A review of nitrogen losses due to leaching and surface runoff under intensive pasture management in Australia

Soil Research ◽  
2014 ◽  
Vol 52 (7) ◽  
pp. 621 ◽  
Author(s):  
Lucy L. Burkitt
Keyword(s):  
New Zealand ◽  
Nitrate Leaching ◽  
Surface Runoff ◽  
Dairy Industry ◽  
Farming Systems ◽  
Dairy Farms ◽  
Future Research ◽  
Pasture Management ◽  
N Losses ◽  
Pasture Production

This paper reviews the literature on nitrate leaching and nitrogen (N) runoff under intensive dairy pasture systems in Australia and draws comparisons with research undertaken under similar climates and farming systems internationally, with the aim to inform future research in this area. An Australian nitrate-leaching study suggests that annual nitrate-leaching loads are lower (3.7–14.5 kg N ha–1 year–1 for nil N and 6–22 kg N ha–1 year–1 for 200 kg N ha–1 applied) than the range previously measured and modelled on New Zealand dairy farms (~18–110 kg N ha–1 year–1). It is likely that nitrate-leaching rates are higher in New Zealand because of the prevalence of free-draining soils and higher average stocking rates. However, this review highlights that there are insufficient Australian nitrate-leaching data, particularly following urine application, to undertake a rigorous comparison. Median N surpluses on Australian dairy farms are higher (198 kg N ha–1) than values for an average New Zealand farm (135 kg N ha–1). Given the facts that many soils used for intensive pasture production in Australia are lightly textured or free-draining clay loams receiving average rainfall of >800 mm year–1, that herd sizes have risen in the last 10 years and that water quality is a concern in some dairy catchments, nitrate leaching could be an issue for the Australian dairy industry. Australian data on surface runoff of N are more available, despite its overall contribution to N losses being low (generally <5 kg N ha–1 year–1), except under border-check flood irrigation or hump-and-hollow surface drainage (3–23 kg N ha–1 year–1). More research is needed to quantify surface N runoff and leaching following effluent application and to examine dissolved organic forms of N loss, particularly in view of the continued intensification of the Australian dairy industry.

An evaluation of a strategic de-stocking regime for dairying to improve nitrogen efficiency and reduce nitrate leaching from dairy farms in nitrate-sensitive areas

2000 ◽  
pp. 105-110
Author(s):  
Cecile De Klein ◽  
Jim Paton ◽  
Stewart Ledgard
Keyword(s):  
New Zealand ◽  
Nitrate Leaching ◽  
Management Practice ◽  
Field Measurements ◽  
Dairy Farms ◽  
Nitrogen Efficiency ◽  
Management Tool ◽  
Pasture Production ◽  
Leaching Losses ◽  
Sensitive Areas

Strategic de-stocking in winter is a common management practice on dairy farms in Southland, New Zealand, to protect the soil against pugging damage. This paper examines whether this practice can also be used to reduce nitrate leaching losses. Model analyses and field measurements were used to estimate nitrate leaching losses and pasture production under two strategic de-stocking regimes: 3 months off-farm or 5 months on a feed pad with effluent collected and applied back to the land. The model analyses, based on the results of a long-term farmlet study under conventional grazing and on information for an average New Zealand farm, suggested that the 3- or 5-month de-stocking could reduce nitrate leaching losses by about 20% or 35-50%, respectively compared to a conventional grazing system. Field measurements on the Taieri Plain in Otago support these findings, although the results to date are confounded by drought conditions during the 1998 and 1999 seasons. The average nitrate concentration of the drainage water of a 5-month strategic de-stocking treatment was about 60% lower than under conventional grazing. Pasture production of the 5-month strategic de-stocking regime with effluent return was estimated based on data for apparent N efficiency of excreta patches versus uniformlyspread farm dairy effluent N. The results suggested that a strategic de-stocking regime could increase pasture production by about 2 to 8%. A cost/ benefit analysis of the 5-month de-stocking system using a feed pad, comparing additional capital and operational costs with additional income from a 5% increase in DM production, show a positive return on capital for an average New Zealand dairy farm. This suggests that a strategic destocking system has good potential as a management tool to reduce nitrate leaching losses in nitrate sensitive areas whilst being economically viable, particularly on farms where an effluent application system or a feed pad are already in place. Keywords: dairying, feed pads, nitrate leaching, nitrogen efficiency, productivity, strategic de-stocking

