Danilo dos Santos Rheinheimer

Bio: Danilo dos Santos Rheinheimer is an academic researcher from Universidade Federal de Santa Maria. The author has contributed to research in topics: Soil water & Tillage. The author has an hindex of 29, co-authored 78 publications receiving 1918 citations.

Impact of Long-Term No-Tillage and Cropping System Management on Soil Organic Carbon in an Oxisol: A Model for Sustainability

Abstract: Soil organic carbon (SOC) was assessed in a long-term (19 yr) experiment comparing conventional tillage (CT) and no-tillage (NT) management systems and various winter cover crop treatments in a Rhodic Hapludox in southern Brazil. After 19 yr, NT resulted in 6.84 Mg C ha -1 , in the upper soil layer (0-10 cm), which represented 64.6% more than CT. In the 0 to 20 cm soil layer, the NT system sequestered 1.24 Mg C ha -1 yr -1 , while CT sequestered 0.96 Mg C ha -1 yr -1 . Independent of soil management, the fallow treatment resulted in the lowest SOC stocks to the 40-cm soil depth compared to all other winter treatments. We compared SOC levels of the experimental site with a nearby-forested area, which has never been cleared. No-till management combined with winter cover crops resulted in soil properties that most closely resembled the undisturbed forest. Maize grain yields and soybean seed yields were 6 and 5% higher, respectively, under NT than CT. Our results point to NT management combined with winter cover crops as the management system of choice to achieve sustainable crop production on Oxisols in the subtropical and tropical regions of the world.

Biodisponibilidade de formas de fósforo acumuladas em solo sob sistema plantio direto

Abstract: A adicao de fertilizantes ao solo provoca aumento dos teores de diversas formas de P com diferentes energias de ligacao com os coloides. Isso tem sido observado na camada superficial de solos cultivados sob sistema plantio direto, porem ha poucas informacoes sobre a disponibilidade de P dessas formas para as plantas. O objetivo do presente trabalho foi avaliar a biodisponibilidade das formas de P acumuladas em um solo cultivado sob sistema plantio direto com diferentes quantidades de P adicionado. Foram coletadas amostras da camada de 0-0,10 m de um Latossolo Vermelho distroferrico tipico que recebeu 0, 180, 360, 540 e 720 kg ha-1 de P2O5 em seis anos de cultivo. As amostras foram secas, moidas, acondicionadas em vasos com capacidade de 2 kg e submetidas a 15 cultivos sucessivos em casa de vegetacao, sem reposicao do P absorvido pelas plantas. Antes dos cultivos e apos cada tres cultivos sucessivos, foram coletadas amostras de solo para analise. Foram realizadas analises de fracionamento das formas de P pelo metodo de Hedley. Os resultados mostraram que o P inorgânico extraido por NaHCO3 0,5 mol L-1 apresenta capacidade e velocidade de tamponamento semelhantes as do P disponivel por resina trocadora de ânions, podendo ser considerado tambem como P labil. Em longo prazo, todas as formas de P do solo atuam na sustentacao do P absorvido pelas plantas; em solos com acumulo de P pela adubacao, as formas inorgânicas e orgânicas de P atuam de forma semelhante no tamponamento do P absorvido pelas plantas. Em solos com baixa ou nenhuma adicao de fertilizantes fosfatados, as formas orgânicas de P sao as principais mantenedoras do P absorvido pelas plantas.

Distribuição do fósforo inorgânico em sistemas de manejo de solo

Abstract: A intensidade das reacoes dos fertilizantes fosfatados no solo deve variar em razao dos diferentes sistemas de manejo do solo. Este trabalho teve o objetivo de avaliar as modificacoes nas fracoes de P inorgânico provocadas por diferentes preparos do solo e sucessoes de cultura. Coletaram-se, em maio de 1997, amostras de solo (Latossolo Vermelho distroferrico tipico, Latossolo Vermelho distrofico tipico e Argissolo Vermelho distrofico tipico), em tres camadas (0-2,5, 2,5-7,5 e 7,5-17,5 cm), de quatro experimentos instalados a partir de 1979, envolvendo os sistemas plantio direto e cultivo convencional com diferentes sucessoes de cultura. Foram determinados o P total e seis fracoes de P inorgânico, em ordem decrescente de labilidade. O conteudo medio de P total foi bem superior ao do seu estado natural, e no sistema plantio direto ocorreu um grande acumulo na camada superficial. Neste sistema, recuperaram-se maiores teores de P inorgânico labil (resina e NaHCO3 0,5 mol L-1) e tambem nao-labil ligado ao Ca (HCl 1,0 mol L-1) na camada superficial. As maiores concentracoes de P inorgânico foram extraidas pelo NaOH 0,1 mol L-1, ditas moderadamente labeis. As sucessoes de cultura tiveram pouca influencia nas fracoes de P inorgânico.

