scholarly journals Quantifying the impact of no‐till on sediment yield in southern Brazil at the hillslope and catchment scales

2021 ◽  
Author(s):  
A. L. Londero ◽  
J. P. G. Minella ◽  
F. J. A. Schneider ◽  
D. Deuschle ◽  
G. H. Merten ◽  
...  
Keyword(s):  
Sediment Yield ◽  
Southern Brazil ◽  
No Till ◽  
The Impact

scholarly journals Overland flow characterization under no-tillage in Southern Brazil

2020 ◽  
Author(s):  
Fabio José Andres Schneider ◽  
Jean Paolo Gomes Minella ◽  
Ana Lucia Londero ◽  
Dinis Deuschle ◽  
Alice Prestes Bisso Dambroz ◽  
...  
Keyword(s):  
Flow Control ◽  
Surface Runoff ◽  
Overland Flow ◽  
Zero Order ◽  
Economic Damage ◽  
Southern Brazil ◽  
Conservation Practice ◽  
No Till ◽  
The Impact ◽  
Runoff Plots

<p>No-till is considered an efficient soil and water conservation practice when accompanied by crop species diversification and overland flow control. However, the last twenty years in south Brazil, farmers under no-till abandoned crop diversification and others soil conservation practice. As a consequence, severe erosion process have been observed caused by overland flow. The overland flow has been intensified due to a combination of problems such as soil compaction and poor surface residues. Understanding the formation and propagation of overland flow when the no-till is submitted to different agronomic conditions and practices mechanics as terraces is crucial for the improvement of conservationist agriculture, since many associated problems have caused environmental and economic damage. Unfortunately, there is currently a lack of information about the surface runoff processes occurring under no-till, which is essential to define the best water management practices. The objective of this study was to determine parameters related to surface runoff under different conditions of no-till, specifically regarding the amount of biomass, mechanical scarification and presence of terraces. The study was performed at the hillslope scale in southern Brazil characterized by a deep, clay and weathered soil under no-till. Two zero order catchments (2.4ha) and four hillslopes runoff plots (0.5ha) were monitored during natural rainfall from 2014 to 2018. These catchments and runoff plots are paired and have different soil management to test their respective effects on infiltration and overland flow. In the catchments the presence of terraces was evaluated and in the runoff plot the amount of biomass and mechanical scarification was evaluated. Precipitation was measured with pluviographs and overland flow was carried out automatically on H flumes with sensor pressures. A set of 63 rainfall-runoff events were monitored at the outlet of zero order catchments (2,4ha) and 27 events were observed in the along the runoff plots (0.5ha). From these events, we derived information reflecting the influence of mechanical scarification, of terraces and of biomass. The variables derived for each management mode were: Runoff coefficient (RC), Peak water discharge (PWD), Curve Number (CN), Sediment Yield (SY) and apparent infiltration (AI). In catchments, the main results demonstrate a, influence of terraces on overland flow control, where the reduction reached 50% for RC, 12% for CN, and 60% for PWD, and 70% for SSC. Furthermore, infiltration increased by 11%. In runoff plots, the influence of increasing biomass with scarification the reduction was 16% for RC, 5% for CN, 6.3% for PWD and 6% for SSC. In runoff plots, the influence of increasing biomass without scarification the reduction was 27% for RC, 5.4% for CN, 13% for PWD and 81% for SSC. The results demonstrated that the presence of terraces mitigated the overland flow; however, despite the positive effect of amount of biomass and mechanical scarification, its performance is of less impact. This set of original results will provide the data to quantify the impact of different management conditions and will assist the local managers in the planning of conservationist practices adapted to the conditions observed in Southern Brazil.</p>

scholarly journals Quantifying the impact of no‐till on runoff in southern Brazil at hillslope and catchment scales

2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Ana L. Londero ◽  
Jean P. G. Minella ◽  
Fabio J. A. Schneider ◽  
Dinis Deuschle ◽  
Danrlei Menezes ◽  
...  
Keyword(s):  
Southern Brazil ◽  
No Till ◽  
The Impact

scholarly journals Radiological impact of phosphogypsum surface application in a no-till system in Southern Brazil

2010 ◽  
Vol 45 (12) ◽  
pp. 1456-1464 ◽  
Author(s):  
Nivea Maria Piccolomini Dias ◽  
Eduardo Fávero Caires ◽  
Luiz Fernando Pires ◽  
Márcio Arruda Bacchi ◽  
Elisabete Aparecida de Nadai Fernandes
Keyword(s):  
Field Experiment ◽  
Human Health ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Southern Brazil ◽  
Small Reduction ◽  
No Till ◽  
Hpge Detectors ◽  
Radiological Impact ◽  
The Impact

