Thanks Jeffrey,
I wish my large lips could manage a trumpet but alas....
The primary reason why on the plans that you've probably seen and are referring have relatively straight lines is that its much easier to set out after you've done the design work on the computer. There are usually anomalies in broader scale landscape settings that, if you are going to be true to Keyline geometry, that are best sought on following a good survey.
I should also mention that the appearance of straight lines is softened by the mechanical chamfering of the changes in direction, which on our plans are quite angular, however in reality are smooothed by the passing of the tractor. These are examples of this point:
The cost per tree of surveying, design and set out is not significant. Back in the 90's when we had our full-establishment service, the average cost per tree for all of this accuracy and therefore Keyline integrity was 5-10% of the tree cost. It all adds up, however we continually find that the feedback of clients since then there are savings in water use and fuel use (i.e. row slope angle, easier access and no 'stub rows', dead-ends or multi-point turns), along with productivity and establishment rates. This applies to all manner of timber and non-timber forestry crops on a vast array of very different sites.
Furthermore many of our clients, back then and today, want a symetrical layout that makes the best use of their land — the symetry is both an aesthetic and productivity function. Being able to create maximum canopy diameter, particularly important with broadleaf trees/shrubs, enables one to obtain the highest productivity you can i.e. the bigger the canopy in timber producing species the bigger the trunk diameter AND the same applies to non-timber forestry crops as well where the bigger the canopy diameter the more surface area there is to produce fruits and nuts etc.
This might seem academic to many smaller scale operators or to those that are not that concerned about extending potential — we typically work with people who are concerned with these matters and so as professionals we do what we can to extend the possibilities of as many positive outcomes as we can.
With regards Pro's/Cons – the following index is from the Regrarians Handbook (p.105)
With this we also did a comparison of 3 different styles of layout (p.104-105 of the Regrarians Handbook) on the same landscape with the following total row length outcomes:
Standard Grid: 11.128km (100%)
Keyline Pattern Cultivation: 10.716km (96% of the Standard Grid)
Contours: 9.315km (83% of the Standard Grid)
Thanks,
Darren J. Doherty