Role of Nematodes in Soil Health

Abstract

Even though the majority of people viewed nematodes from the negative perspective of being destructive to crop plants, however, as microscopic soil dwellers, they contribute positively to a healthy soil ecosystem. Therefore, the paper examines the multifaceted roles of nematodes in ensuring soil health in our agroecosystems. Accordingly, as soil microfauna, nematodes are grouped into the free-living and plant-parasitic ones. The study also highlights the abundance and diversity of nematodes as well as different nematode feeding groups (bacterivores, fungivores, predators, etc.). These different nematode feeding groups are known to enhance soil health through nutrient cycling, decomposition, and bioindication. Their grazing effects on other microbes (bacteria and fungi) facilitate the release of trapped nutrients (mineralization) to the soil for plant uptake, particularly nitrogen, which is essential for their effective growth. Predatory nematodes further contribute by regulating herbivore populations that could lead to excessive nutrient loss from plant roots and, by extension, cause yield losses. Additionally, nematodes act as decomposition dynamos by stimulating microbial activity and accelerating the breakdown of organic matter into usable nutrients (Nitrates and ammonium) to plants. Their contribution also extends to soil structure through the promotion of soil aggregate formation, which improves water infiltration and aeration. Furthermore, the composition of the nematode community serves as a good bioindicator of soil health. Therefore, these provide valuable insights into the overall soil health conditions as well as the need for maintaining the nematode abundance in the soils through various effective soil management practices for sustainable agriculture in the face of global population growth