In the case of Brazilian Amazon forest, indeed there is a negative impact of soybean.
Up to 2006 was a direct impact causing deforestation. But a law passed making it hard to sell soybean cultivated in deforestated areas (specially to the USA).
But still there is an indirect impact, since then. Cattle raising is the main force behind direct forestation of the Amazon on brazilian area. But once the cattle extinguish the resources of the land and move to a new land to deforestate, the soybean farms occupy the empty land they left behind.
So soybean farmers have an interest in supporting cattle raisers deforestation of the Amazon.
I think deforestation isn't going to be solved by going after a single industry/product. Humans will eventually find a reason to destroy any forest we can find. We can target soybeans and cattle, but that'll be replaced by gold prospecting, logging, housing, parking lots, nuclear weapons testing, spaceports, or anything else humans can think of to make a dollar.
For large swaths of the Earth, we need to say "You can't touch this area for any reason. Don't even step foot here. Go away."
Up to 2006 was a direct impact causing deforestation. But a law passed making it hard to sell soybean cultivated in deforestated areas (specially to the USA).
But still there is an indirect impact, since then. Cattle raising is the main force behind direct forestation of the Amazon on brazilian area. But once the cattle extinguish the resources of the land and move to a new land to deforestate, the soybean farms occupy the empty land they left behind.
So soybean farmers have an interest in supporting cattle raisers deforestation of the Amazon.
source: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1414...