Farming systems in the tropics h ruthernberg isbn 9780198594826 kostenloser versand fur alle bucher mit versand und verkauf duch amazon. Farming systems in the tropics ruthenberg hans isbn 9780198594819 kostenloser versand fur alle bucher mit versand und verkauf duch amazon. This analysis of principal farming systems in the tropics with details of farm management problems arising in each case distinguishes seven basically different systems 1 shifting cultivation 2 semipermanent cultivation 3 with regulated ley farming 4 with permanent cultivation on rain fed land 5 with arable irrigation farming 6 with perennial crops 7 grazing in each the