The current situation of environmental degradation makes necessary that agricultural management guarantees the satisfaction of the growing needs of foods that is technically feasible, economically viable, socially justifiable and that neither contaminate the atmosphere, nor damage natural ecosystems.
In Cuba, the intensive exploitation of Red Ferrallitic soils is developed to guarantee the feeding of an important number of people, being this more remarkable in areas of Ferrallitic soils next to Havana, the capital of the country cited by Calzadilla (2016)CALZADILLA, C.M.: “Reporte sobre suelos en cultivos varios”, Granma, primera ed., p. 1, La Habana, Cuba, 2 de noviembre de 2016, ISSN: 0864-0424, Disponible en: internet@granma.cu.. In these soils, several cultivations, sugarcane, grasses, plantain and bananas, among others are sown intensively. The accumulation of organic matter and its preservation in form of carbon in these soils are not uniform and depend on the type of crop and the phytotechnical works applied. Each system of agricultural exploitation affects the physical, chemical and physical-chemical properties with different degree of intensity; where the mitigation of adverse properties is highly determined by the capture of carbon produced in the soils (Mesías et al., 2018MESÍAS, G.F.W.; HERNÁNDEZ, J.A.; MACÍAS, V.L.R.; GUZMÁN, C.Á.M.; CEDEÑO, S.Á.F.; ORMAZA, C.K.P.; LÓPEZ, A.G.A.: “Reservas de carbono orgánico en suelos de la llanura fluvial Calceta-Tosagua, Manabí, Ecuador”, Cultivos Tropicales, 39(4): 27-33, 2018, ISSN: 0258-5936.).
The soil volume density rarely overcomes 1.5 Mg m-3 and, can be even smaller than 1 Mg m-3 in superficial horizons, rich in soil organic matter (MOS). This is due to the accommodation or ordination of the particles that leaves empty spaces among them, as well as to the existence of conduits and structures of biological origin.
The capacity of retention of accessible water for the plants depends on the volume and type of pores that constitute those “empty” spaces. The soil permeability and penetrability by the roots also depend on the characteristics of the porous system. In the pores, the edaphic biota inhabits and carry out important biotic transformations. It is considered that in soils with very low content of MOS, most of the call labile humus has been destroyed, while the most constant forms (the stable humus or recalcitrant humus) have been preserved. In those intervals a narrow lineal relationship exists between its content and the density of volume. It can be interpreted that, as the content of MOS increases its capacity, soil agglutinating particles also increase (Ortega et al., 2002ORTEGA, F.; PONCE DE LEÓN, D.; HERNÁNDEZ, G.: Las reservas de carbono orgánico de los suelos minerales de Cuba. Aporte metodológico al cálculo y generalización espacial, Inst. Instituto de Antropología, La Habana, Cuba, Publisher: UNAH, 2002.; Moghimi et al., 2012MOGHIMI, A.; HAMDAN, J.; SHAMSHUDDIN, J.; SAMSURI, A.; ABTAHI, A.: “Mineralogy and aggregate stability of soils in the arid region of Southeastern Iran”, African Journal of Agricultural Research, 7(11): 1639-1649, 2012, ISSN: 1991-637X.).
Wright & Upadhyaya (1998)WRIGHT, S.F.; UPADHYAYA, A.: “A survey of soils for aggregate stability and glomalin, a glycoprotein produced by hyphae of arbuscular mycorrhizal fungi”, Plant and soil, 198(1): 97-107, 1998, ISSN: 1573-5036. and Rivera et al. (2003)RIVERA, R.; FERNÁNDEZ, F.; HERNÁNDEZ, A.; MARTIN, J.; FERNÁNDEZ, K.: “El manejo eficiente de la simbiosis micorrízica, una vía hacia la agricultura sostenible Estudio de caso: El Caribe”, Ediciones INCA, 2003. a opened a new field of investigation when discovered the paper of Glomalin, a protein product of the activity of Arbuscular Mycorrhizal Fungi (HMA), regarding the formation of aggregates in the soils. Glomalin, root exudates and bacterial mucilage seem to be, in that order, the main forming agents of aggregates with higher agronomic value.
