Agriculture and Environment: Soybeans

Better Management Practices: Fertiliser & Pesticide Use

Practices to reduce fertiliser, insecticide, and herbicide use are certainly possible.

As discussed in the previous section, planting legumes as part of a fallow or crop rotation system can reduce the need for applied nitrogen fertilisers. Another way to minimise the use of agrochemical inputs is to adopt precision fertilisation and pesticide application systems.


These systems avoid excessive applications by targeting the timing and the location of applications on an as-needed basis. In some cases, pesticides can be applied through irrigation systems.

No-till practices and agrochemical use
To minimise the use of fungicides, microbial inoculates that diminish the impact of pathogenic fungi can be sprayed. While no-till has been shown to reduce the use of some agrochemicals, even some of the most harmful ones, it does seem to lead to an increased reliance on glyphosate.

Land tenure and agrochemical use
Another factor that affects agrochemical use in the United States is land tenure. About 50% of the farmland in major soybean-producing states like Iowa is rented (NRDC 2001). Landowners often prefer to rent to those who maintain "nice, clean fields," for example, ones treated with herbicides so they are free of weeds.

Time spent - major concern for producers
Increased management and time commitments are major issues for producers. Producers are reluctant to adopt precision chemical applications if they require more time. One farmer reported herbicide reduction techniques took about 1 hour per acre for soybeans (1.3 hours per acre for corn) and saved $12.50 to $17.50 per hectare ($5 to $7 per acre).

Using ridge-till cultivation (a form of reduced tillage) reportedly saves producers $12.50 to $17.50 per hectare ($5 to $7 per acre) as well. Producers were not willing to maintain these practices because the labour required was at the busiest time for the producers and their families, and it was too expensive to hire others to do the work (NRDC 2001).

Reducing the overall time required & other incentives
From their point of view increased labour costs exceeded other savings. Reducing the overall time required for such practices (or increasing the costs of not adopting such BMPs through taxes or pollution fines) would encourage farmers to make the investment.

Incentives for producers to reduce pesticide applications could include cost-share funds where the government agrees to cover part of the cost, one-on-one technical assistance, insurance premiums that underwrite the risk of crop damage or yield reduction, "green" product labelling, and the development of retail markets for low pesticide products.

In both Brazil and the United States it has been suggested that pesticide applicators, whether contractors or landowners, should be trained. There have also been formal calls for licensing applicators. (This is already required for restricted-use pesticides in the United States, but not for those chemicals classified for general use.)

Credits

Extracts from "World Agriculture & Environment" by Jason Clay - buy the book online from Island Press

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