Influência do cultivo contínuo da cana-de-açúcar em latossolos amarelos coesos do estado de Alagoas: propriedades micromorfológicas

摘要: The effects of continuous sugarcane cropping on the properties a clayey Yellow Latosol were studied in region Low Coastal Tablelands Alagoas State, Brazil. Four sites selected at Caete mill, Sao Miguel dos Campos, AL, involving native forest (Tn) and fields cultivated for periods two (T2), eighteen (T18) twenty-five (T25) years. soils morphologically characterized undisturbed samples A, AB, BA horizons each profile collected micromorphological analysis. results showed that agricultural use promoted morphological changes with development an Ap horizon loss original structure. After evident negative impact physical after first crop (profile T2), management practices partial increase macroporosity surface 18 25 Besides compaction AB cultivation, natural pedogenetic dense layer was observed horizon. This densification is increased use, due to filling pores illuvial clay. Total porosity measurements obtained by image analysis thin sections revealed decreasing cultivation. reduction, however, did not cropping. also very small even under forest, indicating pedogenic origin this Although clay coatings field, micromorphology pedofeatures peds observation significant textural gradient all suggest tendency formation argillic time.