Besides, those compounds are an important source of energy for soil microorganisms and, therefore, of the whole trophic chain. That means that they are consumed with enough speed, that their presence in the soil is due to a dynamic balance between its formation and disappearance. The dynamism of the MOS labile fraction generates cycles with phases of accumulation, when the arrival of fresh organic material to the soil is magnified and destruction phases, when the entrance of fresh material is minimized or when the soil is perturbed by natural events or by the anthropic action, especially the farming (Orellana et al., 2008ORELLANA, G.; ORTEGA, F.; MORENO, A.: “Fracción orgánica ligera del suelo como indicador agroecológico”, Revista de Agricultura Orgánica, 2: 40-41, 2008.; León & Ravelo, 2010LEÓN, N.P.; RAVELO, O.R.: Fitotecnia general: aplicada a las condiciones tropicales, Ed. Editorial Pueblo y Educación, primera ed., La Habana, Cuba, 99-137 p., 2010, ISBN: 959-07-1522-2.).
The objective of this work was to value the properties of Lixiviated Red Ferrallitic soils subjected to different systems of cultivations, during certain time. The valued crops were sugarcane (Saccharum officinarum L.), several cultivations like potato (Solanum tuberosum L), corn (Zea mays L) and sweet potato (Ipomoea batata Lam), medicinal plants like Torongil (Melissa officinalis L.) Caña Santa (Costus spicatus Jacq). Also non-farming conditions were valued.
For the realization of this work three areas were selected, dedicated to different cultivations. The first one, with an extension of 30 hectares of Lixiviated Red ferrallitic soils dedicated to intensive sugarcane cultivation, is located in “Hector Molina” Sugar Mill, San Nicolas de Bari, Municipality, between coordinates 329100-321800 north and 410700-415800 east, Mayabeque Province. In that area, three fields were chosen, a virgin field located in the central part of the area studied, not cultivated for more than a hundred years (A-1) and two fields (A-2 and A-3), cultivated of sugarcane (Saccharum officinarum L.) during 12 and 75 years, respectively.
The characteristics of each of these fields are the following:
A-1 (virgin soil): This soil presents natural vegetation of Royal Palm (Roystonea regia), Algarrobo (Samanea saman Merr.), Ceiba (Ceiba pentandra Lin.), Mango (Mangifera indica L.) and Mamoncillo (Melicocca bijuga Lin). This field has not been cultivated, in the last hundred years.
A-2 (soil cultivated during 12 years with sugarcane and previously with grasses). This field was sowed of sugarcane until the year 1967, and later on with grasses, without applications of fertilizers. Since 2005, it began to be cultivated intensively with sugarcane, variety J60-5 and works were carried out with tractors, the annual fertilization was follows:
In 2005 and 2008, formula 12-8-18 to reason of 376 kg ha-¹
In 2009 and 2010 formula 12-8-18 to reason of 596 kg ha-¹ and additional applications of nitrogen formula 46-0-0 to reason of 149 kg ha-¹
From 2011 to 2017, formula 10-5-14 to reason of 376 kg ha-¹ and nitrogen applications formula 46-0-0 to reason of 149 kg ha-¹
A-3. Soil cultivated with sugarcane during 75 years: This field is sown with sugarcane since the beginning of XX century. The varieties sown in 1942 were Crystalline and POJ-2878, with 36 cuts without demolition. Later on, J-60-5 was sowed.
Fertilization and cultivation works were the same as in the previous field, with the difference that, in the first years of cultivation, fertilizers were not used.
In each of the fields selected for the investigation, 7 soil profiles were taken, distributed randomly. In each profile, a sampling with the following depths was performed; 0-10, 10-20; 20-40; 40-70; 70-100 and more than 100 cm.
