onsequences of land-use change in Brazil's new agricultural frontier: A soil physical health assessmen

Autor(es)

Santos, Rafael S. ^[1] ; Wiesmeier, Martin ^[2] ; Cherubin, Mauricio R. ^[1] ; Oliveira, Dener M. S. ^[3] ; Locatelli, Jorge L. ^[1] ; Holzschuh, Marquel ^[4] ; Cerri, Carlos E. P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Soil Sci, Luiz de Queiroz Coll Agr, Ave Padua Dias 11, BR-13418260 Piracicaba, SP - Brazil

^[2] Tech Univ Munich, Sch Life Sci Weihenstephan, Chair Soil Sci, D-85354 Freising Weihenstephan - Germany

^[3] Univ Fed Vicosa, Inst Ciencias Agr, Campus Florestal, Rd LMG 818 Km 06, BR-35690000 Florestal, MG - Brazil

^[4] SLC Agr, Rua Bernardo Pires 128, BR-90620010 Porto Alegre, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Geoderma; v. 400, OCT 15 2021.
• Citações Web of Science: 4

Resumo

In the so-called MATOPIBA region in northeastern Brazil, large areas of the Brazilian savannah (Cerrado biome) were converted to agricultural areas (e.g., soybean and cotton production) in recent years. However, little is known about the long-term impacts of this land-use change on soil physical properties and related soil functions. We carried out a field experiment in three consolidated agricultural areas (similar to 23 years old) across a 1000-km transect within the MATOPIBA region to quantify land-use change effects from native vegetation (NV) to agricultural areas under no-tillage (NT) on soil physical properties and associated functions; and compare the obtained results with critical values from literature considered as thresholds for soil degradation. Soil samples were collected from paired plots (NV and NT) in each location at 0-5, 5-10, 10-20, and 20-30 cm soil depth to determine key soil physical properties related to soil texture, compaction, porosity, water storage, and structural stability. Additionally, a set of soil physical indicators was added into a soil physical quality index (SPQI) as an integrated and quantitative approach for evaluating changes in soil functions. Our results indicated that conversion from NV to agriculture under NT increased the compaction process and reduced total soil porosity, unbalancing the proportion between soil water and air storage to critical levels. Besides, water infiltration within the soil profile was strongly decreased. The land-use conversion further induced changes on soil aggregate stability, decreasing large macroaggregates (>2000 mu m) and increasing small macroaggregates (250-2000 mu m) and the silt/clay-sized fraction (<53 mu m). The SPQI was reduced by similar to 33% in NT, indicating detrimental effects of agriculture expansion on soil functionality. Based on the SPQI, water availability and air diffusion were the soil functions most affected by land-use change. Our results provide a quantitative assessment of soil physical properties and soil function changes as a consequence of agricultural expansion in the MATOPIBA region, indicating the need to improve NT practices towards alleviating soil compaction and improving soil structure. Best management practices are fundamental to restore soil functionality, ensuring crop yields and other ecosystem services. (AU)

• Processo FAPESP: 19/27378-0 - Mudança do uso da terra no Matopiba: impacto da variação de classes texturais do solo na quantidade e qualidade do carbono
• Beneficiário: Jorge Luiz Locatelli
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 19/17576-9 - Dinâmica da matéria orgânica em função da mudança de uso do solo: efeitos sobre o carbono orgânico dissolvido
• Beneficiário: Rafael Silva Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado