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To assess soil fertility after it has been managed, or to monitor the evolution of its properties when subjected to the impact of some improvement measure, it is necessary to take into consideration physical analysis. Although structure is one of the properties most sensitive to changes, N. I. Savvinov method does not provide precise information related to results of its analysis and soil aggregation state. The present work aim was to evaluate and establish an indicator calibration of structural stability and their relation to the weighted average diameter of aggregates in different soils. To establish the indicator calibration, 161 samples from the cultivable horizon of different types of soils were analyzed. Soils under pasture and forest showed the best indicators of structural stability and a weighted average diameter of their aggregates more favorable for crop development; while those intended for intensive agricultural production showed values indicative of their structure degradation and the prevalence of diameters in their aggregates that affect the proper functioning of soils, so that from results a more accurate interpretation can be made regarding structural stability behavior. [ABSTRACT FROM AUTHOR]

La necesidad de buscar alternativas para mejorar la nutrición de los cultivos ante la baja fertilidad de los suelos agrícolas y la escasez de fertilizantes, cobra cada día mayor importancia. Una de estas alternativas es la aplicación de abonos orgánicos y la inoculación con hongos micorrízicos arbusculares (HMA). El objetivo del presente trabajo fue investigar el efecto de las aplicaciones de vermicompost y la inoculación de un biofertilizante micorrízico sobre el suministro de nutrientes de un suelo Gley Nodular Ferruginoso para plantas de millo perla (Panicum italicum L.). Se ejecutaron dos experimentos en condiciones de mesocosmos en el Instituto Nacional de Ciencias Agrícolas (INCA), se estudiaron cuatro proporciones de suelo-vermicompost, con y sin la inoculación micorrízica, en un diseño completamente aleatorizado con estructura factorial y tres repeticiones. Se evaluaron la altura, la masa seca de la biomasa aérea y la concentración y cantidad de nutrientes en las plantas, la frecuencia e intensidad de la colonización y el número de esporas en el suelo. La aplicación de vermicompost incrementó la disponibilidad de nutrientes del suelo y se reflejó en el incremento de la concentración y la cantidad de nutrientes en las plantas, lo que originó mayor crecimiento y desarrollo de estas; en presencia del millo perla la aplicación de vermicompost hizo disminuir la frecuencia e intensidad de la micorrización, lo que inhibió el efecto de la inoculación con hongos micorrízicos arbusculares y no se afectó la producción de esporas en el suelo. [ABSTRACT FROM AUTHOR]

Various definitions have been established on soil fertility; however, the definition is broad and complex since it depends on the supply of nutrients and other edaphic, environmental factors and the management to which this medium is subjected. The aim of this review has been to integrate various considerations that have been taken regarding the definition of soil fertility in a spread way and present in a broad way results that characterize the fertility of the main Cuban soils. The definition of soil fertility must be broad and complex, since it depends on the supply of nutrients and edaphic, environmental factors, and the management to which this medium is subjected. Based on what has been expressed and considering the complexity of the system where the soil is inserted, the definition of soil fertility is proposed as "the result of the interaction between the plant, the properties of the soil, the environment, the socio-economic phenomena and anthropogenic activity, which give it the ability to serve as a support and supply nutrients in the forms, quantities and proportions that plants require to achieve their growth and development". In the work, chemical, physical-chemical, morphological, physical, biological properties are presented, as well as the impact of socio-economic activities and anthropogenic activity that characterize the fertility of the main Cuban soils. [ABSTRACT FROM AUTHOR]

In the last 20 years in the world, are paying ones paying attention to the problems related with the anthropogenic influence in changes of soil properties, principally at tropical regions for the intensive and continued agriculture use. These investigations are little gone aboard in Cuba, so that in this paper are presenting some results about this problem in Red Lixiviated Ferralitic soils (RLF). These soils occupy about to 150 000 hectares in old Havana province (now Mayabeque and Artemisa province), and they are one of the best agricultural soils of the country. However, they have been submitted during over two centuries to the agricultural exploitation, initially with cultivations like tobacco, sugar cane, coffee and at a later time with viands, grains and vegetables, with models in occasions of tall raw materials, most of all in 1975-1990's period. Taking the above into account we had study the properties of 38 soils profiles of RFL soils in relation with to the use to which they have been subdued, grouping in pattern profiles (under wooded land of forests of over 40 years), preserved (under pasturelands or 20-30's wooded lands years) and agrogenics (under permanent cultivation during a lot of years). The impacts in the biological activity of the soils and the decrease of the relative productivity of the agrogenic soils respect to the soil pattern were examined besides. Finally a series of indicators are proposed to the different type of soils (pattern, preserved and agrogenic) and is emphasized that the sostenibility of the soils in this ecosystem is given to maintain an adequate content in organic matter, than together with the contents and type of clay and the one iron content maintains a formation of a good structure in them. [ABSTRACT FROM AUTHOR]