A-4.The study of the effect of the cultivation of medicinal plants in Lixiviated Red Ferrallitic soils was carried out in the Experimental Station “Delicias Chicas”, in San Antonio de los Baños Municipality, Artemisa Province. It was performed in the coordinates 3,42-3,40o north latitude and 3,45-3,47o west longitude, with an extension of 92,13 ha. This station has been dedicated to the cultivation of medicinal plants for more than 20 years, and there, 7 creeks from 0 to 100 cm of depth were carried out. In these cultivations mineral fertilizers were not used, only bovine manure was utilized to reason of 5 t ha-1
A-5. The study of the effect of the several cultivations in the Lixiviated Red Ferrallitic soils was carried out in the Military Farm “Güines”, located between coordinates 38,6450-32,7900 north and 33,9020-33,0330 east, with an extension of 323.95 ha. In these soils, potato (Solanum tuberosum L), corn (Zea mays L. Merrill), sweet potato (Ipomea sweet potato Lam), bean (Phaseolus vulgaris L) and other crops have been cultivated without a pre-established rotation, during 18 years. Mineral fertilization was applied, in the potato crop to reason of a dose of 0.59 t ha-1 of the formula 9-13-17 and of urea, 0.11 kg ha-1 were applied in fractional form. The rest of the cultivations that were rotated were not fertilized and the residual nutrient that potato crop did not use was utilized.
In the Lixiviated Red Ferrallitic soils, the organic matter (MO) participates very actively in their fertility, in spite of their relative low content and it influences in the growth and development of the plants through varied mechanisms (Kononova, 1981KONONOVA, M.M.: Soil organic matter, its nature, its role in soil formation and in soil fertility., Ed. Pergamon Press, New York, USA, 450 p., publisher: Pergamon press, 1981.; Ortega & Arcia, 1983ORTEGA, F.; ARCIA, M.: “Determination of the rains in Cuba during the glaciation of the Wisconsin, by means of the relictos edáficos”, Ciencia Tierra and Space, 4: 85-104, 1983.).
Since the beginning of agriculture in Cuba, little conservationist practical measures have been applied, with adverse secondary effects like the decrease of organic carbon reservations of the soil and the deterioration of physical, chemical and biological fertilities. Such practices have gone from deforestation, white washed (applied, not with the spirit of amending the reaction of acid soils, but of accelerating humus decomposition for liberating nitrogen to nurture the plantations of coffee and sugarcane according Vigil & Ortega (2000)VIGIL, O.; ORTEGA, A.: “Papel de las causas naturales en la decadencia de la industria cafetalera en Cuba”, En: Antropología 2000, La Habana, Cuba, 2000., until the excess of tillage.
In Table1, it is observed that in all the fields studied of Lixiviated Red Ferrallitic soils, there is a content of clay superior to 70 % with a tendency to increase in depth, due to the lixiviation they suffer; what agrees with the approaches of Agafonov (1981), cited by Hernández et al. (2013)HERNÁNDEZ, J.A.; CABRERA, R.A.; BORGES, B.Y.; VARGAS, B.D.; BERNAL, F.A.; MORALES, D.M.; ASCANIO, G.M.O.: “Degradación de los suelos Ferralíticos Rojos Lixiviados y sus indicadores de la Llanura Roja de La Habana”, Cultivos Tropicales, 34(3): 45-51, 2013, ISSN: 0258-5936..
