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AssigneesAltalanos Iparfejlesztesi Rt., Vizepitooipari Troszt
InventorsOszkar Libor, Gabor Nagy, Tamas Szekely, Rudolf Mester, Kalman Kazareczki, Tibor Muller, Jeno Kiss, Zoltan Saghi, Adam Hosszu
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The present invention relates to a method for producing a closing layer which improves the water and nutrient retention of soils, particularly of sandy soils, characterized in that a layer of clay mineral/polymer gel capable of binding and releasing water in a reversible manner is introduced into the soil, preferably 20-60 cm below the soil surface, in such a way that a clay mineral is reacted either before or after or during activation in the presence of water, with 0.5-30% by weight, calculated for the weight of the clay mineral, of one or more water-soluble polymer capable of reacting with the clay mineral, the water content of the resulting gel is adjusted either before or after or during the reaction to a value at which the resistance of medium of the gel is at least three times higher than that of a polymer-free suspension containing the same amount of the clay mineral, if a non-activated clay mineral has been applied as starting substance, the clay mineral is activated with an alkaline activating agent after reacting it with the polymer, and, if desired, further amounts of a water-soluble polymer, one or more water-insoluble swelling xerogel capable of at least 100% water uptake and forming swollen particles less than 1 mm in diameter and/or one or more chemical for agricultural use, preferably a plant nutrient, a fungicidal substance acting against soil-borne fungi and/or a plant growth increasing substance, is added to the gel either before or after or during the reaction with the polymer, and/or, if desired, the gel and the non-reacted polymer molecules are cross-linked with an aldehyde, and finally the thus-formed gel layer is covered with a soil layer.
A process for improving the water and nutrient retention of soil for agriculture, which comprises forming a barrier layer of a clay mineral-polymer gel at a level under the surface of the soil, or forming in situ at a level under the surface of the soil a moisture barrier layer that can be penetrated by the roots of plants, said barrier layer being formed from a gel that is the reaction product of a clay mineral and a water soluble polymer that can enter into a chemical reaction with said clay mineral, wherein the clay mineral-polymer gel is formed by mixing in the presence of water, at said level under the surface of the soil, an activated or nonactivated clay mineral, with one or more water soluble polymers adapted to react with the clay mineral, adjusting the water content, activating the clay mineral if a nonactivated clay mineral was employed, and if the barrier layer was formed while uncovering the level under the surface of the soil, then covering the uncovered part of the gel layer with soil.
Dependencies are inferred from the claim text.