Cover crop farming system affects macroarthropods community diversity in Regosol of Caatinga, Brazil

Abstract

The influence of a 3-years cultivation of legumes on macroarthropod community composition was investigated. Soil samples were taken from a field experiment which was conducted for three years to characterize the agronomic characteristics of eight cover crops: Crotalaria juncea L., Crotalaria spectabilis Roth, Crotalaria ochroleuca G. Don., Canavalia ensiformis (L.) DC., Mucuna pruriens (L.) DC., Dolichos lablab L., Neonotonia wightii (Wight & Arn.) J.A. Lackey, and Brachiaria decumbens Stapf. cv. Basilisk. The highest values of diversity in the macroarthropod community were found on the plot where M. pruriens was cultivated. Brachiaria decumbens cultivation showed lower values of species richness, Shannon's diversity index and Simpson's dominance index compared to the other studied plant species. Our findings suggest that the cultivation of legume cover crops can change positively the macroarthropod community composition. The results highlight the importance of considering the effects of legumes on the diversity of this biological component and their effect on plant growth and soil organic carbon contents. Thus, legumes may exploit positive feedback in semiarid conditions on a Regosol.

Soil macroarthropod community and soil biological quality index in a green manure farming system of the Brazilian semi-arid

“…This ecoregion is characterized by frequent dry periods, annual rainfall lower than 800 mm, aridity index lower than 0.40 and a unique soil macroarthropod community (Souza et al 2016). However, both the diversity and the dominance of this soil organism community are often restricted by seasonal variation and the quality of soil organic matter (Souza et al 2016;Coyle et al 2017;Roy et al 2018;Melo et al 2019).…”

“…According to Amazonas et al (2018) and Souza and Freitas (2018), plant species of the Fabaceae family with fast growth and high rate of biomass production influence positively the species richness, Shannon's diversity index and Simpson's dominance index of the native macroarthropod community in Brazilian semi-arid conditions. Leguminous species, such as Crotalaria spectabilis Roth and Mucuna pruriens (L.) DC., can increase macroarthropod richness (e.g., on average 200% higher species richness and 140% higher Shannon's diversity index than in non-legume species) (Melo et al 2019). Understanding the effect of the addition of these legumes which may regulate the macroarthropod diversity in a semi-arid ecoregion is essential to explain why soil fauna groups (e.g., litter transformers, herbivores and predators) become less frequent during the dry season (Manwaring et al 2018;Roy et al 2018;Nunes et al 2019).…”

“…In the first one, leguminous plant species promote the soil organisms group due to increases in the fauna's habitat structure, while in the second one (e.g., when plant biomass was incorporated into the soil profile), we promote soil macroarthropod abundance and diversity due to increases in both food and habitat of soil fauna community. Based on the enemies and resource concentration hypotheses, we expected to find higher macroarthropod abundance during the dry period in plots where Fabaceae plant species were cultivated, due to their high biomass production which acts following soil incorporation as both habitat and food for a diverse soil macroarthropod community (Silva et al 2013;Souza et al 2016;Melo et al 2019). Our aim was to determine whether the long-term green manure practice and seasonality alters soil macroarthropod community structure in an agroecosystem of the Brazilian semi-arid.…”

Soil biotic and abiotic characteristics as driven factors for site quality of Araucaria angustifolia plantations

“…Our hypothesis that a high-productivity site presents high biological activity resulting in an increased release of available nutrients and a concomitant increase in ne roots production in a speci c layer, and plant growth, and thus, creating a positive plant-soil feedback was supported. Overall, soil fauna community composition in the high-productivity site was characterized by i) a high abundance of ecosystem engineers (e.g., Termitidae) and predators (e.g., Isotomidae), which give us evidence of sites with a high degree of bioturbation, organic matter decomposition, and biological control (Forstall-Sosa et al 2020;Melo et al 2019); ii) a low abundance of symbionts (e.g., e.g., Claroideiglomus claroideum, Funneliformis mosseae, Glomus sp., and Rhizoglomus intraradices) which re ect a high content of plantavailable nutrients, creating an independence of A. angustifolia plants in this site (Souza et al 2019); and iii) a high abundance of higher trophic levels of soil nematodes, which indicate that soil nematode community are promoting nutrient cycling, plant biomass, net N, and net P (Rosen eld and Müller 2020). These three characteristics created a positive effect in the trophic structure by promoting some important ecological processes such as nutrient cycling, biological control, mutualism, parasitism, and soil organic matter formation (Barel et al 2019;Cuassolo et al 2020;Ge et al 2019;Jo et al 2020;Zhang et al 2018).…”

Soil Biotic and Abiotic Traits as Driven Factors for Site Quality of Araucaria Angustifolia Plantations

“…with a high degree of bioturbation, organic matter decomposition, and biological control (Forstall-Sosa et al 2020;Melo et al 2019); ii) a low abundance of symbionts (e.g., e.g., Claroideiglomus claroideum, Funneliformis mosseae, Glomus sp., and Rhizoglomus intraradices) which re ect a high content of plantavailable nutrients, creating an independence of A. angustifolia plants in this site(Souza et al 2019); and iii) a high abundance of higher trophic levels of soil nematodes, which indicate that soil nematode community are promoting nutrient cycling, plant biomass, net N, and net P (Rosen eld and Müller 2020). These three characteristics created a positive effect in the trophic structure by promoting some important ecological processes such as nutrient cycling, biological control, mutualism, parasitism, and soil organic matter formation(Barel et al 2019;Cuassolo et al 2020;Ge et al 2019;Jo et al 2020;Zhang et al 2018).…”