Winter wheat cover cropping, VA mycorrhizal fungi and maize growth and yield

Abstract

The relationships among winter cover cropping, inoculum potential of vesicular-arbuscular mycorrhizal (VAM) fungi, and the growth and yield of a subsequent maize crop were investigated. In the first experiment, an autumn-sown winter wheat cover crop increased VAM fungal inoculum potential of a field soil as measured by an in situ maize bioassay during the following growing season. Infective extra-radical hyphal densities were significantly increased by cover cropping as interpreted from the effect of soil disturbance on infection of the maize bioassay plants. In a second experiment the following year, the winter wheat cover crop again increased VAM fungal inoculum potential as assessed by an in situ maize bioassay during the following growing season. Moreover, the degree of mycorrhizal infection of maize was correlated with maize growth and yield. This study suggests that the management of mycorrhizal fungi by cover cropping may be a useful practice in sustainable agriculture.

Biological and other soil parameters response to winter cover crops in a mediterranean irrigated system

“…We found that barley increased the number of spores by 42-72%, but vetch was similar to fallow. This result differs from Galvez et al (1995), who found that vetch had more spores number relative to fallow and from Boswell et al (1998), who did not report differences between CC and fallow. The heterogeneity in the results may be due to the methodology.…”

“…Studies involving other main crops are scarce, but the effect of CC was similar, e.g., in leeks (Sorensen et al, 2005). In general, the percentages of increase relative to fallow in this study were moderate compared with other studies in which increments of 3-4-fold were found (Boswell et al, 1998;Kabir and Koide, 2002) or even 12-fold (Deguchi et al, 2007), probably because we found large values for root colonization even under fallow conditions. These large values may be related to the optimal temperature and soil moisture conditions from the beginning of maize growth.…”

“…The (Boswell et al, 1998;Deguchi et al, 2007;Kabir andKoide, 2000, 2002;White and Weil, 2010), even under Mediterranean climate conditions (Njeru et al, 2014). Studies involving other main crops are scarce, but the effect of CC was similar, e.g., in leeks (Sorensen et al, 2005).…”

“…Sampling is recommended to be conducted in the early crop stages, since differences in root colonization may disappear over time (Gavito and Miller, 1998;Sorensen et al, 2005). In addition, AMF infection of the crop in early growth stages may be more important because it can be decisive in the success of the seedling establishment (Boswell et al, 1998). Therefore, the effect of replacing a fallow by a CC on AMF should be considered along with the sampling date.…”

“…At that time, AMF infection may be more important because it can be decisive in the success of the seedling establishment phase (Boswell et al, 1998). Therefore, the influence of the sampling date should be considered along with the effect of the CC on AMF.…”