Present soil conditions of cultivated land in Japan International symposium on distribution, characteristics and utilization of problem soils

asia asie chemicophysical properties clima climat climate condiciones ambientales condition de milieu environment environmental conditions environnement estructura del suelo facteur de production farmland fertilidad del suelo japan japon land manejo del suelo medio ambiente mise en valeur du sol production factors site factors soil fertility soil management soil morphological features soil physicochemical properties soil structure soil zonation structure du sol surface agricole utile terre tierras trait morphologique du sol