Spatialization of soil quality index in the Sub-Basin of Posses, Extrema, Minas Gerais

Abstract

A B S T R A C TThis study aimed to determine and spatialize the soil quality index (SQI), in relation to chemical and physical attributes, and evaluate its use in the payment for environmental services in the Sub-Basin of Posses, Extrema-MG, Brazil, which represents the Atlantic Forest Biome. SQI values were influenced by both the replacement of native forests by stands of eucalyptus and by pastures and annual crops, reflecting in the reduction of soil quality in the sampled layer in the evaluated systems. The spatialization of SQI showed values ranging from 0.40 to 0.80, with some specific areas with high values and others with values above 1.00 (native forest). The reforestation with eucalyptus conditioned most of the soils with low chemical and physical deterioration, due to accumulation of litter. The lowest SQI values are associated with pastures. SQI adjusted to the exponential model, which allowed the use of ordinary Kriging. The SQI has a great potential of use in the payment to farmers who provide services of soil and water conservation.Espacialização do índice de qualidade do solo na Sub-Bacia das Posses, Extrema, Minas Gerais R E S U M O Objetivou-se, com este estudo, determinar o índice de qualidade do solo (IQS), em relação a atributos químicos e físicos, e espacializá-lo, além de avaliar a utilização deste índice no pagamento por serviços ambientais na Sub-Bacia Hidrográfica das Posses, Extrema, Minas Gerais, representativa do Bioma Mata Atlântica. Os valores do IQS foram influenciados tanto pela substituição da mata nativa por povoamento de eucalipto, quanto por pastagens e culturas anuais, refletindo na redução da qualidade do solo na profundidade amostrada nos sistemas avaliados. A espacialização do IQS apresentou valores variando de 0,40 a 0,80, ocorrendo algumas áreas pontuais com elevados índices e algumas com índices superiores a 1,00 (mata nativa). O reflorestamento com eucalipto condicionou solos, em sua maioria, com baixas deteriorações físicas e químicas devido ao acúmulo de serrapilheira. Já os menores valores do IQS estão associados às pastagens. O modelo pelo qual o IQS se ajustou foi o exponencial, possibilitando a krigagem ordinária. O IQS apresenta grande potencial para uso no pagamento de agricultores que prestam serviços de conservação do solo e água.

Monitoring land use impacts on sediment production: a case study of the pilot catchment from the Brazilian program of payment for environmental services

“…However, the contribution of this source for river bed was greater than to lag deposits sediments (Figure 5), which generates a concern that contributions from agriculture may increase in rainy periods. Lima et al (2016) reported the erosion as a response from the preparation of soil, when the topsoil of fields is loosened and overturned, before sowing the crop seeds, which usually occurs at the beginning of the rainy season (between September and October).The situation may be even more complicated, because the region is very hilly (Figure 2c) and that tillage (plowing and tilling) and cropping are traditionally performed up and down the slope, without adoption of any conservationist practice.…”

“…This quantification occurs through the fluorescence energy that is characteristic of each element present in the soil or sediment analyzed. The pXRF sensors provide good analytic precision (Stockmann et al, 2016) and have been successfully used in pedological studies, in soil and water contamination studies, and for diverse environmental studies (Silva et al, 2016;Wu et al, 2016). Despite the wide applicability of this sensor, it has not been explored by PSE programs in the management of sediment source areas, making it of practical and scientific interest to combine the fingerprint technique with the pXRF sensor.…”

Variabilidade espacial de atributos químicos do solo em sistema de agropecuária familiar no Tocantins

“…Em razão da heterogeneidade, da dinâmica e da complexidade do ecossistema, ainda não é possível fazer mensuração direta da qualidade do solo (Lima et al, 2016); entretanto, conforme Araújo et al (2012), indicadores arbitrados pelo homem permitem que a mesma seja estimada.…”