Interior spruce, Douglas-fir and western larch fertilizer screening trials in the British Columbia interior (E.P. 886.08)

Introduction

By the mid-1980's, the fertilization response potential of lodgepole pine had been fairly well documented. However, very little fertilizer response information had been collected for other interior conifers. Foliar nutrient data collected for other species indicated that severe to very severe nitrogen (N) deficiencies were common in young stands. Also, certain site preparation practices (for example, windrowing and broadcast burning) had been implicated as contributing to the poor foliar nutrition and growth of several interior spruce plantations. In 1987, a fertilizer "screening" study was initiated to determine the fertilization response potential of interior spruce, Douglas-fir and western larch. The study was undertaken in co-operation with Dr. G. Weetman, University of British Columbia.

Objectives

The objectives of the study are to: i) document specific nutrient deficiencies affecting the growth of young interior spruce, Douglas-fir, and western larch stands, ii) determine the relative responsiveness of these species to various fertilizer treatments, and iii) identify specific nutrients to be included in future conventional, fixed-area plot trials.

Treatments

Ten fertilizer trials (4 Fdi, 4 Lw, 2 Sx) were established in the southern interior in 1987. In 1988, 17 trials (12 Sx, 5 Fdi) were established in the north-central interior.

Each of the installations was designed as a 3 x 2 factorial experiment using three levels of N (0, 100, and 200 kg N/ha) and two levels of a granulated "complete" fertilizer mix (0 and 1170 kg/ha), which was formulated to deliver (kg/ha): 100P, 102K, 116Ca, 51Mg, 50S, 13Fe, 5Zn, 5Mn, 2Cu, 2B, 1.5Mo. The purpose of the complete fertilizer was to test for nutrient deficiencies other than N. Each of the six treatments was randomly assigned to 10 "mini" plots. Fertilizer was applied by hand to a 6m radius surrounding a dominant "plot centre" tree. Two trees per plot, the "centre" tree and an adjacent "off centre" tree, were identified for subsequent foliar sampling. Post-fertilization patterns of foliar nutrient concentration and needle mass were used to evaluate the nutrient status and fertilization response potential of treated stands.

The study is now inactive.

Publications

The Ministry of Forests, Lands, Natural Resource Operations and Rural Development Publications Search

• Swift K. and R.P. Brockley. 1994. Evaluating the nutrient status and fertilization response potential of planted spruce in the interior of British Columbia. Can. J. For. Res. 24:594–602.
• Brockley, R.P. and K. Swift. 1990. Interior spruce, Douglas-fir, and western larch fertilizer screening trials in the British Columbia interior. B.C. Min. For., Victoria, B.C. FRDA Memo 129.