Coupled water and nitrogen (N) management as a key strategy for the mitigation of gaseous N losses in the Huang-Huai-Hai Plain

Hundreds of millions of smallholders in emerging countries substantially overuse nitrogen (N) fertilizers, driving local environmental pollution and global climate change. Despite local demonstration-scale successes, widespread mobilization of smallholders to adopt precise N management practices remains a challenge, largely due to associated high costs and complicated sampling and calculations. Here, we propose a long-term steady-state N balance (SSNB) approach without these complications that is suitable for sustainable smallholder farming. The hypothesis underpinning the concept of SSNB is that an intensively cultivated soil–crop system with excessive N inputs and high N losses can be transformed into a steady-state system with minimal losses while maintaining high yields. Based on SSNB, we estimate the optimized N application range across 3,824 crop counties for the three staple crops in China. We evaluated SSNB first in ca. 18,000 researcher-managed on-farm trials followed by testing in on-farm trials with 13,760 smallholders who applied SSNB-optimized N rates under the guidance of local extension staff. Results showed that SSNB could significantly reduce N fertilizer use by 21 to 28% while maintaining or increasing yields by 6 to 7%, compared to current smallholder practices. The SSNB approach could become an effective tool contributing to the global N sustainability of smallholder agriculture.

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Extent and Variation of Nitrogen Losses from Non-legume Field Crops of Conterminous United States

Nitrogen ◽

10.3390/nitrogen1010005 ◽

2020 ◽

Vol 1 (1) ◽

pp. 34-51

Author(s):

Amitava Chatterjee

Keyword(s):

United States ◽

Management Strategies ◽

Application Rate ◽

Fertilizer N ◽

N Loss ◽

N Losses ◽

Field Crops ◽

N Application Rate ◽

Spatio Temporal ◽

N Management

Nitrogen (N) losses from field crops have raised environmental concerns. This manuscript accompanies a database of N loss studies from non-legume field crops conducted across the conterminous United States. Cumulative N losses through nitrous oxide-denitrification (CN2O), ammonia volatilization (CNH3), and nitrate leaching (CNO3−) during the growing season and associated crop, soil, and water management information were gathered to determine the extent and controls of these losses. This database consisted of 404, 26, and 358 observations of CN2O, CNH3, and CNO3− losses, respectively, from sixty-two peer-reviewed manuscripts. Corn (Zea mays) dominated the N loss studies. Losses ranged between −0.04 to 16.9, 2.50 to 50.9, and 0 to 257 kg N ha−1 for CN2O, CNH3 and CNO3−, respectively. Most CN2O and CNO3− observations were reported from Colorado (n = 100) and Iowa (n = 176), respectively. The highest values of CN2O, and CNO3− were reported from Illinois and Minnesota states, and corn and potato (Solanum tuberosum), respectively. The application of anhydrous NH3 had the highest value of CN2O loss, and ammonium nitrate had the highest CNO3− loss. Among the different placement methods, the injection of fertilizer-N had the highest CN2O loss, whereas the banding of fertilizer-N had the highest CNO3− loss. The maximum CNO3− loss was higher for chisel than no-tillage practice. Both CN2O and CNO3− were positively correlated with fertilizer N application rate and the amount of water input (irrigation and rainfall). Fertilizer-N management strategies to control N loss should consider the spatio-temporal variability of interactions among climate, crop-and soil types.

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Well-Aerated Southern Appalachian Forest Soils Demonstrate Significant Potential for Gaseous Nitrogen Loss

Forests ◽

10.3390/f10121155 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1155

Author(s):

Peter Baas ◽

Jennifer D. Knoepp ◽

Jacqueline E. Mohan

Keyword(s):

Forest Soils ◽

Nitrogen Loss ◽

Elevation Gradient ◽

High Elevation ◽

N Cycling ◽

N Losses ◽

Northern Hardwood ◽

Southern Appalachian ◽

Nitrifier Denitrification ◽

Gaseous N Losses

Understanding the dominant soil nitrogen (N) cycling processes in southern Appalachian forests is crucial for predicting ecosystem responses to changing N deposition and climate. The role of anaerobic nitrogen cycling processes in well-aerated soils has long been questioned, and recent N cycling research suggests it needs to be re-evaluated. We assessed gross and potential rates of soil N cycling processes, including mineralization, nitrification, denitrification, nitrifier denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) in sites representing a vegetation and elevation gradient in the U.S. Department of Agriculture (USDA) Forest Service Experimental Forest, Coweeta Hydrologic Laboratory in southwestern North Carolina, USA. N cycling processes varied among sites, with gross mineralization and nitrification being greatest in high-elevation northern hardwood forests. Gaseous N losses via nitrifier denitrification were common in all ecosystems but were greatest in northern hardwood. Ecosystem N retention via DNRA (nitrification-produced NO3 reduced to NH4) ranged from 2% to 20% of the total nitrification and was highest in the mixed-oak forest. Our results suggest the potential for gaseous N losses through anaerobic processes (nitrifier denitrification) are prevalent in well-aerated forest soils and may play a key role in ecosystem N cycling.

