Here in Spain arable land often gets left fallow, which is to say left bare for a year to rest from the ardure of producing a crop so that the land can recover. Maybe minerals that will be usefull to crops iron and calcium will have time to dissloved off the mineral part of the earth earth and so at be dispostion of a new crop. The roots of the past crop will have time to rot in the soil and provide nitrogen for the next crop and the pests that like that crop will die from lack of food.
That land
should be left bare to rest is especially common here on modern farms, this mean acres and acres of land left bare every year which mean wind erosion and probably water erosion of the soil on the feild and also a lot of land that is not covered in plants fixing
carbon and now with our global warming problem we need as many plants as possible fixing the carbon in the air, as carbon sinks. In science a thing is called a sink if it takes another thing out of circulation for ever or for a while if the carbon is part of a plant body it is prevented from becoming a gas for a while and if a plant degrades in the right way the carbon that made up its body stands a chance of being covnerted into a humnic acid molecue that holds a certain amount of carbon atoms in it or if it does not rot in the soil, of simply becoming part of the soil long term instead of breaking down as in peat.
I post a photo of feild of land left fallow, possibly a feild that a short time ago was covered in the juniper trees that you can see in the slopes above the feilds. The junipers are the juniperus oxycedrus a hardy tree that grows on dry and soiless land and restores it. They are beautiful and they must hold a lot of carbon and as wooods increase rainfall but many bits of wood like this are disappearing to make way for wheat feilds and for olive grooves.
As olives are severly prunned they provide little shade and as the the earth is left bare at the foot of the trees the ground is not only exposed to the sun because of the small head of these trees but also because of lack of ground cover and also lack of ground cover exposes the soil to heavier erosion from wind and rain than the soil would suffer from if it were covered, so we can't pretend olives are a good substitue for the junipers and hardy mediteranean oaks quercus coccifera, that before lived on this land.
Woods of encinas, evergreen oaks are also being pulled up to make more room for wheat.
The results are that some rains leave the cars in Madrid covered with a fine dust which from the reddish or sandy color of it must be earth or clay from spanish feilds, the legend is that this dust comes from the desert but as there are so many fields of bare earth around and closer to madrid than the Sahara it is hard to believe that this is not the dust they are losing from their own fields.
A photo of clay rain drop smears on cars in Madrid.
Third photo.
In all fairness I have to put in this bit about the traditional farming in Spain here. The sheep are taken to eat the stubble, stubble is a
staple in traditional farming of much live stock here in summer Cesar Sanchez Fuentes, "La Encina en el Centro y Suroeste
de españa".
Straw is also used as feed for the hardy Spainish live stock. Tthey are taken to feed on hte stubble and by so doing seed it with the seed in there heces and so you get the feilds left fallow that aren't bare but full of pasture plants. in the photo different strips of land are different some the color of the young growing wheat and others of land covereed in pasture plants. of pasture.
I have walked the feilds full of pasture plants and i have photoed some of the plants growing in them.
I have both read about sheep being used to seed land and talked to an agricultural expert about it without having asked all the questions on the topic that i should have asked.
If you ever see sheep on a feilds of stubble near the road stop the car, the noise they make munching crisp straw stalks is great, like rain.
I dont know the particulars of how sheep are used to reseed the land with the seed they have eaten in pastures, by which i mean i dont know how they time when to take them to eat from places with lots of seed and how long afterwards they take them over land they want seeded with the seed that manages to go through the sheeps gut without getting destroyed, that that escaped being muched in their gums i suppose.
Feeding seed to sheep is an easier way of making fukoaksa's seed balls than the one he uses.
These two following bits of information are all I have to go on on the subject.
There was a tradition i have read about of leaving the sheep the night of special feilds, those you want for arable land, instead of taking them to the stables, they are kept the night on these feilds to manure the feild and so to enable the owner to get a better crop off it.
I did once find the shepherds all coming home in the evening and taking the sheep through the stubble, one shepherd after another, i had to hurry with my photo of the shepherd i then new best, the photo is not in this lap top , as the next shepherd wanted to move onto the field. Maybe this is the method they use to get the sheep to seed the feilds with pasture plants, they to take them over the stubble in the evenings after a day on the pastures.
This system is ecological the wheat feilds are not left bare and there is pasture on the feilds for the live stock.
Traditionally the wheat is cultivated in the flat lands by the village and where the land slopes up a bit, as you can see in the photo, are woods of juniperus thurifera and maples, the ones here, arce de montpellier, are a good forage plant browse plant. The leaves of the junipers are also eaten, the sweeter ones, it is said some junipers have less bitter leaves than others of the same species. The juniper trunks are what the beams of the houses are made of in all the houses that conserve their traditional beams so htis sylvo pastural tradition is a buildign material pastue one.
I think that the feilds have been cultivated so long that flat area has extended into a wider valley of flatness than it probably originally was. In a next door feild the feild has worn down the earth between rock faces so it is bordered by precipices The feilds run through the hills like a river.
This photo is of what could be a a museum as well as a still in use bit of old sylvo,
i have p0ut in another photo of a shepherd on a ploughed feild the bits of wood here used to take up more of this land the wood is being nibbled away at to increase the rom for wheat. agro, pastoral farming practices.
agri rose macaskie.