Minerals and potentially toxic elements in corn silage from tropical and subtropical Brazil

Our aim was to assess the mineral composition of corn silages produced in four states of Brazil: Goiás, Minas Gerais, Paraná, and Santa Catarina. In total, seventy-three samples were analyzed. Total element content was extracted by HNO3 and H2 O2 microwave-assisted digestion, and inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine concentration. Of the 31 elements analyzed (Ag, Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Se, Sr, Ti, Tl, U, V, and Zn), 21 had concentrations above equipment detection limits. No elements reached the maximum tolerable concentration, but concentrations of Ca (0.14-0.15%), Cu (3.4-5.6 mg kg−1), P (0.13-0.16%), S (0.06-0.08%), and Zn (13-19 mg kg−1) were below the adequate concentration for good nutritional balance. The strong and consistent correlation observed between Fe and Ti in silage samples indicated contamination by soil. Mean concentrations of Cu, Mn, Mo, P, S, and Zn were different among states, and canonic analyses successfully discriminate samples according to their state of origin. Minerals from corn silage should be considered when formulating balanced cattle diets. To ensure silage quality, farmers must adopt strategies that reduce contamination by soil during the ensiling process.(AU)

Earthworms (Amynthas spp. ) increase common bean growth, microbial biomass, and soil respiration / Minhocas (Amynthas spp. ) aumentam o crescimento do feijoeiro, a biomassa microbiana e a respiração do solo

Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp.) on growth in the common bean (Phaseolus vulgaris L.) and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot). Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of commonbean crop residues to the soil.(AU)

Poucos estudos têm avaliado o efeito de minhocas nas plantas e nos atributos biológicos do solo, principalmente em plantas leguminosas, como o feijoeiro (Phaseolus vulgaris L.). Assim, o objetivo deste trabalho foi avaliar a influência de minhocas (Amynthas spp.) no crescimento do feijoeiro e nos atributos biológicos do solo. O experimento foi realizado em casa de vegetação em delineamento completamente casualizado, com cinco tratamentos e oito repetições. Os tratamentos foram constituídos de cinco níveis de inoculação (0, 2, 4, 6 e 8 minhocas por vaso) de minhocas do gênero Amynthas spp. Cada unidade experimental foi composta por um vaso de plástico, contendo 4 kg de solo e duas plantas de feijoeiro. O período experimental foi encerrado após 38 dias da emergência das plantas. Foram determinadas a matéria seca e a altura das plantas, a respiração edáfica, a respiração microbiana, a biomassa microbiana do solo e o quociente metabólico. A recuperação de minhocas foi alta em número e massa, com todos os valores acima de 91,6% e 89,1%, respectivamente. Adicionalmente, a massa de minhocas diminuiu apenas no tratamento com oito minhocas por vaso. A presença de minhocas aumentou o crescimento da planta e atributos biológicos do solo, sugerindo que práticas agrícolas que favoreçam a presença de minhocas podem vir a ser utilizadas para aumentar a produção de feijoeiro e, a elevação da emissão de CO2 causada pelas minhocas pode ser parcialmente mitigada pela adição deresíduos culturais de feijoeiro no solo.(AU)

Earthworms (Amynthas spp. ) increase common bean growth, microbial biomass, and soil respiration / Minhocas (Amynthas spp. ) aumentam o crescimento do feijoeiro, a biomassa microbiana e a respiração do solo

Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp.) on growth in the common bean (Phaseolus vulgaris L.) and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot). Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of commonbean crop residues to the soil.

Poucos estudos têm avaliado o efeito de minhocas nas plantas e nos atributos biológicos do solo, principalmente em plantas leguminosas, como o feijoeiro (Phaseolus vulgaris L.). Assim, o objetivo deste trabalho foi avaliar a influência de minhocas (Amynthas spp.) no crescimento do feijoeiro e nos atributos biológicos do solo. O experimento foi realizado em casa de vegetação em delineamento completamente casualizado, com cinco tratamentos e oito repetições. Os tratamentos foram constituídos de cinco níveis de inoculação (0, 2, 4, 6 e 8 minhocas por vaso) de minhocas do gênero Amynthas spp. Cada unidade experimental foi composta por um vaso de plástico, contendo 4 kg de solo e duas plantas de feijoeiro. O período experimental foi encerrado após 38 dias da emergência das plantas. Foram determinadas a matéria seca e a altura das plantas, a respiração edáfica, a respiração microbiana, a biomassa microbiana do solo e o quociente metabólico. A recuperação de minhocas foi alta em número e massa, com todos os valores acima de 91,6% e 89,1%, respectivamente. Adicionalmente, a massa de minhocas diminuiu apenas no tratamento com oito minhocas por vaso. A presença de minhocas aumentou o crescimento da planta e atributos biológicos do solo, sugerindo que práticas agrícolas que favoreçam a presença de minhocas podem vir a ser utilizadas para aumentar a produção de feijoeiro e, a elevação da emissão de CO2 causada pelas minhocas pode ser parcialmente mitigada pela adição deresíduos culturais de feijoeiro no solo.