Why? How?
A growing number of scientists agree that the use of pesticides is a serious threat to our environment. Of these, herbicides account for over half of consumption and some are very dangerous substances indeed.
Herbicides are a threat to water quality as they are either washed out of the soil and carried into the groundwater or rivers or taken up into the atmosphere and are then found in rainwater.
This is a serious threat to the ecosystem that is disrupted by the decline in some sensitive species and the increase in resistant species and this for both animal and plant life.
Ultimately they are a threat to our own health as pesticide residues eventually end up in the produce we eat. Direct ingestion is commonplace either by the users themselves but also by local residents as the spray cloud is carried by the wind.
What can be done to avoid the use of chemicals?
Many techniques and methods exist for family gardens, urban green belts and farms.
Preventive methods
1. Working the soil
There are several ways to reduce the weed seed bank in the soil. Firstly it is necessary to stop adding new seeds. Weeds in the vicinity of cultivated plots but also within the plantations and crops must be destroyed before seed germination… Composting at a temperature above 60°C prevents germination of any seeds present in the compost. Again this involves working the soil before planting (the false seedbed technique). This enables weeds to germinate and they can then be destroyed mechanically or thermally once they have germinated. This technique can only be applied on unplanted soil, such as in a nursery or before new beds are planting. The GUERILUs pading fork (same use as the Grelinette TM) enables the soil to be worked without splitting weed roots.
2. Covering the land
The idea here is to cover the soil in order to limit the growth of weeds. The soil can be covered using ground cover plants in perennial or green manure beds in the nursery. However ground cover plants require fairly intensive maintenance in the early years. Common examples are: ivy, cotoneaster, fern, periwinkle …
An “organic mulch”, with bark, brush compost, wood chips or cocoa shells, severely limits the growth of weeds in perennial beds and banks. For greater efficiency, an anti-grass fabric of the PLANTEX type can be laid under the mulch. This fabric is made from synthetic porous material (it lets water through and is an effective weed barrier). There are also micro-perforated agricultural plastics (which have the disadvantage of not ageing well), nonwoven films made from thermally bonded polypropylene fibres that are highly resistant, porous and non-degradable. For individual protection of young plantations, there are slabs of biodegradable mulch that can be placed at the foot of trees or shrubs (Unaplant, Cecoplant, Biojute). Good growth is ensured through the elimination of weed competition and greater water savings. Finally, there are also recycled rubber discs that can be placed at the foot of traffic signs for example.
Curative methods
Thermal weed control is a relatively recently applied technique that fully respects the environment.