Agriculture and Environment: Bananas

nvironmental Impacts of Production: Soil Erosion & Degradation

Due to their high nutritional needs, banana plantations are established on the most fertile lands.

Because the production systems are intensive and lack methods to prolong the sustainability of the plantations, production tends to degrade soils after twenty to thirty years.

The lack of ground cover and the elimination of buffer strips lead to the further degradation of soils in plantation areas. In addition, increasing populations of nematodes and other persistent pests eventually make the soil unsuitable for bananas as well as many other crops.

Pesticide residues & heavy metals
Over time, high levels of pesticide residues and heavy metals such as copper (from the breakdown of copper sulphate used as a pesticide) accumulate in the soils of plantations. Due to the heavy use of pesticides, the organisms that normally aerate the soil are eliminated over time.

Effects of soil compaction
The soil compacts, the rain is not absorbed, and the runoff causes erosion. Even the addition of massive quantities of fertiliser cannot offset the nutrient losses from serious erosion. At some point, the purchase of fertiliser becomes simply too expensive and it becomes cheaper to move to a new area to plant to bananas.

To insure an adequate supply of the nutrients, commercial banana plantations apply chemical fertilisers. Fertilisers can be applied up to ten times per year and are most often applied on an entire plantation rather than as needed in specific locations.

Tradeoffs between conventional & organic banana plantations
Chemical inputs and the labour required to apply them are two of the largest costs of banana producers aiming at the export market. In Costa Rica these costs can be as much as half the total cost of production. By contrast, in Costa Rica labour costs for producing organic bananas represent as much as 70% of the costs of production, as labour is substituted for chemicals.

At EARTH University the commercial farm operators have found that the cost of producing low input conventional bananas and organic bananas is about the same, but labour's proportion of the total costs is much higher for organic production.

Impacts of "clean cultivation"
The use of clean cultivation (i.e., eliminating all weeds and ground cover) also exacerbates soil degradation. Without any soil cover, soils in banana plantations are easily eroded. In addition, the finer clay particles can be carried down through the soil structure to a depth of 1 metre or so where they form a hard pan that tends to prevent drainage of rainwater and increase flooding.