GB1598913A

GB1598913A - Method and apparatus of applying liquid fertiliser to crops

Info

Publication number: GB1598913A
Application number: GB3176577A
Authority: GB
Original assignee: Ranks Hovis McDougall Ltd
Current assignee: Ranks Hovis McDougall Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-09-23

Description

(54) AN IMPROVED METHOD AND APPARATUS OF APPLYING LIQUID FERTILISER TO CROPS (71) We, RANKS HOVIS MC DOUGALL LIMITED, of RHM Centre, 152 Grosvenor Road, London SW1V 3JL, a British Company, do hereby declare the invention to be described in and by the following statement: TECHNICAL FIELD.

This invention relates to an improved method of and apparatus for applying liquid fertiliser to growing crops.

BACKGROUND ART.

In the intensive growing of crops, it is necessary to apply appropriate amounts of herbicide, pesticide, fertiliser and the like to promote and obtain maximum disease-free growth. Crop spraying has developed rapidly since 1950 to meet the demands of large scale farming and has become highly specialised and mechanized. Conventional crop spraying equipment is normally mounted on a tractor and comprises a reservoir tank con nected to a crop spraying boom from which the liquid is sprayed via jets spaced usually 18 inches apart. Liquid is propelled by a pump which is driven from the tractor engine.

For ground spraying, hydraulic or gear pumps are used and pressures of up to 100 pounds per square inch are common.

The spray boom connected to the tank is usually made of plastics pipe with the spray nozzles tapped off along its length.

Different types of nozzles are used to produce different effects e.g. cone nozzles, fan nozzles, anvil nozzles and the like are all known. The design of these nozzles is such as to disperse the liquid over a wide area by spreading the liquid into a film. This film splits into lateral filaments which in turn break up into droplets of various sizes which fall onto the crop.

For spraying crops with pesticides and herbicides, it is desirable to form a mist of droplets on the plants comprehensively to cover all the leaf surfaces of the plant.

In liquid fertiliser application, however, it is desirable to apply the fertiliser to the base of the growing plant where it is taken up by the soil and thence by the roots of the plants. The application of liquid fertiliser which normally contains ammonium nitrate and urea in low concentration in solution, to the leaf of the plant, can cause "leaf scorch" which reduces the growth of the plant and in some cases can even kill the plant if the application is incorrectly carried out.

Previous methods of applying liquid fertilisers have included the use of pendant dribble tubes which are fixed to the boom nozzle apertures and extend to slightly above the ground. These dribble tubes are normally flexible of rubber or polythene. A disadvantage of this type of application is that the nozzle becomes easily blocked through contact with the plants and the ground. Furthermore, the tubes are easily bent sideways from their path of movement and therefore the application of the fertiliser is irregular.

It is of paramount importance when applying liquid fertiliser to growing crops to avoid "leaf scorch" and it is also desirable that the application of the liquid fertiliser be evenly spread over the ground.

DISCLOSURE OF INVENTION.

According to the present invention there is provided a method of applying liquid fertiliser to the ground, which includes moving a plurality of spaced jet devices mounted on a tractor over the ground at a constant speed, feeding liquid fertiliser to all such jet devices at equal pressure and discharging said liquid fertiliser from each said jet device through a plurality of outlets therein, the liquid discharged from each outlet being at sufficiently low pressure to cause the liquid to form large drops the average size of which is between 200 and 1200 microns and the rate of discharge of the liquid being substantially equal from each of the outlets.

The invention also includes the method as aforesaid in which the jet devices are constructed and disposed so that on being moved simultaneously over the ground, the liquid discharged from any two outlets does not cover the same area of ground.

The invention also includes apparatus for applying liquid fertiliser to the ground, comprising a jet device through which liquid fertiliser may be discharged, said jet device including a hollow body having an inlet for liquid fertiliser, a metering disc having a hole therein said disc being replaceable by an altemative disc to control the rate of flow of the liquid, and a plurality of outlets, the construction of the device and the disposition of the inlet and outlets being such that on a constant low inlet pressure, liquid is discharged from all the outlets at - equal discharge rates to form large drops the average size of which is between 200 and 1200 microns.

The apparatus of the invention also includes a plurality of jet devices as aforesaid mounted in spaced relation for movement over the ground and a common pressure source for feeding fertiliser liquid to the devices at equal pressure.

