Soil chemical management drives structural degradation of Oxisols under a no-till cropping system

Autor(es)

Nunes, Marcio R. ^[1] ; da Silva, Alvaro P. ^[1] ; Denardin, Jose E. ^[2] ; Giarola, Neyde F. B. ^[3] ; Vaz, Carlos M. P. ^[4] ; van Es, Harold M. ^[5] ; da Silva, Anderson R. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Soil Sci, Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[2] Embrapa Trigo, Rodovia BR 285, Km 294, BR-99001970 Passo Fundo, RS - Brazil

^[3] Univ Estadual Ponta Grossa, Dept Soil Sci & Agr Engn, BR-84030900 Ponta Grossa, Parana - Brazil

^[4] Embrapa Agr Instrumentat, BR-13560970 Sao Carlos, SP - Brazil

^[5] Cornell Univ, Soil & Crop Sci Sect, Sch Integrat Plant Sci, Ithaca, NY 14853 - USA

^[6] Fed Inst Goiano, Dept Agron, Urutai, Go - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOIL RESEARCH; v. 55, n. 8, p. 819-831, 2017.
• Citações Web of Science: 2

Resumo

Physical degradation of the subsurface layer of soils reduces the effectiveness of no-till (NT) as a sustainable soil management approach in crop production. Chemical factors may reduce the structural stability of Oxisols and thereby exacerbate compaction from machinery traffic. We studied the relationship between chemical management and structural degradation in Oxisols cultivated under NT at three sites in southern Brazil. The surface and subsurface layers of the soils were characterised chemically and mineralogically and three physical attributes related to soil structural stability (readily dispersible clay in water, mechanically dispersible clay in water, and water percolation) were quantified for each layer. The same characterisations were performed on Oxisols collected from adjacent non-cultivated areas, to provide reference data for non-degraded soil. The levels of dispersed clay in the cultivated soil from the surface layer matched those of the non-cultivated soil, but for the subsurface layer higher dispersed clay levels in the cultivated soil showed that it was physically degraded relative to the non-cultivated soil. Water percolation was found to be slower through the Oxisols cultivated under NT, irrespective of the soil layer. The relationships between the three indicators of soil structural stability and the measured chemical and mineralogical variables of the soils were explored through an analysis of canonical correlation. The principal variables associated with the lower stability of the cultivated vs non-cultivated Oxisols were the lower concentrations of organic carbon and exchangeable aluminium and, for the surface layer, the higher pH. It is argued that structural degradation of Oxisols cultivated under NT, observed predominantly in the subsurface layer, has been aggravated by the accumulation of amendments and fertilisers in the surface soil and reduced levels of organic matter, especially in the subsurface layer. (AU)

• Processo FAPESP: 15/12934-3 - Fatores da degradação estrutural de solos argilosos sob "plantio direto"
• Beneficiário: Márcio Renato Nunes
• Modalidade de apoio: Bolsas no Brasil - Doutorado