Chemical losses off dairy catchments located on a texture-contrast soil: carbon, phosphorus, sulfur, and other chemicals

Soil Research ◽  
1998 ◽  
Vol 36 (6) ◽  
pp. 979 ◽  
Author(s):  
N. K. Fleming ◽  
J. W. Cox
Keyword(s):  
Environmental Impact ◽  
Soil Carbon ◽  
Overland Flow ◽  
South Australia ◽  
Farming Practices ◽  
Organic C ◽  
Dissolved Organic C ◽  
Texture Contrast ◽  
Minimal Environmental Impact ◽  
Dissolved Form

Runoff (overland flow and A/B horizon interflow) from 2 grazed dairy pastures at Flaxley, South Australia, accounted for <15% of April{October rainfall in 1996; 88{96% of runoff was overland flow. A range of chemicals, including carbon (C), phosphorus (P), and sulfur (S), was measured in runoff As much as 2·3 kg P/ha, 10·7 kg/ha of total dissolved C, and 1·8 kg S/ha was lost from the catchments in that year. Loads of other chemicals ranged from 0·6 g/ha (boron) to 39·8 kg/ha (aluminium). Over 92% of P, 76% of total dissolved C, and 93% of S was lost in overland flow. Between 50% and 60% of P, and 60% and 85% of S, was in the dissolved form; 64-96% of total dissolved C was dissolved organic C. Other chemicals varied from 0% (aluminium) to 97% (sodium) as the dissolved form. Relatively high losses of P and dissolved organic C are important to a dairy industry which is under increasing pressure to demonstrate minimal environmental impact from farming practices.

Water quality of gully drainage from texture-contrast soils in the Adelaide Hills in low rainfall years

Soil Research ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 959 ◽  
Author(s):  
J. W. Cox ◽  
R. Ashley
Keyword(s):  
Overland Flow ◽  
Environmental Concern ◽  
South Australia ◽  
Drainage Water ◽  
Agricultural Catchments ◽  
Environmental Guidelines ◽  
Texture Contrast ◽  
Carbon Concentrations ◽  
Dissolved Form

The volume and quality of drainage water in a gully cutting through a series of waterlogged, saline, sodic, and sulfidic Xeralfs in the Adelaide Hills, South Australia, was studied over 3 years. This was done to gain a better perspective of the relative quantities of contaminants being exported from agricultural catchments in low rainfall agricultural environments. It was found that in low rainfall years, when little overland flow occurs and gully flow is predominantly groundwater discharge and throughflow, loads in the drainage gully were up to 41 kg/ha.year of sodium and 2 kg/ha.year of sulfur. Losses of sulfur, magnesium, and calcium followed a similar trend to sodium losses and could be predicted with significant accuracy. The losses of phosphorus (5–7 g/ha.year) and nitrate (<2 g/ha.year) were less predictable. Phosphorus concentrations were of environmental concern each year whereas nitrate concentrations were only above environmental guidelines in the driest year. All phosphorus in the gully drainage was transported in the dissolved form. Dissolved organic carbon concentrations were usually >26 mg/L and will be costly to treat if used for public water supply.

Chemical concentrations of overland flow and throughflow from pastures on sloping texture-contrast soils

2001 ◽  
Vol 52 (2) ◽  
pp. 211 ◽  
Author(s):  
J. W. Cox ◽  
A. Pitman
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Overland Flow ◽  
South Australia ◽  
Annual Rainfall ◽  
Nitrate Losses ◽  
Nitrate Concentrations ◽  
Texture Contrast ◽  
Carbon Losses ◽  
Carbon Concentrations

Shallow drains are increasingly being installed to allow cropping and improve pastures in soils prone to waterlogging. Concentrations and loads of a range of chemicals including nitrate, dissolved organic carbon, and phosphorus were measured in overland flow and throughflow (drainage) from grazed standard and improved pastures in a region of the Adelaide Hills, South Australia, with 544 mm annual rainfall. In low to average rainfall years, nitrate losses from standard pastures were up to 21 times higher in throughflow (up to 0.3 kg/ha.year) than in overland flow. Dissolved organic carbon losses from standard pastures were also highest in throughflow (up to 3.5 kg/ha.year) as were loads of Na, Cl, Al, Fe, K, and Mg. Total P loads were higher in throughflow (0.15 kg/ha.year) than in overland flow. However, P concentrations in throughflow were similar to overland flow (up to 0.5 mg/L). Chemical loads from improved pastures were higher in throughflow than in overland flow. Nitrate, dissolved organic carbon, and P losses from improved pastures were up to 0.8, 8.5, and 0.1 kg/ha.year, respectively. Improved pastures had higher dissolved organic carbon concentrations (14 mg/L) and nitrate concentrations than either the standard pastures or those reported off some dairy pastures in the region. Nitrate concentrations were highest in throughflow in subsurface tube drains below the improved pastures (up to 67 mg/L).