When valuing the field T-1, without cultivating during 100 years, the dispersion factor varies from 14.38 (0 to 10 cm deep) up to 19.80 (70 to 100 cm deep), what is valued as patron profile, Hernández et al. (2013)HERNÁNDEZ, J.A.; CABRERA, R.A.; BORGES, B.Y.; VARGAS, B.D.; BERNAL, F.A.; MORALES, D.M.; ASCANIO, G.M.O.: “Degradación de los suelos Ferralíticos Rojos Lixiviados y sus indicadores de la Llanura Roja de La Habana”, Cultivos Tropicales, 34(3): 45-51, 2013, ISSN: 0258-5936. as a reflex of the little influence of the anthropic activity in the area studied. In the fields A-2 and A-3, sowed of sugarcane during 12 and 75 years, respectively, the dispersion factor was increased in the surface to 32.14 and 46.46, respectively, what is classified as agrogenic profile. In the areas of medicinal plants, these cultivars are subjected to few cultural activities making that the dispersion factor is less than 20, valuing it as preserved profile Hernández et al. (2013)HERNÁNDEZ, J.A.; CABRERA, R.A.; BORGES, B.Y.; VARGAS, B.D.; BERNAL, F.A.; MORALES, D.M.; ASCANIO, G.M.O.: “Degradación de los suelos Ferralíticos Rojos Lixiviados y sus indicadores de la Llanura Roja de La Habana”, Cultivos Tropicales, 34(3): 45-51, 2013, ISSN: 0258-5936..
In the areas of several cultivations, where the phytotechnical activities are intense, for the establishment of the continuous cultivation, the value of the dispersion factor is bigger than 20, what demonstrates the peptization the soil structure suffers, being classified the profile like acrogenic, what agrees with the approaches by Hernández et al. (2013)HERNÁNDEZ, J.A.; CABRERA, R.A.; BORGES, B.Y.; VARGAS, B.D.; BERNAL, F.A.; MORALES, D.M.; ASCANIO, G.M.O.: “Degradación de los suelos Ferralíticos Rojos Lixiviados y sus indicadores de la Llanura Roja de La Habana”, Cultivos Tropicales, 34(3): 45-51, 2013, ISSN: 0258-5936..
In Table 2, it is observed that, in the area without cultivation, the pH is neuter, and the hydrolytic acidity is 1.04, what is classified as low. In this field, calcium suffers an accumulation in an approximate surface of 8 776 kg ha-1, due to the extraction and deposition that roots and vegetable remains make of the calcium coming from the calcareous rock that originate these soils; what coincides with the results published by WRB (2007)WRB: Base Referencial Mundial del Recurso Suelo. Un marco conceptual para clasificación, correlación y comunicación internacional, WRB, pp. 91., 2007. and Elberling et al. (2013)ELBERLING, B.; BREUNING, M.H.; KNICKER, H.: “Carbon sequestration in iron-nodules in moist semi-deciduous tropical forest soil”, Geoderma, 200: 202-207, 2013, ISSN: 0016-7061..
In the fields T-2 and T-3, sowed with sugarcane, the pH and the hydrolytic acidity have the tendency to be acidified, due to the fertilizers of acid character that are used in the crop, what agrees with the approaches of Humbert (1965)HUMBERT, R.P.: El cultivo de la caña de azúcar, Ed. Continental México, Ediciones Universitarias ed., México, 787 p., 1965..
This acid effect of the mineral fertilizers contributed to that the interchangeable calcium was washed and diminished its content in surface, also facilitating that the relationship Ca / Mg approaches to the normality.
When valuing the capacity of exchanging bases, in the field without cultivating, it was found that, from 0 to 20 cm of depth, it surpasses the 20 cmol kg-1 , what is valued of high, due to the extraction and deposition of bases that the natural vegetation makes, while in the soils cultivated of sugarcane, the extraction and export made of the interchangeable bases with the crop, allow that the CCB is inferior to 15 cmol kg-1 what is valued of medium, aspect that agrees with the approaches of Kölln et al. (2013)KÖLLN, O.; GAVA, G.; CANTARELLA, H.; FRANCO, H.; RHEIN, A.; TRIVELIN, P.: “Macronutrient accumulation and export in sugarcane as affected by N rate under subsurface drip irrigation.”, En: International Society of Sugar Cane Technologists: Proceedings of the XXVIIIth Congress, June 24 to June 27, 2013, São Paulo, Brazil, Ed. Sociedade dos Técnicos Açucareiros e Alcooleiros do Brasil (STAB) & The …, São Paulo, Brazil, pp. 72-73, 2013, ISBN: 0-949678-27-9. In the field T-4 cultivated with medicinal plants, the CCB is inferior to 10.92 cmol kg-1 in surface and it diminishes with depth, due to the strong extraction of bases and nutrients that makes this type of plant, for the production of essential oils, what agrees with Jacob & Uexkull (1967)JACOB, A.; UEXKULL, H.V.: Fertilización: Nutrición y abonado de los cultivos tropicales y subtropicales, Ed. Editorial Revolucionaria, EUROAMERICANAS, ed., La Habana, Cuba, 207 p., 1967..
