Fundamentally large-scale monocultures are inefficient because they require large scale external inputs. When the overall cost of these inputs (transportation, source-site damage, energy inputs, requisite equipment, etc.) are considered in aggregate, the approach does not make sense economically. Obviously, it is also unsustainable.
I believe a sustainable, long-term agriculture would include in its design the following features: multi-crop/intercrop by design (ecosystem vs. monoculture), reduction of emphasis on uniformity, iterative rather than total harvesting.
Perhaps the main issue with such an approach is currently harvesting technology. Densely interplanted crops may be hard to access and thus hard to harvest. And yet, because they should tend to require less external inputs, be more resistant to pathogens, and provide healthier soils, improved water retention, reduced wind exposure, and multiple crops on the same land, there should be a budget for this.
I believe a sustainable, long-term agriculture would include in its design the following features: multi-crop/intercrop by design (ecosystem vs. monoculture), reduction of emphasis on uniformity, iterative rather than total harvesting.
Perhaps the main issue with such an approach is currently harvesting technology. Densely interplanted crops may be hard to access and thus hard to harvest. And yet, because they should tend to require less external inputs, be more resistant to pathogens, and provide healthier soils, improved water retention, reduced wind exposure, and multiple crops on the same land, there should be a budget for this.