Nutrient transfer by runoff under no tillage in a soil treated with successive applications of pig slurry

AbstractHigh rates and successive applications of pig slurry can cause nutrient transfer by surface runoff. The aim of this study was to evaluate the importance of surface runoff in transferring nitrogen (N), phosphorus (P) and potassium (K) under a no tillage system and for successive applications of pig slurry. The research was carried out in the Agricultural Engineering Department of the Federal University of Santa Maria, Brazil, from 2002 to 2007 in a Typic Hapludalf soil. Pig slurry rates of 0, 20, 40 and 80m3ha−1 were applied, scattered on the surface, before the sowing of each species in a cultivation sequence. On average 119, 238 and 475kgha−1yr−1 of N; 102, 203 and 406kgha−1yr−1 of P and 43, 87 and 173kgha−1yr−1 of K were added, for rates of 20, 40 and 80m3ha−1 of pig slurry, respectively. Samples of water runoff from the soil surface were collected during the entire period and the minerals, N, P and K were determined. Successive applications of pig slurry decreased surface runoff. In relative terms, the K losses were higher than N and P. As regards total nutrients applied through pig slurry, losses through surface runoff were of 2.74, 1.61 and 1.37% of mineral N; 6.29, 5.01 and 3.51% of available P and 17.16, 9.01 and 11.14% of available K, for the three rates of applied pig slurry, respectively. Repeated applications of pig slurry on a no tillage managed soil caused losses of N, P and K from the soil through surface runoff, in the sequence: K>P>N. The losses of N and K are positively related to the volume of surface runoff, whereas the losses of P are positively related to the quantities of P added through pig slurry. Applications of pig slurry along the years decrease the surface runoff

Nitrógeno total y sustancias húmicas en agregados del suelo cultivado con cebolla bajo siembra directa y preparación convencional

1 recurso en línea (páginas 166-174).Se evaluaron los niveles de nitrógeno total (NT) y N de las sustancias húmicas (SH) de la materia orgánica en agregados de suelo cultivado con cebolla bajo siembra directa de hortalizas (SDH) y sistema de preparación convencional (SPC), comparando con un área de bosque. Los tratamientos evaluados fueron: vegetación espontánea; 100% avena; 100% centeno; 100% nabo; cultivos asociados de nabo (14%) + centeno (86%); cultivos asociados de nabo (14%) + avena (86%); área bajo SPC de cebolla (±37 años) y de bosque secundario de ±30 años). Cinco años después de la implantación del SDH fueran recogidas muestras no disturbados del suelo en las capas 0-5, 5-10 y 10-20 cm y obtenidos los agregados (entre 2,0 y 8,00 mm). En estos se determinaron los niveles de NT y el N de las SH, subdivididos en fracción ácidos fúlvicos (N-FAF), ácidos húmicos (N-FAH) y humina (N-HUM). La conversión de áreas de SPC a SDH favorece el aumento de los niveles de NT y N-HUM en la capa de 0-5 cm. Entre las especies de plantas de cobertura utilizadas en el SDH, los cultivos asociados de avena + nabo favorecieron el aumento del N-HUM (0-20 cm) en comparación a los demás tratamientos. La avena solo y el control con vegetación espontánea aumentaron los niveles de N-FAH y N-FAF, respectivamente, en la capa de 10-20 cm, en comparación a los demás tratamientos en SDH y SPC. El SPC con mijo como planta de cobertura aumentó los niveles de N-FAF (0-20 cm) en comparación con el SDH.The objective of this study was to evaluate the soil total nitrogen (TN), and N contents in humic substances (HS) of the organic matter in aggregates of soils cultivated with onion under no-till system for horticulture (NTSH) and conventional tillage system (CTS), comparing with an area of forest. The evaluated treatments were natural vegetation (control), 100% black oats, 100% rye, 100% oilseed radish, intercrop of oilseed (14%) + rye (86%), intercrop of oilseed (14%) + black oats (86%), area under CTS of onion for ±37 years, and area with secondary forest for ±30 years. Five years after the NTSH implementation, undisturbed soil samples from the layers 0-5 cm, 5-10 cm, and 10-20 cm were collected; these samples presented aggregate sizes between 2.0 mm and 8.00 mm. The TN, and N contents of the HS were subdivided into fulvic acids (N-FA), humic acids (N-HA), and humin (N-HU) fractions. The change from CTS to NTSH increases the TN and N-HU contents in the 0-5 cm soil layer. The intercrop of oats and oilseed radish, used as soil plant cover species in NTSH, presented a greater increase in N-HU (0-20 cm) than the other treatments. Black oats, and naturalBibliografía y webgrafía: páginas 173-17

