Enrichment of natural 15N abundance during soil N losses under 20 years of continuous cereal cropping

2017 ◽  
Vol 574 ◽  
pp. 282-287 ◽  
Author(s):  
Andrew R. Jones ◽  
Ram C. Dalal
Keyword(s):  
Soil N ◽  
N Losses ◽  
Natural 15N Abundance ◽  
15N Abundance

Natural 15N abundance of soil N pools and N2O reflect the nitrogen dynamics of forest soils

2007 ◽  
Vol 295 (1-2) ◽  
pp. 79-94 ◽  
Author(s):  
Katja Pörtl ◽  
Sophie Zechmeister-Boltenstern ◽  
Wolfgang Wanek ◽  
Per Ambus ◽  
Torsten W. Berger
Keyword(s):  
Forest Soils ◽  
Nitrogen Dynamics ◽  
Soil N ◽  
Natural 15N Abundance ◽  
Soil N Pools ◽  
15N Abundance

scholarly journals Development of an Online Tool for Tracking Soil Nitrogen to Improve the Environmental Performance of Maize Production

2021 ◽  
Vol 13 (10) ◽  
pp. 5649
Author(s):  
Giovani Preza-Fontes ◽  
Junming Wang ◽  
Muhammad Umar ◽  
Meilan Qi ◽  
Kamaljit Banger ◽  
...  
Keyword(s):  
Real Time ◽  
N Uptake ◽  
Growing Season ◽  
Weather Data ◽  
N Availability ◽  
Soil N ◽  
N Losses ◽  
Online Tool ◽  
Support Tool ◽  
Soil N Availability

Freshwater nitrogen (N) pollution is a significant sustainability concern in agriculture. In the U.S. Midwest, large precipitation events during winter and spring are a major driver of N losses. Uncertainty about the fate of applied N early in the growing season can prompt farmers to make additional N applications, increasing the risk of environmental N losses. New tools are needed to provide real-time estimates of soil inorganic N status for corn (Zea mays L.) production, especially considering projected increases in precipitation and N losses due to climate change. In this study, we describe the initial stages of developing an online tool for tracking soil N, which included, (i) implementing a network of field trials to monitor changes in soil N concentration during the winter and early growing season, (ii) calibrating and validating a process-based model for soil and crop N cycling, and (iii) developing a user-friendly and publicly available online decision support tool that could potentially assist N fertilizer management. The online tool can estimate real-time soil N availability by simulating corn growth, crop N uptake, soil organic matter mineralization, and N losses from assimilated soil data (from USDA gSSURGO soil database), hourly weather data (from National Weather Service Real-Time Mesoscale Analysis), and user-entered crop management information that is readily available for farmers. The assimilated data have a resolution of 2.5 km. Given limitations in prediction accuracy, however, we acknowledge that further work is needed to improve model performance, which is also critical for enabling adoption by potential users, such as agricultural producers, fertilizer industry, and researchers. We discuss the strengths and limitations of attempting to provide rapid and cost-effective estimates of soil N availability to support in-season N management decisions, specifically related to the need for supplemental N application. If barriers to adoption are overcome to facilitate broader use by farmers, such tools could balance the need for ensuring sufficient soil N supply while decreasing the risk of N losses, and helping increase N use efficiency, reduce pollution, and increase profits.

Pattern of natural 15N abundance in lakeside forest ecosystem affected by cormorant-derived nitrogen

2006 ◽  
pp. 69-86 ◽  
Author(s):  
Kayoko Kameda ◽  
Keisuke Koba ◽  
Satoru Hobara ◽  
Takashi Osono ◽  
Masakazu Terai
Keyword(s):  
Forest Ecosystem ◽  
Natural 15N Abundance ◽  
15N Abundance

scholarly journals Management Intensity Controls Nitrogen-Use-Efficiency and Flows in Grasslands—A 15N Tracing Experiment

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 606
Author(s):  
Marcus Zistl-Schlingmann ◽  
Steve Kwatcho Kengdo ◽  
Ralf Kiese ◽  
Michael Dannenmann
Keyword(s):  
Land Use ◽  
N Balance ◽  
15N Tracer ◽  
15N Recovery ◽  
Soil N ◽  
N Losses ◽  
Soil System ◽  
Land Use Intensification ◽  
Plant Soil ◽  
Montane Grasslands

The consequences of land use intensification and climate warming on productivity, fates of fertilizer nitrogen (N) and the overall soil N balance of montane grasslands remain poorly understood. Here, we report findings of a 15N slurry-tracing experiment on large grassland plant–soil lysimeters exposed to different management intensities (extensive vs. intensive) and climates (control; translocation: +2 °C, reduced precipitation). Surface-applied cattle slurry was enriched with both 15NH4+ and 15N-urea in order to trace its fate in the plant–soil system. Recovery of 15N tracer in plants was low (7–17%), while it was considerably higher in the soil N pool (32–42%), indicating N stabilization in soil organic nitrogen (SON). Total 15N recovery was only 49% ± 7% indicating substantial fertilizer N losses to the environment. With harvest N exports exceeding N fertilization rates, the N balance was negative for all climate and management treatments. Intensive management had an increased deficit relative to extensive management. In contrast, simulated climate change had no significant effects on the grassland N balance. These results suggest a risk of soil N mining in montane grasslands under land use intensification based on broadcast liquid slurry application.

Nitrogen balance in Australia and nitrogen use efficiency on Australian farms

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 435 ◽  
Author(s):  
J. F. Angus ◽  
P. R. Grace
Keyword(s):  
Agricultural Land ◽  
International Standards ◽  
N Balance ◽  
Yield Potential ◽  
N Fixation ◽  
Soil N ◽  
N Losses ◽  
Dryland Farming ◽  
Australian Continent ◽  
Fertiliser Application

The amount of reactive N in soils on the Australian continent appears to be increasing, mainly because of biological N-fixation by permanent pastures in the dryland farming zone. This gain is partly offset by N-mining by crops, which we estimate have removed between one-fifth and one-quarter of the original soil N. The vast areas of non-agricultural land and arid rangelands appear to be in neutral N balance and the relatively small area of intensive agriculture is in negative balance. There are regional N losses from the sugar and dairy industries to groundwater, estuaries and lagoons, including the Great Barrier Reef. Fertiliser N application is increasing, and is likely to increase further, to compensate for the soil-N mining and to meet increasing crop yield potential, but fertiliser-N represents a relatively small fraction of the Australian N balance. The dryland farming zone utilises the largest amounts of native and fertiliser N. The average fertiliser application to dryland cereals and oilseeds, 45 kg N ha–1, is low by international standards because of the small N-demand by dryland crops and because there are no subsidies on crops or fertiliser that promote overuse. The efficiency of N-use is relatively low, for example about 40% of fertiliser N is recovered in the aboveground parts of dryland wheat and the rest is retained in the soil, denitrified or otherwise lost. We suggest further research on fertiliser-application methods to increase crop recovery of fertiliser, as well as research to reduce the surplus N from permanent pasture.

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