This time of year is always dusty. The soil is dry. The air is dry. Farmers harvest the summer crops and turn the soil to plant the winter’s grass. It’s not unusual for a wind to kick up, sending newly-turned soil into the air.
I don’t know how much soil farmers in Canterbury lose this way (they’re also getting soil from the farms upwind and loess blown off the mountains), but I do know that where my back yard meets the neighbour’s field, my property is significantly higher. At least some of that soil is being lost.
Interestingly, there seems to be a place on the neighbours’ farms where soil is being made.
A hundred and fifty years ago, farmers in Canterbury were planting gorse hedges for shelter and fencing. Many of those gorse hedges remain (indeed, they’re hard to get rid of). The original plants are almost certainly long gone, as gorse is a short-lived shrub, but new plants are continuously growing from seeds cast by the mature plants.
It’s quite possible that my neighbour’s gorse hedges have been here since Joseph Price took up the original 5000-acre run number 79 in 1853.
Gorse is dense when pruned into a hedge. New outer growth shades out growth in the middle of the hedge. Thorns and branches fall and form a dense, prickly mass at the base of the plant. Over time, this detritus breaks down and forms soil.
Quite a lot of soil, by the looks of it.
Some gorse hedges were planted on ridges–ditch and dyke, it was called–the farmer dug a ditch to help drain the land, and planted a hedge on the resulting pile of soil scooped out of the ditch. Some hedges were just planted on the level ground. This is how the hedges along my lunchtime walk were planted, but today it looks like they were sown on a tall, narrow wall of soil.
The build-up of soil under the gorse hedges is impressive. In some places, it is as high as my waist. It is most visible where the gorse has been herbicided off to make way for native hedging plants. There you can see how the twisted trunks and branches have caught the detritus and held it in place, even after it has rotted.
How important are these ridges of new soil in a landscape that is losing soil? Probably not terribly important–they cover just a tiny fraction of the landscape–but I find them intriguing, nonetheless. Our agricultural landscapes–as modified, controlled and cultivated as they are–still hold interesting stories.