The apparatus of the invention may also include, in association with each jet device, a one way valve arrangement to prevent dribble and the escape of liquid fertiliser when the spraying machine is stationary.

BRIEF DESCRIPTION OF DRAWINGS.

In order to illustrate the invention, one embodiment thereof will now be described, by way of example only, and with reference to the accompanying drawings, in which: FIGURE 1 is a cross-sectional view through a jet device constructed in accordance with the invention; and FIGURE 2 is a diagrammatic representation of a plurality of jets devices arranged for movement over the ground.

BEST MODE OF CARRYING OUT THE INVENTION.

The device of Figure 1 includes a nozzle body 1 for attachment to a boom 2 and having an inlet passage 3 connected by a flexible tube 4 to a source of liquid fertiliser contained in a tank 5. Housed in the body 1 is a one-way valve 6, the rating of the valve 6 being such as to prevent the flow of liquid fertiliser through the passage 3 when the pressure is lower than approximately 5 psi.

Attached to the body 1 by a union 7 is a T-piece having a bored shank 8 leading to a hollow body portion 9. Between the shank 8 and the valve 6 is a metering disc 10 which chokes the entry of liquid into the hollow body portion 9, the size of the hole therein being dependent on the concentration (viscosity) of the liquid fertiliser to give a desired flow rate. Each end of the body portion 9 is externally screw-threaded to receive an internally screw-threaded cap 11 which holds a tubular member 12 in place.

The body portion 9 has holes 13 drilled therein.

It will be noted from Figure 1 that the inner ends of the tubular pieces 12 terminate at approximately the same positions the location of holes 13 thereby ensuring that liquid fertiliser discharged from the holes 13 and the outer ends of tubes 12 is at equal rates. The bores of tubes 12 should be approximately equal to the diameters of holes 13.

The pressure of discharge of liquid fertiliser from the body portion 9 should be low sufficiently to ensure that the liquid forms itself into large drops so as not to cause "leaf scorch".

As will be seen from Figure 2 the body portions 9 are disposed on the boom 2 at such an angle (alpha) in relation to the direction of movement of the boom 2 indicated at 14, that liquid fertiliser discharged from the jets falls on the ground in different areas thereby ensuring substantially even distribution of fertiliser over the ground.

The construction of jet device in accordance with the invention may be modified from that described above so long as the formation of large drops is ensured and the liquid is discharged from the holes in the jet devices at equal rates.

As will be appreciated, there are several parameters which have to be rationalised to result in effective application of the liquid fertiliser to avoid scorch. These parameters are the spacing of the jets on the boom; the rate of application of the liquid fertiliser; the pressure discharging the liquid from the jets and the speed of movement over the ground. The following table is typical of several tables which may be compiled to achieve a desired coverage in gallons per acre. The jet spacings were 18 inches.

M.P.H.

e 3 1 -4 41/2 5 6 Metering Dise psi 10 15.7 11.8 10.6 9.4 7.8 1 m.m. dia hole 15 19.2 14.4 13.0 11.5 9.6 20 22.2 16.7 15.2 13.6 11.1 25 24.9 18.7 16.8 14.9 1 12.4 M 25.6 19.2 17.3 15.3 12.8 10 30.0 22.5 20.3 18.0 i 15.0 1 m.m. dia hole 15 36.6 27.5 24.8 22.0 18.3 20 42.2 31.7 28.5 25.3 21.1 25 47.2 35.4 31.9 28.3 23.6 71/2 39.8 29.8 26.6 23.8 1 19.9 10 45.5 34.5 30.6 27.6 22.7 2 m.m. dia hole 15 55.8 42.2 37.5 33.8 27.9 20 64.4 48.8 43.3 39.0 32.2 72.0 54.5 48.4 46.6 36.0 The invention provides apparatus for varying the rates of application of the liquid fertiliser from 1} cwts per acre to 4 cwts per acre, or expressed in volumetric terms, 15p galls per acre to 36 galls per acre. This is with using a liquid containing 28 nitrogen.

However, other rates of application can be obtained by dilution.

