scholarly journals Nitrogen loss mitigation using duration-controlled grazing: Field observations compared to modelled outputs

2012 ◽  
pp. 115-119 ◽  
Author(s):  
C.L. Christensen ◽  
M.J. Hedley ◽  
J.A. Hanly ◽  
D.J. Horne
Keyword(s):  
Field Trial ◽  
Nitrogen Loss ◽  
Management Strategies ◽  
N Leaching ◽  
Dairy Farmers ◽  
N Losses ◽  
Loss Mitigation ◽  
Dc System ◽  
Runoff Losses ◽  
The Impact

Dairy farmers in New Zealand are encouraged to adopt a range of management strategies, both well established and emerging, to reduce nitrogen (N) losses to waterways. In most regions the OVERSEER® nutrient budgeting software (Version 6) (hereafter referred to as Overseer) is the tool of choice in the assessment of N losses for both regulatory and monitoring purposes. As part of these processes, Overseer is used to assess the impact of improved farm practices on N leaching and runoff from individual farms. In a 3-year dairy system field trial at Massey University, N losses in leaching and runoff under duration-controlled grazing (DC; 4 hours per grazing) were compared with those under standard grazing (SG; 7 hours per day-grazing, 13 hours per night-grazing). A 36% reduction in total nitrogen (TN) losses under DC grazing was measured (14 kg TN/ha) relative to standard grazing (22 kg TN/ha). Farmers adopting DC grazing as a mitigation strategy will only be able to claim the reduction in TN losses estimated by Overseer, and thus observations from the field trial were compared with outputs from Overseer. There was good agreement between the Overseer predictions of N leaching and values measured at the trial site for both the SG and DC grazing treatments. A second Overseer simulation of a DC system suggests that while Overseer is able to predict the reductions in N leaching under DC grazing reasonably well, some issues such as runoff losses and storage of effluent need further consideration. Keywords: Duration-controlled grazing; OVERSEER®; N leaching

scholarly journals Coconut shell derived biochar to enhance water spinach (Ipomoea aquatica Forsk) growth and decrease nitrogen loss under tropical conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fengliang Zhao ◽  
Ganghua Zou ◽  
Ying Shan ◽  
Zheli Ding ◽  
Minjie Dai ◽  
...  
Keyword(s):  
Production System ◽  
Nitrogen Loss ◽  
Application Rate ◽  
Coconut Shell ◽  
N Leaching ◽  
N Loss ◽  
Water Spinach ◽  
Ipomoea Aquatica ◽  
Tropical Conditions ◽  
The Impact

AbstractFarms usually apply excessive nitrogen (N) fertilizers, especially in a vegetable production system, resulting in severe N leaching loss. Although there have been some reports on the impact of biochar on the N leaching in farmlands, most of them focused on field crops in temperate or subtropical religions. Limited information about N leaching in the tropical vegetable system is available regarding the quantitative data and effective countermeasures. A field experiment was conducted to quantify N leaching in a tropical leafy production system (Ipomoea aquatica Forsk) and to evaluate the effects of coconut shell biochar on N loss and crop growth. The results showed that compared to conventional fertilization with the 240 kg N ha−1 application rate (NPK), biomass yield of water spinach increased by 40.1% under the high biochar application rate of 48 t ha−1 (HBC), which was significantly higher than that of NPK treatment. Moreover, The HBC treatment decreased N leaching by 34.0%, which can be attributed to enhanced crop uptake which increased by 40.3% as compared to NPK treatment. The NH4+/NO3− ratio in leachates was between 0.01 and 0.05. It was concluded that coconut shell derived biochar improved the biomass yields of water spinach and reduced the leaching N loss, which provides a promising amendment in tropical regions.

scholarly journals Integration of measures to mitigate reactive nitrogen losses to the environment from grazed pastoral dairy systems

2014 ◽  
Vol 152 (S1) ◽  
pp. 45-56 ◽  
Author(s):  
R. M. MONAGHAN ◽  
C. A. M. DE KLEIN
Keyword(s):  
Nitrification Inhibitor ◽  
N Leaching ◽  
N Loss ◽  
N Losses ◽  
Mitigation Options ◽  
N Efficiency ◽  
Farm Systems ◽  
Dairy Systems ◽  
Autumn And Winter ◽  
The Impact

