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

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

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

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