Biointensive Market Gardening

Technical articles

Market gardening Market gardening

Introduction

The market gardening organic-intensive (or small-scale market gardening, also known as the French Method) is an application in the market gardening sector of biointensive microagriculture techniques. It is an organic agricultural system aimed at producing food on small plots by increasing biodiversity and supporting soil fertility. It is a sustainable, self-fertile, and seed-autonomous system.

This method is inspired by 19th-century market gardeners and aims to produce high yields on small surfaces. It was highlighted by Eliot Coleman, an American farmer and author, and popularized in recent years by Jean Martin Fortier, a Quebecois farmer and entrepreneur.

Bio-intensive market gardening relies on several principles.

Optimizing space

Bio-intensive market gardening aims to produce a high yield on a small area. Thus, vegetables within a bed are grown very close to each other, but this is made possible thanks to better soil health. The high planting density allows to save space but also time. Indeed, a full soil cover limits weed emergence due to lack of light and space, which saves time on weeding. The planting density is calculated so that the cultivated plants do not interfere with each other, but once the soil is covered by the crop, the remaining space and light are insufficient for weeds. Moreover, since the cultivation area is smaller, harvesting and planting are also faster.

Bio-intensive market gardening crops are grown in permanent beds, i.e., on raised soil mounds (about 10 to 15 cm high).

These mounds allow:

• better drainage in the cultivation area
• greater soil depth for roots and thus a better-developed root system in depth to prevent root systems of crops from interfering
• a cultivation space favoring soil life because the cultivation beds are not trampled and are lightly worked

Generally, beds are about 75cm wide and the length is chosen according to the farm's needs. Having beds of the same width throughout the farm allows to standardize work and equipment (tarps, insect nets…). Beds are spaced sufficiently to allow movement between them without trampling.

Improving soil quality

Bio-intensive market gardening aims to grow vegetables on good quality soils: loosely compacted, with significant biodiversity and a high organic matter content .

Minimal soil tillage

Bio-intensive market gardening requires little soil tillage. The soil is worked only on the surface, which preserves its biodiversity .

On this type of farm, there is low mechanization: generally, there is no need to use a tractor; a rototiller or a micro-tiller may suffice, and their use is less harmful to the soil and environment: for example, soil compaction and fuel consumption are much lower.

Other tools used are manual tools: broadfork, hoe…

Crop diversification and rotation

Diversification and rotation of crops are also key principles of bio-intensive market gardening . Indeed, the diversity of root systems and root depths helps to avoid soil depletion. Furthermore, rotations help to limit the spread of pests and diseases, as crop succession disrupts the development cycles of pests which thus have more difficulty finding an environment to develop. Thus, the use of plant protection products is limited.

Closed cycle operation with element recycling and soil organic matter enrichment

For the system to be as productive, a fertile soil is necessary. It is important to enrich the soil so that plants can produce a lot on a small area while maintaining a healthy and fertile soil in the long term.

Thus, adding a source of organic matter such as compost to the soil is necessary. To maintain soil fertility, it is also necessary to return crop residues to the plot and export only the edible part of the plant to avoid loss of organic matter.

Various amendments other than compost can be added such as green manure, biochar, compost tea…

Water management

To avoid water waste, market gardeners use irrigation drip systems. Moreover, systematic mulching of the soil is recommended to retain moisture.

Use of greenhouses and tunnels

The use of greenhouses and tunnels allows to extend the production season by creating controlled microclimates and protecting crops from bad weather and temperature fluctuations.

Advantages

Bio-intensive market gardening presents various advantages:

Environmental:

• Sustainable system: fertile soils, few inputs and little soil tillage…

Moreover, if the farmer has areas not used for crops, these can be used to establish agroecological infrastructures such as hedges, ponds…

• Product quality: bio-intensive market gardening favors vegetable quality over quantity.

Economic:

• Low production costs: few chemical inputs and little equipment needed
• Allows a farm with a small area to be profitable by setting up the necessary conditions for this system: 1 ha can be enough to have a profitable farm

Social:

• Time saving: the high planting density allows full soil cover which limits weed emergence due to lack of light and space, saving time on weeding.
• Good working conditions: the farm is profitable, there is little exposure to chemical inputs, the farm is of scale manageable by humans…
• This system is accessible to a larger number of farmers (low costs and surface area needed)

Disadvantages

• Complete change of technical itinerary: this system can be difficult to implement on a farm already established in conventional market gardening. However, it is well suited for a farmer wishing to farm a small plot.
• Construction and maintenance of beds require time and effort
• Use of some plant protection products allowed in Organic farming: if the soil is not rich and healthy enough, crops can be susceptible to diseases and then biocontrol products must be used. Bio-intensive market gardening limits input use but does not completely eliminate it.
• Large amounts of amendments are necessary to ensure vegetable growth
• Requires excellent organization (crop calendar…) to limit competition between crops