As we develop our farm plan, we’re incorporating the philosophies and practices of organic agriculture, agroecology, Holistic Management, silvopasture, agroforestry, applied ecology, and keyline design, to frame our vision of a future for farming that is resilient and regenerative. One of the tools and practices we’ll be using is the keyline plow, a tool that is utilized globally for regenerative and conservation agriculture.
Soil is the source of health for all the plants and animals we raise on the farm. Therefore, the keyline plow is an important tool in the Farm’s regenerative practices that we will use to help improve the infiltration and drainage of water through the soil and to eliminate soil compaction in our fields and pastures.
The first thing to understand about how the key line works to help drain and infiltrate water through the soil is that water naturally wants to move through the landscape. Water will always move at 90-degrees to the contour of the land (i.e., water always moves downhill) from the ridges to the valleys. This is why valleys are green or even boggy in some areas and ridges are dry and can sometimes become eroded. The goal with keyline is to help evenly disperse water through the landscape, so to accomplish this the keyline plow is used to make furrows following parallel lines in the landscape that we chart using a topographic map so that the furrows move from uphill in the valley to downhill toward the ridge. One way to picture this is that the furrows are like miniature canals. When it rains, water will fill these little canals and flow from uphill in the valley to downhill toward the ridge, instead of moving straight downhill into the valley. In reality, a drop of water that falls in the center of the valley is not going to travel all the way toward the ridge because the water will be absorbed into the soil well before it reaches the ridge. However, it will move toward the ridge a few inches or more depending on the saturation of water in the soil. If every drop of rain moves a few inches toward the ridge, then there will be a net result of more hydration toward the ridges instead of away from the ridges.
When we till with the keyline plow it also creates deep furrows that loosen the soil and break up compacted areas beneath the soil surface without turning the soil. This minimal disruption of the soil layers helps preserve the natural soil structure and biology allowing deeper infiltration of water and oxygen. When oxygen can get deeper into the soil, and water infiltrates more evenly, then beneficial soil life can move deeper and deeper into the soil, even to the subsoil level. When beneficial soil life reaches the subsoil level, then over time, the subsoil will eventually turn into topsoil. This process is much like the natural processes that built soil over millennia.