English chemist Sir Humphry Davy’s work on agricultural practices outlined ways to produce food more sustainably and efficiently. Davy was invited to give a lecture at the Royal Institution (Ri) in 1801, and later became a professor of chemistry there in 1802. During his time at the Ri, he gave several lectures to the Board of Agriculture on agricultural chemistry, which were published in 1813. Although you may not realise it, chemistry plays a very important role in producing your food! Using the study of chemistry, Davy delved into topics such as the improvement of soils, the effect of sunlight and the use of manures in food production.
Despite Davy’s findings, the way that we produce food today is not very sustainable. Food production accounts for 30% of greenhouse gas emissions due to the clearing of lands and use of heavy machinery. When growing food, toxic chemicals are also released into the environment, and an excessive amount of water is used. However, there are many practices being implemented to solve these issues today, including organic farming, conservation of water and no-till farming.
Organic farming uses organic fertilisers and ecological pest controls instead of the toxic synthetic fertilisers and pesticides usually used. While plants get carbon from the atmosphere, and oxygen and hydrogen from water, they take up other nutrients from the soil. Fertilisers are applied to the soil to supply the plant with the nutrients it still needs. Organic fertilisers, which include farm manure and compost, are made from animal and plant wastes. Another way to supply nutrients is through green manuring, where additional plants are grown to absorb atmospheric nitrogen and supply it to the soil. Organic farming also avoids the use of pesticides, which are chemicals used to kill unwanted animals and plants. Instead, we can use other insects to kill insect pests, showing how natural mechanisms can solve this issue.
Water scarcity is also very important to address when growing food. After plants take in water through their roots, the water travels to the leaf of the plant and is used in photosynthesis. Despite how essential water is for plants, our supplies of water are decreasing, and we need to conserve them. One way farmers can do this is through drip irrigation, a practice where the water is taken directly to the roots of the plants. This dramatically reduces the water used for plants since no water is wasted from evaporation or leakage. Meanwhile, rainwater harvesting involves collecting and storing water runoff for later use, allowing plants to consume water over longer periods. Additionally, dry farming involves producing crops without irrigation in areas with little rainfall, which is achieved through efficient use of the moisture in the soil.
Finally, no-till farming can be used to improve soil health, which then helps crops grow faster. Conventional cultivation of crops often involves the use of machinery to prepare the soil for planting. However, no-till farming does not involve ploughing or any cultivation machinery, so the soil does not get disturbed. This causes less damage to the soil and organisms in it, and also helps keep water and nutrients in the soil.
Undaunted, a collaboration between the Ri and Imperial College London’s Grantham Institute, has been supporting PES Technologies, a company that helps farmers monitor soil health. Soil is incredibly important since it affects crop growth, and can also take in greenhouse gasses from our atmosphere. However, our harmful agricultural practices have caused soil degradation, and there is currently no efficient and comprehensive approach to measuring soil health. PES Technologies is working to address this issue through creating a sensor that evaluates 14 indicators of soil health using a sample taken from the soil surface! This will allow farmers to easily understand how soil health can be improved, leading to better crop yields and storage of carbon.
Overall, several practices are being implemented to improve agricultural practices, many of which relate back to the chemistry principles that Davy was studying. With these practices, we can ensure that every meal we eat was produced sustainably and efficiently.