Conservation agriculture helps meet the challenges of climate change, study concludes
Farmers around the world face a long list of problems, including climate changethe Urban sprawl and the soil degradation, among others. To combat these challenges, researchers are searching for solutions and have begun to focus their studies on the feasibility of sustainable farming practicessuch as cover crops.
Cover calls are additional crops that can be integrated along with the main one or used to cover the land as a shield, in order to protect the soil from the erosive effects of wind, rain and high temperatures outside the main production cycle.
Cover crops are planted in the short period of time following harvest and ‘removed’ before planting of the next cash crop.
Cover crop roots help stabilize the soil and improve the soil by absorbing and storing excess nitrogen fertilizer. that may be present in the soil after a commercial crop harvest.
They also help prevent fertilizer and sediment from seeping into waterways and damage freshwater ecosystems.
The most common plant species used as cover crops are grasses (wheat, rye, oats, barley…), the brassicas (radish, turnip, canola, mustard…), and legumes/fabaceae (peas, broad beans, peas, clovers…). This practice is highly appreciated in crop rotation, no-till and organic farming..
Key role in soil health
“By influencing soil organic carbon (SOC), cover crops play a key role in shaping soil health and therefore the long-term sustainability of the systemIt’s the first sentence of a report on the benefits of cover crops just published in the Agronomy Journal.
The research provides an overview of what the authors call “conservation agriculture technology“, using cover crops, as a strategy to minimize land degradation, climate change challenges and food insecurity issues in developing countries.
They also analyzed the impact of cover crops on SOC and Emissions of greenhouse gases in maize growing systems, through a meta-analysis of previous studies, coupled with field experiments.
Among the researchers’ findings, it stands out that cover crops increase SOC by 7.3%. This is a significant amount, since that carbon is the measurable component of soil organic matter and a key element to determine the quality of the land. A higher percentage of organic carbon in the soil indicates greater soil health.
“As a last resort, cover crops are taking carbon dioxide from the atmosphere and ‘burying’ it in the soil“, explains Deepak Joshi, one of the authors of the study. “That means that cover crops help improve the growing climate problem and also soil health“, Add.
High carbon ‘sequestration’ rate
The researchers discovered that maize fields with cover crops have a high SOC ‘sequestration’ rate. They calculated that if all corn fields in the United States used cover crops, 29.12 million Mg (megagrams or metric tons) of SOC could be ‘sequestered’ each year, which is equivalent to 107 million metric tons of CO2.
According to the US Environmental Protection Agency, this figure is equivalent to the greenhouse gas emissions of 23.8 million gasoline-powered vehicles driven for one year.
“Our results suggest that current cover crop-based maize production systems sequester 5.5 million Mg of SOC per year in the United States and have the potential to sequester 175 million Mg per year globally.” Joshi indicates.
“The conclusion is that cover crops improve soil microorganisms, moisture and carbon. And, ultimately, “also increase crop yield for the following harvest season,” he adds.
The meta-analysis showed that the adoption of cover crops increases maize yield by 23%.
Already in 2021 an international study, with the participation of the CSIC, the University of Alicante and the Rey Juan Carlos University, revealed that the vegetation cover of cereal crops increases their yield agronomic and improves soil biodiversity, climate regulation and soil fertility.
The results of that study suggested the importance of extending the duration of the vegetation cover beyond the limitations imposed by the climatic conditions of the area to the cereal crop. For example, using cover crops to cover the time interval between the cereal harvest and the establishment of the next crop.
Reference report: https://acsess.onlinelibrary.wiley.com/doi/10.1002/agj2.21340
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