Release of phosphorus forms from cover crop residues in agroecological no-till onion production

Cover crops grown alone or in association can take up different amounts of phosphorus (P) from the soil and accumulate it in different P-forms in plant tissue. Cover crop residues with a higher content of readily decomposed forms may release P more quickly for the next onion crop. The aim of this study was to evaluate the release of P forms from residues of single and mixed cover crops in agroecological no-till onion (Allium cepa L.) production. The experiment was conducted in Ituporanga, Santa Catarina (SC), Brazil, in an Inceptisol, with the following treatments: weeds, black oat (Avena sativa L.), rye (Secale cereale L.), oilseed radish (Raphanus sativus L.), oilseed radish + black oat, and oilseed radish + rye. Cover crops were sown in April 2013. In July 2013, plant shoots were cut close to the soil surface and part of the material was placed in litterbags. The bags were placed on the soil surface and residues were collected at 0, 15, and 45 days after deposition (DAD). Residues were dried and ground and P in the plant tissue was determined through chemical fractionation. The release of P contained in the tissue of cover crops depends not only on total P content in the tissue, but also on the accumulation of P forms and the quality of the residue in decomposition. The highest accumulation of P in cover crops occurred in the soluble inorganic P fraction, which is the fraction of fastest release in plants. Black oat had the highest initial release rate of soluble inorganic P, which became equal to the release rate of other cover crop residues at 45 DAD. Weeds released only half the amount of soluble inorganic P in the same period, despite accumulating a considerable amount of P in their biomass. The mixtures of oilseed radish + rye and oilseed radish + black oat showed higher release of P associated with RNA at 45 DAD in comparison to the single treatments

Atributos químicos do solo em áreas de vinhedos na região sul do estado de Santa Catarina

The objective of this work was to evaluate changes in the soil chemical properties and the critical environmental limit for phosphorus (CEL-P) in vineyards, in the southern region of the state of Santa Catarina, Brazil. Soil samples were collected at 0–5, 5–10, 10–20, and 20–40 cm soil depths, in vineyards aged 22, 36, and 60 years, and in the area of an adjacent native forest. The following parameters were analyzed: granulometry, pH in water, and exchangeable Al levels, to obtain potential acidity and Al saturation; and available levels of P and K, and exchangeable levels of Ca and Mg, to determine base saturation, cation exchange capacity; and soil organic matter (SOM). In comparison with the forest soil, the vineyard soils showed increased pH values, P, K, Ca, Mg, Cu, Zn, and SOM levels, and base saturation, as well reduced Al saturation, with more accentuated effects in areas with the longest cultivation time. The vineyards show changes in soil chemical properties with time and P levels above the CEL-P, at least in one of the soil layers.O objetivo deste trabalho foi avaliar alterações nas propriedades químicas do solo e o limite crítico ambiental para o fósforo (LCA-P), em vinhedos da região sul do estado de Santa Catarina, Brasil. Amostras de solo foram coletadas às profundidades do solo 0–5, 5–10, 10–20 e 20–40 cm, em vinhedos com 22, 36 e 60 anos de idade, e em uma área de mata nativa adjacente utilizada como referência. Os seguintes parâmetros foram analisados: granulometria, pH em água, e teores trocáveis de Al, para cálculo de acidez potencial e saturação por Al; e teores disponíveis de P e K e teores trocáveis de Ca e Mg, para determinação de saturação por bases, capacidade de troca de cátions e matéria orgânica do solo (MOS). Em comparação ao solo da mata, os solos dos vinhedos apresentaram aumento nos valores de pH, nos níveis de P, K, Ca, Mg, Cu, Zn e MOS, e na saturação por bases, além de redução na saturação de Al, com efeitos mais acentuados nas áreas com maior tempo de cultivo. Os vinhedos da região sul de Santa Catarina apresentam alterações nas propriedades químicas do solo, com o tempo, e teores de P acima do LCA-P, pelo menos em uma das camadas do solo