The areas dedicated to several cultivations present a content of calcium and magnesium of 15 and 10.5 cmol kg-1, superior to the fields sowed of sugarcane and medicinal plants because the watering waters used possess a high concentration of salts (Table 3).
This high content of bases in the watering waters is due to the intensity of the carsism in calcareous rocks which originate to the floors Red Ferrallitic, product of the increment of the CO2 like consequence of the climatic change what agrees with the approaches from Hernández et al. (2013)HERNÁNDEZ, J.A.; CABRERA, R.A.; BORGES, B.Y.; VARGAS, B.D.; BERNAL, F.A.; MORALES, D.M.; ASCANIO, G.M.O.: “Degradación de los suelos Ferralíticos Rojos Lixiviados y sus indicadores de la Llanura Roja de La Habana”, Cultivos Tropicales, 34(3): 45-51, 2013, ISSN: 0258-5936. and Herrera (2018)HERRERA, L.: Cambios de algunas propiedades de los suelos Ferralíticos Rojos lixiviados dedicados al cultivo de la papa (Solanum tuberosum L.)., Universidad Agraria de La Habana “Fructuoso Rodríguez Pérez”, Facultad de Agronomía, Departamento de Suelo y Agua, Trabajo de Diploma en opción al Título de Ingeniero Agrónomo, San José de las Lajas, Mayabeque, Cuba, 2018..
When underground water enriched in HCO3 passes through the rocks, it dissolves the bases which enrich it and, when it is applied to the cultivations, through the watering, the content of bases in the soils also increases and makes the pH superior to 7. It can be observed that, cations and anions content is superior at the end of the less humid period, affecting fundamentally to potato and tobacco cultivations (Herrera, 2018HERRERA, L.: Cambios de algunas propiedades de los suelos Ferralíticos Rojos lixiviados dedicados al cultivo de la papa (Solanum tuberosum L.)., Universidad Agraria de La Habana “Fructuoso Rodríguez Pérez”, Facultad de Agronomía, Departamento de Suelo y Agua, Trabajo de Diploma en opción al Título de Ingeniero Agrónomo, San José de las Lajas, Mayabeque, Cuba, 2018.; Ricote, 2018RICOTE, O.J.: Mejora de la calidad comercial del tabaco (Nicotiana tabacum, l.) ‘Criollo-98’ mediante enmienda con turba ácida, Instituto de Investigaciones Fundamentales en Agricultura Tropical “Alejandro de Humboldt”, Tesis en opción al Grado Científico de Doctor en Ciencias Agrícolas, La Habana, Cuba, 2018.).
In Table 4, it was found that Field A-1, on the surface, the content of organic matter is 5.35% due to the contribution that is made of organic waste, through 100 years by perennial plants (Ponce de León, 2002PONCE DE LEÓN, D.: Los suelos minerales de Cuba, aporte metodológico al cálculo y generalización espacial, Universidad Agraria de La Habana. Facultad de Agronomía. Dpto. Riego Drenaje y Ciencias del Suelo, Tesis presentada en opción al grado científico de Doctor en Ciencias Agrícolas, San José de las Lajas, Mayabeque, Cuba, 122 p., 2002.).
