ABSTRACT

Two trials addressing soil preparation, weed control, fertiliser application and planting density were established on dry, high-elevation sites as part of a program to develop site-specific management. The sites differed in soils and the level of pasture improvement. The objectives included identifying treatment combinations that had greatest productivity and best stem and branch form, considering that poor stem form is an issue on pasture sites. The trials were assessed at 13 years of age. Volume production was high compared with a plantation established earlier on a native forest site, but it was not possible to determine whether this was a result of higher survival, higher nutrition, improved weed control or improved genetics. There was little difference in the effects of soil preparation treatments, and there was no effect at 13 years of the small early-fertiliser application. Weed control was important, with effects on volume production varying between sites and having a greater effect on the highly improved pasture site. Increasing stocking from 1000 stems ha⁻¹ to 1500 stems ha⁻¹ increased volume production by about 24% where weed control was applied. There were differences in stem and branch form between sites, and the highly improved pasture site had a higher level of multi-leaders, probably attributable to low boron. The study shows the value of small, standardised silvicultural trials in the development of site-specific management.

摘要

作为制定特定地点管理计划的一部分，在干燥、高海拔地区开展了两项针对整地、杂草控制、施肥和种植密度的试验。这些地点的土壤和牧场改良水平各不相同。目标包括确定具有最高生产力和最佳茎和枝条形状的处理组合，考虑到不良的茎形状是牧场上的一个问题。这些试验在 13 岁时进行评估。与早期在原生林地建立的种植园相比，产量较高，但无法确定这是否是由于更高的存活率、更高的营养、改善的杂草控制或改善的遗传的结果。整地处理效果差异不大，13年小量早施肥没有效果。杂草控制很重要，不同地点对产量的影响不同，对高度改良的牧场影响更大。从 1000 株公顷开始增加放养量^-1至1500茎ha ^-1在进行杂草控制的情况下产量增加了约24%。不同地点之间的茎和枝形态存在差异，高度改良的牧场具有较高的多领导水平，这可能归因于低硼。该研究显示了小型标准化造林试验在发展特定地点管理方面的价值。