scholarly journals Land use, farm businesses and environmental policy in the Lake Taupo catchment

2001 ◽  
pp. 69-72
Author(s):  
B. Thorrold ◽  
J. Finlayson ◽  
G. Lambert ◽  
S. Ledgard ◽  
D. Smyth ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Nitrate Leaching ◽  
Stocking Density ◽  
N Leaching ◽  
Lake Water Quality ◽  
Study Approach ◽  
The North ◽  
Farm Systems ◽  
Farm Business

Lake Taupo is a high quality lake in the centre of the North Island, New Zealand. Local government aims to control nitrogen (N) inputs into the lake to preserve lake water quality. In this paper we discuss the implications of this policy for land use and farm management in the Lake Taupo catchment. To do this we used a case study approach, based on a typical farm, to examine the effects of stocking density and management system on farm cash surplus, farm capital value and nitrate leaching. The study showed that intensification of land use is a profitable option for farmers and any restrictions on land use in the Lake Taupo catchment will have large effects on the profitability and value of existing farm businesses. Farm systems can be adapted to reduce N leaching, however the options that we studied all resulted in a decrease in farm cash surplus. Further evaluation and experimentation on new systems is required. Rules that control farm activities in an attempt to control N leaching may not result in the gains desired owing to legitimate adjustments that farmers may make to re-optimise their farm business. Keywords: economic evaluation, farm systems, modelling, nitrate leaching, water quality

Monitoring land use change in the Lake Taupo catchment between 1975, 1990 and 2002 using satellite remote sensing data

2007 ◽  
pp. 17-22
Author(s):  
H. Lilienthal ◽  
A. Brauer ◽  
K. Betteridge ◽  
E. Schnug
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Satellite Remote Sensing ◽  
Remote Sensing Data ◽  
Native Vegetation ◽  
Lake Water Quality ◽  
Livestock Farming ◽  
Slow Decline

Conversion of native vegetation into farmed grassland in the Lake Taupo catchment commenced in the late 1950s. The lake's iconic value is being threatened by the slow decline in lake water quality that has become apparent since the 1970s. Keywords: satellite remote sensing, nitrate leaching, land use change, livestock farming, land management

scholarly journals Limitations of Improved Nitrogen Management to Reduce Nitrate Leaching and Increase Use Efficiency

2001 ◽  
Vol 1 ◽  
pp. 10-16 ◽  
Author(s):  
James L. Baker
Keyword(s):  
Water Quality ◽  
Nitrate Leaching ◽  
Management Practices ◽  
Nitrate Nitrogen ◽  
Nitrogen Management ◽  
N Leaching ◽  
N Loss ◽  
Use Efficiency ◽  
Rate Method ◽  
N Management

The primary mode of nitrogen (N) loss from tile-drained row-cropped land is generally nitrate-nitrogen (NO3-N) leaching. Although cropping, tillage, and N management practices can be altered to reduce the amount of leaching, there are limits as to how much can be done. Data are given to illustrate the potential reductions for individual practices such as rate, method, and timing of N applications. However, most effects are multiplicative and not additive; thus it is probably not realistic to hope to get overall reductions greater than 25 to 30% with in-field practices alone. If this level of reduction is insufficient to meet water quality goals, additional off-site landscape modifications may be necessary.

Physical Limnology and Water Quality Modeling of North American Great Lakes

1994 ◽  
Vol 29 (2-3) ◽  
pp. 129-156 ◽  
Author(s):  
C.R. Murthy ◽  
W.M. Schertzer
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Large Scale ◽  
Coastal Upwelling ◽  
Water Quality Modeling ◽  
Kelvin Wave ◽  
Lake Water Quality ◽  
The North ◽  
Coastal Boundary Layer ◽  
Coastal Boundary

Abstract Physical limnological research relevant to large lake water quality issues conducted in the Laurentian Great Lakes over the last two decades is presented. Particular attention is given to Lake Ontario. Persistent boundary currents are observed near the north and especially the south shore. The coastal boundary layer characteristics are defined as well as coastal upwelling and coastal circulation characteristics, including the occurrence of internal Kelvin wave propagation following major upwelling events. In addition, fundamental turbulent diffusion characteristics, based on large scale experiments and specialized studies, are described.

scholarly journals Suspended sediment and phosphorus budget and trophic status of Bukit Merah Reservoir, Perak, Malaysia

2017 ◽  
Vol 10 (3-4) ◽  
pp. 1-8 ◽  
Author(s):  
Sumayyah Aimi Mohd Najib ◽  
Wan Ruslan Ismail ◽  
Mohamad Adam Omar
Keyword(s):  
Water Quality ◽  
Suspended Sediment ◽  
Flood Control ◽  
Lake Water Quality ◽  
High Productivity ◽  
The North ◽  
Reservoir Volume ◽  
Total Input ◽  
Sediment Input ◽  
Total Sediment

Abstract Bukit Merah Reservoir (BMR) is one of the 51 impoundments in Malaysia. BMR is the oldest reservoir built in the early 1900s originally to store water for irrigation, but nowadays its functions include also flood control and water supply. Nowadays, it is threatened by land use change in the upper catchments and surrounding activities, which feeding eroded material and chemicals into the reservoir. Suspended sediment, as well as, nutrient fluxes into BMR are becoming an increasing threat to the reservoir, as its sedimentation and eutrophication accelerate. This paper discusses our study on the BMR carried out between March 2008 and April 2009 to assess the water quality status, and to determine the sediment and Total Phosphorus (TP) influx into the south pool lake. An estimated amount of suspended sediment fluxes of about 2,900 t year−1 came from the north pool lake (18%) and 12,900 t year−1 from the main Kurau River inlet (82% of the total input to the BMR). Of these total sediment input (nearly 15,800 t) about 5,600 t (36%) of the total sediment influx was trapped in the BMR. TP influx was about 18.8 t year−1 and about 7 t (37%) was trapped in the reservoir. The amount sediment and TP stored in the BMR affect the water quality of the lake, therefore the mean trophic state of the lake is eutrophic (TSI of 54.4) related to high productivity. Increasing sediment input into the reservoir has affected the reservoir volume and frequent flooding down-stream of the reservoir during rainy seasons, while eutrophication has caused the lake water quality deterioration.

scholarly journals Reducing nitrate leaching losses from a Taupo pumice soil using a nitrification inhibitor eco-n

2007 ◽  
pp. 131-135 ◽  
Author(s):  
K.C. Cameron ◽  
H.J. Di ◽  
J.L. Moir ◽  
A.H.C. Roberts
Keyword(s):  
Water Quality ◽  
Nitrate Leaching ◽  
Nitrification Inhibitor ◽  
N Leaching ◽  
N Transfer ◽  
Management Options ◽  
N Losses ◽  
Leaching Losses ◽  
Significant Contributor ◽  
Annual Loss

The decline in water quality in Lake Taupo has been attributed to nitrogen (N) leaching from surrounding land areas. Pastoral agriculture has been identified as a significant contributor to this N transfer to the lake through animal urine deposition. There is therefore an immediate need for new management options to reduce N losses. The objective of this study was to measure the effectiveness of using a nitrification inhibitor (eco-n) to reduce nitrate leaching losses from a pasture soil of the Taupo region. A 3-year study was conducted using 20 lysimeters on Landcorp's 'Waihora' sheep and beef farm, within 10 km of Lake Taupo. The results show that animal urine patches were the main source of nitrate leaching (>95% of the total annual loss) and that eco-n significantly (P

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