SUMMARYThe need for nitrogen (N) efficiency measures for dairy systems is as great as ever if we are to meet the challenge of increasing global production of animal-based protein while reducing N losses to the environment. The present paper provides an overview of current N efficiency and mitigation options for pastoral dairy farm systems and assesses the impact of integrating a range of these options on reactive N loss to the environment from dairy farms located in five regions of New Zealand with contrasting soil, climate and farm management attributes. Specific options evaluated were: (i) eliminating winter applications of fertilizer N, (ii) optimal reuse of farm dairy effluent, (iii) improving animal performance through better feeding and using cows with higher genetic merit, (iv) lowering dietary N concentration, (v) applying the nitrification inhibitor dicyandiamide (DCD) and (vi) restricting the duration of pasture grazing during autumn and winter. The Overseer®Nutrient Budgeting model was used to estimate N losses from representative farms that were characterized based on information obtained from detailed farmer surveys conducted in 2001 and 2009. The analysis suggests that (i) milk production increases of 7–30% were associated with increased N leaching and nitrous oxide (N2O) emission losses of 3–30 and 0–25%, respectively; and (ii) integrating a range of strategic and tactical management and mitigation options could offset these increased N losses. The modelling analysis also suggested that the restricted autumn and winter grazing strategy resulted in some degree of pollution swapping, with reductions in N leaching loss being associated with increases in N loss via ammonia volatilization and N2O emissions from effluents captured and stored in the confinement systems. Future research efforts need to include farm systems level experimentation to validate and assess the impacts of region-specific dairy systems redesign on productivity, profit, environmental losses, practical feasibility and un-intended consequences.

Gaseous nitrogen loss from temperate perennial grass and clover dairy pastures in south-eastern Australia

2003 ◽  
Vol 54 (6) ◽  
pp. 561 ◽  
Author(s):  
R. J. Eckard ◽  
D. Chen ◽  
R. E. White ◽  
D. F. Chapman
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Loss ◽  
Perennial Grass ◽  
Management Strategies ◽  
The Other ◽  
N Losses ◽  
South Eastern ◽  
Eastern Australia ◽  
Different Seasons ◽  
South Eastern Australia

The use of nitrogen (N) fertiliser on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concerns have been raised about the economic and environmental impact of N loss through volatilisation and denitrification. Emissions of NH3, N2, and N2O were measured for 3 years in the 4 different seasons from a grazed grass/clover pasture, with or without 200 kg N fertiliser/ha, applied as ammonium nitrate and urea.Nitrogen-fertilised treatments lost significantly more N than the control treatments in all cases. More NH3 was lost from urea-fertilised treatments than from either the control or ammonium nitrate treatments, whereas ammonium nitrate treatments lost significantly more N through denitrification than the control or urea treatments in all seasons, except for summer. More NH3 was lost in summer than in the other seasons, whereas denitrification and N2O losses were highest in winter and lowest in summer. The total annual NH3 loss from the control, ammonium nitrate, and urea treatments averaged 17, 32, and 57 kg N/ha.year, respectively. Annual denitrification losses were estimated at around 6, 15, and 13 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. Total gaseous N losses were estimated to be 23, 47, and 70 kg N/ha.year from the control, ammonium nitrate, and urea treatments respectively.Although the use of ammonium nitrate fertiliser would significantly reduce NH3 volatilisation losses in summer, this fertiliser costs 45% more per unit N than urea, so there is no economic justification for recommending its use over urea for the other seasons. However, the use of urea during the cooler, wetter months may result in significantly less denitrification loss. The results are discussed in terms of potential management strategies to improve fertiliser efficiency and reduce adverse effects on the environment.

Impacts of fire and fire surrogate treatments on ecosystem nitrogen storage patterns: similarities and differences between forests of eastern and western North America

2008 ◽  
Vol 38 (12) ◽  
pp. 3056-3070 ◽  
Author(s):  
R. E.J. Boerner ◽  
Jianjun Huang ◽  
Stephen C. Hart
Keyword(s):  
Management Strategies ◽  
N Deposition ◽  
Atmospheric N Deposition ◽  
N Losses ◽  
Total N ◽  
Wildfire Hazard ◽  
Forest Sites ◽  
C And N ◽  
C And N Cycling ◽  
The Impact

The Fire and Fire Surrogates (FFS) network is composed of 12 forest sites that span the continental United States, all of which historically had frequent low-severity fire. The goal of the FFS study was to assess the efficacy of three management treatments (prescribed fire, mechanical thinning, and their combination) in reducing wildfire hazard and increasing ecosystem sustainability. This paper describes the impact of the FFS treatments on nitrogen (N) storage and distribution. At the network scale, total ecosystem N averaged 4480 kg·ha–1, with ∼9% in vegetation, ∼9% in forest floor, ∼2% in deadwood, and ∼80% in soil. The loss of vegetation N to fire averaged (±SE) 25 ± 11 kg·ha–1, whereas the mechanical and combined mechanical and fire treatments resulted in N losses of 133 ± 21 and 145 ± 19 kg·ha–1, respectively. Western coniferous forests lost more N from each treatment than did eastern forests. None of the manipulative FFS treatments impacted >10%–15% of total N of these ecosystems. Management strategies that maximize ecosystem carbon (C) gain by minimizing loss of N should be a focus in western forests, where C and N cycling are tightly linked, but perhaps not in those eastern forests where atmospheric N deposition has decoupled C and N cycles.