scholarly journals Nitrogen balances and losses on intensive dairy farms

1997 ◽  
pp. 49-53 ◽  
Author(s):  
S.F. Ledgard ◽  
J.W. Penno ◽  
M.S. Sprosen
Keyword(s):  
New Zealand ◽  
Nitrate Leaching ◽  
N2 Fixation ◽  
Meat Products ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Stocking Rate ◽  
N Losses ◽  
Farm System ◽  
South West England

Nitrogen (N) balances were constructed for "average" dairy farms in New Zealand, south west England and The Netherlands, and for Dairying Research Corporation (DRC) farmlets varying in stocking rate and use of N fertiliser and maize grain. N surpluses were calculated to indicate the potential impact on the environment and these were compared with measured N losses from the DRC farmlets. On the average New Zealand farm, annual N inputs of 186 kg N/ha/year (mainly from N2 fixation) resulted in N outputs in milk+meat of 55 kg N/ha/year (30% efficiency) and a N surplus of 131 kg N/ha/year. Dutch farms produced 70% more milk/ha but had N inputs of 568 kg/ha, N outputs in produce of 81 kg/ha (14% efficiency) and a N surplus of 487 kg/ha. English farms were intermediate. In the DRC farmlets, applying fertiliser N at 400 kg N/ha/year increased N surpluses and nitrate leaching by 3-4 fold, resulting in nitrate-N concentrations in drainage of 2.5× the recommended maximum for drinking water. The most efficient farm system received no N fertiliser and was highly stocked (3.3 Friesian cows/ha) for very high pasture utilisation. This resulted in similar milk production/ha to Dutch farms (with 1/3 the N inputs) and a 45% efficiency of conversion of N inputs from N2 fixation into milk and meat products. Keywords: dairy farm, nitrate leaching, nitrogen balance, nitrogen fertiliser, stocking rate

scholarly journals System-level evaluation of dicyandiamide (DCD) for improved environmental outcomes on New Zealand dairy farms

2010 ◽  
pp. 67-70
Author(s):  
G.J. Doole ◽  
U.H. Paragahawewa
Keyword(s):  
New Zealand ◽  
Nitrate Leaching ◽  
Dairy Farms ◽  
System Level ◽  
Nitrification Inhibitors ◽  
Pasture Production ◽  
Farm Profit

Nitrification inhibitors are an important mitigation practice for nitrate leaching since they reduce leaching loads and can potentially increase farm profit through promoting pasture production.

Automatic Milking Systems: an option to address the labour shortage on New Zealand dairy farms?

2002 ◽  
pp. 39-43
Author(s):  
J.G. Jago ◽  
M.W. Woolford
Keyword(s):  
New Zealand ◽  
Dairy Industry ◽  
Research Programme ◽  
Working Hours ◽  
Dairy Farms ◽  
Small Scale ◽  
Labour Shortage ◽  
Commercial Farms ◽  
Grazing Systems ◽  
Automatic Milking Systems

There is a growing shortage of labour within the dairy industry. To address this the industry needs to attract more people and/or reduce the labour requirements on dairy farms. Current milk harvesting techniques contribute to both the labour requirements and the current labour shortage within the industry as the process is labour-intensive and necessitates long and unsociable working hours. Automated milking systems (AMS) have been in operation, albeit on a small scale, on commercial farms in Europe for a decade and may have the potential to address labour issues within the New Zealand dairy industry. A research programme has been established (The Greenfield Project) which aims to determine the feasibility of automated milking under New Zealand dairying conditions. A Fullwoods MERLIN AMS has been installed on a protoype farmlet and is successfully milking a small herd of 41 cows. Progress from the prototype Greenfields system offers considerable potential for implementing AMS in extensive grazing systems. Keywords: automated milking systems, dairy cattle, grazing, labour

scholarly journals Nutrient losses in drainage and surface runoff from a cattle-grazed pasture in Southland