The objective of this work was to determine the impact of phosphogypsum application on 226Ra and 228Ra activities in the soil and on their accumulation in soybean grains. A field experiment was carried out in Paraná state, Brazil, on a loamy Typic Hapludox, under no-till system, with increasing phosphogypsum rates: 4, 8, and 12 Mg ha-1. GammA ray spectrometry was carried out using HPGe detectors with 45 and 10% relative efficiencies, for soybean grains and soil, respectively. No increment of 226Ra and 228Ra activities was observed due to the increase in phosphogypsum rates in the soil, and a small reduction was noticed in the grains. Average values found for 226Ra and 228Ra activities were 37 and 57 Bq kg-1 in the soil and 1.44 and 3.19 Bq kg-1 in soybean grains. The application of phosphogypsum for no-till soybean production is a safe practice regarding the risks of radiation damage to human health

scholarly journals Impact on sediment yield due to the intensification of tobacco production in a catchment in Southern Brazil

2006 ◽  
Vol 36 (2) ◽  
pp. 669-672 ◽  
Author(s):  
Gustavo Henrique Merten ◽  
Jean Paolo Gomes Minella
Keyword(s):  
Sediment Yield ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Flow Rates ◽  
Profound Impact ◽  
Sediment Yields ◽  
Tobacco Production ◽  
Tobacco Cultivation ◽  
The Impact ◽  
Rural Catchment

Tobacco production in Southern Brazil has caused a profound impact in the environment, resulting in heavy sediment yields and diminishing water quality. Public programmes have attempted to address these problems by encouraging the implementation of erosion control practices. To evaluate the impact of these programmes, a small rural catchment (1.33km²) in Arvorezinha county, in the state of Rio Grande do Sul, Brazil, has been monitored since 2001. Instruments to automatically monitor flow rate and precipitation were installed in the catchment and sediment has been measured manually using a DH-48 sampler. Despite lower rainfall in 2003, there was a significant increase in the frequency of low and average flow rates, and sediment yield increased 25% in 2003 (91Mg km-2 year-1), compared with 2002 (73Mg km-2 year-1). These results can be explained by a 37.7% increase in the area dedicated to tobacco cultivation in 2003, due to a rise in tobacco prices.

Effect of Tillage Systems on Soil Organic Carbon and Soil Quality in a Purple Paddy Soil

2011 ◽  
Vol 183-185 ◽  
pp. 1190-1194
Author(s):  
Jun Ke Zhang ◽  
Qing Ju Hao ◽  
Chang Sheng Jiang ◽  
Yan Wu
Keyword(s):  
Organic Carbon ◽  
Soil Quality ◽  
Paddy Soil ◽  
Conventional Tillage ◽  
Water Infiltration ◽  
Purple Soil ◽  
Tillage Systems ◽  
Field Station ◽  
No Till ◽  
The Impact

The impact of conservation tillage practices on carbon sequestration has been of great interest in recent years. This experiment analyzed the organic carbon status of soils sampled at depth increments from 0 to 60 cm after 20 years in a purple paddy soil. The tillage experiment was established in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China, located in the farm of Southwest University (30°26′N, 106°26′E), Chongqing. In this paper, five tillage treatments including conventional tillage with rice only system (DP), conventional tillage with rotation of rice and rape system (SL), no-till and ridge culture with rotation of rice and rape system (LM), no-till and plain culture with rotation of rice and rape system (XM) and tillage and ridge culture with rotation of rice and rape system (LF) were selected as research objectives to measure SOC storage and stratification ratio of SOC (CSR). The SOC storage under different tillage systems was calculated based on an equivalent soil mass. The CSR can be used as an indicator of soil quality because surface organic matter is essential to erosion control, water infiltration, and the conservation of nutrients. Results showed that in soil under no-till SOC was concentrated near the surface, while in tilled soil SOC decreased equably with the increase of soil depth. The difference of SOC contents between the five tillage systems was the largest in the top soil and the lowest in the bottom soil. The order of SOC storage was LM (158.52 Mg C•ha-1) >DP (106.74 Mg C•ha-1) >XM (100.11 Mg C•ha-1) >LF (93.11 Mg C•ha-1) >SL (88.59 Mg C•ha-1), LM treatment was significantly higher than the other treatments. The CSR of 0-10/50-60 cm was 2.65, 2.70 and 2.14 under LM, XM and LF treatments, while 1.54 and 1.92 under DP and SL treatments. We considered CSR>2 indicate an improvement in soil quality produced by changing from tillage to no-tillage, as well as changing from plane to ridge. Overall, long-term LM treatment is a valid strategy for increasing SOC storage and improving soil quality in a purple paddy soil in Southwest China.

scholarly journals Climate, tectonics or morphology: what signals can we see in drainage basin sediment yields?

