25 July 1995 Lincoln Agroforestry Trial Attracts Wide Interest

Domestic and international interest in Lincoln University's agroforestry trial remains high as the pinus radiata trees enter their sixth year in the ground on the six-hectare experimental site near the campus.

Research projects associated with the trial range over many areas from the trees ' root systems to their crown and canopy architecture and the fundamental matter of their competitiveness in a pasture/grazing regime.

Specific projects recently initiated include joint work with the Forest Research Institute on nutrient sourcing and storage in relation to pruning and other tree management activities and a look at the use of computer modelling in relation to the water balance between trees and pasture.

The agroforestry trial involves pinus radiata trees planted in 1990 with six different pasture covers underneath. Five genotypes of Pinus radiata are represented in the trial which is concerned with studying the competition processes between the trees and the under-storey pasture treatments.

"We're looking at the nutritional and physiological 'whys' and 'hows' to complement data which has already been gathered from the trials of others on the viability or combining trees and pasture," says Dick Lucas of Lincoln's Plant Science Department.

"It's already known what will happen when you put the two together, but with our trial we're trying to explain how it happens."

The Lincoln trial has a number of unique aspects – it's the only one in New Zealand in a dry environment, it's the only one using a range of different pasture covers, and it's the only one using different genotypes of pine tree.

Earlier this year the site was visited by 120 tree physiologists associated with the International Union of Forestry Research Organisations. They were in New Zealand on a Summer Travelling Workshop and Lincoln staff showed them around the agroforestry trial.

Its size and scale impressed them. Many were used to having to work in remote stands of forest far from their institutions, but at Lincoln here was a controlled experiment taking place on a discrete block of land close to the University with all of its laboratory and backup facilities.   

Ian Collins, Journalist, Lincoln University, Canterbury, New Zealand.