Analyzing the impact of different dryland cropping histories in Southern NSW Australia on mycorrhizal colonization and biomass of upland cereal and legume crops in glasshouse

Abstract

This study aimed to examine the impacts of different cropping sequences of dryland crops in southern NSW Australia on root colonization levels by the native arbuscular mycorrhizal fungi (AMF) of the soil and biomass weight of some upland cereal and legume crops (sorghum, oats, soybean, and sub-clover) grown on the soil samples in the glasshouse of the University of Western Sydney. The field soil samples were taken from southern NSW areas having different histories of dryland cropping, namely pasture only (PO), pasture-canola-wheat (PCW), and pasture-wheat (PW). For each category of cropping history, there were two sites sampled, each with two bulk field replicates. Each replicate of field soil sample was also analyzed for its content of nutrients and AMF spores and colonization levels of the field crop roots. The results indicated that there were no significant different in soil properties between categories of cropping history, except for Mg and Na contents, which were highest in PO than in PCW and PW soil. There were positive significant correlation between field root colonization and sub-clover colonization and soybean biomass, between total spores and colonization of sorghum and sub-clover, between available P and biomass of sorghum, sub-clover and oats, between Mg or Na and sorghum colonization, between Ca and oats biomass, and negative correlation between Mg and sorghum biomass. However, there were significant interaction between cropping history and several soil properties, indicating significant impacts of cropping history on the relationship between soil properties or AMF colonization and biomass of the glasshouse crops