Significance of mycorrhizal network in no-tillage cultural systems

点击翻译按钮获取中文摘要

No-tillage systems have several advantages reducing soil erosion and production cost comparing with conventional tilled ones, and also they would be suitable for current demand for environmental sound technologies such as saving energy inputs and carbon dioxide exhausted. However, it is pointed out that reduced tillage may cause increased soil compaction which is detrimental to crop growth, especially for inhibited nutrient acquisitions due to restricted root system development. Most species of crop plants enable to form symbiotic associations with arbuscular mycorrhizal fungi, nutrient uptake particularly immobile elements of phosphorus are enhanced with the associations. This study showed that restricted root functions could be restored by utilizing the mycorrhizal symbiosis. The mycorrhizal fungi colonize with host plant roots, establishing the hyphal network structure in soils. This structure functions not only in nutrients transport to the plants from soils but also in exploring other hosts. The hyphal structure is disturbed in conventional tilled systems, but remained in no-tillage ones hence mycorrhizal benefits to help root functions are greatly displayed. As such, we found that the mycorrhizal association under notilled soil conditions counteracts compacted soil stress for pigeon pea. It was also observed that decreases in the fungal infective potential due to the soil disturbance are different among fungal species and also with the presence of other species. Moreover, we demonstrated that the plant can not acquire phosphate sufficiently only with root exudates to solubilize sparingly soluble sources, a mycorrhizal network function as the interaction is significant. Probably, the root and rhizosphere microbes would compete for phosphate released from the sources, the mycorrhizal fungi could increase the competitive ability of the plants due to their larger surface area.