Protection and recovery method

Abstract

The purpose of the invention is to prevent eutrophication caused by substances from soil layers (10) entering our water bodies and ultimately the sea (7) through a new protection and collection method. The invention aims to stop residual substances dissolved from fertilizers applied to the soil from being carried with water through the soil layer (10) into water bodies and the sea (7). The concept involves digging a trench (4) extending down to clay / moraine (15) or a similar soil formation, lined with a fabric barrier (3) and filled with absorbent material (6); if necessary, a deeper trench structure (17) is excavated. The trench walls are lined with water-permeable or impermeable fabric barriers (3), with the width of the filling opening maintained by a cross-shaped support structure (5) or equivalent. A machine (1) is used to unroll the fabric barrier (3) from a reel (2) into the trench (4) and to fill it with absorbent material (6) via a filling pipe (9) from a trailer (12). One method near streams (11) or the sea (7) combines barrier materials, especially when the soil layer (10) is subsurface-drained (13) and water movement is high. The approach uses a water-permeable fabric barrier (3) on the drainage side and a water-impermeable fabric structure (14) toward the sea (7), directing water into one or more curved trench structures to prevent residual substances from reaching the sea (7). During rainfall, to prevent excessive water from entering the absorbent material (6), the trench (4) is covered with a special cover (16).

Description

[0001] PROTECTION AND RECOVERY METHOD

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a protective method for preventing water eutrophication as defined in the preamble of claim 1.

[0004] BACKGROUND OF THE INVENTION

[0005] It is known that the nitrogen- and phosphorus -rich fertilizer, commonly used to promote the growth of grain and other crops, gradually dissolves over time when spread on fields, and that the portions of the fertilizer not absorbed by plants seep through porous soil layers down to clay, moraine, or similar strata, and eventually into water bodies. It is also known that the amount of water from melting snow or rainfall determines the rate at which the fertilizer dissolves, and that any substances left unused during the growing season are carried from the soil by water into rivers, lakes, and ultimately the sea. As a result, these dissolved substances cause abnormal growth in aquatic environments. Eutrophication leads to a strong suffocating effect on seabed vegetation, the death of bladderwrack, and, over time, the disappearance of fish food sources and spawning grounds. Consequently, fish populations decline, and net fishing becomes more difficult as large masses of vegetation, formed on the seabed and carried by sea currents, get entangled in nets - especially in archipelago conditions. It is known that lime, gypsum, and willows planted along shores have been used in attempts to reduce the impact of fertilizers. However, gypsum (calcium sulfate) is not suitable for agricultural drainage areas. These methods have aimed to remove or bind fertilizer residues and thus prevent the eutrophication of our waters, but the question remains whether their effect is sufficient to eliminate the massive marine problem in the Baltic Sea, where humusrich water is also considered a pollutant. Against this background, new types of solutions are needed to prevent eutrophication, particularly in our archipelago, and to address the problem as a whole.

[0006] PURPOSE OF THE INVENTION

[0007] The aim of the new invention is to provide a preventive solution to stop substances that cause pollution from entering our water bodies and to prevent excessive eutrophication of the sea.

[0008] SUMMARY OF THE INVENTION

[0009] The purpose of the invention is to prevent residual substances, dissolved from fertilizers applied to agricultural soil during sowing, from being carried by rainfall or melting snow into water bodies and ultimately into the sea as pollutants. The concept involves digging a trench down to clay, moraine, or a similar soil formation, the walls of which are lined with one or two compatible fabric-like barriers, such as polypropylene or similar material unrolled from a reel. The width of the filling opening of the fabric barrier is intended to be maintained by a cross-shaped support structure. The installation of the fabric barrier is designed to be carried out using farm machinery.

[0010] The trench is to be filled with an absorbent material that best captures fertilizer residues and can be replaced. The filling material must be porous and highly water-permeable, while allowing sufficient time for fertilizer residues to bind to the absorbent before it is replaced. The goal is to recycle the captured residues for agricultural use, thereby also achieving economic benefits. Legally and for environmental protection reasons, fertilizer application rates have been reduced. However, this has reached a point where crop yield and quality — and thus farmers’ income and profitability — are affected. There is a need and desire in agriculture to use more fertilizers to achieve optimal yields without promoting eutrophication of water bodies.

[0011] Considering the additional fertilizer requirements in farming and their economic impact, the aim is to recover fertilizer residues from the absorbent material through industrial separation and recycle them for agricultural use. At the same time, nature is protected by preventing nutrients from reaching and enriching water bodies. Equipment such as a trailer equipped with a filling pipe can be used for filling and emptying the trench.

[0012] It is clear that if the efficiency of residue recovery improves by digging deeper than clay, moraine, or similar formations, nothing prevents deviating from the original concept. Among the alternatives, the idea is to use fine sawdust, a by-product of the wood industry, as the absorbent material, as it is inexpensive, widely available domestically, and easily replaceable. Near the shore, where water movement is partly high due to drainage, one method is to use a special fabric barrier system. In such a case, the wall on the drainage side is water-permeable, while the wall facing the shore is impermeable, slowing the flow of water filtered through the absorbent and extending the absorption time before the water reaches one or more curved trench structures filled with a large amount of absorbent material before entering the sea. During rainy periods, to prevent the absorbent from becoming oversaturated, it is not excluded that the trench should be covered both in width and length.

[0013] The invention is not limited to the examples presented above; many modifications are possible as long as they remain within the inventive concept defined by the patent claims.

