1.74 | Fall 2020 | Graduate

Land, Water, Food, and Climate

SECTION 3 | Reconciling Demand and Supply: Context

Class 9: New Technologies and Practices: Genetic Engineering, Precision Agriculture

Our analysis so far suggests that our water and land resources may not be sufficient to grow the additional food required to provide global food security throughout this century, at least with current technology and management practices. It seems quite possible that climate change may make things even more difficult. Also, there is no guarantee that it will be possible to meet food demands with sustainable intensification that raises yield on existing cropland through increased nutrient and pesticide inputs and expanded irrigation infrastructure. So it is natural to ask whether new technologies and the improved management practices they enable could be the answer.

This class looks at two promising and much discussed new technologies—agricultural biotechnology and precision agriculture. One of the primary goals of biotechnology in the agricultural sector is to improve plant capabilities for dealing with environmental stresses that limit yield. Of particular interest are stresses from pests and disease, and from extreme events such as heat waves, droughts, and floods. Other important goals include increasing potential (unstressed) crop yields, reducing pesticide use, and improving crop nutritional quality. It is worth mentioning that biotechnology also has a role in improving the quantity and quality of livestock products. This aspect is important but not discussed here.

The paper by Ronald (2011) provides a useful introduction to agricultural biotechnology. It focuses on examples of insect resistant, herbicide resistant, and viral resistant crops that are all being used in the field and it provides shorter discussions of possible future applications that go beyond pest control.  The examples are illustrated and updated in Ronald’s TED video. The video by Jill Farrant provides an interesting example of ongoing research on drought resistance, which has yet to be put into practice. The optional paper by Ricroch & Hénard-Damave (2016) gives a sense of the range of genetically engineered agricultural products in development at the publication time. Hefferon and Herring (2017) discuss some new approaches in genomic technology.

The stated goals of agricultural genetic engineering are generally admirable but the means used to achieve these goals are controversial. Although some have raised concerns about human health impacts the most credible concerns are related to ecological aspects. Some examples are:

  • New varieties of pests that are resistant to genetic innovation can evolve through natural selection. This is a problem that is also associated with the use of traditional chemical pesticides.
  • Genetically engineered crops could be invasive, with related loss of biodiversity
  • Genetically engineered crops could have adverse effects on non-target organisms and ecosystems, including soil microbiological communities
  • New viruses with unknown properties could develop in transgenic viral-resistant plants.

The paper by Wolfenberger and Phifer (2000) reviews some of these concerns. Gilbert (2013) provides a journalistic look at resistance as well as some other ecological and social issues that have been raised by opponents of genetic engineering.

Concerns about genetic engineering were largely hypothetical and speculative when the Wolfenberger and Phifer (2000) paper was published. The situation has not changed much since then. The community that voices these concerns still has strong but thinly documented reservations about possible adverse environmental impacts but rarely mentions the possibility that modern biotechnology could provide additional food for millions. On the other hand, the community advocating genetic engineering barely mentions environmental concerns. There are still surprisingly few data-driven papers that address both sides of the issue. The controversy has become quite polarized, partly because of strict European limits on the development and use of genetic engineering in agriculture. The optional reading by Paarlberg (2010) provides an interesting policy perspective, considering differences between European and African food security needs. The reading by the US National Academy of Sciences (2016) summarizes an effort to build a consensus position.

Overall, biotechnology is a promising development for food security that has already had an impact on agricultural production (see S12). Much of the practical success to date has been in genetically engineered pest control techniques that improve on traditional pesticides but share the need to continually deal with acquired pest resistance. There is still much uncertainty about the longer-term effectiveness and environmental impacts of current genetic engineering technology.

Our second technology, precision agriculture, seems to have little downside, other than affordability. Precision agriculture technologies are designed to make crop production more efficient, with respect to the use of water, nutrients, pesticides, labor, capital, and other inputs. They do this by combining new high-resolution sensors, information technology, and cultivation equipment in an integrated package. Widespread adoption of precision agriculture methods could have positive environmental impacts if they reduce water use and undesirable off-farm losses of fertilizer and pesticides. The article by Gebbers and Adamchuk (2010) provides a concise overview of relevant technology while the paper by Bogue (2017) surveys some precision agriculture sensors and equipment in current use or in development. The Millennial Farmer video shows an example of a popular precision agriculture product on a large US farm.

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There are few comprehensive studies of the effects of precision agriculture on crop yield and farm revenue. Some of the equipment required is expensive so its advantages must be weighed in light of the capital investment required, especially for applications to small farms in developing countries. However, it seems likely that demand for precision agriculture technology will increase and prices will fall if this technology can be shown to significantly reduce crop inputs while also improving yield. To date, precision agriculture innovations have tended to be driven by corporate research and development but academic research can be expected to have an increasingly important role in sensor development and in applications of robotic, “big data,” and artificial intelligence technologies to the agricultural sector. The challenge will be to ensure that these developments will find their way to smallholders and poorer farmers.

Required Readings

Genetic Engineering and Food Security

Ecological Risks of Genetically Engineered Crops

Summary Statement on Genetic Engineering

Precision Agriculture

Optional Readings

Genetic Engineering


The Case for Genetically Engineered Food

Genetic Engineering for Drought Resistance

Precision Agriculture Demonstration

Discussion Points

  • How would you compare the desirability and feasibility of meeting projected food demand by 1) reducing meat consumption and closing developing country yield gaps by expanding fertilizer use and irrigation vs. 2) replacing traditional crops with more robust higher yield genetically engineered crops?
  • Do we really need genetically engineered crops?
  • What kinds of precision agriculture products do you think would attract a market among small farmers in the developing world?

Course Info

As Taught In
Fall 2020
Learning Resource Types
Lecture Notes
Instructor Insights