The “soil microbial loop” is not always needed to explain protozoan stimulation of plants

摘要: Protozoa stimulate plant growth, but we do not completely understand the underlying mechanisms, and different hypotheses seek to explain this phenomenon. To test these hypotheses, grew grass Yorkshire fog (Holcus lanatus) in pots with soil, which contained either (1) no organisms bacteria - or (2) protozoa. Half of received a glucose treatment so as mimic an additional root exudation. We measured growth nitrogen uptake, along various microbial pools processes that support growth. Protozoan presence significantly enhanced soil mineralization, uptake from organic sources, content, By contrast, found evidence addition, mimicking exudation, increased availability uptake. Moreover, although protozoan affected bacterial community structure, it did affect proportion IAA-producing morphology. These results refute "soil loop" suggest stimulation complex interactions between roots, Our experiment thus favours simple explanation is key factor behind positive effect on exploit natural resources efficient environmentally friendly way, need detail functioning ecosystems. This study stresses achieve this, still urgent, besides investigating intricate food-web signal compound interactions, also focus basic stoichiometric energetic aspects organisms.