SU1547723A1 - Method of erosion control of soil on slopes - Google Patents

Abstract

This invention relates to agriculture. The purpose of the invention is to increase the moisture availability of agricultural crops due to a more uniform redistribution of moisture on the slopes, as well as a decrease in environmental pollution by chemical means used in growing crops. On the slope along its horizontal, water retaining trenches are arranged and filled with water-absorbing material. On both sides, stump slots with a zero slope, symmetrically from the trench, are arranged in rows at an angle to the horizontal m of the slope and staggered in such a way that the ends of the mole of one row are blocked in the horizontal and vertical planes of the mole of the adjacent row. The molehills are filled with organic material. 2 Il.

Description

The invention relates to agriculture, namely to methods for the redistribution of moisture on the slopes.

The purpose of the invention is to increase the moisture availability of agricultural crops due to a more uniform redistribution of moisture on the slopes, as well as a decrease in environmental pollution by chemical means used in growing crops.

FIG. 1 schematically shows an example of the method, plan; in fig. 2 - section AA on the fit. one.

Across the slope 1 with horizons 2, approximately parallel to its horizontal are the water retaining trenches 3, filled with water-absorbing material 4, and mole 5, which can be filled with organic material 6, such as straw.

The distance B between the trenches 3 is determined by hydrological calculation from the condition of their interception of the flow formed by melting

snow or rainfall, with the avoidance of blurring water velocities. The depth of the laying of trenches 3 should ensure that the molehills fall into them, i.e.

I, + // 2

(one)

where yat

depth of laying water retaining trenches, m;

H - minimum depth of laying of molehills, m; Hz - maximum bookmark depth

mole

 Based on the technical characteristics of the adopted crooker, the maximum depth of laying of molehills Hi, distance / 2, passed by the mobber during the working body burial from the soil surface to the depth // 2, and the distance /, passed by the mobbler during the working body exit are determined on the soil surface with a minimum depth of laying molehills N,

SP 4 1 3

Yu

OE

determined by the condition of the protection of molehills during the subsequent agricultural processing of the field (the value of Hi can be taken 10-30 cm more than the thickness of the topsoil).

At an angle a to the horizontal m of the slope on the slope, dead-end boneless mole 5 are arranged, which can be filled with organic material 6 to increase the service life and improve water absorption.

a arcsin

l (/ 2 + M

(2)

where a is the angle between the molehill and the horizontal of the slope, degrees;

B — distance between water retaining trenches, m;

t is the width of water retaining trenches, m;

i - slope surface slope.

The angle a is recommended within 45-60 ° from the condition of better interception of the flow, since the experience of designing and building a drainage and collecting network, also intended for this purpose, shows that in general it should be at the smallest possible angle to the horizontal m ( in each case, this angle is determined on the basis of the analysis of specific topographic, hydrogeological, and other conditions). At the same time, the angle between the molehill and the trench is less than 45 ° impractical for technological reasons.

Taking into account that the main flow volume is intercepted by water-absorbing trenches, the goal is achieved at virtually any angle a (except constructively impossible).

When snow is thrown or when rain falls, runoff is intercepted by trenches 3, then it enters mole 5, from which it is absorbed into the soil.

Stagging of molehills in staggered order with overlapping of their ends in horizontal and vertical planes ensures uniform distribution of moisture over the soil profile, and the depression of molehills near water retaining trenches is compensated by the fact that water in these areas is additionally absorbed into the soil directly from the trenches themselves.

Thus, the entire flow volume is distributed in the soil directly on the slope without dumping it into the underlying relief elements.

