Leguminous plants significantly increase soil nitrogen cycling across global climates and ecosystem types

Abstract

Leguminous plants are an important component of terrestrial ecosystems and significantly increase soil nitrogen (N) cycling and availability, which affects productivity in most ecosystems. Clarifying whether the effects of legumes on N cycling vary with contrasting ecosystem types and climatic regions is crucial for understanding and predicting ecosystem processes, but these effects are currently unknown. By conducting a global meta-analysis, we revealed that legumes increased the soil net N mineralization rate (R min ) by 67%, which was greater than the recently reported increase associated with N deposition (25%). This effect was similar for tropical (53%) and temperate regions (81%) but was significantly greater in grasslands (151%) and forests (74%) than in croplands (−3%) and was greater in in situ incubation (101%) or short-term experiments (112%) than in laboratory incubation (55%) or long-term experiments (37%). Legumes significantly influenced the dependence of R min on N fertilization and experimental factors. The R min was significantly increased by N fertilization in the nonlegume soils, but not in the legume soils. In addition, the effects of mean annual temperature, soil nutrients and experimental duration on R min were smaller in the legume soils than in the nonlegume soils. Collectively, our results highlighted the significant positive effects of legumes on soil N cycling, and indicated that the effects of legumes should be elucidated when addressing the response of soils to plants.

Above- and below-ground links mediated by arboreal ants and host tree modify soil aggregation scaling, infiltration, and chemistry

“…Results here showed equivalent scaling exponents among macro-aggregates across both ant nest sites and host tree species, but not for micro-aggregates across host tree species, suggesting an interpretation that micro-aggregates were about one-third more likely to continue enlarging smaller, previously aggregated soil clusters into larger soil aggregates, thereby increasing self-similarity of all fine-scale soil aggregates, under leguminous nitrogen-fixing Inga trees, through two mm but before six mm. This faster scaling rate under a legume tree species could be explained by more fungal growth given higher nitrogen availability (Gou et al 2023), since bacteria (Rashid et al 2016) and fungi are well-studied soil aggregators (Ritz and Young 2004; Siddiky et al 2012; Leifheit et al 2014; Baumert et al 2018; Lehmann and Rillig 2015; Lehmann et al 2020), until soil aggregates get massive enough to be influenced more by plant roots than by thinner fungal hyphae (Rillig et al 2015).…”

Impact of varied NPK fertilizer application rates and seed quantities on barley yield and soil nutrient availability in chestnut soil of Azerbaijan

“…This practice likely contributed to soil improvement, potentially explaining the yield increase observed during that specific period. The studies (Freidenreich et al, 2022;Gou et al, 2023) have shown that incorporating leguminous plants into the soil as cover crops increases crop production. Prior to setting up the experiment, leguminous plants, which were used as cover crops in the field, were mixed with the soil just before the experiment, followed by barley planting.…”

The effect of intercropping leguminous green manure on theanine accumulation in the tea plant: A metagenomic analysis

“…Soil microbial functions related to nutrient cycling functions were significantly enhanced, especially soil nitrogen cycling. Legumes have a significant positive effect on soil nitrogen cycling (Gou et al, 2023). In addition, several bacterial genera can perform dissimilatory nitrate reduction to ammonium and denitrification, which are competing dissimilatory NO 3 − /NO 2 − reduction (Nelson et al, 2016).…”