Pathways of phosphorus, nitrogen, and carbon movement over and through texturally differentiated soils, South Australia

Soil Research ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 679 ◽  
Author(s):  
D. J. Chittleborough ◽  
J. W. Cox ◽  
D. P. Stevens
Keyword(s):  
Organic Carbon ◽  
Overland Flow ◽  
South Australia ◽  
Catchment Management ◽  
Catchment Scale ◽  
Through Flow ◽  
Close Proximity ◽  
Significant Loading ◽  
Restrict Movement ◽  
Texture Contrast

One method for preventing the degradation of water supplies through contamination with phosphorus (P), nitrate (NO3), and dissolved organic carbon (DOC) is to restrict movement of these contaminants from the catchment into water bodies. The purpose of the study was to quantify and characterise the proportion of NO3, P, and DOC moving from duplex soils by overland flow and through-flow on a sub-catchment scale, and to characterise soil properties that influence their movement. Two sites in the Adelaide Hills (South Australia) with contrasting duplex soils were instrumented to collect overland flow and through-flow from the soils A and B horizon. Each site contained 2 sub-catchments in close proximity. Sub-catchments were well defined by the natural topography sloping from hillcrest to a stream headwater. Soil type, especially the degree of texture contrast, the macroporosity, and the proportion of clay in the B horizon, had a large influence on the pathways of water, and therefore P, DOC, and NO3 movement. Environmentally significant concentrations of P (>0�1 mg/L) and NO3-N (>0�5 mg/L) moved overland and through these soils in 1997. High DOC loads (25 mg/L), which would also impact on water treatment costs, moved through some soils. Significant loading of P moved through and over soils in both dissolved (0�5 mg/L) and particulate (0�3 mg/L) forms. Consequently, through-flow cannot be ignored as a contributor to P in streams and both dissolved and particulate P must be measured under these conditions to define the full impact of P. The findings from this research have implications for research on catchment management to restrict DOC and nutrient movement into waterways.

Sustainable Management of Soil for Carbon Sequestration

2017 ◽  
Vol 5 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Kewat Sanjay Kumar ◽  
Keyword(s):  
Carbon Sequestration ◽  
Soil Carbon ◽  
Sustainable Management ◽  
Management Practices ◽  
Atmospheric Co2 ◽  
Carbon Pools ◽  
Carbon Stabilization ◽  
Organic C ◽  
Soil Ecosystems ◽  
C Stocks

Mechanisms governing carbon stabilization in soils have received a great deal of attention in recent years due to their relevance in the global carbon cycle. Two thirds of the global terrestrial organic C stocks in ecosystems are stored in below ground components as terrestrial carbon pools in soils. Furthermore, mean residence time of soil organic carbon pools have slowest turnover rates in terrestrial ecosystems and thus there is vast potential to sequester atmospheric CO2 in soil ecosystems. Depending upon soil management practices it can be served as source or sink for atmospheric CO2. Sustainable management systems and practices such as conservation agriculture, agroforestry and application of biochar are emerging and promising tools for soil carbon sequestration. Increasing soil carbon storage in a system simultaneously improves the soil health by increase in infiltration rate, soil biota and fertility, nutrient cycling and decrease in soil erosion process, soil compaction and C emissions. Henceforth, it is vital to scientifically explore the mechanisms governing C flux in soils which is poorly understood in different ecosystems under anthropogenic interventions making soil as a potential sink for atmospheric CO2 to mitigate climate change. Henceforth, present paper aims to review basic mechanism governing carbon stabilization in soils and new practices and technological developments in agricultural and forest sciences for C sequestration in terrestrial soil ecosystems.

Changes in soil carbon under long-term maize in monoculture and legume-based rotation

2001 ◽  
Vol 81 (1) ◽  
pp. 21-31 ◽  
Author(s):  
E G Gregorich ◽  
C F Drury ◽  
J A Baldock
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Magnetic Resonance ◽  
Soil Carbon ◽  
Crop Residues ◽  
Cropping Systems ◽  
Natural Abundance ◽  
Organic C ◽  
Soil C