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Contrasting nitrogen and phosphorus budgets in urban watersheds and implications for managing urban water pollution

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1618536114 ◽

2017 ◽

Vol 114 (16) ◽

pp. 4177-4182 ◽

Cited By ~ 105

Author(s):

Sarah E. Hobbie ◽

Jacques C. Finlay ◽

Benjamin D. Janke ◽

Daniel A. Nidzgorski ◽

Dylan B. Millet ◽

...

Keyword(s):

Mississippi River ◽

Nutrient Management ◽

Urban Watersheds ◽

Nitrogen And Phosphorus ◽

N Losses ◽

Storm Drainage ◽

High Street ◽

Storm Drain ◽

P Movement ◽

N Management

Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains.

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Recovery of 15N-labelled fertilizers applied to barley on two artificially eroded soils in north-central Alberta

Canadian Journal of Soil Science ◽

10.4141/s97-071 ◽

1998 ◽

Vol 78 (2) ◽

pp. 377-383 ◽

Cited By ~ 2

Author(s):

R. Pradhan ◽

R. C. Izaurralde ◽

S. S. Malhi ◽

M. Nyborg

Keyword(s):

Field Experiments ◽

Water Saturation ◽

Nutrient Use Efficiency ◽

N Loss ◽

Hordeum Vulgare L ◽

N Losses ◽

North Central ◽

Major Mechanism ◽

Erosion Level ◽

N Management

Soil erosion induces variability in soil properties which may influence nutrient use efficiency. A 2-yr field study was conducted with the following objectives: (1) to determine the recovery of 15N-labelled fertilizers applied to barley growing on artificially eroded soil, and (2) to compare N losses from nitrate- and ammonia-based N fertilizers. Field experiments were conducted in north-central Alberta in 1991 and 1992 on an Orthic Gray Luvisol (Site 1) and on an Eluviated Black Chernozem (Site 2) soil. At each site, a factorial experiment of three levels of artificial erosion (0, 10 and 20 cm) and three N sources (KNO3, urea, and control) was laid out as a split-plot design with four replications. The 15N-labelled fertilizers (5.63 atom % abundance) were banded in June 1991 at 150 kg N ha−1 within 46-cm by 46-cm steel frame microplots. The proportion of added N recovered by barley (Hordeum vulgare L.) was not affected by erosion level. Periodical water saturation and NO3− availability suggested denitrification as a major mechanism of N loss. The N losses ranged from 12 to 51 g N ha−1 in 1991 and 20 to 80 kg N ha−1 over the 2-yr period, but the N losses did not relate to erosion level. The N losses after 2 yr were greater from KNO3 than from urea at Site 1. Most of the added 15N was found in the surface 0- to 15-cm layer, but amounts of 15N were detected in the 15- to 30-cm or 30- to 45-cm layers. The results call for continued development of N management techniques geared to optimize crop growth and minimize losses from fields. Key words: Artificial erosion, barley, fate of applied N, 15N-labelled fertilizers, N immobilization, N loss

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GASEOUS NITROGEN LOSSES FROM CONVENTIONAL AND CHEMICAL SUMMERFALLOW

Canadian Journal of Soil Science ◽

10.4141/cjss85-020 ◽

1985 ◽

Vol 65 (1) ◽

pp. 195-203 ◽

Cited By ~ 18

Author(s):

M. S. AULAKH ◽

D. A. RENNIE

Keyword(s):

Soil Moisture ◽

Field Studies ◽

Soil Core ◽

Gaseous Nitrogen ◽

N Losses ◽

Factors Affecting ◽

Major Factors ◽

Chemical Fallow ◽

Lower Slope ◽

Gaseous N Losses

The gaseous losses of N (N2O + N2) measured for 130 days (May-September 1983) from conventional fallow at Yorkton, Oxbow and Weyburn soil sites ranged from 9 to 11, 15 to 31 and 60 to 87 kgN∙ha−1 for upper, middle and lower slope positions, respectively. The corresponding values for chemical fallow were 18–28, 24–51, and 69–98 kgN∙ha−1. In both tillage systems, gaseous N losses increased in the order of upper < middle < lower slope positions and were associated with the variations in soil moisture. The results obtained from additional widely scattered field studies on chernozemic soils further confirmed that the more dense surface soil and relatively higher soil moisture (lower air-filled porosity) were the major factors affecting increased denitrification under chemical fallow. Volumetric soil moisture was the only factor which showed a very highly significant correlation with N2O emmisions. Key words: Acetylene inhibition-soil core technique, chemical fallow, denitrification, nitrification

