See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)
Potential root zone formats were analyzed with and without the gravel CBs for variables including: depth of CB; barrier separating the root zone from the surrounding soil; and root zone soil texture. Field and lysimeter studies were conducted with bell pepper (Capsicum annuum) plants, comparing root-zones with and without an underlying CB and irrigated at various rates with either desalinated (DW, EC = 0.2 dSm-1)) or brackish (SW, EC = 3.8 dS m-1) water.
Field and simulated results revealed that artificial CBs increased root zone water content and changed water flow dynamics. Plants grown above a CB, when irrigated with SW, yielded 24% higher biomass than control plants for all irrigation applications, but when DW was irrigated, only a 6% advantage for the CB root-zone was observed. Biomass yield for the root-zone containing a CB was only slightly affected by water salinity, while yields significantly decreased when irrigated with SW in the control. The extent of water uptake, plant growth and yield responses to the presence of a CB were found to be climate dependent. When VPD was low, smaller responses were measured, while more pronounced response was found when VPD increased.