In the mid-nineties, Letitia and I lived in Chile for a couple of years. I worked with a Chilean forestry company called Forestal Bio Bio based in Concepcion and amongst my tasks I researched eucalypt plantation silviculture. The Chileans have been growing eucalypts for well over 150 years and regard them as native!
I discovered an excellent planting technique that, while labour intensive, was viable to use in wide scale planting where wages are low. The SIPCO planting system recognizes that maximum tree growth and minimum planting shock is achieved by thorough and immediate connection of root hairs with soil particles.
Firstly, dig your hole and create a tilth in the bottom of the pit. Add a palmful of phosphorous fertiliser (no nitrogen at this stage as it will burn the roots) and a capful of water retaining gel crystals. Now add water to this mix to create a mud slurry.
Loosen your seedling from its container and gently tease the roots then lower the root mass into the slurry.
Carefully backfill the hole as you would do normally and liberally water in as you go. The SIPCO system then suggests placing nitrogen fertiliser at 4 equidistant points on the soil surface, around the planted seedling at the perimeter of the leaf crown as it would project onto the ground. Teesh and I usually mulch well and create a small soil barrier to catch in incoming water.
I’ve used this system during the droughty and difficult growing periods in Queensland and generally enjoy seedling tree growth and healthy plants – especially over the drier winter months. Whilst the system is intensive it is ideal for our riparian zone tree plantings.
Recently, I had the opportunity to re-visit some Eucalyptus nitens (Shining gum) plantations planted by the Shell Company at Monte Aguila in the Andes foothills 20 years ago using SIPCO. The wood quantity per hectare was approximately 1,000 tonnes and the growth rate was almost 200 times our best natural, wet sclerophyll gum tree forests! Not a bad rap for this Chilean planting technique…
Incidentally, some of my forestry colleagues recommend dropping a Confidor pill into the mud slurry in the planting hole…for a period of systemic pesticide protection.