Using Cover crops in arable farming to improve soil health and prevent leaching.

Using cover crops in arable farming is a viable long-term strategy that has the ability to improve soil health and reduce the effects of soil deterioration. Cover cropping creates an agroecosystem distinct from bare fallow, as a result, the microbiome responds to the altered environment. Cover crops in Ireland are becoming increasingly popular due to their wide range of benefits such as preventing soil erosion and nutrient leaching, weed suppression and carbon sequestration. Cover crops are used in Ireland with farmers recognising the impact they have on soil quality and crop yield overall. A recent study in the Journal of Soil Biology and Biochemistry analysed the true extent of the benefits cover crops have on soil microbiome.

Using meta-analysis of 60 studies conducted in 2019, this study found that cover crops enhance soil microbial abundance, activity and to lesser effect, diversity. When compared to bare fallow, results state that cover cropping significantly increased parameters of soil microbial abundance by 27%, activity by 22% and diversity by 2.5% (Kim, et al., 2020).

“This meta-analysis showed that the soil microbiome can become more robust under cover cropping when properly managed with other agricultural practices.” –

(Kim, et al., 2020).

Cover crops are mainly used to improve and maintain soil structure in an overall bid to enhance soil health. Spring barley is the most popular choice of crop grown in Ireland, so this leaves a considerable proportion of the arable area fallow over winter. Farmers are encouraged to plant cover crops to later in the year after winter barley, as it leads to a greater land area being covered in cover crops over winter, reducing the amount of fallow land. Properly managing cover with other agricultural practices may be producing crops that can be used for forage. (Cottney, et al., 2021) stated that soil structure concern was the most prevalent acknowledged problem on farms in Ireland.

“In Republic of Ireland, 63% of respondents receiving subsidies would continue to use cover crops if this monetary incentive ceased.” Results from a study on cover crops in Ireland by (Cottney, et al., 2021) states that there is a subsidy scheme for arable farmers to plant cover crops. This shows that Irish farmers are willing to continue using cover crops as they see the advantages in using them yearly. However, this study also stated that only 20% of farmers in Ireland are growing cover crops already to reduce leaching.

Cover crops are already used in Ireland with a subsidies initiative for farmers to join, however this scheme only selects certain cover crops which could be further extended.  With this study showing that cover crops enhance soil microbial abundance, activity and to lesser effect, diversity and with only 20% of farmers using cover crops to prevent leaching, possible further education on the should be giving to farmers to raise the awareness about the improvements on soil health they have.

Notes: Eoghan Mc Dermott, M.Sc. Agri-food Sustainability & Technology, 21251365, E.McDermott19@nuigalway.ie

References

Cottney, P., Williams,, P. N., White, E. & Black, L., 2021. The perception and use of cover crops within the island of Ireland. Annals of Applied Biology.

Kim, N., Zabaloy, M. C., Guan, K. & Villamil, M. B., 2020. Do cover crops benefit soil microbiome? A meta-analysis of current research. Soil Biology and Biochemistry, Volume 142.