Description

Method and apparatus for disinfecting and/or disinfesting soil, in particular agricultural soil

Technical Field

This invention relates to a method and apparatus for disinfecting and/or disinfesting soil, in particular agricultural soil .

Background Art

Methods and apparatuses for disinfecting and/or disinfesting soil, especially agricultural soil, are known in which steam is injected into the soil in order to destroy the infesting organisms, whether animal pests or weeds.

According to these prior art disinfecting and/or disinfesting methods, however, the sterilising steam cannot effectively reach all the parts of the soil that harbour the nuisance organisms. Moreover, the steam injected into the soil does not always produce sufficient heat to destroy highly resistant organisms such as the seeds of certain weeds. As a result, the soil is not always optimally disinfected and/or disinfested, leading to problems for the crops subsequently planted in it. Other known methods involve spraying the soil with a sterilising and/or disinfesting substance. In this case, too, however, the active sterilising ingredient does not effectively reach all the parts of the soil that harbour the nuisance organisms .

Summary of the Invention

Therefore it is provided a method for disinfecting and/or disinfesting soil, especially agricultural soil, characterised in that it causes a sterilising and/or disinfesting agent to be produced in the soil itself.

It is also provided an apparatus for disinfecting and/or disinfesting soil, especially agricultural soil, comprising a supporting frame and means for disinfecting and/or disinfesting the soil characterised in that said disinfecting and/or disinfesting means comprise means designed to enable a sterilising and/or disinfesting agent to develop in the soil itself.

Thus, an optimum and particularly effective disinfecting and/or disinfesting treatment can be applied to the soil.

Other advantageous aspects of the invention are set out in the other claims.

Brief Description of the Drawings

These and other technical characteristics of the method and apparatus according to the invention are clearly described in the claims below, and their advantages will become more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate preferred embodiments of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which: - Figure 1 is a schematic side view of a first preferred embodiment of a soil disinfecting and/or disinfesting apparatus that implements the method according to this invention;

Figure 2 is a schematic side view of a second preferred embodiment of a soil disinfecting and/or disinfesting apparatus that implements the method according to this invention.

Description of the Preferred Embodiments of the Invention

According to one advantageous aspect, it is provided a method for disinfecting and/or disinfesting soil, especially agricultural soil, where a sterilising and/or disinfesting agent is produced inside the soil itself.

More specifically, the method according to the invention causes a chemical reaction that produces said sterilising and/or disinfesting agent in the soil. The reaction is such that the soil comes into contact with ammonia, particularly in the form of ammonia gas.

Thus, an optimum and particularly effective disinfecting

and/or disinfesting treatment can be applied to the soil. Indeed, the sterilising agent, that is to say, the ammonia, is particularly active and its development directly in the soil enables it to be distributed better and more effectively using relatively simple implements to apply the treatment.

The preferred method according to the invention causes a reaction of the following type to take place in the soil:

A + B -> D + NH ₃

where, preferably, A is a compound containing nitrogen, and B is a base.

To obtain this reaction in the soil, a first substance is brought into contact with the soil, said substance being the substance that contains the active component of the sterilising and/or disinfesting agent in contact with the soil and, hence, contains nitrogen in an appropriate form.

In particular, the nitrogen containing substance may be any simple or composite mineral substance, preferably ammonium sulphate,, urea or ammonium nitrate.

The nitrogen containing substance may also be a simple or composite nitrogenous organic substance, preferably natural bone meal, dried blood or hydrolysed epithelium.

The nitrogen containing substance may also be a simple or composite organo-mineral nitrogenous substance.

According to an advantageous aspect, for developing the sterilising and/or disinfesting agent in the soil, a second sterilising substance is also applied to the soil, said second substance being, in particular, a basic substance. More specifically, the second, or basic, substance is preferably calcium oxide, magnesium oxide, magnesian quicklime or potassium hydroxide.

Further, for developing the sterilising and/or disinfesting agent in the soil, a third substance can be applied to the soil in order to solubilize the substances that produce the sterilising and/or disinfesting agent in the soil. Specifically, the third substance, or substance for solubilizing the substances that

produce the sterilising and/or disinfesting agent in the soil, is water.

It will be understood, however, that although this embodiment, where the first and second substances are solid, and specifically in easy-to-use powder or granular form, is especially preferred, according to another aspect, the first and second substances might be provided in liquid form, so as to facilitate contact with the soil or in such a way as to directly fulfil the solubilizing function. In this case, the third substance need not be applied to the soil.

