11 July 2014

Future agriculture: what we gain and lose with organic farming

This blog post was written by postgraduate student Yuan Amata as part of the course, Research Methods in Ecology (Ecol608). Yuan revisits a Lincoln University research area that looks at soil quality from organic farming in 2010.

Tuner Organic farm
Photo by Paul Hamilton

Organic farming is on the rise around the world as it is considered a better alternative to conventional farming. However, problems with organic farming have also been reported. How does organic farming influence the environment? Is it possible for us to make improvements?

You may be wondering what the problems are. Before we talk about this, let's first clarify what organic farming is because I've found that many people are confused about the concept. So, what is organic farming? I found this to be a really tricky question. Lots of people have different ideas about organic farming, and what kinds of "organic" should be marketed as organic. As a result, organic standards have been created  by many countries and regions. If farms can meet the requirements of the standard, the products can be marketed as organic. Generally, these standard include the regulation of site selection, cultivation methods and crop condition. Synthetic pesticide and fertiliser are not allowed, but some pesticides can still be used under certain conditions.

Then, let's look at what we have gained and lost by growing crops organically according to a recent research. Leo Condron and his colleague in Lincoln University studied the environmental effects under organic farming systems in New Zealand. They started by investigating 'soil health' in organic farms. To evaluate 'soil health', some determining factors such as soil quality, nutrition dynamics and balance were tested.

Many problems from organic farms were reported in the research. Their were imbalances of phosphorus (P) and sulphur (S),  two essential nutrients for plant growth. This is because many native soils are low in P and S in New Zealand and synthetic fertilisers are forbidden in organic farming. Organic fertilisers, however, have relative low nutrient concentrations and, therefore, large amount of organic fertiliser may be needed to meet the nutrient needs of crop plants. In addition, it is also hard to control the degradation of organic materials. Because of these issues, organic farming can lose nutrients from the soil. For example, an organic farm in Canterbury was found with lower "Olsen P" and "phosphate-extractable S" than equivalent local native soil. Even even worse P and S budgets were found to be negative on biodynamic farms. In other words, the nutrients in soil cannot be kept in balance with ongoing cropping. Without intervention, the soil nutrient conditions will get progressively worse.

Soil in organic farm
photo by Amber Case
Organic farming is seen as better for the environment because of its lower nutrition losses. However, the authors also challenged the environmental benefits of organic farming. It is true that organic farming generally has a low nutrition loss especially in N and P. However, they pointed out that N losses may only depend on the quantity of N rather than the form. If the nutrition inputs are equal on an organic farm and a conventional farm, their impacts on environment are likely to be same.

Organic farming systems normally require more frequent soil cultivation to control pests and weeds. However, this practice can also damage soil aggregates and increase N loss by leaching. There is currently no strict standard to regulate the practice.

It is noticeable that certified/modern organic farming does not mean chemical free. Some chemicals are permitted to be used in organic farming system. Although these chemicals are regulated, many of them were still reported to have negative effects on the environment. For example, copper (Cu) compounds used for pest control will affect soil organisms under high concentrations. Rotenone is toxic to fish. Pyrethrum will kill some beneficial organisms. The fine dust of diatomaceous earth is a lung irritant. And so on. All of these could be a hidden danger for human health if the usage is not carefully managed.

Organic Berry Farm - Yakima
An Organic berry farm.
Photo by Mark Davis. CC BY-NC-ND 2.0

Despite there are problems, researchers also confirmed that organic farming has some advantages, such as improved soil structure and quality, especially compared to conventional farming. Therefore,  organic farming is still, typically, a better alternative to conventional farming. What I am trying to say is that organic farming is not a perfect option. Organic farming could have negative impacts on the environment if it cannot be well managed. However, the question can be raised about whether it is necessary to be organic if we just want cleaner products and less environmental impacts when natural fertilisers and pesticides could also generate environmental and healthy outputs? It is my view that we should focus more on how to produce healthier plant products with minimal impact on the earth rather than dogmatically believing all natural ingredients are best. I think it is better for future agriculture to use organic fertiliser as fundamental inputs combined with integrated pest management (IPM), but chemical fertiliser could also be used to keep the balance among soil nutrition, biological activity and plant growth. Pesticides should be avoided or only used in some limited conditions. In short, I think further agriculture should more focus on reducing negative environmental impacts. Chemical fertilisers and some pesticides could still be used, but should be treated as "medicine" rather than "food" for plants and soils.

I just hope future farming can be better for both the environment and people.

Condron, L. M., Cameron, K. C., Di, H. J., Clough, T. J., Forbes, E. A., Mclaren, R. G., & Silva, R. G. (2010). A comparison of soil and environmental quality under organic and conventional farming systems in New Zealand. New Zealand Journal of Agricultural Research, 43(4), 443-466.

1 comment:

Unknown said...

Excellent and helpful post… i am so glad to left comment on this.
Organic input for agriculture