Soil Chemical Attributes under Crop-Livestock-Forest Integration System and in Different Land Uses in Mata dos Cocais Region

Abstract

The sustainability of ecosystems is closely linked with the assessment of soil properties that estimate their quality. This work proposes to evaluate soil chemical attributes as a function of the implantation of a crop-livestock-forest integration system (ICLF) in the region of Mata dos Cocais in the state of Maranhão, Northeast Brazil. The four different land uses evaluated were native vegetation with babassu, capoeira vegetation, degraded pasture and area under ICLF system (with marandu grass, maize and eucalyptus consortium). The samples were collected up to one meter deep, comprising seven layers: 0.00-0.10, 0.10-0.20, 0.20-0.30, 0.30-0.40, 0.40-0.60, 0.60-0.80 and 0.80-1.0 m. The chemical attributes evaluated were pH, Ca, Mg, Al, P, K and Na, potential acidity, base sum, base saturation and soil cation exchange capacity (CEC). The levels of P, in the 0.00-0.10 m layer, were higher in the ICLF system than those of the native forest with babassu. The levels of K in the ICLF system and degraded pasture were higher than the other land uses up to a depth of 0.40 m, ranging from 0.92 cmolc dm-3 to 0.62 cmolc dm-3 and 1.04 cmolc dm-3 and 0.67 cmolc dm-3, respectively. Base saturation was higher in soils under ICLF system and degraded pasture than those observed in native forest and capoeira vegetation. There was an effect in chemical attributes of the soil such as a function of land use and, in general, the highest values were found in areas with degraded pasture and ICLF.

Dynamic Changes in Soil Physico-Chemical Properties with the Application of Inorganic Fertilizers

“…In this study, use of K fertilizers in soil had minimum effect in altering the soil pH. This is also supported by Reis et al, (2018) who observed that potassium fertilizer levels did not affect soil pH. Although decrease in soil pH with the application of fertilizers was expected, it was not seen in this case of study.…”

Spatial and temporal variability of soil and plant attributes after application of cellulose residue

“…It is worth noting that in these cases variability decreased over the experimental period. According to Reis et al (2018), variations of chemical soil attributes are related to irregular fertilization and liming. Statistically, it can be translated into high heterogeneity around the average for chemical attributes in the assessed area.…”

“…This nutrient dynamic is exacerbated by the sandy texture and consequently high macroporosity of Quartzarenic Neosols. However, it can be improved -given the soil's low cohesion between particles and low levels of cementing agents (Reis et al, 2018). In any case, according to the authors, such low levels of Ca and Mg would be sufficient to reach average annual increments of up to 20 m 3 ha -1 year -1 in timber production.…”

“…The high levels of Al and low pH in the soil are associated with intense rainfall over the years, which leads to large lixiviation, remaining in the exchange complex, predominantly, the cations H and Al (Reis et al, 2018). Kochian et al (2015) reports that, in tropical regions, acid soils are generally heterogeneous with respect to pH and aluminum saturation, where pH may have great variability in small areas.…”

Avaliação da variabilidade espacial em plantações de eucalipto

“…Os teores de K, Ca, Mg e Al apresentaram variabilidade alta, variando entre 33,2 e 79,9%. Segundo REIS et al (2018), as variações dos atributos químicos do solo podem ser causadas por manejos silviculturais irregulares ou alocação de clones não específicos para a área. De maneira geral, é retratada alta heterogeneidade dos atributos químicos nas áreas avaliadas.…”