Preferably, the second, or basic, substance is applied to the soil after the first substance, or substance containing the active component, while the third, or solubilizing, substance is applied to the soil after the first and second substances have been applied.

In equally preferable manner, the first substance, or substance containing the active component, the second, or basic, substance and the third, or solubilizing, substance are applied to the soil when the soil is in a loosened up or crushed state. Thus, the reagents come into contact with the soil particles in broken up form and the reacting material can be distributed more easily in the soil. In another imaginable embodiment, one or more of the substances might be applied to the soil before it is loosened up or crushed or to compacted ground, as will become more evident below.

A first preferred embodiment 10 of a soil disinfecting and/or disinfesting apparatus, in particular, agricultural soil, is illustrated in Figure 1.

The apparatus 10, mounted on a tractor 11 to which it is connected by respective hitches 11' , comprises a supporting frame 12 and means for disinfecting and/or disinfesting the soil 9.

Although the illustration shows a tractor-mounted apparatus for disinfecting and/or disinfesting soil, other apparatus designs are imaginable, for example, mounted on any other suitable vehicle or self-propelled.

Advantageously, the apparatus ^~ according to the invention comprises disinfecting and/or disinfesting means which in turn

comprise means designed to enable a sterilising and/or disinfesting agent to be produced in the soil.

Distribution of the sterilising agent in the soil can thus be optimised so that sterilising and/or disinfesting treatment is particularly effective.

More specifically, the means enabling sterilising or disinfesting agent to be produced in the soil are means that can cause a chemical reaction whereby the sterilising and/or disinfesting agent is evolved in the soil. The disinfecting and/or disinfesting means comprise means for making the soil come into contact with a sterilising or disinfesting agent which advantageously consists of ammonia, in particular, ammonia gas.

Ammonia gas, especially when it evolves directly in the soil, provides a particularly strong sterilising action effective also on organisms such as the seeds of certain weeds that are resistant to treatments known up to now.

As illustrated, the disinfecting and/or disinfesting means comprise means for applying to the soil a first substance "A" from which the sterilising or disinfesting agent evolves, and, more specifically, a substance containing nitrogen.

The means for applying the first substance to the soil comprise means 14, in the form of a respective tank, for containing a granular or powder product and emitting means 16 for placing the substance in contact with the soil.

More specifically, the emitting means 16 consist of nozzles designed to let the substance A fall onto the soil. The nozzles 16, which are not illustrated in detail in the drawing, give onto the guard 12' located on the supporting frame and in which or under which a sterilising chamber between the guard 12' and the soil is made. As illustrated, the tank 14 for the first substance is mounted above the guard 12'.

In particular, as mentioned above, the nitrogen containing substance may be any simple or composite mineral, preferably ammonium sulphate, urea or ammonium nitrate.

The nitrogen containing substance may also be a simple or composite organic nitrogenous substance, preferably natural bone

meal, dried blood or hydrolysed epithelium.

The nitrogen containing substance may also be a simple or composite organo-mineral nitrogenous substance.

Other substances are, however, imaginable. It will be understood that, alternatively, the first substance might also be any other substance that applies another component to the soil.

According to another aspect, the disinfecting or disinfesting means comprise means for applying a second sterilising substance "B" which consists, more specifically, of a basic substance.

As illustrated, the means for applying the second, or basic, substance to the soil comprise means for containing the substance in granular or powder form and consisting of a respective tank 18 mounted on the guard 12' on the supporting frame 12, and also comprise emitting means 20 for placing the substance in contact with the soil, said means consisting of nozzles giving onto the guard 12' and designed to let the substance B fall onto the soil.

Said basic substance is preferably calcium oxide, magnesium oxide, magnesian quicklime or potassium hydroxide. Other substances are, however, imaginable.

It will be understood that, alternatively, the second substance might also be any other substance that applies another component to the soil.

The disinfecting or disinfesting means also comprise means for applying a third substance "H" that solubilizes the substances from which the sterilising and/or disinfesting agent is evolved. These means comprise means for containing the third substance and consisting, more specifically, of a respective tank 22 mounted on the frame 12 of the apparatus, and emitting means 24 for applying the third substance to the soil.

As illustrated, the means 24 consist of a nozzle located at the end of a respective conduit 24' connected to the tank 22.

The third substance for solubilizing the other substances is, more specifically, water. It will be understood that, alternatively, the third substance might also be any other substance that applies another component to the soil .

Thus, the sterilising apparatus according to the invention is

has a relatively overall structure and, what is more, unlike sterilising machines that use steam according to prior art, does not reguire a boiler for heating the sterilising water.