scholarly journals Soil Nitrogen in Response to Interseeded Cover Crops in Maize–Soybean Production Systems

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1439
Author(s):  
Yesuf Assen Mohammed ◽  
Swetabh Patel ◽  
Heather L. Matthees ◽  
Andrew W. Lenssen ◽  
Burton L. Johnson ◽  
...  
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Cropping Systems ◽  
Management Strategies ◽  
N Leaching ◽  
Winter Rye ◽  
Soil N ◽  
N Accumulation ◽  
Poor Growth ◽  
The Impact

Improved agronomic management strategies are needed to minimize the impact that current maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) production practices have on soil erosion and nutrient losses, especially nitrogen (N). Interseeded cover crops in standing maize and soybean scavenge excess soil N and thus reduce potential N leaching and runoff. The objectives were to determine the impact that pennycress (Thlaspi arvense L.) (PC), winter camelina (Camelina sativa (L.) Crantz) (WC), and winter rye (Secale cereale L.) (WR) cover crops have on soil N, and carbon (C) and N accumulation in cover-crop biomass. The cover crops were interseeded in maize at the R5 growth stage and in soybean at R7 in four replicates over two growing seasons at four locations. Soil and aboveground biomass samples were taken in autumn and spring. Data from the maize and soybean systems were analyzed separately. The results showed that cover crops had no effect on soil NH4+-N under both systems. However, winter rye decreased soil NO3−-N up to 76% compared with no-cover-crop treatment in the soybean system. Pennycress and WC scavenged less soil N than WR. Similarly, N and C accumulation in PC and WC biomass were less than in WR, in part because of their poor growth performance under the interseeding practice. Until PC and WC varieties with improved suitability for interseeding are developed, other agronomic practices may need to be explored for improving N scavenging in maize and soybean cropping systems to reduce nutrient leaching and enhance crop diversification.

scholarly journals Comparing nitrogen management on dairy farms – Canterbury case studies

2018 ◽  
pp. 201-206 ◽  
Author(s):  
Ina B Pinxterhuis ◽  
J Paul Edwards
Keyword(s):  
Environmental Impact ◽  
Environmental Performance ◽  
Management Strategies ◽  
Dairy Farms ◽  
Farm Management ◽  
Nitrogen Management ◽  
N Leaching ◽  
N Fixation ◽  
Dairy Farmers ◽  
Mitigation Options

Five Canterbury dairy farmers participate in the Forages for Reduced Nitrate Leaching programme (FRNL) to co-develop options for less environmental impact. Farm practices were adapted and new mitigation options were implemented. To assess farm environmental performance, the Overseer model was used to estimate nitrogen (N) leaching, N surplus and N conversion efficiency (NCE) for each farm and each year. When discussing the results with farmers, it appeared that these indicators for environmental performance are limited when comparing farm management strategies. The Overseer estimates include N fixation, which is influenced by model assumptions, and N leaching, estimates that strongly depend on soil type and climate entered into the model. To enable better comparisons between farms and years, a simplified N surplus and NCE were calculated using farmer recorded N inputs and N outputs, i.e. fertiliser, imported supplement, production and exported supplements. Effects of improved management and new mitigation options are presented. Four of the farms improved their N surplus and NCE and three reduced their Overseer-estimated N leaching over 3 years (2014, 2015 and 2016).

scholarly journals Immunization Strategies for Funding Multiple Inflation-Linked Retirement Income Benefits

Risks ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 60
Author(s):  
Cláudia Simões ◽  
Luís Oliveira ◽  
Jorge M. Bravo
Keyword(s):  
Interest Rate ◽  
Yield Curve ◽  
Risk Measure ◽  
Management Strategies ◽  
Interest Rate Risk ◽  
Insurance Companies ◽  
Retirement Income ◽  
Investment Strategies ◽  
Immunization Strategies ◽  
The Impact

Protecting against unexpected yield curve, inflation, and longevity shifts are some of the most critical issues institutional and private investors must solve when managing post-retirement income benefits. This paper empirically investigates the performance of alternative immunization strategies for funding targeted multiple liabilities that are fixed in timing but random in size (inflation-linked), i.e., that change stochastically according to consumer price or wage level indexes. The immunization procedure is based on a targeted minimax strategy considering the M-Absolute as the interest rate risk measure. We investigate to what extent the inflation-hedging properties of ILBs in asset liability management strategies targeted to immunize multiple liabilities of random size are superior to that of nominal bonds. We use two alternative datasets comprising daily closing prices for U.S. Treasuries and U.S. inflation-linked bonds from 2000 to 2018. The immunization performance is tested over 3-year and 5-year investment horizons, uses real and not simulated bond data and takes into consideration the impact of transaction costs in the performance of immunization strategies and in the selection of optimal investment strategies. The results show that the multiple liability immunization strategy using inflation-linked bonds outperforms the equivalent strategy using nominal bonds and is robust even in a nearly zero interest rate scenario. These results have important implications in the design and structuring of ALM liability-driven investment strategies, particularly for retirement income providers such as pension schemes or life insurance companies.