2000 ◽  
pp. 99-104 ◽  
Author(s):  
R.M. Monaghan ◽  
R.J. Paton ◽  
L.C. Smith ◽  
C. Binet
Keyword(s):  
Surface Runoff ◽  
Dairy Herd ◽  
Drainage Water ◽  
Primary Objective ◽  
Stocking Rate ◽  
N Losses ◽  
Pasture Production ◽  
Leaching Losses ◽  
Drinking Water Standard ◽  
Nitrate N

In response to local concerns about the expanding Southland dairy herd, a 4-year study was initiated in 1995 with the primary objective of quantifying nitrate-N losses to waterways from intensively grazed cattle pastures. Treatments were annual N fertiliser inputs of 0, 100, 200 or 400 kg N/ha. Stocking rate was set according to the pasture production on each of these four treatments, and over the 4 years of study ranged between the equivalent of 2.0 cows/ha for the 0N treatment, to 3.0 cows/ha for the treatment receiving 400 kg N/ ha/year. Mean annual losses of nitrate-N in drainage were 30, 34, 46 and 56 kg N/ha for the 0, 100, 200 and 400 kg N/ha/year treatments, respectively. Corresponding mean nitrate-N concentrations in drainage waters were 8.3, 9.2, 12.5 and 15.4 mg/ l, respectively. Very little direct leaching of fertiliser N was observed, even for drainage events in early spring, shortly after urea fertiliser application. The increased nitrate-N losses at higher rates of N fertiliser addition were instead owing to the indirect effect of increasing returns of urine and dung N to pasture. In Years 2 and 3, leaching losses of Ca, Mg, K, Na and sulphate-S averaged 61, 9, 11, 28 and 17 kg/ha/year, respectively, in the 0N fertiliser treatment. Increasing fertiliser N inputs significantly increased calcium and, to a lesser extent, potassium leaching losses but had no effect on losses of other plant nutrients. Surface runoff losses of Total-P, nitrate-N and ammonium- N were less than 0.5 kg/ha/year. For this well-drained Fleming soil, surface runoff was a relatively minor contributor of N to surface water, even for plots receiving high rates of fertiliser N and at a stocking rate of 3.0 cows/ha. Extrapolating these results to a 'typical' dairy pasture in Eastern Southland would suggest that the safe upper limit for annual fertiliser N additions to this site to achieve nitrate in drainage water below the drinking water standard is approximately 170 kg N/ha. Although losses of Ca in drainage were large, returns of this nutrient in maintenance applications of superphosphate-based products and lime should ensure Ca deficiencies are avoided in Southland dairy pastures. Keywords: cation-anion balances, dairy, N fertiliser, nitrate leaching, surface runoff, Southland

Value of chicory crops to pasture-based dairy farms in the Waikato region of New Zealand

2014 ◽  
Vol 153 (1) ◽  
pp. 124-137 ◽  
Author(s):  
A. J. ROMERA ◽  
G. J. DOOLE ◽  
E. N. KHAEMBAH
Keyword(s):  
New Zealand ◽  
Linear Optimization ◽  
Dairy Farms ◽  
High Quality ◽  
Pasture Production ◽  
Relative Growth ◽  
Increase Milk Production ◽  
Broad Variation ◽  
Milk Solids ◽  
To Receive