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Farm nitrogen balances in six European agricultural landscapes – a method for farming system assessment, emission hotspot identification, and mitigation measure evaluation

Biogeosciences Discussions ◽

10.5194/bgd-9-8859-2012 ◽

2012 ◽

Vol 9 (7) ◽

pp. 8859-8904 ◽

Cited By ~ 7

Author(s):

T. Dalgaard ◽

J. F. Bienkowski ◽

A. Bleeker ◽

J. L. Drouet ◽

P. Durand ◽

...

Keyword(s):

Large Scale ◽

Farming System ◽

Agricultural Landscapes ◽

N Losses ◽

Livestock Farms ◽

N Management ◽

Short Time ◽

Measure Evaluation ◽

On Farm

Abstract. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK) were studied, and a common method was developed for undertaking farm inventories and the derivation of farm nitrogen (N) balances and N surplus from the in total 222 farms and 11 440 ha of farmland. In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha−1yr−1, respectively. However, all landscapes showed hotspots, especially from livestock farms, including a special UK case with landless large-scale poultry farming. So, whereas the average N surplus from the land-based UK farms dominated by extensive sheep grazing was only 31 ± 10 kg N ha−1yr−1, the landscape average was similar to those of PL and DK (122 ± 20 and 146 ± 55 kg N ha−1yr−1, respectively) when landless poultry were included. However, the challenge remains how to account for indirect N surpluses and emissions from such farms with a large export of manure out of the landscape. We conclude that farm N balances are a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate levels in soils and groundwater, measured during the landscape data collection campaign from 2007–2009. This indicates that farm N surpluses may be used as an independent dataset for validation of measured and modelled N emissions in agricultural landscapes. However, no significant correlation was found to N measured in surface waters, probably because of the short time horizon of the study. A case study of the development in N surplus from the landscape in DK from 1998–2008 showed a 22 % reduction, related to statistically significant effects (p < 0.01) of measures targeted at reducing N emissions from livestock farms. Based on the large differences between the average and the most modern and N-efficient farms, it was concluded that N-surplus reductions of 25–50 % as compared to the present level were realistic in all landscapes. The implemented N-surplus method was thus effective at comparing and synthesizing results on farm N emissions and the potentials of mitigation options, and is recommended for use in combination with other methods for the assessment of landscape N emissions and farm N efficiency, including more detailed N sink and N source hotspot mapping, measurements and modelling.

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Nitrogen Release in Soils Amended with Different Organic and Inorganic Fertilizers under Contrasting Moisture Regimes: A Laboratory Incubation Study

Agronomy ◽

10.3390/agronomy11112163 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2163

Author(s):

Shihab Uddin ◽

Mohammad Rafiqul Islam ◽

Mohammad Mofizur Rahman Jahangir ◽

Mohammad Mojibur Rahman ◽

Sabry Hassan ◽

...

Keyword(s):

Soil Type ◽

N Mineralization ◽

Poultry Manure ◽

Order Kinetic ◽

Strongly Correlated ◽

N Losses ◽

N Application ◽

Moisture Regimes ◽

N Release ◽

Gaseous N Losses

Understanding nitrogen (N) release patterns and kinetics is a key challenge for improving N use efficiency in any agroecosystem. An incubation experiment was done to study the N release pattern and kinetics of contrasting soils amended with compost (CO), poultry manure (PM), rice husk biochar (RHB), poultry manure biochar (PMB) and cowdung (CD) combined with chemical fertilizer (integrated plant nutrient system, IPNS approach) under two moisture regimes, viz. field capacity (FC) and continuous standing water (CSW) at 25 °C for 120 days. Our results revealed that NH4+-N was the dominant under CSW conditions, whereas NO3−-N was dominant under FC conditions. Net mineral N data fitted well to the first order kinetic model. Both N release potential (N0) and rate constant (k) were greater in acidic soil than those of charland soil. The maximum N release varied between 24.90–76.29% of input depending on soil type and moisture status. N mineralization was strongly correlated with urea N application. PM and PMB mineralized in all soil and moisture conditions whereas N immobilization was observed in the case of RHB. N mineralization was strongly correlated with urea N application. Gaseous N losses were different for the organic amendments exhibiting more gaseous N losses in PM, CD and CO based IPNS whereas the lowest gaseous N loss was observed in PMB based IPNS. Biochar based IPNS increased soil pH in all conditions. Thus, the present study suggests that N release depends on soil type, soil moisture and type of organic amendment. However, CO, PM and CD based IPNS can be recommended for both acidic and charland soils in terms of N release as short duration crops will suffer from N deficiency if biochar based IPNS is used in the field.

