A new applied technology could help farmers identify consistently low-yielding parts of their cropland, and drastically reduce the needless application of fertilizer there, a new study find
Researchers at Michigan State University use remote sensing technology to identify unproductive land and have discovered that this could save US corn and soybean farmers. UU An estimated cost of $ 500 million in fertilizers, and stop 6.8 million metric tons of carbon dioxide equivalent that escape the unused nitrogen fertilizer. the atmosphere. That's roughly the same as the emissions generated by 1.5 million cars in a year.
This is especially important in regions such as the Midwestern United States, where the existence of an immense and lucrative corn belt means that fertilizers are widely used to stimulate crop growth. But because farmers can not predict where crops will succeed and where they will not, fertilizers are applied evenly throughout the land. Therefore, in areas of low yield, a certain amount of fertilizer will always stay in the soil instead of being absorbed by growing crops. This makes its way into waterways, and finally reaches the Gulf of Mexico, where the nutrient-rich substance stimulates the growth of algae that causes the growth of dead zones in the ocean.
To try to combat this problem from its origin, the researchers looked for a way to align the fertilizer application with the American corn belt of crop productivity. They analyzed eight years of satellite data covering fields of corn and soybeans distributed on 30 million hectares of the Midwestern states. This gave them a detailed look at the region's maize production, and helped them identify portions of cropland that repeatedly had low yields over the years.
Combined with the available data on the amount of fertilizer applied on the land and taking into account the amount of fertilizer used as the crops grow, the researchers were able to estimate how much nitrogen, one of the main nutrients / contaminants in the fertilizer, it was left unused in the soil in low yield plots.
Their analysis revealed that approximately 50% of the farmland is high yield. But the remaining half consisted of low yield fields (26%) or plots that produced a mix of higher and lower yields (28%). Then, with a quarter of the cropland confirmed as unproductive, the researchers were able to calculate that only half the nitrogen in the fertilizer that had been applied was actually absorbed by the plants. In other words, the remaining 50% is wasted on the ground, which costs farmers millions, expels greenhouse gases and, ultimately, is washed away by the rain into the waterways.
The researchers found that, in other words, consistently low-yield maize croplands represent an astonishing 44% of the nitrogen contamination of the region covered in the study.
Researchers believe that applying a fertilizer more intentionally to equalize yields in the corn belt could reduce a large part of the pollution that eventually reaches the Gulf. But a The main advantage of its approach is that, since it is based on long-term satellite data that is now ubiquitous, it could also be used as a tool in other parts of the world to identify low-yield crops over time and speed up the use of fertilizers in those areas also
It is also worth noting the many other resources that are devoted to agriculture, from phosphorus, insecticides and herbicides, to costly labor. If calculated together, the cost of wasted resources on low-yield lands could actually reveal that these areas are not profitable for the farm. Finding this would depend on further investigation to calculate the overall costs. But if that is the case, the researchers suggest that, ultimately, it might be better to convert these parcels of land into strips of wild habitats, for example, to encourage pollinators.
For now, this satellite-based approach could empower farmers in one of the most intensive parts of the world's agriculture to at least make more informed decisions about where to apply fertilizers and how much. "Nobody wins when fertilizers are wasted in areas they do not produce," the researchers to write. "Once farmers identify these areas, they can save money and help the environment."