SUMMARYChicory (Cichorium intybusL.) crops can increase milk production on New Zealand dairy farms through providing high-quality feed in late lactation. Non-linear optimization models of three Waikato dairy farms, differing in the degree to which imported supplement is used, were employed to evaluate chicory crops in this environment. At a baseline milk price of $NZ 7/kg milk solids, it was only profitable for chicory to be used on a farm where no imported supplement was fed. However, even then, only 0·04 of the farm area was planted and profit only increased by $NZ 30/ha (0·006 of baseline profit), relative to where it was not used. It was not optimal to plant any chicory on farms where imported feed was available, at the baseline milk price and cost of establishment considered here. This was evident because imported feed is more flexible than chicory for filling temporary feed gaps; also its use does not displace pasture production. Sensitivity analysis indicated that the unprofitability of chicory is robust to broad variation in calving date and the relative growth of chicory and pasture. Overall, results indicate that farmers are unlikely to receive adequate reward for the additional complexity arising from the utilization of chicory crops, especially when imported supplement provides more flexibility.

scholarly journals Opportunities to decrease the water quality impact of spring forage crops on dairy farms

2012 ◽  
pp. 45-50
Author(s):  
S.J. Dennis ◽  
R.W. Mcdowell ◽  
D.R. Stevens ◽  
D. Dalley
Keyword(s):  
Water Quality ◽  
Growth Rate ◽  
Surface Runoff ◽  
Dairy Farms ◽  
Rate Data ◽  
Pasture Management ◽  
Forage Crops ◽  
Forage Crop ◽  
Farm Profitability ◽  
Water Quality Impact

Currently spring forage crops are used to manage late calving cows on the dairy platform, protect spring pasture from pugging damage, and allow the animals to feed on a mix of brassica and pasture to transition to a pasture-based diet. In addition, like winter forage crops, they could contribute considerable water quality contaminants via surface runoff. However, it may be possible to manage farms without spring forage crops. Two Southland dairy farms were used to show: 1) flowweighted mean concentrations of many water quality contaminants in surface runoff from a spring-grazed forage crop were similar to those found in studies of winter-grazed forage crops; and 2) that, using growth rate data for 2007-2012, in no year was the modelled forage crop beneficial from a feed supply perspective, and in all years the farms had similar financial performances and fewer feed deficits under all-grass management. Hence, good pasture management (e.g. avoiding treading damage using a stand-off pad and short grazing times) may negate the need for a spring forage crop, decreasing contaminant losses while not impairing farm profitability. Keywords: surface runoff, transition diet, water quality, winter forage crop.

scholarly journals Effects of effluent and urea application on groundwater, soil and pastures at WTARS

2000 ◽  
pp. 173-178 ◽  
Author(s):  
C.G. Roach ◽  
G. Stevens ◽  
D.A. Clark ◽  
P. Nicholas
Keyword(s):  
Dairy Cows ◽  
Nitrate Leaching ◽  
Animal Health ◽  
Dairy Farms ◽  
Nitrogen Application ◽  
Pasture Production ◽  
Dairy Effluent ◽  
Application Rates ◽  
Magnesium Status ◽  
Health Application

encouraged by many regional councils, and the use of urea fertiliser on dairy farms has increased over recent years. A 3-year trial was started in September 1997 to investigate the effects of urea and dairy effluent applications on pastures, soils and groundwater quality. Twenty-one 0.25 ha paddocks received urea or dairy effluent at rates of 0, 100, 200, or 400 kg N/ha/yr, and were grazed by dairy cows. Increasing nitrogen application rates resulted in increased pasture production and ryegrass content, and nitrate leaching to ground water. Nitrate leaching was estimated to be 14, 18, 26 and 56 kg N/ha/yr for the 0, 100, 200 and 400 kg N/ha/yr application rates respectively. No differences in these responses were measured between urea and effluent when applied at the same rate of nitrogen. Application of dairy effluent resulted in increased average pasture potassium levels from 3.65%DM to 4.00%DM, which may have implications for animal health. Application of dairy effluent also decreased soil sulphur levels and increased soil magnesium status. Keywords: dairy effluent, groundwater, nitrate leaching, nitrogen, pasture, soil, urea

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