Mycotrophy of crops in rotation and soil amendment with peat influence the abundance and effectiveness of indigenous arbuscular mycorrhizal fungi in field soil

Abstract

Mycotrophy of previous crops has been shown to have an impact on arbuscular mycorrhizal fungi (AMF), and the growth and productivity of succeeding crops. We studied the impact of 3 years of cultivation of eight crops with different degrees of mycotrophy, including mycorrhizal (strawberry, rye, timothy, onion, caraway) and non-mycorrhizal (turnip rape, buckwheat, fiddleneck) hosts, as well as the impact of peat amendment, on the effectiveness, amount and diversity of indigenous AMF. A field experiment having a split-plot design with peat amendment as the main plot, crop cultivation as a sub-plot and three replications, was carried out on silt clay mineral soil in 1999-2001. A well-humified dark peat was applied immediately before establishment of the field experiment. Each year, the relative mycorrhizal effectiveness of soil collected in September, in terms of shoot dry weight (RME(DW)), was determined in a bioassay. In the 3rd year of the experiment, AMF spores were also extracted and identified from the field soil. Expressed as the mean of 3 years of cropping in unamended soil, the mycorrhizal crops strawberry and caraway maintained RME(DW) most effectively, while the values were lower in the non-host crops buckwheat, turnip rape and fiddleneck. In addition, the numbers of AM spores detected in soil were considerably greater during 3 years of strawberry cultivation. In soil under caraway, there were high numbers of AM spores compared to the other crops. In soil amended with peat, the situation was in some cases opposite of that of unamended soil; RME(DW) was highest in rye and onion and lowest in strawberry and caraway. The reasons behind the negative impact of peat on mycorrhizal effectiveness in strawberry soil may be due to the microbiological properties of peat. The importance of including mycotrophic species in crop rotations for maintaining high soil quality and for increasing yields of subsequent crops is discussed.

Arbuscular mycorrhizal fungi in field crop production: Potential and new direction

“…The creation of non-mycorrhizal controls through the chemical destruction of native AMF (Buttery et al 1988;Liu et al 2002Liu et al , 2003Gazey et al 2004) or their repression using non-host crops (Vestberg et al 2005), fallow (Abu-Zeyad et al 1999) in rotation, or deep tillage (Miller et al 1995;Kabir et al 1998;Drijber et al 2000;Miller 2000) have revealed that AMF influence crop development. Considering the profound influence of AMF on many aspects of plant physiology and the complexity of the soil system, it is virtually impossible to pinpoint the mechanisms responsible for the AMF effect in any particular case.…”

Effect of different plant densities on the diversity of arbuscular mycorrhizal fungi community in a long-term maize monocrop system

“…This decrease in diversity is attributed to a complex selective pressure of agricultural practices, such as ploughing, fertilization and fungicide application, on the AMF communities (Douds and Millner, 1999;Roldan et al, 2007). Besides agroecosystems plant species, soil types, weeds and previous crop have an effect on AMF population as well (Jansa et al, 2002;Mathimaran et al, 2005;Vestberg et al, 2005). Van der Heijden et al (1998) showed that both plant diversity and plant productivity rise with increasing diversity of mycorrhizal fungi.…”

Efecto De Pre-Cultivos Hospederos Y No Hospederos en El Crecimiento Y Propágulos Micorrícicos De Trigo en Andisol E Inceptisol De Chile

“…Estos compuestos poseen actividad biocida que incluye efectos fitotóxicos (Petersen et al, 2001), nematicidas (Henderson et al, 2009) y fungicidas (Dunne et al, 2003). Algunas investigaciones han informado que el sistema de cultivo y la rotación afectan las esporas y colonización de las raíces (Jeffries y Barea, 2001); pero, al incluir plantas hospederas en la rotación se pueden mantener las comunidades fúngicas con incremento en el rendimiento del cultivo siguiente (Vestberg et al, 2005).…”