Atributos químicos de Latossolo após sucessivas aplicações de composto orgânico de dejeto líquido de suínos

The objective of this work was to determine changes in the chemical attributes of an Oxisol after successive applications of organic compounds with pig slurry and wood shavings, under a no‑tillage system. The experiment was conducted in the municipality of Chapecó, in the state of Santa Catarina, Brazil, in an Oxisol, from September 2005 to August 2011. The doses of 0, 2, 4, 8, and 16 Mg ha-1 compound with pig slurry and shavings were applied annually, as well as a treatment with mineral fertilizer (NPK). After six applications, soil was collected at the 0–4, 4–8, 8–12, 12–16, 16–20, 20–40, and 40–60‑cm layers and the chemical attributes were evaluated. The highest doses of the organic compound increased soil pH and reduced potential acidity. The applications of the organic compound derived from swine manure and wood shavings promoted changes in the chemical attributes of the evaluated Oxisol, especially in the upper soil layers, with greater emphasis on increased soil pH and P, K, Cu, and Zn contents. The use of 4 Mg ha-1 of the compound maintains the soil chemical attributes similar to those of the NPK treatment, which followed official recommendation for the states of Rio Grande do Sul and Santa Catarina, besides keeping the P content in the surface layers within the environmental critical limit for soils with high clay content.O objetivo deste trabalho foi determinar as alterações em atributos químicos de um Latossolo Vermelho após aplicações sucessivas de composto orgânico de dejeto líquido de suínos com maravalha, em sistema plantio direto. O experimento foi conduzido em Chapecó, SC, em Latossolo Vermelho, de setembro de 2005 a agosto de 2011. Foram aplicadas anualmente as doses de 0, 2, 4, 8 e 16 Mg ha-1 de composto de dejeto líquido de suínos com maravalha, além de um tratamento com adubação mineral (NPK). Após seis aplicações, coletaram-se amostras de solo nas camadas de 0–4, 4–8, 8–12, 12–16, 16–20, 20–40 e 40–60 cm e avaliaram-se os atributos químicos. As maiores doses do composto orgânico incrementaram o pH do solo e reduziram a acidez potencial. As aplicações de composto orgânico derivado de dejeto de suínos e maravalha promoveram alterações nos atributos químicos do Latossolo Vermelho avaliado, especialmente nas camadas superficiais do solo, com maior ênfase para aumento do pH do solo e dos teores de P, K, Cu e Zn. A utilização de 4 Mg ha-1 do composto mantém os atributos químicos do solo semelhantes aos do tratamento NPK, que seguiu recomendação oficial para os estados do Rio Grande do Sul e de Santa Catarina, além de manter os teores de P nas camadas superficiais dentro do limite crítico ambiental para solos com altos teores de argila

Soil aggregation indexes and chemical and physical attributes of aggregates in a Typic Hapludult fertilized with swine manure and mineral fertilizer

Purpose The objective was to evaluate the effects of mineral fertilizers and swine manure fertilization on soil aggregation indexes and on chemical and physical attributes of aggregates in Typic Hapludult managed under minimum tillage system. Method Experiment was implemented in 2013, in southern Brazil. The treatments were control, mineral fertilization (MF), swine manure compost + MF (SMC+MF); pig slurry + MF (PS+MF); PS to supply N for maize and black oat (PS100). In May 2015 and 2016, undisturbed soil samples were collected to obtain soil aggregates. Aggregates stability was evaluated through the mean weight diameter (MWD) and mean geometric diameter (MGD) indexes and aggregate distribution by diameter classes. In macroaggregates, total organic carbon (TOC), total nitrogen (TN), clay flocculation degree (CF%) and ∆pH were evaluated. Results The use of swine manure, associated or not to MF, increases TOC and TN contents in soil aggregates in 67.02 and 125.87%, respectively, for SMC+MF treatment. However, it was not efficient in improving soil physical attributes, reducing soil aggregation indexes, mainly in the 5-10 cm layer, by the decreased values of MWD and MGD. This result corroborates with the increase in microaggregates in all treatments. This was a result of the negative ∆pH values and the increased CF%. Conclusion Despite the increase in organic matter contents observed in this study, this was not enough to guarantee an improvement in soil physical attributes over 4 years. These results show that management must be supported by several conservationist techniques in order to have soil quality

