Appearance

• Caliche can appear as a soil layer lighter than the soil surrounding it, according to the University of Arizona Cooperative Extension. It also forms as rock-hard, white or creamy-white lumps mixed through the soil.
  
  

Caliche's Effects

• Roots struggle to penetrate caliche. Adequate water may not reach the roots that do penetrate it. Caliche's high calcium content can interfere with plants' iron absorption, resulting in yellow new leaves on those affected.
  
  

Working with Caliche

• Removal is the best solution, advises the University of Arizona Cooperative Extension website. Dig holes large enough to hold the plants' mature root systems. Replace the caliche with a soil mix. Drill holes for water drainage in caliche layers that are too thick for complete removal.
  
  

Another Solution

• Build raised beds of good soil above caliche layers that are too thick to remove or drill. Use a mix of 50 percent garden soil and 50 percent vermiculite, sand, perlite or an artificial soil mix, recommends the University of Arizona's horticulture agent Robert Call and vegetable specialist emeritus Norman Oebker.