This is what you didn't know about GM soy..

Genetically modified (GM) crop production has been at the heart of a number of very heated debates in the recent years and with our loved/hated soybean as the most popular GM crop in the world, covering a total area just short of 80 million hectares,  this post and the arguments I will hereby explore were long due. So I ask myself :

Is GM soy better for the environment than non-GM soy?

Soybeans are the most common GM crops in the world

GM soy became is most popular in North America and Argentina but it is not restricted geographically and studies prove that over 90% of the world soy plantations are GM. The overwhelming popularity of the GM crop is due to its ability to tolerate herbicides as its RR gene was modified in order to make this crop immune to a primary chemical found in pesticides: glyphosate. 

The argument that is usually brought forward by experts who support GM crops is that they are more resistant to plagues and harsh environmental conditions, so they require less fertilizers and pesticides- including herbicides, insecticides and fungicides. This would be great news as both types chemicals lead to a number of not only local but global negative implications for biogeochemical flows.

However, this argument may not be as accurate in the case of soybeans.

In fact, the renowned agronomist Charles Benbrook proved that over the course of ten years farmers applied 318 million more pounds of herbicides on GM soy fields than on non-GM soy. The finding that modified crop required 26% more chemicals than the non-GM challenged the pro-GM argument at its very core. 

More studies proved that GM soy not only caused a 92% increase in pesticide application in North America, but also drove a considerable rise in agrochemical application in Argentina as each year farmers had to employ greater amounts of glyphosate in order to achieve the same results the previous year. They also had to spray the crop more often leading to an increase of the number of average yearly applications from 1.8 to 2.5 in the course of 6 years.

The negative implications of the ever increasing amount of pesticides used in GM soy crops are numerous and to an extent still unclear. The most relevant concern to effect of chemicals on the surrounding ecosystems and on human health.

Pesticides have to be sprayed in more quantities and more frequently because weeds develop and become resistant to the chemicals applied. This not only leads to changes in soil biomass composition, soil chemistry and nutrient availability but also to causes a decline in the overall biodiversity across the ecosystem. From the human health perspective, expert Alavanja proved that population living around GM soy cropland in Argentina are already experiencing the negative impact of the toxicity of glyphosate. 

A short documentary on the impact of soybean agriculture 

on some indigenous communities

A constructive debate

Having considered some of the negative implications of GM soy, it becomes quite evident that most of the literature regards GM soy as an unsustainable choice for the future of agriculture. Nevertheless the debate around genetically modified crops and the associated research can be at times biased and a level of discussion should be maintained in order to avoid polarisation in the argument.

Cover of the original report by the GM Soy Debate

In order to achieve a balanced debate, in 2008 the Plant Research International of Wageningen University established the GM Soy Debate, whose objective is to summarize scientific and balanced arguments pro and against GM soybean mass production. The report they produced evaluates the claims that are often made about GM soybean production, with particular reference to Latin American agriculture.

1. GM soy yield is higher than non-GM soy

________

2. GM soy leads to a change in pesticides application

________

3. GM soy causes the development of herbicide-resistant weeds

________

4. GM soy aggravates problems in the control of volunteer soybean in subsequent crops

________

5. GM soy encourages direct drilling/ zero tillage

________

6. GM soy allows farmers to perform mono-cropping on their land

________

7. GM soy has a significant effect on biodiversity in the surrounding ecosystem

________

8. GM soy can easily spread to non-GM soybean croplands

________

9. GM traits in soy can spread and persist outside agricultural fields

________

10. GM soy facilitates the expansion of soy production into natural areas

________

11. GM soy affects the genetic diversity of soy varieties in Latin America

________

12. GM soy changes the scale of soy farming in Latin America

________

The debate considers twelve of the most common public assumptions of the environmental impacts of GM soy  (summarized above) and reached three constructive conclusions. Firstly, the GM soybeans do not require less pesticide than non-GM. This finding endorses the arguments proposed by Charles Benbrook.  

Secondly, the ecological impact of higher levels of herbicides applications without doubt leads to a shift in biodiversity at a regional scale. Finally given similar nutrient and water availability, yields of GM and non-GM soybean crops are not significantly different.

In conclusion, there is a wide amount of scientific research as well as not-so-scientific debate over the impacts of GM soybean. A rather complex topic is often made more impenetrable by biased media coverage and uninformed arguments so if you are looking into finding out more about this I would thoroughly recommend you follow the GM Soy Debate. 

Despite being pro GM crops, I believe that the way at which GM soy in particular is cultivated across the world is inherently unsustainable and could lead to harmful implications in the near future, threatening not only food security but also human health as a whole.

Remember that you should never take anything as a given fact, not even this blog post. So feel free to disagree and don’t be scared to let me know your opinion on this debate in the comment section below!

Are pesticides sustainable?

All about the weeds..

Scientists demonstrated that the most weed infestations tend to develop in rain-fed cropland, which make up 80% of the world cropland. Farmers have to apply large quantities of herbicides in order to control such infestations and to maximize the crop yield but they could be inadvertently be affecting the soil conditions. 

When weeds are left in the field after harvest they decompose and become primary input components of the total system influencing its productivity. The input of nutrients from the weeds could be affecting the dynamics of soil chemistry and the micriobiotic biomass, which mainly consists of bacteria and fungi. 

Hence, removing such weeds in the first place could lead to increased competition over scarcer nutrient availability and lack of resources.

Pratibha Singh found that in soybean fields there is a positive correlation between the total yield of crops and the amount of fungi and bacteria found in the soil. This could be due to the fact that such organisms are a source of nutrients for the soy bean, which extracts nitrogen and minerals from the microbial biomass. 

