Wind protection is a long-standing indigenous practice in traditional agriculture of many regions. In attempts to improve or establish wind protection schemes with trees, it makes sense to study the link which can be observed between traditional and relatively recent but promising agroforestry practices. And it makes sense as well to try to quantify phenomena taking place in such traditional and such promising practices alike.
In the case study in Croatia reported here, the farmer requested CCRES to assist in providing the agrometeorological input into the set-up of experiments under conditions in farmers’ fields, with a system of wind barriers with trees, in irrigated crops in Lika Region.
The choice to use multiple tree breaks appears justified by the increase in roughness over a larger area in addition to separate wind break effects, and by the multipurpose use of trees and their products which is economically possible. In larger scale agriculture, where irrigated cash and food crops have to be protected against very strong winds, relatively narrow rows of trees are to be preferred above wider belts as an intercrop or scattered trees or bushes.
As mentioned earlier, where mechanical damage from strong winds is the primary limiting factor, the agronomist member of the team should pay primary attention to phenology, growth and yield parameters and visual or even microscopic observations of actual mechanical damage. This will make it possible to observe differences between unprotected crops and protected ones at different distances from belts.
Whether in strip cropping, in using narrow tree rows or in mixed experiments, cost/benefit ratio determinations are absolutely necessary to understand the proper gain from the multipurpose role of trees and from yield (quality) increases due to the trees or crops applied for protection from wind.
Zeljko Serdar, Croatian Center of Renewable Energy Sources (CCRES)