Effects of mixed cropping, earthworms (Pheretima sp.), and arbuscular mycorrhizal fungi (Glomus mosseae) on plant yield, mycorrhizal colonization rate, soil microbial biomass, and nitrogenase activity of free-living rhizosphere bacteria

Plant: soil interactions in temperate multi-cropping production systems

“…Contrasting patterns of fine and coarse root biomass of different plants, and distribution throughout the soil profile can also lead to complementarities in resource use (Craine et al 2003;Zarea et al 2009). Beans (Phaseolus vulgaris) were shown to produce higher root biomass compared to barley.…”

“…In plantsoil systems enzymes, derived from microorganisms, plant roots and plant and animal residues play a significant role in organic matter decomposition and nutrient cycling (Zarea et al 2011). Multi-cropping, with different plant species and specific functional groups, such as N-fixing legumes, affect the abundance, activity and composition of soil enzymes and decomposer communities (Zarea et al 2009). Hence differences in the amount and type of SOC present in a multiple-crop context would be hypothesised.…”

“…Several studies have assessed the increase in N uptake due to intercropping, and have found that in general: (i) cereallegume/N-fixing tree intercrops and N transfer increased N uptake in both crops grown in close proximity (Seiter and Horwath 1999;Zhang et al 2004); (ii) N-transfer is greater in perennial systems, such as clover-grass pastures, compared to annual crops (Jørgensen et al 1999;Høgh-Jensen and Schjoerring 2001); (iii) no beneficial effects on N uptake have been recorded in cereal-cereal intercrops (Wang et al 2007a). The rate at which N is transferred between crops is affected by biomass ratio between the component crops (Dahlin and Stenberg 2010) and the presence of mycorrhizal connections (Zarea et al 2009). In nutrient poor conditions, N transfer increased when roots were able to interact (Xiao et al 2004;Thorsted et al 2006).…”

“…Within multiple-crop systems several mechanisms by which weeds are suppressed have been described. Belowground competitive processes by which weedy plants may be outcompeted have frequently been reported in cereal-legume intercrops, and include the rapid exhaustion of existing resources (light, water and nutrients) and niches (Hauggaard-Nielsen et al 2001b;Singh et al 2003;Poggio 2005;Zarea et al 2009). In addition, allelopathic traits of certain crops have the potential to inhibit the growth of weeds (Batish et al 2001).…”

Arbuscular Mycorrhizal Fungi Alleviate the Negative Effects of Iron Oxide Nanoparticles on Bacterial Community in Rhizospheric Soils

“…Indeed, the roles of AMF in stress attenuation in plants that grow in soils contaminated with a variety of pollutants, such as heavy metals (Andrade et al, 2010), salt or alkali (Labidi et al, 2012), and organic pollutants (Wu et al, 2011), have been widely reported. Because plant physiology is affected by AMF symbiosis, root exudates are also influenced by the production of a new biochemical, resulting in the alteration of microbial activities (Zarea et al, 2009). For example, Aghababaei et al (2014) revealed that the presence of AMF increased soil microbial activity that might be partially attributable to the greater plant biomass under heavy metal stress.…”