Legume-based cropping systems could help to increase crop productivity and soil organic matter levels, thereby enhancing soil quality, as well as having the additional benefit of sequestering atmospheric C. To evaluate the effects of 35 yr of maize monoculture and legume-based cropping on soil C levels and residue retention, we measured organic C and 13C natural abundance in soils under: fertilized and unfertilized maize (Zea mays L.), both in monoculture and legume-based [maize-oat (Avena sativa L.)-alfalfa (Medicago sativa L.)-alfalfa] rotations; fertilized and unfertilized systems of continuous grass (Poa pratensis L.); and under forest. Solid state 13C nuclear magnetic resonance (NMR) was used to chemically characterize the organic matter in plant residues and soils. Soils (70-cm depth) under maize cropping had about 30-40% less C, and those under continuous grass had about 16% less C, than those under adjacent forest. Qualitative differences in crop residues were important in these systems, because quantitative differences in net primary productivity and C inputs in the different agroecosystems did not account for observed differences in total soil C. Cropping sequence (i.e., rotation or monoculture) had a greater effect on soil C levels than application of fertilizer. The difference in soil C levels between rotation and monoculture maize systems was about 20 Mg C ha-1. The effects of fertilization on soil C were small (~6 Mg C ha-1), and differences were observed only in the monoculture system. The NMR results suggest that the chemical composition of organic matter was little affected by the nature of crop residues returned to the soil. The total quantity of maize-derived soil C was different in each system, because the quantity of maize residue returned to the soil was different; hence the maize-derived soil C ranged from 23 Mg ha-1 in the fertilized and 14 Mg ha-1 in the unfertilized monoculture soils (i.e., after 35 maize crops) to 6-7 Mg ha-1 in both the fertilized and unfertilized legume-based rotation soils (i.e., after eight maize crops). The proportion of maize residue C returned to the soil and retained as soil organic C (i.e., Mg maize-derived soil C/Mg maize residue) was about 14% for all maize cropping systems. The quantity of C3-C below the plow layer in legume-based rotation was 40% greater than that in monoculture and about the same as that under either continuous grass or forest. The soil organic matter below the plow layer in soil under the legume-based rotation appeared to be in a more biologically resistant form (i.e., higher aromatic C content) compared with that under monoculture. The retention of maize residue C as soil organic matter was four to five times greater below the plow layer than that within the plow layer. We conclude that residue quality plays a key role in increasing the retention of soil C in agroecosystems and that soils under legume-based rotation tend to be more “preservative” of residue C inputs, particularly from root inputs, than soils under monoculture. Key words: Soil carbon, 13C natural abundance, 13C nuclear magnetic resonance, maize cropping, legumes, root carbon

An optimal plan for food consumption with minimal environmental impact: the case of school lunch menus

2016 ◽  
Vol 129 ◽  
pp. 704-713 ◽  
Author(s):  
Luca Benvenuti ◽  
Alberto De Santis ◽  
Fabio Santesarti ◽  
Luigino Tocca
Keyword(s):  
Environmental Impact ◽  
Food Consumption ◽  
School Lunch ◽  
Optimal Plan ◽  
Minimal Environmental Impact

scholarly journals Changes in Soil Carbon Sequestration during Woody Plant Encroachment in Arid Ecosystems

2021 ◽  
Vol 4 (4-5) ◽  
pp. 266-276
Author(s):  
Pratap Naikwade
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Soil Carbon ◽  
Atmospheric Carbon Dioxide ◽  
Global Climate ◽  
Terrestrial Ecosystems ◽  
Greenhouse Gas Mitigation ◽  
Arid Ecosystems ◽  
Woody Encroachment ◽  
Organic C

Carbon sequestration is one of the most important and highly recommended measures for mitigating climate change. Soil organic carbon (SOC) has potential to sequester the largest amount of carbon (C) for the longest time period in the midst of the organic C sinks in terrestrial ecosystems of the earth. In recent years, apprehension of the role of soils as sink for carbon on a wide-ranging scale has become dynamic. From last 150 years, encroachment of trees and shrubs into grasslands and the ‘thicketization’ of savannas have been reported and is a global phenomenon. One possibly beneficial effect could be that the shrub and tree-dominated ecosystems will sequester more carbon and will be a buffer for elevated atmospheric carbon dioxide (CO2) levels. The question of what is impact of woody encroachment on soil carbon balance of an ecosystem has proved difficult to answer, and the results remain debatable. The magnitude and pattern of changes in the SOC with woody encroachment are exceedingly abstruse and varies from significant increases, to significant decreases to no net change in SOC. Impact of wood plant encroachment on carbon sequestration is discussed in this paper considering various studies with different results so it will lead to better understanding of the complex phenomenon. SOC sequestration is effective greenhouse gas mitigation strategy and a vital ecosystem service. Increasing SOC may helpful to mitigate negative effects of growing concentration of CO2 in atmosphere and may be advantageous in decelerating or reversal in global climate change rate.

A Heideggerian Analysis of Renewable Energy and The Electric Grid

2020 ◽  
Vol 17 (2) ◽  
pp. 291-315
Author(s):  
Rudy Kahsar ◽  
Keyword(s):  
Renewable Energy ◽  
Environmental Impact ◽  
Commodity Chain ◽  
Energy Technology ◽  
Electric Grid ◽  
On Demand ◽  
Positive Expression ◽  
Energy Needs ◽  
Local Sources ◽  
Minimal Environmental Impact

Renewable energy technology is often seen as a positive expression of technology, meeting energy needs with minimal environmental impact. But, by integrating nature (e.g., wind and sunlight) with the ordering of the electric grid, renewables silently convert that nature into what Martin Heidegger referred to as standing reserve—resources of the technological commodity chain to be ordered, controlled, converted, and consumed on demand. However, it may be possible to mitigate the downsides of this process through a transition to more decentralized, local sources of renewable energy operations and management that maintain awareness of the ways in which energy is generated and distributed.

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