scholarly journals Foliar Urea with N-(n-butyl) Thiophosphoric Triamide for Sustainable Yield and Quality of Pineapple in a Controlled Environment

2021 ◽  
Vol 13 (12) ◽  
pp. 6880
Author(s):  
Mohammad Amdadul Haque ◽  
Siti Zaharah Sakimin ◽  
Phebe Ding ◽  
Noraini Md. Jaafar ◽  
Mohd Khanif Yusop ◽  
...  
Keyword(s):  
Nitrogen Loss ◽  
Growth Yield ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Urea Solution ◽  
Urease Inhibitor ◽  
N Losses ◽  
N Accumulation ◽  
Yield And Quality

In agricultural production, nitrogen loss leads to economic loss and is a high environmental risk affecting plant growth, yield, and quality. Use of the N fertilizer with a urease inhibitor is thus necessary to minimize N losses and increase the efficiency of N. This study aimed to evaluate the effects of N-(n-butyl) Thiophosphoric Triamide (NBPT) on the growth, yield, and quality of pineapple. The experiment involved two foliar fertilizer treatments: 1% (w/v) urea solution with NBPT (2.25 mL kg−1 urea) was treated as NLU (NBPT Liquid Urea), and the same concentration of urea without NBPT served as the control. Both were applied 12 times, starting 1 month after planting (MAP) and continuing once a month for 12 months. The application of urea with NBPT notably increased the above-ground dry biomass per plant (20% and 10% at 8 and 12 MAP, respectively), leaf area per plant (23% and 15% at 8 and 12 MAP, respectively), N accumulation per plant (10%), PFPN (Partial Factor Productivity) (13%), and average fruit weight (15%) compared to the treatment with urea alone (control). The analysis of quality parameters indicated that urea with NBPT improves TSS (Total Soluble Solids) (19%), ascorbic acid (10%), and sucrose (14%) but reduces the total organic acid content (21%) in pineapple. When using urea with a urease inhibitor (NBPT), there was a significant improvement in growth, yield, quality, and nitrogen use efficiency, with the additional benefit of reduced nitrogen losses, in combination with easy handling. Hence, urea with a urease inhibitor can be used as a viable alternative for increasing pineapple yield by boosting growth with better fruit quality.

scholarly journals Understanding the Impact of Different Landscape-Level Fuel Management Strategies on Wildfire Hazard in Central Portugal

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira
Keyword(s):  
Management Strategies ◽  
Treatment Strategies ◽  
Fire Season ◽  
Burned Area ◽  
Treatment Area ◽  
Fuel Treatment ◽  
The North ◽  
Wildfire Hazard ◽  
Central Portugal ◽  
The Impact

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.

scholarly journals The implications of lag times between nitrate leaching losses and riverine loads for water quality policy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. W. McDowell ◽  
Z. P. Simpson ◽  
A. G. Ausseil ◽  
Z. Etheridge ◽  
R. Law
Keyword(s):  
Water Quality ◽  
Mean Transit Time ◽  
Lag Time ◽  
Practice Change ◽  
N Leaching ◽  
N Losses ◽  
Leaching Losses ◽  
Nitrate N ◽  
The Mean ◽  
Lag Times

AbstractUnderstanding the lag time between land management and impacts on riverine nitrate–nitrogen (N) loads is critical to understand when action to mitigate nitrate–N leaching losses from the soil profile may start improving water quality. These lags occur due to leaching of nitrate–N through the subsurface (soil and groundwater). Actions to mitigate nitrate–N losses have been mandated in New Zealand policy to start showing improvements in water quality within five years. We estimated annual rates of nitrate–N leaching and annual nitrate–N loads for 77 river catchments from 1990 to 2018. Lag times between these losses and riverine loads were determined for 34 catchments but could not be determined in other catchments because they exhibited little change in nitrate–N leaching losses or loads. Lag times varied from 1 to 12 years according to factors like catchment size (Strahler stream order and altitude) and slope. For eight catchments where additional isotope and modelling data were available, the mean transit time for surface water at baseflow to pass through the catchment was on average 2.1 years less than, and never greater than, the mean lag time for nitrate–N, inferring our lag time estimates were robust. The median lag time for nitrate–N across the 34 catchments was 4.5 years, meaning that nearly half of these catchments wouldn’t exhibit decreases in nitrate–N because of practice change within the five years outlined in policy.

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