Changes in soil quality following humping/hollowing and flipping of pakihi soils on the West Coast, South Island New Zealand

2007 ◽  
pp. 265-270 ◽  
Author(s):  
S.M. Thomas ◽  
M.H.Beare C.D. Ford ◽  
V. Rietveld
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
West Coast ◽  
Land Development ◽  
Hot Water ◽  
Limited Information ◽  
The West ◽  
Organic Matter Quality ◽  
Pasture Production ◽  
Soil C

Humping/hollowing and flipping are land development practices widely used on the West Coast to overcome waterlogging constraints to pasture production. However, there is very limited information about how the resulting "new" soils function and how their properties change over time following these extreme modifications. We hypothesised that soil quality will improve in response to organic matter inputs from plants and excreta, which will in turn increase nutrient availability. We tested this hypothesis by quantifying the soil organic matter and nutrient content of soils at different stages of development after modification. We observed improvements in soil quality with increasing time following soil modification under both land development practices. Total soil C and N values were very low following flipping, but over 8 years these values had increased nearly five-fold. Other indicators of organic matter quality such as hot water extractable C (HWC) and anaerobically mineralisable N (AMN) showed similar increases. With large capital applications of superphosphate fertiliser to flipped soils in the first year and regular applications of maintenance fertiliser, Olsen P levels also increased from values

Towards a minimum data set to assess soil organic matter quality in agricultural soils

1994 ◽  
Vol 74 (4) ◽  
pp. 367-385 ◽  
Author(s):  
E. G. Gregorich ◽  
M. R. Carter ◽  
D. A. Angers ◽  
C. M. Monreal ◽  
B. H. Ellert
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Quality ◽  
Minimum Data Set ◽  
Data Sets ◽  
Data Set ◽  
Organic Matter Quality ◽  
Carbon And Nitrogen ◽  
Minimum Data ◽  
Soil Organic Matter Quality

Soil quality is a composite measure of both a soil’s ability to function and how well it functions, relative to a specific use. Soil quality can be assessed using a minimum data set comprising soil attributes such as texture, organic matter, pH, bulk density, and rooting depth. Soil organic matter has particular significance for soil quality as it can influence many different soil properties including other attributes of the minimum data set. Assessment of soil organic matter is a valuable step towards identifying the overall quality of a soil and may be so informative as to be included in minimum data sets used to evaluate the world’s soils.In this review, soil organic matter is considered to encompass a set of attributes rather than being a single entity. Included among the attributes and discussed here are total soil organic carbon and nitrogen, light fraction and macroorganic (particulate) matter, mineralizable carbon and nitrogen, microbial biomass, soil carbohydrates and enzymes. These attributes are involved in various soil processes, such as those related to nutrient storage, biological activity, and soil structure, and can be used to establish different minimum data sets for the evaluation of soil organic matter quality. Key words: Biological activity, minimum data set, nutrient storage, soil organic matter, soil quality, soil structure

A regional paleolimnological assessment of the impact of clear-cutting on lakes from the west coast of Vancouver Island, British Columbia

2001 ◽  
Vol 58 (3) ◽  
pp. 479-491 ◽  
Author(s):  
Kathleen Laird ◽  
Brian Cumming ◽  
Rick Nordin
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
West Coast ◽  
Forest Harvesting ◽  
Diatom Species ◽  
The West ◽  
Clear Cutting ◽  
Before And After ◽  
The Impact ◽  
Reference Lakes

The impact of forest harvesting on lakes within the temperate rainforest on the west coast of Vancouver Island was examined in a paleolimnological study of four lakes that had 35–92% of their watersheds progressively clear-cut over a period of 15–30 years (impact lakes) and four lakes that had experienced little or no known anthropogenic disturbance in their watersheds (reference lakes). Changes in diatom species composition and percent organic matter in the 210Pb-dated sediment cores were compared over the last 100 years in each of the impact lakes before and after the onset of forest harvesting, which began in 1950, and before and after 1950 in the four reference lakes. Only one impact lake showed significant changes in percent organic matter. Significant changes (p < 0.05) in species composition following forest harvesting were detected in all four impact lakes and in one of the four reference lakes. However, the changes in diatom species composition following clear-cutting in the impact lakes were small, with changes in the relative abundance of the most common species being maximally 20%, but more typically 3–10%.

Total soil organic matter and its labile pools following mulga (Acacia aneura) clearing for pasture development and cropping 1. Total and labile carbon

Soil Research ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 13 ◽  
Author(s):  
R. C. Dalal ◽  
B.P. Harms ◽  
E. Krull ◽  
W.J. Wang
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Land Use Change ◽  
Soil Organic C ◽  
Organic Matter Quality ◽  
Organic C ◽  
Soil C ◽  
Acacia Aneura ◽  
Soil Organic Matter Quality

Mulga (Acacia aneura) dominated vegetation originally occupied 11.2 Mha in Queensland, of which 12% has been cleared, mostly for pasture production, but some areas are also used for cereal cropping. Since mulga communities generally occupy fragile soils, mostly Kandosols and Tenosols, in semi-arid environments, clearing of mulga, which continues at a rate of at least 35 000 ha/year in Queensland, has considerable impact on soil organic carbon (C), and may also have implications for the greenhouse gas emissions associated with land use change in Australia. We report here the changes in soil C and labile C pools following mulga clearing to buffel pasture (Cenchrus ciliaris) and cereal (mostly wheat) cropping for 20 years in a study using paired sites. Soil organic C in the top 0.05 m of soil declined by 31% and 35% under buffel pasture and cropping, respectively. Land use change from mulga to buffel and cropping led to declines in soil organic C of 2.4 and 4.7 t/ha, respectively, from the top 0.3 m of soil. Using changes in the δ13C values of soil organic C as an approximate representation of C derived from C3 and C4 vegetation from mulga and buffel, respectively, up to 31% of soil C was C4-derived after 20 years of buffel pasture. The turnover rates of mulga-derived soil C ranged from 0.035/year in the 0–0.05 m depth to 0.008/year in the 0.6–1 m depths, with respective turnover times of 29 and 133 years. Soil organic matter quality, as measured by the proportion/amount of labile fraction C (light fraction, < 1.6 t/m3) declined by 55% throughout the soil profile (0–1 m depth) under both pasture and cropping. There is immediate concern for the long-term sustainable use of land where mulga has been cleared for pasture and/or cropping with a continuing decline in soil organic matter quality and, hence, soil fertility and biomass productivity. In addition, the removal of mulga forest over a 20-year period in Queensland for pasture and cropping may have contributed to the atmosphere at least 12 Mt CO2-equivalents.

scholarly journals Low to very high temperature thermal energy recycling – 3 case studies

2021 ◽  
Vol 313 ◽  
pp. 09001
Author(s):  
Arne Høeg ◽  
Tor-Martin Tveit
Keyword(s):  
High Temperature ◽  
Heat Source ◽  
Case Studies ◽  
Heat Pump ◽  
Thermal Energy ◽  
West Coast ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
The West ◽  
Very High

In this paper we present three case studies of the installation of a stirling-cycle high temperature heat pump applied to recycling thermal energy including steam generation. Many industries have heat demand at temperatures above 100°C and often the preferred energy carrier is steam. The optimal integration of a heat pump can be determined by investigating the thermal need of the process with pinch technology. For many industries, the pinch temperature is too high for conventional heat pumps. We present a heat pump solution that can recycle thermal energy and deliver this to a heat source up to 200°C, as hot water or steam. The heat pump can be integrated in a thermodynamic efficient way placing the sink and source in-between the pinch temperature. The working medium is a gas throughout the process cycle, with no evaporation or condensation. Thus, the process can auto-adjust to temperature variations and achieve very high efficiencies compared to the Carnot heat pump cycle. The coefficient of performance (COP) of the heat pump vary with the sink/source temperatures as the temperature fraction varies. Another important feature is that the medium has both a global warming potential (GWP) and ozone depletion potential (ODP) of zero. The thermodynamics of the heat pump is explained in more detail in the introduction section. The first installation is at a dairy plant on the west coast of Norway. In this installation, the heat pump provides cooling at 0-5°C and converts this heat into hot water at 120°C. The second installation is also at a dairy in Norway. Here the heat pump cools the ammonia from the cooling compressors at about 25-30°C and converts the heat to hot water at 110C°. The third installation is at a beverage plant on the west coast of Norway. Here the heat pump is providing cooling to compressors and other equipment. The final temperature of the heat source varies from 20-70°C. The heat is converted into steam at 168°C. In the case study sections, the installations are discussed in more details, together with the performance and a discussion of the experiences with the technology.

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