Alterações de atributos do solo pela calagem superficial e incorporada a partir de pastagem natural

Abstract: A aplicacao superficial de calcario pode ser uma alternativa para a correcao da acidez do solo sob plantio direto. Este trabalho avaliou as modificacoes em alguns atributos quimicos provocadas pela aplicacao de calcario superficial e incorporado ao solo a partir de pastagem natural. O experimento foi feito na area Experimental do Departamento de Solos da Universidade Federal de Santa Maria (RS), num Argissolo Acinzentado distrofico plintico. Os tratamentos, com 0,0, 2,0, 8,5 e 17,0 t ha-1 de calcario incorporado na camada de 0-20 cm e em superficie, foram distribuidos em blocos ao acaso, com quatro repeticoes. Aos 24 meses, reaplicou-se em superficie a dose no tratamento de 2,0 t ha-1. Aos 6, 18, 36 e 48 meses da aplicacao do calcario, coletaram-se amostras de solo nas profundidades de 0,0-2,5; 2,5-5,0; 5,0-10,0 e 10,0-15,0 cm. Avaliaram-se os atributos quimicos relacionados com a acidez do solo. A correcao da acidez do solo foi proporcional a dose de calcario aplicada, independentemente do modo de aplicacao. A aplicacao de calcario superficial criou uma frente de correcao da acidez em profundidade proporcional a dose e ao tempo. Foram necessarios 36 meses para que a saturacao com aluminio atingisse nivel proximo de zero na camada de 0,0-2,5 cm com a aplicacao de 2,0 + 2,0 t ha-1; 36 meses para a camada 2,5-5,0 cm com 8,5 t ha-1; e 48 meses para a camada 5,0-10,0 cm com 17,0 t ha-1.

Investigation of the occurrence of pesticide residues in rural wells and surface water following application to tobacco

Abstract: In this work the exposure of wells and surface water to pesticides, commonly used for tobacco cropping, was assessed. Water consumption wells and surface water flows were sampled at different times. After a preconcentration step with solid phase extraction (SPE), the selected pesticides were determined by gas chromatography with electron capture detection (GC-ECD) or high performance liquid chromatography with diode array detection (HPLC-DAD). No pesticides were detected in the well water samples and surface water flow in the winter season. However, in the spring and summer higher concentrations of chlorpyrifos and imidacloprid were found in the water source samples. Atrazine, simazine and clomazone were also found. The occurrence of pesticides in collected water samples was related with the application to tobacco.

Brazil's neglected biome: The South Brazilian Campos

Abstract: The South Brazilian grasslands occupy some 13.7 million ha and support very high levels of biodiversity. This paper reviews the current state of ecological knowledge on South Brazilian Campos and of threats and challenges associated with their conservation. The principal factors shaping grassland physiognomy and diversity are discussed, and information is presented on diversity of plant species; best estimates suggest that 3000–4000 phanerophytes occur in the South Brazilian grasslands. It is argued that, despite their high species richness, Campos vegetation is not adequately protected under current conservation policies. In the past three decades, approximately 25% of the grassland area has been lost due to land use changes, and this trend continues. However, representation of Campos grasslands in conservation units is extremely low (less than 0.5%), and the management in most of these is inadequate to preserve the grasslands, as grazing and fire are important factors for their persistence. In conclusion, the following urgent needs are identified: (1) to create more conservation units in different regions, including different grassland types throughout southern Brazil, (2) to develop proper management strategies where grasslands are subject to shrub encroachment and forest expansion, (3) to conduct research on biodiversity and ecological processes in the Campos region and (4) to raise public awareness of the value and vulnerability of this vegetation type.

Fecal Contamination of Drinking-Water in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Abstract: Background: access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator “use of an improved source,” which does not account for water quality measurements. Our objectives were to determine whether water from “improved” sources is less likely to contain fecal contamination than “unimproved” sources and to assess the extent to which contamination varies by source type and setting. Methods and findings: studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for “improved” sources than “unimproved” sources (odds ratio [OR] = 0.15 [0.10–0.21], I2 = 80.3% [72.9–85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52–3.71]; p Conclusion: access to an “improved source” provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality