) application significantly increased the stem volume under the same N, P and K treatment.Conclusion]P and B are both important for P. caribaea var. caribaea growth after canopy closure. The proportion of N and P plays an essential role in regulating the fertilizer response of P. caribaea var. caribaea.