4.1 Root channels
Soil porosity is a sine qua non of soil, and root channels are an important part of soil macropores in the soil system. Root distribution of Jerusalem artichoke was influenced by soil salt content, water content, pH, and other factors (Hartle, Fernandez & Nowak, 2006). In the present study, the root system of Jerusalem artichoke had the best growth under moderate salt stress. Jerusalem artichoke avoided salt damage by not extending roots to deep soil, so most of the root system of NY-1 mainly grew in the soil layer 75-175 mm deep. Hence, the root distribution pattern reflected the adaptive mechanisms of Jerusalem artichoke under salinity stress. Root channels represent a complex interface that is not only the living space of plant roots, microbes and soil animals, but also plays an important role in dynamics of water, nutrients, gas, heat, and other factors in soil (Gupta et al., 2008; Gupta, Naushad & Baker, 2015; Wang, Zhang, Yang, Li & Liu, 2018). The root channels of Jerusalem artichoke improved the physical structure of saline soil and provided basic conditions for the optimization of the soil micro-ecological environment.