Further, the apparatus according to this invention can move over the soil at a relatively high speed compared to sterilising machines based on steam.

As illustrated, the means 20 for emitting the second, or basic, substance are mounted, relative to the normal direction of travel of the apparatus, behind or upstream of the means 16 that emit the first substance containing the sterilising agent.

It is thus possible to make the basic substance B come into contact with the soil after the substance A has been applied to the soil. This causes a reaction that is particularly effective in producing the sterilising agent in the form of a gas which is spread in a substantially uniform manner in the soil.

As illustrated, the means for emitting the third substance H, which is, more specifically, a substance that solubilizes the other substances, are mounted, relative to the normal direction of travel of the apparatus, behind or upstream of the means 16 that emit the first substance A and of the means 20 that emit the second, or basic, substance B.

It is believed that this greatly accelerates the reaction from which the ammonia evolves .

Advantageously, means are also provided for breaking up the soil, consisting of a tiller equipped with tools, labelled 31, for breaking up the soil and rotating in the direction indicated by the arrow R or in the direction opposite the direction of the arrow R.

As illustrated, the means for emitting the substance A that contains the sterilising agent A release the substance on the soil when the soil is in a loosened up state, while the tiller 30 is breaking it up and lifting it into the air and while the means for emitting the second, or basic, substance B and the means for emitting the third, or solubilizing, substance H are also releasing the respective substances . There are also mulching means 26 that apply a layer of mulch 28 on the soil.

These mulching means keep the soil as long as possible in

contact with the ammonia gas that has in the meantime been given off by the reaction which has taken place in the soil itself.

Although this embodiment is especially preferred, it will be understood that the first and second substances might also be provided in liquid form, in such a way that they themselves perform the required solubilizing function. In this case, the tank for the third substance might be dispensed with.

Further, the first and second substances might also be applied to the soil in front of the means that break up the soil, that is to say before the soil is actually broken up by said means, as described below.

Figure 2 shows a second preferred embodiment 100 of the apparatus according to this invention, where the parts that are the same as those of the first embodiment are denoted by the same reference numerals and, for the sake of brevity, are not described again in detail.

In this second preferred embodiment 100 of the sterilising apparatus, the active substances "A", "B" and "H" are applied to the soil before, and more specifically, just before, the soil 9 is mechanically worked and loosened up by the tiller 30.

Advantageously, the reaction can start almost immediately, thus speeding up the whole process. In addition, it is believed that the reagents are more likely to come into contact with each other, thus improving yield and allowing savings on product. Applying the reagents partly on soil that has not been tilled and partly on soil that has been tilled is also imaginable.

In this second preferred embodiment, the invention advantageously contemplates the application on the soil of the first substance "A", specifically a substance from which the sterilising or disinfesting agent evolves, in particular the nitrogen containing substance, together with the third substance

"H", specifically the substance that solubilizes the substances from which said sterilising and/or disinfesting agent evolves. In practice, the water and the ammonium sulphate are mixed together. Thus, the substance "A" is better distributed in the substance "H".

In this second preferred embodiment, the first substance "A", specifically a substance from which the sterilising or disinfesting

agent evolves, in particular the nitrogen containing substance, is applied to the soil in liquid form.

In this second preferred embodiment, the first substance "A", specifically a substance from which the sterilising or disinfesting agent evolves, in particular the nitrogen containing substance, is applied to the soil before the second, or basic, substance "B" is applied to the soil.

Further, in this second preferred embodiment, the third substance "H", specifically a substance that solubilizes the substances from which said sterilising and/or disinfesting agent evolves is applied to the soil before the second, or basic, substance "B" is applied to the soil.

For this purpose, the ammonium sulphate, or substance A, in liquid form, is added to a tank 122 containing the water, or substance H, and these two substances mixed together are applied to the soil through a respective conduit 124' leading to an opening 124 that is located - relative to the direction of travel of the apparatus - downstream or in front of the opening 120 through which the second substance "B", that is, the calcium oxide, is emitted. As illustrated, a tank 18, containing the basic substance B, discharges said substance through a conduit 120' leading to an opening 120 in front of the means 30 for breaking up the soil, in the same way as the first and third substances.

In practice, the machine of this embodiment comprises only a first and a second tank 18, 122, the former for the substance B and the latter for the substances A and H mixed together.

According to another aspect, other means for breaking up the soil, different from the ones illustrated, might also be used.

It will be understood that the invention described may be useful in many industrial applications and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.