If we assess the organic carbon reserve in Profile A-1, from 0 to 30 cm deep, it is 48.38 Mg ha-1, according to González et al. (2014)GONZÁLEZ, M.L.; ACOSTA, M.M.; CARRILLO, A.F.; BÁEZ, P.A.; GONZÁLEZ, C.J.M.: “Cambios de carbono orgánico del suelo bajo escenarios de cambio de uso de suelo en México”, Revista mexicana de ciencias agrícolas, 5(7): 1275-1285, 2014, ISSN: 2007-0934. is classified as Alto, which provides the soil with a better structure and a greater cation exchange capacity (Espinoza, 2004ESPINOZA, Y.: “Calidad de la materia orgánica bajo diferentes prácticas de manejo en un suelo ácido tropical.”, Revista de la Facultad de Agronomía (LUZ), 21(2): 126-141, 2004, ISSN: 0378-7818.).
In fields A-2 and A-3 (Table 4) planted with sugar cane (Saccharum officinarum L.) for 12 and 75 years respectively, and where burning is not practiced, there has been an accumulation of organic matter from 0 to 10 cm of 4.44 and 4.41%, which is valued from high (Molina & Meléndez, 2002MOLINA, E.; MELÉNDEZ, G.: Tabla de interpretación de análisis de suelos, Inst. Universidad de Costa Rica, Centro de Investigación Agronómicas. San José, San José, Costa Rica, 2002.; Martín & Martín, 2018MARTÍN, N.; MARTÍN, G.: Tablas de interpretación de análisis de suelos, Inst. Universidad Agraria de La Habana, Publicación UNAH, San José de las Lajas, Mayabeque, Cuba, 2018.). This grass is of the C-4 type, which makes a high contribution of dry matter to the soil. This has protected the crop from the detrimental effect of weed plants and the retention of moisture by reducing evaporation. In depth, the organic content is classified as high, due to the contribution of the grass root system, which coincides with the criteria of Chopart et al. (2010)CHOPART, J.; AZEVEDO, M.; LE MEZO, L.; MARION, D.: “Sugarcane root system depth in three different countries”, Int. Soc. Sugar Cane Technol, 27: 1-8, 2010..
The COS reserve in Mg ha-1 for both fields is (A-2 = 61.37 and A-3 = 64.6) at the depth of 0 to 30 cm, they are estimated as very high, according to González et al. (2014)GONZÁLEZ, M.L.; ACOSTA, M.M.; CARRILLO, A.F.; BÁEZ, P.A.; GONZÁLEZ, C.J.M.: “Cambios de carbono orgánico del suelo bajo escenarios de cambio de uso de suelo en México”, Revista mexicana de ciencias agrícolas, 5(7): 1275-1285, 2014, ISSN: 2007-0934..
Field A-4 is planted with medicinal plants, mainly Caña Santa (Costus spicatus Jacq) and Toronjil (Melissa officinalis L.), to obtain essential oils for medicinal use and perfumery.
These cultivars are mainly used on the leaves, but the roots have a content of essential oils, incorporating a high content of organic matter, in depth, distributed in isohumic form up to one meter deep, which has allowed a carbon capture of 0 to 30 cm of 89.3 Mg ha-1 which is valued as extremely high according to González et al. (2014)GONZÁLEZ, M.L.; ACOSTA, M.M.; CARRILLO, A.F.; BÁEZ, P.A.; GONZÁLEZ, C.J.M.: “Cambios de carbono orgánico del suelo bajo escenarios de cambio de uso de suelo en México”, Revista mexicana de ciencias agrícolas, 5(7): 1275-1285, 2014, ISSN: 2007-0934.. It should be noted that the soil has a low cation exchange capacity due to the extraction made by the crop in the formation of essential oils, an aspect that has not been much studied (Jacob y Uexkull, 1967JACOB, A.; UEXKULL, H.V.: Fertilización: Nutrición y abonado de los cultivos tropicales y subtropicales, Ed. Editorial Revolucionaria, EUROAMERICANAS, ed., La Habana, Cuba, 207 p., 1967.).
