Are burning crop residues and grass good for soil health and fertility? Views from a farmer and an agricultural researcher

    | January 6, 2014

    Download this story

    This week, FRW reprints a Nigerien story from earlier this year that focuses on soil fertility. One way that some farmers attempt to increase soil fertility is by burning crop residues. Crop residues are the remains that are left over after the plant or crop has been put to use – for household food, for fodder, for sale, etc.  But what is the effect of burning crop residues and other vegetation on soil fertility?

    In this script, a smallholder farmer and an agricultural researcher give different opinions on whether burning crop residues and grasses is a good idea. The farmer sees that burning residues makes her farming work easier. Burning controls weeds and pests, and improves yields in the season after burning. On the other hand, the agricultural researcher says that, over the long-term, burning destroys the soil. It causes increased soil erosion; it kills beneficial soil organisms, and eventually causes lower yields.

    This is a complicated subject. Some researchers say that, in humid environments like western Kenya, it is not as harmful to burn residues as it would be in dryer environments. In dry environments, burning residues can reduce soil fertility quite quickly.

    For some farmers, it may be easier and cheaper to burn residues and grass, even if it is not a good long-term strategy. Farmers may not have the labour or resources to grow cover crops, dig residues into their fields, or adopt other practices for long-term soil fertility and conservation. Cutting bush and pulling weeds by hand is labour intensive.  But, when farmers burn their fields, they see immediate gains.

    Broadcasters should help farmers understand that cover crops, incorporating residues, and other soil-building practices – including the residue and agroforestry practices suggested by the agricultural researcher in this script – are a good long-term investment.  An investment which will help them achieve good yields over the long-term. But it’s important to note that not all these practices work in every climate. For example, farmers in dryer areas may not have sufficient mulch or crop residues to use some of these practices. Or all the residues may be needed to feed livestock.