Nutrient acquisition and nitrate reductase activity of mycorrhizal Retama sphaerocarpa L. seedlings afforested in an amended semiarid soil under two water regimes

Abstract

Abstract. We studied the effect of inoculation with three arbuscular‐mycorrhizal (AM) fungi (Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge) and Glomus mosseae ([Nicol & Gerd.] Gerd. & Trappe) and the addition of composted sewage sludge on root nitrate reductase (NR, EC 1.6.6.1.) activity, mycorrhizal colonization, plant growth and nutrient uptake in Retama sphaerocarpa L. seedlings afforested in a semiarid, degraded Mediterranean soil under well‐watered and non‐watered conditions. Six months after planting, the mycorrhizal inoculation and the irrigation of plants had a strong effect on the growth parameters. The effect on plant growth was a negative interaction between plant irrigation and mycorrhizal inoculation and a positive interaction between plant irrigation and composted sewage sludge addition. The latter treatment had a significant, but moderate, effect on the growth but conferred no additional benefit when combined with mycorrhizal inoculation. Mycorrhizal inoculation, composted sewage sludge and irrigation had a significant effect on NR activity in roots and on foliar nutrients. The irrigation significantly increased the positive effect of composted sewage sludge on NR activity and the concentrations of foliar N and K. The effect of mycorrhizal inoculation on NR activity did not depend on the water regime. The effectiveness of mycorrhizal inoculation on the establishment and growth of R. sphaerocarpa seedlings in these Mediterranean conditions was independent of water regime. The addition of composted sewage sludge was only effective when soil water was freely available. The combination of mycorrhizal inoculation and composted sewage sludge addition had no synergistic effect on plant growth.

Biologically Regulated Nutrient Supply Systems

“…While some studies have begun to investigate this question (e.g. Caravaca et al, 2005, Pueschel et al, 2011, this is an area ripe for further investigation.  While short-term studies are valuable, there is a need for longer-term studies that assess the effects of compost and AMF on ultimate agricultural yields, under realistic management conditions.…”

“…addition of other microorganisms or materials, or comparisons of whole farming systems). The publications from which tally data were ultimately derived are cited herein (Adewole and Ilesanmi, 2011, Alguacil et al, 2004, Bilalis and Karamanos, 2010, Caravaca et al, 2005, Caravaca et al, 2002b, Caravaca et al, 2003b, Caravaca et al, 2003c, Caravaca et al, 2002c, Copetta et al, 2011, Douds and Reider, 2003, Duong et al, 2012, Jacquot-Plumey et al, 2003, Jacquot-Plumey et al, 2001, Kaushish et al, 2011, Krey et al, 2011, Krey et al, 2013, Linderman and Davis, 2001, Marosz, 2012, Noyd et al, 1996, Osorio et al, 2002, Palenzuela et al, 2002, Puschel et al, 2008, Roldan et al, 2008, Sainz et al, 1998, Simon et al, 2006, Tanwar et al, 2013, Tarkalson et al, 1998, Totola and Borges, 2000, Caravaca et al, 2003a, Caravaca et al, 2002a, Viti et al, 2010, Wu et al, 2011, Celik, 2009, Celik et al, 2004, Daynes et al, 2013, Ortas et al, 2013, Celik et al, 2010…”

“…For example, Alguacil et al (2004) found that when three different AMF were added to the soil along with compost, there was an increase in the growth of a woody shrub compared to where neither compost nor AMF were added. However, when working with the same fungi and plant species, the same group found that under irrigated conditions there was an increase in growth with the same fungi, and that this was only true for two of the fungi under unirrigated conditions (Caravaca et al, 2005). In another study, in which compost and AMF effects on the growth of four different plant species were investigated, it was found that again responses differed amount plant species (Palenzuela et al, 2002).…”

Abiotic Stress Remediation by the Arbuscular Mycorrhizal Symbiosis and Rhizosphere Bacteria/Yeast Interactions

“…Besides an increase of plant nutrition and growth, an enhancement of plant tolerance to drought or heavy metal stress has also been reported. Some of the mechanisms involved in that tolerance are reduction of heavy metal translocation to the shoots (Medina et al, 2006), an increase of the osmolytes proline and sugar content in plant tissues, and an increase of antioxidant enzyme activity (Caravaca et al, 2005;Medina et al, 2010a).…”

Seasonality and host preference of arbuscular mycorrhizal fungi of five plant species in the inner Mongolia steppe, China

“…AM fungi comprise the largest component (mycelia and spores) of the microbial biomass in soil (14, 30, 32) and can increase plant nutrient and water uptake, particularly in nutrient poor soil of arid and semiarid ecosystems (1, 8, 10, 22, 24). AM fungi therefore play an important ecological role in determining the plant diversity, productivity, and species composition in terrestrial ecosystems (26, 43, 44, 45).…”