The method is feasible if the molehills of one row do not fall into the water retaining trench of the next row. In addition, water near the trenches is absorbed into the soil directly from the trenches themselves, wetting the soil for some distance (as the experience of the subsoil wetting shows, this distance depends on the water physical properties of the soil and can be accepted for medium-sized soils equal 0.5-0.8 m, for heavy R and peat 0.8-1.4 m). Therefore, it is advisable not to bring the mole of one row to the trenches of the next row to distance a, which characterizes the soil moisture zone of the trenches. According to the relief conditions, the method will be performed under the condition

ten

(3)

where i is the average slope surface slope

(across horizontals);

a - soil moisture zone of trenches, m; Hz - maximum depth of laying molestones up the slope, m; H - minimum depth of laying of molehills down the slope, m. Formula (3) is valid for any angle a. Indeed, for any value of the angle a (Fig. 1)

/ - / c sina

(four)

25

Then the distance between the trenches

0 2a + l + t (t + 2a) + la-sina ,,.

l - -2 (O)

The average slope of the slope surface (across the contours) and the average slope of the slope surface along the molehill ia are related by

in i-sina.

(6)

In addition, Yag-Hi, Gt-N

,OR

(7)

.rJLDJIJ I.Q.,

Substitute (6) and (7) in (5) and get i (t + 2a) + (H2-Hl)

AT

2i

(eight)

An increase in the parameter B at a given i is impossible, since it is impossible to increase the low frequency and the decrease of H. On the other hand, it is possible to decrease Hz and increase H, that is, in the general case, formula (8) can be written as (3).

In addition to the relief limitations, it is also necessary to take into account the fact that the distance between the trenches should not exceed the distance obtained as a result of hydrological calculations of Br, i.e.

With this in mind, formula (3) can be written as

(9)

B) -Hf / 2 - // i) 21

where Br is the distance between water-retaining trenches, determined by hydrological calculations, m.

Example. The method is carried out on a slope with a slope, 01. The hydrological calculation made, for example, according to the formula of A. N. Kostkov, establishes the distance between the trenches of the m. Krotovyna is performed by the MD-B hopper with a maximum depth of 7 m and a minimum of H of 0.3 m. Trenches of an average depth of 5 m are performed by an ETC-202A multi-bucket excavator with unloading of open ground down the slope, followed by leveling it with a layer of 0.1-0.2 m, trench width, 5 m. (Trenches can also be torn off with any plow trench digger or even a shrub-biological plow, since the cross section shape of the trenches is being influence the implementation of the method. The trenches are filled with a straw layer of 0.2-0.3 m, and then with peat and sand (or their mixture). The distance between the water retaining trenches is determined from the relation (9):, 25

The distance between the water retaining trenches m.

At an angle of 45 ° between the molehills and horizontals of the slope, the molehill length is

In-

2B-2a-t

sina.

, 9 m.

The length of molehills is within acceptable limits. Wandering is carried out by a continuous pass of the mole on the slope with a cut through the middle of the mole of the filled water-absorbing trench. To increase the stability of the molehill and to increase its moisture capacity at the same time as the trenches, they can be filled with organic material, such as straw.

When snow is thrown or when rain falls, runoff is intercepted by trenches, then falls into mole cells, from which it is absorbed into the soil. Intrasoil runoff during pereuv

6

The soil is also intercepted by trenches and molehills (as they are angled to its main direction of movement) and redistributed in the soil profile.

The main advantage of the proposed method is that the moisture is redistributed and accumulates directly on the slope, while by a known method the excess moisture is removed outside the slope - solid molehills, even filled with straw, increase the subsurface drainage, as the straw filtration coefficient is much more soil filtration coefficient. According to the proposed method, the molehills are used to transfer surface runoff intercepted by a water-retaining trench to the soil, as well as to partially intercept the internal soil flow.

ten

15

Claims (1)

Invention Formula A method of combating soil erosion on slopes, including the manufacture of water retaining trenches across the horizontal m of the slope and filling them with water-absorbing material, as well as making rows at an angle to the horizontal m of the slope and filling the molehills with organic material, characterized in that - provision of agricultural crops due to more uniform redistribution of moisture on the slopes, as well as reduction of environmental pollution by chemical agents used in growing crops, molehills Execute dissolved deadlock and with zero bias, placing them symmetrically by trenches on both sides, wherein a wormhole staggered so that the ends krotovinas one row overlap in horizontal and vertical planes wormhole adjacent row. BUT L fug / Aa Fig