In field A-5 where different short-cycle cultivars are planted such as potato (Solanum tuberosum L), corn (Zea mays L. Merrill), sweet potato (Ipomea batata Lam.), Pumpkin (Cucurbita moschata Duch) and others, the leached Red Ferralitic soils are prepared for sowing on several occasions, intensively, applying various tasks, promoting the oxidation-mineralization of organic matter (León y Ravelo, 2010LEÓN, N.P.; RAVELO, O.R.: Fitotecnia general: aplicada a las condiciones tropicales, Ed. Editorial Pueblo y Educación, primera ed., La Habana, Cuba, 99-137 p., 2010, ISBN: 959-07-1522-2.).
In Table 4, it can also be observed that in this field A-5, from 0 to 10 cm deep, the content of organic matter is 1.66, which is valued as low Martín & Martín (2018)MARTÍN, N.; MARTÍN, G.: Tablas de interpretación de análisis de suelos, Inst. Universidad Agraria de La Habana, Publicación UNAH, San José de las Lajas, Mayabeque, Cuba, 2018. and its depth distribution is not isohumic. All this conditions that at a depth of 30 to 50 cm a plow soil is formed where the volume density is 2.25 kg dm-3, which is valued as compact. Martín & Martín (2018)MARTÍN, N.; MARTÍN, G.: Tablas de interpretación de análisis de suelos, Inst. Universidad Agraria de La Habana, Publicación UNAH, San José de las Lajas, Mayabeque, Cuba, 2018., preventing the drainage of the soil and the penetration of the root system of the plant. It should also be noted that the accumulation of carbon from 0 to 30 cm is 27 Mg ha-1, which is valued as very low González et al. (2014)GONZÁLEZ, M.L.; ACOSTA, M.M.; CARRILLO, A.F.; BÁEZ, P.A.; GONZÁLEZ, C.J.M.: “Cambios de carbono orgánico del suelo bajo escenarios de cambio de uso de suelo en México”, Revista mexicana de ciencias agrícolas, 5(7): 1275-1285, 2014, ISSN: 2007-0934..
In Figure 1, the discontinuity of the content of organic matter is appreciated in depth, because the contribution of the radical system of these perennial plants is smaller. However, where herbaceous vegetation prevails there was an isohumic distribution of the organic residuals, contributed by the root system of the plants (Ponce de León, 2002PONCE DE LEÓN, D.: Los suelos minerales de Cuba, aporte metodológico al cálculo y generalización espacial, Universidad Agraria de La Habana. Facultad de Agronomía. Dpto. Riego Drenaje y Ciencias del Suelo, Tesis presentada en opción al grado científico de Doctor en Ciencias Agrícolas, San José de las Lajas, Mayabeque, Cuba, 122 p., 2002.).
The diversity of crops sown in the Lixiviated Red Ferrallitic soils and the methodologies used for that, make the accumulation of organic matter and the reservations of carbon in these soils varied, which influences in the soil properties and in the yield of the cultivations.
The capacity of change of bases (CCB) diminishes in the fields sowed with sugarcane and medicinal plants compared to the area without cultivating, while in areas with several crops, it is superior due to the fertilizers applied and to the quality of the watering waters enriched with calcium produced by the intense carcism.
The quality of the watering water has varied due to the increase of its content of anions and cations, which varied the pH of the Lixiviated Red Ferrallitic soils, dedicated fundamentally to the cultivation of potato (Solanum tuberosum L) and sweet potato (Ipomoea sweet potato Lin.)-
Crop rotation and the effect of using green manures should be studied in order to increase carbon capture and to diminish the pH variations in the Lixiviated Red Ferrallitic soils.
Study the behavior of carbon sequestration in different sub types of Lixiviated Red Ferrallitic soils, and its effect in the properties of these soils.