Spatial designs of polycultures

Let's start by pointing out that polycultures are systems in which two or more plant species are planted with sufficient spatial proximity to result in an inter-specific competition and/or complementarity. The design of polycultures seeks to minimize competition and maximize complementarity between the species of the mixture, the adoption of a certain design depends on nutritional needs, local preferences, economic feasibility and the advantages provided by the mixture in yield, among other aspects that agricultural producers can consider.

Among the spatial designs, which means how the crops will be established on the surface intended for production, among the spatial designs we can name the crops interspersed by furrows consisting of the simultaneous sowing of the species in defined arrangements of furrows, that is, the simultaneous cultivation of two or more crops on the same land, has a great potential and constitutes an alternative to substantially optimize the cultivation systems thanks to diversification. Mixed intercropping can also be established, which consists of sowing two or more species simultaneously in an irregular way, without a defined sowing pattern, in addition to sowing at the edges, which consists of establishing some crops at the edges or perimeter of the surface intended for production.

When establishing this type of spatial designs, some factors must be taken into account since crops are being associated and the use of natural resources such as water, light, nutrients, oxygen and carbon dioxide are factors of fundamental need for plant growth. available on the ground. Also when growth occurs, the proximity of the aerial parts and the radical systems cause a situation of mutual interference in the absorption and interception of certain elements.

To establish a spatial design it is necessary to consider the morphological characteristics of the plants, growth habits, nutritional needs, life cycle radical system among other aspects of interest. in order to avoid a more intense competition for light and for the crops to harm each other, the height, arrangement and opening of the leaf crown of the member species of the association should be considered.

The species chosen for the association system must have foliar systems with different height and architecture, to avoid competition for light in the phase of their phenological stage. After being established, the higher-altitude crop will always intercept more sunlight, which gives it some advantage over the smaller one. Therefore, it is important to first establish the crop that is considered to have the slowest growth and its lowest or creeping growth habit.

According to what was stated in the previous paragraph, we can mention according to the experience in association of forage crops, that there are plants such as tropical grasses that are photosynthetically more efficient than others such as legumes, therefore, the growth is more accelerated, to establish a creeping legume such as the arachis pintoi, with tropical grass of erect growth, the ideal would be to sow the arachis first and then wait a few weeks for the establishment of the grass thus avoiding the initial competition for light and water.

There may also be competition for water and nutrients. Everything will depend on the depth of the radical system of plants and the consumption for a certain nutrient. It is important to consider these aspects because the effects caused by water deficiencies can be counteracted with different agricultural practices, among which is the variation of the space between plants, looking for an optimal density.

In the initial stage of growth the roots are sufficiently far apart and there is no competition between plants. As growth begins, plants with deeper radical systems will not have problems with the availability of water and can possibly pump water into the upper layers of the soil that can be used by plants with more superficial radical systems.

Dear readers, as you can see, there are no recipes in agriculture. To implement any agricultural production method, the fundamental aspects must be thoroughly investigated. In the case of the design of polycultures, the structure of the plants, the growth habits among other characteristics should be considered, taking into account that they are autotrophic organisms that produce their own food, but for this, they need water, light and space to develop.