Changes in Soil Acidity Attributes in Areas of Municipal Organic Waste Composting, Santa Catarina, Brazil

Composting is an alternative for treating and recycling municipal solid waste. Composting directly on the soil changes the attributes related to soil acidity. The study aimed to evaluate the influence of municipal solid waste composting in a small scale system on the attributes related to the acidity of soils used for making compost piles. Soil samples were collected at depths of 0-5, 5-10, 10-20, 20-30 and 30-40 cm in four areas under composting (1C, 2C, 3C and 4C) and four adjacent reference areas with no history of composting (1R, 2R, 3R and 4R). The soil was submitted to evaluation of pH in water, total organic carbon (TOC), potential acidity (H+Al), aluminum saturation and base saturation. We found the composting in a small scale system with piles directly on the soil promoted the increase of soil pH values, TOC contents and base saturation up to 40 cm, regardless of the time of use. This shows the potential of the leachate to reduce acidity and aluminum saturation in the subsoil

Espécies e atividade de alumínio na solução de solo arenoso com adição de dejetos líquidos de suínos

The application of slurry may reducing the bioavailability the aluminum (Al), by increasing the concentration of soluble ligands. The study aimed to assess how the long-term use of pig slurry is able to modify the exchangeable Al content, activity, and distribution of chemical species of Al in soil solution. Soil samples of Typic Hapludalf were obtained from an experiment conducted for eight years with 19 pig slurry applications of 0, 20, 40 and 80 m3 ha-1 at the Federal University of Santa Maria, in Santa Maria, Rio Grande do Sul (RS), Brazil. The soil samples was collected stratified in layers, to determine exchangeable Al content and extract the solution. The soil solution concentrations of the main cations, anions, dissolved organic carbon and pH were assessed. The distribution of the chemical species of Al and the activity of the Al3+ species was obtained through Visual Minteq software. The history of pig slurry applications did not modify the exchangeable Al content and had little impact on Al3+ activity in soil solution. Pig slurry applications reduce the phytotoxic potential of Al by increasing the concentration of soluble inorganic ligands, thus increasing the proportion of AlHPO4+ and AlSO4+ in soil solutionO objetivo deste trabalho foi avaliar o efeito das aplicações de dejetos líquidos de suínos no teor de Al trocável, na atividade e na distribuição das espécies químicas de Al na solução do solo. Amostras de um Argissolo foram obtidas de um experimento conduzido durante oito anos, com 19 aplicações de 0, 20, 40 e 80 m3 ha-1 de dejetos líquidos de suínos. As amostras de solo foram coletadas em camadas, para determinação do Al trocável e extração da solução do solo pelo método da pasta de saturação. Na solução, foram determinados as concentrações dos principais cátions e ânions, o carbono orgânico dissolvido e o pH. A distribuição das espécies químicas de Al e a atividade da espécie Al3+ foram obtidas pelo programa Visual Minteq. A aplicação de dejetos líquidos de suínos não altera o teor de Al trocável no solo e a atividade de Al3+ na solução do solo. A baixa atividade de Al3+ nas camadas superficiais não apresenta risco de toxidez para a maioria das culturas. A adição de dejetos líquidos de suínos aumenta a proporção das espécies AlHPO4+ e AlSO4+ na solução do solo, por incrementar a concentração de ligantes inorgânicos solúveis

Use of Swine Manure in Agriculture in Southern Brazil: Fertility or Potential Contamination?

A major challenge in agricultural production systems is the maximization of resources used to promote the development of crops with a minimum of environmental impact. In this sense, the use of fertilizers of animal origin has great potential to promote the improvement of soil properties. In southern Brazil, swine manure (SM) is widely used in agricultural areas, allowing nutrient cycling within pig units and reducing costs for chemical fertilizers. Much of this manure is applied in liquid form (PS), but other strategies are often used, such as PS compost and swine bedding (DL). The use of these SMs improves the chemical, biological, and physical attributes of the soil, contributing to increased fertility and productivity of crops. However, prolonged use or applications with high doses of SM can result in the accumulation of metals and phosphorus in soils, representing a risk of contamination of soils and surface water resources, mainly due to losses by runoff, and subsurface, by leaching. Therefore, the adoption of criteria and the rational use of PMs need to be adopted to avoid dangerous effects on the environment, such as plant toxicity and water contamination. The potentialities and risks of SM applications are discussed in this chapter