When soil amending your vegetable garden beds.What is the best ingredient to add if your trying to contain moisture and alleviate calishie?

Caliche is the spelling. Ultimately for both purposes, organic matter such as compost, sphagnum peat moss (NOT sedge peat). Caliche is found in high pH soils and can be in granular forms or rock hard layers. It takes time and physical effort, there is no fast cure. Water holding, once again organic matter as it acts like sponges to hold water and nutrients. If your soil is sandy (and I suspect it is from this question), then nutrients cannot stay in a sand soil due to lack of cation ion exchange in sand........technical, let's call them docking stations for soil nutrients. Organic matter has the docking stations so fertilizers don't run thru the soil, organic matter hold water.......a win-win for your soil. Plus as organic matter breaks down it releases humic acids which attacks the caliche........hit trick for the garden. I'd avoid manure or so called "top soil".......the latter in arid climates is nothing more than dried manure and sand and a carrier such as saw dust. Better to find real compost and of course start making your own for the garden. Use mulches to retard water loss from the soil (which also contributes to caliche).

I have no idea what calishie some new fad I imagine. Put on 2" of compost and get a soil analysis done by your State Agricultural Extension Service. Go on line to find out what to do and where to send the samples.

I believe the best material to be peat. This is acidic, moisture retentive and should break up chalky soil.