2013 ◽  
Vol 1 (1) ◽  
pp. 13-27 ◽  
Author(s):  
T. J. Coulthard ◽  
M. J. Van de Wiel
Keyword(s):  
Sediment Yield ◽  
Drainage Basin ◽  
Sediment Yields ◽  
Internal Storage ◽  
Storage Effects ◽  
Climatic Drivers ◽  
Basin Morphology ◽  
The Impact ◽  
Small Basin

Abstract. Sediment yields from river basins are typically considered to be controlled by tectonic and climatic drivers. However, climate and tectonics can operate simultaneously and the impact of autogenic processes scrambling or shredding these inputs can make it hard to unpick the role of these drivers from the sedimentary record. Thus an understanding of the relative dominance of climate, tectonics or other processes in the output of sediment from a basin is vital. Here, we use a numerical landscape evolution model (CAESAR) to specifically examine the relative impact of climate change, tectonic uplift (instantaneous and gradual) and basin morphology on sediment yield. Unexpectedly, this shows how the sediment signal from significant rates of uplift (10 m instant or 25 mm a−1) may be lost due to internal storage effects within even a small basin. However, the signal from modest increases in rainfall magnitude (10–20%) can be seen in increases in sediment yield. In addition, in larger basins, tectonic inputs can be significantly diluted by regular delivery from non-uplifted parts of the basin.

scholarly journals Physico-chemical variability and heavy metal pollution of surface sediment in a non-channeled section of Dilúvio Stream (Southern Brazil) and the influence of channeled section in sediment pollution

2019 ◽  
Vol 14 (1) ◽  
pp. 1 ◽  
Author(s):  
Pedro Alexandre Sodrzeieski ◽  
Leonardo Capeleto de Andrade ◽  
Tales Tiecher ◽  
Flávio Anastácio de Oliveira Camargo
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Total Concentration ◽  
Mineralogical Composition ◽  
Sediment Pollution ◽  
Anthropogenic Influence ◽  
Southern Brazil ◽  
Physico Chemical ◽  
Chemical Variability ◽  
The Impact

Dilúvio Stream flows through an area with a great population density in Porto Alegre, Southern Brazil. The anthropogenic influence in the surroundings impacted negatively the quality of the sediments of Dilúvio Stream and Lake Guaíba. This study evaluated the physico-chemical variability of surface sediments in a non-channeled section of Dilúvio Stream. Additionally, we compared the concentration of several heavy metals in this section with data from previous studies in the margins of Lake Guaíba near the outflow of Dilúvio Stream in order to evaluate the impact of urbanization on sediment pollution. The pH, bulk density, particle-size distribution, electrical conductivity, organic carbon, assimilable phosphorus, total nitrogen, mineralogical composition (X-ray diffractogram) and pseudo total concentration of several metals (Fe, Al, Ca, Mg, Na, K, Mn, Ba, Zn, V, As, Pb, Cu, Cr, Co, Ni, Cd, Mo, and Se) were evaluated. The results showed that the sediments in the non-channeled section of Dilúvio Stream are predominantly sandy, with heavy metal contents below the quality reference values. Quartz and feldspar predominated in all sites. The concentration of Zn, Pb, Cu, Cr, and Ni were lower than that observed in the margins of Lake Guaíba near the outflow of Dilúvio Stream, possibly due to pollution input throughout the channeled section. The Dilúvio Stream shows indications of an anthropogenic influence in the heavy metals concentration through the channeled area.

scholarly journals Biomarkers responses in fish (Atherinella brasiliensis) of paranaguá bay, southern Brazil, for assessment of pollutant effects

2013 ◽  
Vol 61 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Ciro Alberto de Oliveira Ribeiro ◽  
Alberto Katsumiti ◽  
Patrícia França ◽  
Jocieli Maschio ◽  
Eliandra Zandoná ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Protected Areas ◽  
Aquatic Organisms ◽  
Southern Brazil ◽  
Paranaguá Bay ◽  
Fuel Oils ◽  
Polycyclic Aromatic ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
The Impact

Paranaguá bay is a complex estuary located in southern Brazil containing three protected areas listed by UNESCO. Historically, the estuary has been affected by urban, industrial, agricultural and harbor activities, and occasional accidents. Specifically, the explosion of the Chilean ship Vicuña in December 2004 spilled methanol and crude and fuel oils which affected both protected and non-protected areas. The present study sought to investigate the pollution threat to aquatic organisms in order to evaluate the potential effects of pollutants. One hundred and twenty adult fish Atherinella brasiliensis were collected from different sites within Paranaguá estuary, including the harbor and open ocean, during summer, autumn and winter of 2005. Among the biomarkers, the somatic index, chemical analysis of bile, biochemical, genetic and morphological parameters were considered. Chemical analysis of bile showed a continuous bioavailability of polycyclic aromatic hydrocarbons (PAHs) according to proximity to the harbor site. The histopathological findings have demonstrated aconsiderable incidence of severe pathologies in the liver and gills, corroborated by biochemical disturbances and genetic damage. These findings indicate that more studies are necessary to evaluate both water quality and fish health so as to permit a better analysis of the impact of pollution in Paranaguá estuary.

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