Can you please advise me whether it makes sense to dig swales on countour of sandy hill? Rain water sinks in the hill very fast, I have never seen it flowing downhill really. The hill has only some poor grass vegetation and a few scattered pines, and the purpose of swales would be to encourage other vegetation. My preference would be to plant a hedge along swales - be it blackthorn, siberian pea shrub, pears, whatever thorny and hard to pass. I'm limited to manual labour, so the swales cannot be very deep or wide.
Another question is what to use to fill the swale - I've figured that when filled with organic matter it will promote plant growth along the swale and will hold moisture.
I do not have a source of rich soli, all is sandy, so I'm wondering where to plant - the berm would be a poor sand (no good) - does planting directly in a swale work? Sand under it still provides perfect drainage in my opinion, but I'm really not sure if it all makes any sense.
From your post on another thread I checked to see what you have been doing and found this question was unanswered.
On my section of sandy fast draining south slope the horses and goats that used to be on the property had pawed out a hole to dust themselves. I decided to use it for a burn pit. Around and below it became a green oasis.
Apparently the ashes supplied the nutrients to spur vigorous growth and also provide clay like particles and charcoal that slowed down and retained the water during the winter. The increasing root mass then took over so that each year it stays green longer into the summer.
Wood ash from burning in place or from heating and cooking is an effective remediation for a sandy hill that drains to fast to support vegetation.
Very interesting, thanks Hans Quistorff. I use up all ashes from my wood stove in a garden but I do have plenty of pine trees that need to be thinned.
On the other hand, a previous owner created a pile of pine branches and then burned it. In this place nothing was growing for many years. But it has been not in a pit, just on slope.
What is the slope of the hill? There is a technique called SALT (Strategic Agriculture Land Technology) that might be a possibility for you. It usually is applied to steeper slopes (eg. 20% or above), but can work on more modest ones too.
Basically, you plant double rows on contour of a fast-growing legume - Lucaena, Glyricidia (Vetiver grass works too, but is not a legume). The rows are about a meter apart and the trees are planted very close (no gaps). You trim the trees like a bush and toss the nitrogen-rich cuttings above the rows.
Plant cover crops above the rows to increase biomass. You will build soil. The rows will serve to trap wind-blown debris. Eventually, you will wind up with a system of terraces, without needing to dig a shovel of dirt.
For steeper slopes, the rows also work to prevent water erosion, but it does not seem like you have that problem. In addition to cover crops, you can plant fruit or nut trees above the rows, or plant vegetable crops, or both.
If you see no/hardly any run off, it is maybe better to plow your swales.
I have never tried it myself before but if I would get a sloping piece of land in my area, that is what I would do (they tend to make white glass from my sub-soil )
The burning could work, but bringing in ashes from your cooking fire might also do the trick and requires probably less kgs of material transported. Maybe even make a very rough compost with wood chips (or other material) and ashes?
My plan of attack (I have one parcel that has 2m slope on 50m) is to plant asparagus in the middle
and for some reason, unknown to me, the post didn't went online so now it's maybe a little lame but anyway, it's a different method again
a previous owner created a pile of pine branches and then burned it. In this place nothing was growing for many years.
Burning can sterilize already lacking soil building organisms. Therefore charcoal and ashes need to be inoculated with soil building organisms. Thinking more about it after each time I burned I began piling new pile of vines and branches on top of the ases which would accumulate for months before burning again.
Burning and adding ashes are disturbances. In permaculture disturbance is used as part of a plan to produce a desired result. Unplanned disturbance can produce undesirable results. I happened to observe desired results from an unplanned disturbance but to replicate it needs a plan that incorporates the factors that produced the desired results.
You have branches and sand; come up with a plan that combines them in a way that holds water and supports root growth which in turn will hold more water allowing more growth creating a surplus.
Many thanks everyone for your input.
Originally I have posted here three years ago and during this time I have surely tried a few things. I was trying various strategies, starting from less invasive ones (minimum disturbance, maximum effects) and gradually moving towards more "disturbing" since so far none worked well. Observation leads me to a conclusion that only very heavy mulching might give some effects, but even then, some watering will be required. For instance, hugel beds are a big disappointment, they do not hold water and dry out in summer entirely. I'm thinking about low terraces on contour, made of pine logs, and filled with whatever organic matter I will be able to get. Something like here: https://www.tenthacrefarm.com/2014/10/heres-a-quick-way-to-terrace-a-hill/
It's a pleasure to see superheros taking such an interest in science. And this tiny ad:
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