If plant productivity is to be sustained – in order to maintain high yield crops – it is important that management practices take into consideration reducing the amounts of herbicides and maintain a certain level of weeds.

In an habitat with relatively high levels of weeds the organisms in the soil are more likely to grow faster increasing soil fertility and ultimately crop yield.

To further understand the impact of herbicides on local ecosystems and organisms I will look at a case study presented by Zhang in one of his recent studies in the Northeastern China Plain.

Herbicides in soybean agriculture

The China plain is one of the main agricultural areas in central asia and vast amounts of Imazethapyr - a selective herbicide - are used every year to suppress weeds infestations across the soybean fields. 

Studies have estimated that up to 6000tons of Imazethapyr are applied to soils in this area every year leading to critical implications for the local environment. In fact, pesticides are proven to be toxic to a variety of plants and not necessarily just the ones that they are meant to target.

Zhang carried out a study in order to assess how this herbicide influenced the local microbial biomass and affected changes over time. He proceeded by applying this chemical into three different soil samples and analyzing the different results over two years. He didn’t apply the pesticide in one sample and maintained it as a control variable, leaving the chemical in the other two samples for respectively 1 and 2 years. 

The effect of imazethapyr on soil microbes in soybean fields in northeast China

The results clearly highlight that the pesticide changed the composition of the microbial biomass community, leading to a shift in presence of fungi and bacteria species. As the chemical properties of the soil changed, the microflora was subject to higher levels of stress which could have affected the productivity levels and in turn increased competition amongst organisms leading to a reduction in the abundance of populations.

In conclusion, herbicides can bring about negative implications for the soil ecology in soybean cropland. This is not only worrying in terms of conservation but most importantly in terms of crop yield. When herbicides are applied, the total productivity of crops can be compromised as fungi and bacteria decrease in numbers leading to lower levels in nutrients in the soil.

Farmers can’t afford to loose crops to weed infestation but by applying herbicides they could be compromising the sustainability of agricultural practices in their region. 

Could genetically modified crops that are resistant to plagues be a more sustainable answer to this issue?

 Stay tuned for further discussions and feel free to leave a comment below!

Phosphorus Peak: a Blessing in Disguise?

Since the beginning of the Industrialisation, humans have been putting the earth system under an ever-growing amount of pressure in terms of resources depletion and environmental degradation. Such pressure resulting from anthropogenic activities is believed to have caused an unexpected shift into a new geological era: the Anthropocene.

These recent changes in global environmental systems are worrying and lead us to question:

How long we can continue with business-as-usual before our wellbeing is compromised by our choices?

The answer is suggested by William Steffen who recently explored the limits to which we can push the planet before it changes irreversibly. 

He identified that a planetary boundary for phosphorus discharge into our oceans is 10 times its pre-industrial levels. Globally, 14.2 Tg/year of phosphorus are washed off from cropland into freshwater ecosystems and eventually our oceans - a rate that effectively surpasses the 11 Tg/year suggested by scientists as the safe limit.

Our agriculture currently highly depends on phosphorus to maximize and support crop yields so demanding a reduction in fertilizers usage could lead to a threat to food security. Despite the positive implications of reducing the wash-off of pollutants, it is difficult to imagine that markets and governments will put at risk human well-being to safe guard the environment.

In fact, the world population is bound to increase by 75% reaching 10 billion by the end of the century. Not only we will have to produce more food but an increasing amount of the world population is demanding for more meat. Experts believe this demand will lead to a doubling in the production of grains as well as soybeans- due to their high protein content- for livestock feed.

The issue 

Phosphorus is a non-renewable resource and studies found that if its consumption was to continue at the current rate it will run out before the end of the century. The peak in demand is thought to be in 2030 – what is known as the Phosphorus Peak. On top of the issue of quantity of phosphorus available, the rising demand is being matched by ever decreasing quality of the substance as well as increasing prices.

While reading about the negative effect of phosphorus and the dangers associated with our dependency on it for food production, I began to question:

Is this peak a blessing in disguise or a terrifying prospect? 

As the peak approaches with associated rise in prices, more and more studies have shifted their attention towards finding a more economically sustainable way to feed the world population without sacrificing the environment.  

Interestingly, the answer may lie in the investigation of the distribution of phosphorus across different landscapes and its heterogeneity across different scales. Although the exact date of the Phosphorus Peak is still widely debated, concerns remain as there is still no likely substitute to this chemical:

if we are to continue producing food for the growing world population we have to start managing the allocation of existing phosphorus in a more effective manner.

For instance, in some regions freshwater ecosystems are suffering from an excess in phosphorus inputs leading to a rise in nutrients and increasing eutrophication. On the other hand, at a global scale we are experiencing a shortage of this resource because areas that currently export phosphorus, such as West Saharan countries, are now under excessive pressure.

G. K. MacDonald, E. M. Bennett, P. A. Potter, N. Ramankutty

Looking at the map produced by MacDonald and Bennet it becomes evident that there is an imbalance in the way fertilizers are being used. For instance, Ukraine is known as the bread basket of the Russian empire despite suffering from very serious phosphorus deficit. On the other hand, Brazil is flashed as an hotspot where fertilizers are being over-used.

I strongly believe that taking spatial variability in the distribution of phosphorus would allow for a global approach to agriculture that could prevent a further rise in freshwater pollution. 

The Phosphorus Peak is a terrifying prospects but it is essentially forcing markets and global entities to develop a more sustainable approach to agriculture which would not have been considered otherwise. 

Do you agree this could be nature's blessing in disguise?