How to work on a clay / sandy type of soil?

Hello you all,

I need some advise. I just got a piece of land in the Mediterranean area. When it rains the soil gets an clay structure, but in dry weather it becomes quite sandy. 

The land has not been worked on for quite a while. At the moment there are a few vines, apple trees and pines growing on it.

What is the best way to start working on this land, what can I grow here best to make the soil fertile?

Jantra

By the way, the field is about 35m by 30m long.
It is on a small slope facing south.
Summer temperature can go to 35 degrees Celsius and winter 10 degrees below zero.

tap rooted plants, big ones, and lots of them.

I'm far from the mediterranian area but my soil us mostly clay ..deep clay, with a nice topsoil over it..and then there are strips of pure white sand that run through it above the clay here and there..so it is similar to yours other than the climate.

if you would like to check out my blog below, there are lists of plants that I grow here ..but I'm zone 4/5 rather than your warmer climate..so I'm not sure how much help it will be for you

I had the same problem, and I lasagne sheet mulched around the trees.


From top down:


dolomite / lime

water it

hay

high carbon materials

high nitrogen materials

double layer of cardboard

trampled grasses, weeds, and other organic scraps of food.







It takes time to break down, but in the long run, I found it works out the best for large areas that need help. 

We live in a similar situation.  The soil becomes dust in the "growing season" and waterlogged in the winter.

A combination of raised dug-beds works well for veg.  The wall of the raised beds are about a foot above the ground so the soil can drain in wet weather and the roots not rot.  Inside the bed, we dig down about two feet. But not right away when making the bed.  Each year when something comes out, we dig a bit deeper until the soil is three fork lengths deep.  It allows it to capture moisture in the winter which the plants can draw on during the summer.