WHAT WE CLAIM IS:- 1. A method of applying liquid fertiliser to the ground, which includes moving a plurality of spaced jet devices mounted on a tractor over the ground at a constant speed, feeding liquid fertiliser to all such jet devices at equal pressure and discharging said liquid fertiliser from each said jet device through a plurality of outlets therein, the liquid discharged from each outlet being at sufficiently low pressure to cause the liquid to form large drops the average size of which is between 200 and 1200 microns and the rate of discharge of the liquid being substantially equal from each of the outlets.

2. The method as claimed in Claim 1, in which the pressure at which the liquid is discharged from the jets is between 5 and 30 p.s.i.

3. The method as claimed in either Claim 1 or Claim 2, in which the jet devices are constructed and disposed so that on being moved simultaneously over the ground, the liquid discharged from any two outlets does not cover the same area of ground.

4. Apparatus for applying liquid fertiliser to the ground, comprising a jet device through which liquid fertiliser may be discharged, said jet device including a hollow body having an inlet for liquid fertiliser, a metering disc having a hole therein said disc being replaceable by an alternative disc to control the rate of flow of the liquid, and a plurality of outlets, the construction of the device and the disposition of the inlet and outlets being such that on a constant low inlet pressure, liquid is discharged from all the outlets at equal discharge rates to form large drops the average size of which is between 200 and 1200 microns.

5. Apparatus as claimed in Claim 4, in which said metering disc is at the outlet of the body portion.

6. Apparatus as claimed in either Claim 4 or Claim 5, in which the body portion houses a one-way valve capable of preventing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. M.P.H. e 3 1 -4 41/2 5 6 Metering Dise psi 10 15.7 11.8 10.6 9.4 7.8 1 m.m. dia hole 15 19.2 14.4 13.0 11.5 9.6 20 22.2 16.7 15.2 13.6 11.1 25 24.9 18.7 16.8 14.9 1 12.4 M 25.6 19.2 17.3 15.3 12.8 10 30.0 22.5 20.3 18.0 i 15.0 1 m.m. dia hole 15 36.6 27.5 24.8 22.0 18.3 20 42.2 31.7 28.5 25.3 21.1 25 47.2 35.4 31.9 28.3 23.6 71/2 39.8 29.8 26.6 23.8 1 19.9 10 45.5 34.5 30.6 27.6 22.7 2 m.m. dia hole 15 55.8 42.2 37.5 33.8 27.9 20 64.4 48.8 43.3 39.0 32.2 72.0 54.5 48.4 46.6 36.0 The invention provides apparatus for varying the rates of application of the liquid fertiliser from 1} cwts per acre to 4 cwts per acre, or expressed in volumetric terms, 15p galls per acre to 36 galls per acre. This is with using a liquid containing 28 nitrogen. However, other rates of application can be obtained by dilution. WHAT WE CLAIM IS:-

1. A method of applying liquid fertiliser to the ground, which includes moving a plurality of spaced jet devices mounted on a tractor over the ground at a constant speed, feeding liquid fertiliser to all such jet devices at equal pressure and discharging said liquid fertiliser from each said jet device through a plurality of outlets therein, the liquid discharged from each outlet being at sufficiently low pressure to cause the liquid to form large drops the average size of which is between 200 and 1200 microns and the rate of discharge of the liquid being substantially equal from each of the outlets.

liquid flow at very low pressure.

7. Apparatus as claimed in any one of Claims 4 to 6, in which connected to the outlet of the nozzle body is a T-piece having a bored shank leading to a hollow body portion, each end of which receives a screwed cap retaining a tubular member through which liquid can flow, the body portion having outlet holes therein located near to the inner ends of the tubular members and of substantially the same diameter as the diameter of the bore in the tubular members to give substantially equal flow rates therethrough.

8. Apparatus as claimed in any one of Claims 4 to 7, in which the outlets from the jet device are between 50 thou and 150 thou in diameter.

9. Apparatus for applying liquid fertiliser to the ground, including a plurality of jet devices as claimed in any one of Claims 4 to 8 mounted in spaced relation on a boom for movement over the ground and a common pressure source for feeding fertiliser liquid to the devices at equal pressure.

10. Apparatus as claimed in Claim 9, mounted on a wheeled vehicle.

11. A method of applying liquid fertiliser to the ground substantially as herein described.

12. Apparatus for applying liquid fertiliser to the ground substantially as herein described with reference to the accompanying drawings.