Phosphorus in humped and hollowed soils of the Inchbonnie catchment, West Coast, New Zealand: I. Variation with age and distribution

McDowell, R. W.

doi:10.1080/00288230809510461

Cited by 7 publications

(6 citation statements)

References 28 publications

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“…Of the factors that could be managed on dairy farm paddocks, decreasing the P lost from fertiliser and improving the P retention capacity of the soil are two that have been highlighted as simple and potentially costeffective (McDowell 2008b). Methods to decrease P lost from fertilisers have focused on using fertilisers with little water-soluble P (e.g.…”

Section: Introductionmentioning

confidence: 98%

Evaluation of two management options to improve the water quality of Lake Brunner, New Zealand

McDowell

2010

New Zealand Journal of Agricultural Research

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Lake Brunner, located on the west coast of the South Island of New Zealand, has been identified as threatened by phosphorus (P) inputs from neighbouring dairy farms. A two-year study was undertaken to determine if the application of reactive phosphate rock (RPR) with or without the addition of aluminium (Al) sulphate (alum) at 20 kg Al ha (1 could decrease P losses in surface runoff from dairy pastures compared to the same rate of P applied as superphosphate (30 kg P ha (1 ). The study was conducted on nine humped and hollowed plots (1100Á3500 m 2 ). Frequent and reliable rainfall year round (totalling 4000Á5000 mm yr (1 ) translated into more than 50 surface runoff events per year and large losses of P from superphosphate-treated plots (flowweighted mean filterable reactive P (FRP) 00.072 mg l (1 ; mean load 8.2 kg P ha (1 yr (1 ). In contrast, the flow-weighted mean FRP concentration in the RPR-treated plots was significantly less (0.034 mg l (1 ; mean load 4.0 kg P ha (1 yr (1 ). No effect was found on other P forms. Alum did not decrease P losses, most likely due to Al being washed off in surface runoff before it could bind to the soil. Enhanced P losses from superphosphate-treated plots were attributed to the greater availability of P within 21 days of application (water solubility 80Á95%) compared with RPR ( :1% water soluble), and the occurrence of surface runoff during this period (especially in year 1). The use of RPR is recommended as one management practice to decrease FRP inputs to Lake Brunner and may be useful in other regions where rainfall and soil pH allow

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Section: Introductionmentioning

confidence: 98%

Evaluation of two management options to improve the water quality of Lake Brunner, New Zealand

McDowell

2010

New Zealand Journal of Agricultural Research

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“…Biennial assessments showed that soil physical and biological quality can generally be considered good despite the very wet conditions and the intensive farming operations within the catchment. An exception was the measured soil Olsen P concentrations (Table 1), which increased over time beyond the optimum concentration of 25-30 mg L À1 required for pasture production (McDowell 2008b). These enriched concentrations are uneconomic and pose increased risk of P loss in surface runoff to waterways.…”

Section: Farm Surveysmentioning

confidence: 99%

“…The large losses of P for the Inchbonnie catchment (compared with dairy farms outside of the West Coast region) can be attributed to the combination of high source and transport risk factors for P loss from the dairy farms. Source risk factors include the regular inputs of fertiliser P to maintain an enriched soil Olsen P concentration, a soil type with poor P retention (McDowell 2008b), stock stream crossings and runoff of farm dairy effluent (FDE) from the hump-and-hollow land forms common to the dairy farms in the catchment. Leakage from FDE storage or treatment ponds was another potential source risk factor, but one that was difficult to quantify.…”

Section: Surface Water-groundwater Interactionmentioning

confidence: 99%

Managing pollutant inputs from pastoral dairy farming to maintain water quality of a lake in a high-rainfall catchment

Wilcock¹,

Monaghan²,

McDowell³

et al. 2013

Mar. Freshwater Res.

