[Study on the stabilizing substances of the aggregation in soils rich in organic matter. 1: Stable aggregates composition [Spain]]

English. For six organic-matter-rich soils of N.O. Spain, the composition of aggregates that were stable under simulated rain was determined and compared with that of the total soil and with that of the other soils. Farming was found greatly to reduce structural stability, increasing the concentration of coarse materials in stable aggregates; silt-rich soils suffered the greatest deterioration of structural stability. Of the various cementing agents, only organic matter was significantly correlated with aggregation: carbohydrate content was grater in macroaggregates and natural sols than in total farmed soil. Fe and Al oxides failed to act as stabilizers, and clay appeared to behave as inert material rather than as a binding agent

Italian. [Per sei terreni ricchi di sostanza organica del N.O. della Spagna, la composizione degli aggregati stabili sotto piogge simulate e' stata determinata e paragonata con quella del terreno normale e con quella di altri terreni. La coltivazione si e' dimostarta importante per la riduzione della stabilita' strutturale, aumentando la concentrazione di materiali grezzi negli aggregati stabili. I terreni ricchi di limo risentivano del grandissimo deterioramento della stabilita' strutturale. Dei vari agenti cementificanti, solo la sostanza organica e' stata messa in significativa correlazione con l'aggregazione: il contenuto di carboidrati era maggiore nei macroaggregati e nei terreni naturali rispetto ai terreni coltivati. Gli ossidi di Fe e Al non si comportavano come stabilizzanti e la argilla sembrava agire da materiale inerte piu' che da agente aggregante]