Nutrients in soil layers under no-tillage after successive pig slurry applications

Abstract

SUMMARY RESUMO: NUTRIENTES EM CAMADAS DE SOLO SUBMETIDO A SUCESSIVAS APLICAÇÕES DE DEJETO LÍQUIDO DE SUÍNOS E SOB PLANTIO DIRETO 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60

Available content, surface runoff and leaching of phosphorus forms in a typic hapludalf treated with organic and mineral nutrient sources

“…Nevertheless, with successive nutrient applications, saturation may occur at the adsorption sites of inorganic particles of the soil surface layers, promoting P migration in the soil profile (Table 2), which is in agreement with the data obtained by Lourenzi et al (2013) in a Typic Hapludalf after 19 PS applications. For their part, Girotto et al (2013), in a study performed with the application of 0, 20, 40 and 80 m 3 ha -1 PS, also emphasize that the P quantities applied in manure and the increase in the available content of the nutrient in the soil are the main factors that contribute to P transfer through leaching.…”

“…That is because P is predominantly found in inorganic form in the manure, readily available to plants. This may be seen in figure 1, where the greatest available P contents were observed in the first days of soil incubation, which indicates that a large part of the P present in the manure is found in the inorganic form, which is the predominant form of accumulation in soils treated with manure (Chardon et al, 2007;Gatiboni et al, 2008;Ceretta et al, 2010a;Guardini et al, 2012a;Lourenzi et al, 2013). Furthermore, the absence of tilling in the no-tillage system favors P accumulation in the soil surface layers because, in the soil, the P may be adsorbed to the surface of functional groups of reactive particles, normally forming inner sphere complexes (specific adsorption) (Barrow, 1999).…”

“…This index refers to the total quantity of nutrients contained in the manure which may be transformed from the organic to the mineral form during the period of crop development (CQFS-RS/SC, 2004). However, frequent manure applications in the same area, especially on soils under no-tillage, may lead to accumulation of nutrients, including P, in surface soil layers (Ceretta et al, 2003;Adeli et al, 2008;Scherer et al, 2010;Guardini et al, 2012a,b;Lourenzi et al, 2013). That is because the P applied on the soil, derived from manure or mineral fertilization, may be adsorbed with high binding energy to the functional groups in the mineral fraction of the topsoil.…”

“…Furthermore, the addition of high P quantities to the soil, especially in areas treated with successive manure applications, may reduce the binding energy between the ion and the functional group involved, due to saturation of the adsorption sites. There is thus P accumulation in inorganic labile fractions, especially in the soil surface layers, but also in deeper layers (Gatiboni et al, 2008;Ceretta et al, 2010a;Guardini et al, 2012a;Lourenzi et al, 2013). Among the methods used for evaluating P availability in the soil is the anion exchange resin (AER) method (Bolland et al, 1996;Berwanger et al, 2008;Guardini et al, 2012b), used for determining P availability to plants (CQFS-RS/SC, 2004) and also as an indicator of the contamination potential in soils with sequential application of animal manure (Guardini et al, 2012b).…”

Qualidade Física, Química E Biológica De Um Latossolo Com Diferentes Manejos E Fertilizantes

“…No entanto, sistemas de manejo que promovem mínima perturbação do solo, como o plantio direto associado a práticas conservacionistas, tendem a melhorar a fertilidade (Karlen et al, 2013), estrutura do solo (Vezzani e Mielniczuk, 2011) e atividade biológica (Franchini et al, 2007;Silva et al, 2010a), mantendo ou melhorando o equilíbrio e, consequentemente, a QS (Vezzani e Mielniczuk, 2009 Lourenzi et al, 2013). Estudos têm demonstrado que sucessivas aplicações de DLS em superfície, sob sistemas sem revolvimento, promovem alterações nas propriedades do solo, como: melhorias da fertilidade nas camadas superficiais do solo, especialmente daqueles nutrientes com menor mobilidade (Scherer et al, 2010;Guardini et al, 2012;Lourenzi et al, 2013); pouco ou nenhum efeito sobre os teores de carbono orgânico (Arruda et al, 2010;Scherer et al, 2010;Brunetto et al, 2012) e atributos de acidez do solo ; favorecimento da atividade microbiológica (Balota et al, 2012) e abundância de organismos no solo ; e manutenção da qualidade estrutural do solo (Arruda et al, 2010).…”