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Abstract.A study ) of a dairy catchment stream entering an oligotrophic lake in an area of very high rainfall (,5 m year À1 ) yielded median concentrations of total nitrogen (TN), total phosphorus (TP), suspended sediment (SS) and Escherichia coli (E. coli) of 0.584, 0.074 and 3.7 g m À3 , and 405/100 mL (most probable number method), respectively. Trend analysis indicated significant (P , 0.01) decreases for TN (À0.08 AE 0.02 g m À3 year À1 ), TP (À0.01 AE 0.005 g m À3 year À1 ) and SS (À0.45 AE 0.14 g m À3 year À1 ) and were partly attributable to improved exclusion of cattle from the stream. Water balance calculations indicated that approximately one-half the rainfall left as deep drainage that by-passed catchment outlet flow recorders. Estimates of catchment yields for TN were improved by taking into account groundwater hydrology and concentrations from well samples. Storm-flow monitoring inflows exceeding the 97.5th percentile contributed ,40% of total loads leaving the catchment so that specific yields for SS, TN and TP augmented by groundwater inputs and storm flows were ,960, 45 and 7 kg ha À1 year À1 , respectively. These compared well with modelled results for losses from dairy farms in the catchment of 40-60 kg N ha À1 year À1 and 5-6 kg P ha À1 year À1 and indicated that attenuation losses were relatively small.

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“…Paddocks examined in the Lake Brunner catchment in 2006 had been humped and hollowed from 1 to 13 years ago, suggesting that the amount of land contoured into humps and hollows has increased since the early 1990s (McDowell 2008a). Extensive humping and hollowing has led to concern that nutrients are drained faster to the lake and that increased agricultural runoff from dairy farms in particular may affect the lake's water quality.…”

Section: Introductionmentioning

confidence: 99%

“…Average annual rainfall in the Lake Brunner catchment is 3-7 m year À1 , and in order to enhance drainage of ponded surface water, farmers contour the land into long ridges with hollows between, a process known as 'humping and hollowing' (Brown 2004;McDowell 2008aMcDowell , 2008b. Paddocks examined in the Lake Brunner catchment in 2006 had been humped and hollowed from 1 to 13 years ago, suggesting that the amount of land contoured into humps and hollows has increased since the early 1990s (McDowell 2008a).…”

Section: Introductionmentioning

confidence: 99%

Effects of nutrient loading on the trophic state of Lake Brunner

Verburg

Horrox

Rutherford

et al. 2013

Mar. Freshwater Res.

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Abstract. Lake Brunner, an oligotrophic monomictic lake on the West Coast of the South Island of New Zealand, is under pressure from urban expansion and increased farming activity, which has led to concern for the effects on water quality in the lake. Epilimnetic nitrogen, phosphorus and chlorophyll a concentrations have increased since 1992, and Secchi depth decreased. This suggests an increased algal productivity caused by increased nutrient inputs, further supported by increased hypolimnetic oxygen depletion since 1992. These observations are likely to have resulted from enhancement of pasture drainage and effluent inputs from expanding dairy farms. The Vollenweider model predicted a mean phosphorus concentration in the lake close to that observed, from estimated catchment loading, suggesting that the Vollenweider model adequately estimated the retention of phosphorous. With the Vollenweider model the effects of potential future loading scenarios were explored. Modelling suggested that a 70% increase in phosphorus loading could turn the lake into a mesotrophic state. Trend analysis of total phosphorus suggests that, with present land uses in the catchment (intensive dairy farming) continuing to develop at the same rate using the same land management practises, this transition to a mesotrophic state will occur by 2040.

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Phosphorus in humped and hollowed soils of the Inchbonnie catchment, West Coast, New Zealand: I. Variation with age and distribution

Cited by 7 publications

References 28 publications

Evaluation of two management options to improve the water quality of Lake Brunner, New Zealand

Evaluation of two management options to improve the water quality of Lake Brunner, New Zealand

Managing pollutant inputs from pastoral dairy farming to maintain water quality of a lake in a high-rainfall catchment

Effects of nutrient loading on the trophic state of Lake Brunner

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