What is Topsoil
The surface layer of the surface remains completely exposed, and the drops of rain falling at high speed disintegrate the soil aggregates from the surface. On a variable thickness, the surface soil layer is sprayed, compact, with much-reduced permeability. This part of the soil is known as the topsoil.
In this state of the topsoil precipitation or irrigation water infiltrates very slowly and the amount of water stored in the deeper layers is low. Unfiltered water in the soil pores and then is lost by direct evaporation on flat surfaces or leaks and causes erosion on inclined surfaces. By working with the harrow, the cultivator, etc., the surface layer of soil that becomes compact by the mechanical action of the water in the rain rises again, but it becomes compact again after the rains that fall after the work.
A layer of organic matter at the surface of the soil removes the negative effects mentioned. This vegetal cover may consist of straw or stalks of crushed corn, undesired litter, peat, etc. The vegetal cover can also be grown from among the crop rows. This latter cover is called “live”, unlike the first one, which is called “dead”. The raindrops first fall on the vegetation layer and then, with the slowing down velocity, infiltrate into the soil. Surface soil aggregates are no longer decomposed, no compact waterproof layer is formed, and water is infiltrated in large quantities. This is how large amounts of water accumulate in the deeper layers of the soil.
Topsoil And Water Storage
How much the protective layer helps to store water in the soil can be found on a lush soil with a 4% slope and covered with straw: in the rainfall range of 389.3 (open field) and 406.3 mm the water absorbed in the soil is 159.2 mm (open field) and 395.7 mm respectively (straw covered with straw) and the water leaked to the soil surface is 230.1 mm (open field), respectively 10.6 mm (field covered with straw). Here, the water leaked to the surface of the soil is about 22 times higher in the case of the open field, compared to the water lost to the soil surface in the case of the straw-covered with oak.
On the other hand, the vegetation layer greatly reduces the loss of water by direct evaporation, because a saturated atmosphere of vapors is created in the vegetation layer, interposed between atmospheric air and the damp layers of the soil. The most significant effect of the protective layer is recorded on the sloping land. It is understood that the crops obtained on the slope lands covered with vegetation layer are higher.
In corn crops, after the sowing, more and more straw was applied, and the yields were higher, depending on the amount of straw between the cornrows. The surface layer of the soil covering the space between the corn rows partially combats the weeds. Weeds sprout under this layer, but many die out of lack of light. Those appearing on the surface can be combated with herbicides.
In the latter case, maintenance work is minimized. By reducing maintenance work, soil structure is maintained and labor productivity is increased. The plant protection layer, after 2 or 3 years of use, is completely buried and replaced with a new one. Soil embedded in the soil increases the supply of organic matter.
But not only the “dead” vegetal layer can serve as a protective layer, but also a “living” vegetable layer consisting of plants that grow in the time from the harvesting of the pre-plant and until it resembles another agricultural species. From the experiments performed, it was found that if corn is cultivated as the main plant after itself, then, as soon as the maize is harvested, the autumn is planted (vetch + rye) and grows in autumn and spring, and before sowing another plant agricultural is incorporated into the soil. It is possible to insert the “live” vegetable layer also in the case of maize if it resembles red clover rows or another plant after the last piglet. The red clover covers the surface of the soil until the soil is prepared for the next spring crop.
What Is The Best Depth To Plant With Topsoil
Cultivation of plants with “live” vegetative layer is possible only in areas with high humidity during the summer or in areas where crop irrigation is applied. In order to obtain a richer vegetable mass of clover or other crop grown between corn rows, additional chemical fertilizers may be applied.
By maintaining the soil layer on the soil improves the soil structure, the content of organic matter in the soil layer of 15 cm improves (doubles) and the nitrogen content increases proportionally with the amount of vegetal layer. The harvests were higher than those obtained without a vegetal layer or vegetation layer buried each spring with the plow at a depth of 12-15 cm. In all the experiments carried out, quite large amounts of nitrogen were used, both in the untreated control parcels and in the parcels with protective vegetation layer.
Organic matter, rich in carbonates and particularly in cellulose, needs to accelerate the decomposition of additional amounts of nitrogen. The use of high doses of nitrogen also helps to form a large amount of organic and underground matter in cultivated plants. This solves a problem of special importance for agriculture, namely maintaining the content of organic matter at a high level and, indirectly, preserving the favorable physical and chemical characteristics of the soil. Accumulation of organic matter in soils is primarily a problem of nitrogen.
In order to keep the protective layer “dead” as much as possible on the surface of the soil, it is necessary to do all the work with other agricultural tools than the ones commonly used. Instead of the usual plow that turns the furrow and binds the vegetal remains, cultivators can be used that mobilize the soil in the depth without the burial of the surface layer of vegetation.
But the active parts are different. Some of them may be similar to triangular-shaped “goosefoot” pieces, but with long wings or strong blades. By working with such agricultural machinery, after four consecutive works, 50 to 75% of the vegetal remains remain on the surface. The depth to which this type of agricultural machinery is working is 8-15 cm. To prepare the soil for autumn sowing, two or three works with such cultivators are required. You can also use deep-grain scraper plows or plows that work and mobilize the soil without turning it back.
The active parts are chisel-shaped, with a thickness of 5 cm and spaced apart at about 25 cm. Working with these cogs, 50 to 75% of the vegetable remains remain after two consecutive work. Often, the soil worked under the plant layer remains too loose and the seeds can not germinate uniformly. In these cases, a starter harrow is used, which removes the soil but without crowding the straw and burying them. The sowing of strawberries is done without much weight in the soil covered with a vegetal layer.
Before each seed drill, colter has attached a disc that removes the plant layer on a small portion in front of the colter. There is a strip of soil without a vegetation cover in which the seed is inserted and the vegetal layer remains between the rows. After each tube of the sowing, a small roller is attached, which establishes a more intimate contact between the soil and the seeds.
For plants that are sour, the same is done, using discs or rat-like devices that run through the sowing colters, you can use one of the best garden tiller for the job. For the maintenance of the hoeing, crops are used cultivators with active pieces, goosefoot type, which feeds the soil between the rows under the vegetal cover. The breeding operation is only attempted once or twice, and the weeds that appear to be destroyed by herbicides. By the above, the vegetation cover fulfills its main functions of storing and preserving water in the soil and removing (as much as possible) the phenomenon of erosion.