Organic Foods
Enviornmental Impacts
Studies find one of the largest motivations to eating organic foods is saving the environment. There are three main factors to consider when comparing the impact on the environment of organic to conventional farming: soil health, chemical contamination and land use.
Soil Health & Biodiversity
In addition to avoiding certain pesticides, to become organically certified, organic farms need to rotate the land on which they grow their crops each season. When you do that, the soil does not get sapped of the same set of nutrients year after year.
Organic farms also use manure instead of synthetic fertilisers for soil health. Science shows all these organic practise work, do trigger processes in the soil that make them more nutrient-rich and thrive with good bacteria, fungi and worms, which may cause some plants to become more resistant to some pests and diseases.
​
The healthy soil and diverse crop also bring more birds and insects into the farmland. One meta-analysis of 94 studies found that organic farms have on average 30% more biodiversity and species richness than conventional farms [1].
Chemicals & Contamination
Conventional farms often add synthetic fertilisers to help crops grow. What makes fertilisers so good at what they do in making the plants grow big is the chemical nitrogen. Though this is great for crop yields, a problem arises when fertilisers are added in excess where the plants do not absorb all the nitrogen. Excess nitrogen can run off into lakes river and even oceans causing the contacted water's oxygen supply to choke up through the overstimulation of growth of aquatic plants and algae leading to eventual killing plants and animals.
Organic farming practice does not allow the use of synthetic high concentrated nitrogen. But organic farms still need fertiliser and utilise alternatives such as compost, blood meal, bone meal and manure. But alike synthetic fertilisers, when applied in high amounts, there is a risk of nitrogen runoff into the environment.
​
A review paper in Europe shows that there was more nitrogen leaching from organic farms vs conventional [2]. Organic has the potential to leach more because manure, unlike precise lab, made fertilisers, it is difficult to give crops just the right amount of nitrogen that they need, potentially leaving more on the ground and more to run off. Additional, due to its chemical structure, nitrogen in manure tend to bind tightly to the soil and only releases slowly over time and is therefore difficult to apply the desired dose to crops, instead you just have to dump the manure and hope the crops absorb as much nitrogen as possible.
Yield & Land Use
A review paper found on average; acre for acre, organic farms produce around 25% less food than conventional farms, and that's because conventional farms cannot use the most effective fertilisers [3]. So if you want the same yields to conventional, you're are going to need a lot more land. Another potential yield problem for organic farmers is their inability to use the most powerful pesticide to kill a particularly nasty pest, which can potentially wipe out a farmers crop.