[0014] LIST OF DRAWINGS

[0015] The invention will now be described in detail with reference to the accompanying drawings, in which:

[0016] FIG. 1 shows a side and top view of the basic functions of the drainage system.

[0017] FIG. 2 shows a side and top view of the basic drainage functions and the method for filling the fabric barrier.

[0018] FIG. 3 shows a cross-sectional view of the principle of operation of the fabric barrier filled with absorbent material placed in the trench within the soil layer.

[0019] FIG. 4 shows a top view of a subsurface-drained field area near a stream and the sea, as well as the fabric barrier filled with absorbent material.

[0020] FIG. 5 shows a special arrangement for fields located near water bodies in different configurations.

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] FIG. la illustrates, in a side view, a fabric barrier (3) being unrolled from a reel (2) by a machine (1) into a trench (4) down to clay / moraine (15).

[0023] FIG. lb illustrates, in a top view, the machine (1) unrolling the fabric barrier (3) from the reel (2) into the trench (4).

[0024] FIG. 2a illustrates, in a side view, the machine (1) unrolling the fabric barrier (3) from the reel (2) into the trench (4) down to clay / moraine (15). The figure also shows a cross-shaped support structure (5) for maintaining the width of the barrier opening, and a filling pipe (9) placed in the trailer (12) of the machine (1) for adding absorbent material (6).

[0025] FIG. 2b illustrates, in a top view, the machine (1) unrolling the fabric barrier (3) from the reel (2) into the trench (4), as well as the cross-shaped support structure (5) of the barrier (3).

[0026] FIG. 3a illustrates, in cross-section, a deeper trench structure (17) dug below clay / moraine (15) near the sea (7), and the cross-shaped support structure (5) for maintaining the barrier opening.

[0027] FIG. 3b illustrates, in cross-section, a deeper trench structure (17) near the sea (7) filled with absorbent material (6) inside the fabric barrier (3). The figure also shows the cross-shaped support structure (5) and a cover (16) intended to prevent rainwater infiltration.

[0028] FIG. 4a illustrates, in a top view, a subsurface-drained (13) field area near a stream (11) and the sea (7), showing the soil layer (10). The figure also shows the cross-shaped support structure (5), the trench (4) filled with absorbent material (6), with a water-permeable fabric barrier (3) on the drainage side and a water- impermeable fabric structure (14) on the shore side.

[0029] FIG. 5a illustrates, in cross-section, a trench (4) filled with absorbent material (6) extending down to clay / moraine (15) near the sea (7), with walls lined with different materials: a water- permeable fabric barrier (3) on the drainage side and a water-impermeable fabric barrier (3) on the sea side. The figure also shows the cross-shaped support structure (5) for maintaining the barrier opening.

[0030] FIG. 5b illustrates, in a top view, a trench (4) filled with absorbent material (6) near a stream (11) and the sea (7), lined with a water-permeable fabric barrier (3) on the drainage side and a water- impermeable fabric structure (14) on the sea side. The figure also shows a partially water-impermeable curved structure intended as the trench end.

[0031] REFERENCE NUMERALS IN THE DRAWINGS

[0032] 1 - machine

[0033] 2 - fabric barrier reel

[0034] 3 - fabric barrier

[0035] 4 - trench

[0036] 5 - cross-shaped support structure

[0037] 6 - absorbent material

[0038] 7 - sea

[0039] 9 - filling pipe

[0040] 10 - field

[0041] 11 - stream

[0042] 12 - trailer

[0043] 13 - subsurface drainage

[0044] 14 - fabric structure

[0045] 15 - clay / moraine

[0046] 16 - cover

[0047] 17 - deeper trench structure

Claims

AMENDED CLAIMS received by the International Bureau on 17 February 2026 (17.02.2026)1. A method for binding eutrophying residual substances, nitrogen and phosphorus, dissolved from fertilizers applied to agricultural land and carried with meltwater or rainwater through soil formations down to clay or moraine, and for protecting waters, characterized in that a fabric-like protective structure, comprising a water-permeable side facing the field and a water-impermeable side facing the water body and intended to be filled with an absorbent material, is lowered into a trench excavated in the shoreline area of the field, covering the soil layers comprehensively. The structure slows down the flow of water and binds dissolved residual substances, thereby preventing them from entering the water body.

2. The method according to claim 1, characterized in that on the water-body side of the trench structure, one or more curved, stepwise arranged trench structures containing a large amount of absorbent material are applied to further slow water flow, bind residual substances to a minimum level, and prevent nutrient load from entering the water body.

3. The method according to claim 1, characterized in that a cross-shaped support structure maintains the width of the filling opening of the fabric-like absorbent structure, thereby enabling efficient filling and structural stability.

4. The method according to claim 1, characterized in that the accumulation of residual substances carried by water is prevented by excavating deeper than the clay or moraine layer and leveling the bottom of the trench, thereby improving water flow and the collection of residual substances into the absorbent material.

5. The method according to claim 1, characterized in that a reel equipped with a fabric-like protective structure manufactured according to the depth of the trench forms, when lowered into place with a work machine, a protective structure corresponding to the adjustable trench configuration.

6. The method according to claim 1, characterized in that by collecting the residual substances into the absorbent material, it becomes possible to increase fertilization in cultivation as needed to improve growth and yield, while the recovered absorbent material can be reused as a soil-improving agent for the field.

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