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Optimal Nitrogen Practice in Winter Wheat-Summer Maize Rotation Affecting the Fates of 15N-Labeled Fertilizer

Agronomy ◽

10.3390/agronomy10040521 ◽

2020 ◽

Vol 10 (4) ◽

pp. 521

Author(s):

Haiyan Liang ◽

Pengfei Shen ◽

Xiangze Kong ◽

Yuncheng Liao ◽

Yang Liu ◽

...

Keyword(s):

Crop Yield ◽

N Uptake ◽

N Fertilization ◽

Nitrogen Recovery ◽

Shaanxi Province ◽

Recovery Efficiency ◽

N Losses ◽

Nitrogen Recovery Efficiency ◽

Potential Losses ◽

N Management

Lower nitrogen recovery efficiency (NRE) and negative environmental impacts caused by excessive nitrogen (N) fertilization threaten the sustainability of agriculture. Efficient and appropriate fertilization practices are extremely important to achieve higher crop yield with minimum N loss. A field microplot experiment was conducted in a wheat-maize rotation system in Shaanxi province, at North China Plain, using the 15N isotope tracer technique to qualify the different annual N managements in terms of crop yield, NRE, N distribution in plant-soil, and N losses to optimize the N management. The experiment included four N treatments: conventional practice with 510 kg ha−1 annually in four applications (N1), and three optimized N treatments, reducing N rate to 420 kg ha−1, adjusting topdressing fertilizer times and using slow-release fertilizer (SRF) (N2, N3, N4). The results showed that the grain yield and N uptake did not differ significantly among treatments. N from fertilizer taken up (Ndff) by wheat was not affected by N management; however, in maize, Ndff performed differently. Optimized treatments significantly decreased the Ndff as compared to N1 treatment. Furthermore, NRE of wheat and annual nitrogen recovery efficiency (annual NRE) did not differ among treatments in 2016 but significantly increased in 2017 compared to N1. Annual NRE in 2017 was similar to that obtained for wheat. For maize, optimized N managements decreased the NRE in N3 and N4 treatments of two years. Potential losses in wheat were also similar amongst treatments, but in maize, N3 and N4 had lower residual N in the soil’s top 60 cm but resulted in higher potential losses than N1 and N2. Overall, our results demonstrate that applying 420 kg N ha−1 annually in three applications and combining SRF and urea are effective to sustain crop yield, improve the efficiency of N usage by maize, and reduce N losses in this region.

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THE EFFECT OF VARIOUS CLOVER MANAGEMENT PRACTICES ON GASEOUS N LOSSES AND MINERAL N ACCUMULATION

Canadian Journal of Soil Science ◽

10.4141/cjss83-060 ◽

1983 ◽

Vol 63 (3) ◽

pp. 593-605 ◽

Cited By ~ 25

Author(s):

M. S. AULAKH ◽

D. A. RENNIE ◽

E. A. PAUL

Keyword(s):

Management Practices ◽

Nitrogen Accumulation ◽

Clay Loam ◽

N Losses ◽

Mineral N ◽

N Accumulation ◽

Gaseous Loss ◽

Second Year ◽

Inhibition Technique ◽

Gaseous N Losses

A 2-yr field study was carried out to assess gaseous losses of N as N2O + N2 from two Black Chernozemic soils, where during year 1 wheat was underseeded to clover and in year 2, the clover in late June was (a) green-manured and the field fallowed, (b) harvested for hay and then fallowed, or (c) harvested for hay and allowed to regrow. Gaseous losses during year 1 were small and ranged from 1.3 kg N∙ha−1 (Blaine Lake clay loam) to 4.7 kg N∙ha−1 (Hoey clay loam). Gaseous losses were somewhat higher during the second year, but differences between the various clover management practices were generally small. The contribution of lower soil horizons towards gaseous nitrogen losses were shown to be negligible. Soil moisture, mean air temperature, nitrate + nitrite, and ammonia N concentrations collectively accounted for 37–66% of the variations in N2O fluxes. It is concluded that incorporation of clover followed by a partial fallow results in substantially less gaseous loss of nitrogen than the standard summerfallowing practice, and at the same time significantly increases mineral nitrogen accumulation in the soil. Key words: Acetylene inhibition technique, denitrification, nitrification, mineralization, green manuring

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