INTERACTIVE EFFECTS OF ATMOSPHERIC CO2AND SOIL-N AVAILABILITY ON FINE ROOTS OFPOPULUS TREMULOIDES

The influence of soil N availability on growth, on seasonal C allocation patterns, and on sulfate-S content in sugar maple seedlings (Acersaccharum Marsh.) was tested experimentally. Relative to controls, the production of foliage doubled in response to high N availability, and the production of foliage, stems, coarse roots, and fine roots was halved in response to N deprivation. The period of foliage production was lengthened by fertilization and the period of fine root production was shortened by N deprivation compared with controls. In August, a shift in priority C allocation from foliage to roots occurred in the N-deprivation treatment. Therefore, during this month alone, the shoot to root ratio was greater in fertilized plants (1.0) than in N-deprived plants (0.5). Allocation to storage reserves was highest in N-deprived and lowest in fertilized plants (average 160 vs. 125 mg glucose/g biomass produced), and storage in roots of unfertilized plants commenced earlier (August) than in fertilized plants (after September). This resulted in unfertilized plants having higher fine root starch concentrations (5.2%) than fertilized plants (4.0%) in December, although sugar concentrations were similar (5.7%). The lengthened season of shoot growth and the low starch to sugar ratios in fine roots of fertilized plants are symptoms consistent with a higher risk of frost injury and microbial pathogen infection. Although soil N availability did not influence the sulfate-S content in foliage, N deprivation resulted in higher organic S to N ratios. This suggests that more S-containing proteins are produced when N availability is poor.

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

Sustainability ◽

10.3390/su13105649 ◽

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.

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Nitrous oxide emissions from red clover and winter wheat residues depend on interacting effects of distribution, soil N availability and moisture level

Plant and Soil ◽

10.1007/s11104-021-05030-8 ◽

2021 ◽

Author(s):

Arezoo Taghizadeh-Toosi ◽

Baldur Janz ◽

Rodrigo Labouriau ◽

Jørgen E. Olesen ◽

Klaus Butterbach-Bahl ◽

...

Keyword(s):

Nitrous Oxide ◽

Winter Wheat ◽

Red Clover ◽

Moisture Level ◽

Nitrous Oxide Emissions ◽

N Availability ◽

Soil N ◽

Soil N Availability

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Predicting Loblolly Pine Growth Response from N Fertilizer, using Soil-N Availability Indices

Soil Science Society of America Journal ◽

10.2136/sssaj1982.03615995004600050043x ◽

1982 ◽

Vol 46 (5) ◽

pp. 1096-1099 ◽

Cited By ~ 11

Author(s):

Russ Lea ◽

Russ Ballard

Keyword(s):

Loblolly Pine ◽

Growth Response ◽

N Fertilizer ◽

N Availability ◽

Soil N ◽

Soil N Availability

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Atmospheric CO 2 , Soil-N Availability, and Allocation of Biomass and Nitrogen by Populus tremuloides

Ecological Applications ◽

10.2307/2640984 ◽

2000 ◽

Vol 10 (1) ◽

pp. 34 ◽

Cited By ~ 1

Author(s):

Donald R. Zak ◽

Kurt S. Pregitzer ◽

Peter S. Curtis ◽

Christoph S. Vogel ◽

William E. Holmes ◽

...

Keyword(s):

Populus Tremuloides ◽

N Availability ◽

Soil N ◽

Soil N Availability

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Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

The Scientific World JOURNAL ◽

10.1100/tsw.2001.267 ◽

2001 ◽

Vol 1 ◽

pp. 22-29 ◽

Cited By ~ 19

Author(s):

S. Kuo ◽

B. Huang ◽

R. Bembenek

Keyword(s):

Cover Crops ◽

Cover Crop ◽

N Fertilizer ◽

N Leaching ◽

Corn Yield ◽

N Availability ◽

Soil N ◽

Soil N Availability ◽

N Concentration ◽

Fertilizer Rates

Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during the high N leaching period for vetch cover crop treatment and for the control without the cover crops. The correlation, however, failed for other cover crops largely because of variable effectiveness of the cover crops in reducing NO3leaching during the 5 years of this study. Further research is needed to determine if relay cover crops planted into standing summer crops is a more appropriate approach than fall seeding in this region to gain sufficient growth of the cover crop by fall. Testing with other main crops that have earlier harvest dates than corn is also needed to further validate the effectiveness of the bicultures to increase soil N availability while protecting the water quality.

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Above- and belowground response of Populus grandidentata to elevated atmospheric CO2 and soil N availability

Belowground Responses to Rising Atmospheric CO2: Implications for Plants, Soil Biota, and Ecosystem Processes ◽

10.1007/978-94-017-0851-7_5 ◽

1994 ◽

pp. 45-51 ◽

Cited By ~ 1

Author(s):

Peter S. Curtis ◽

Donald R. Zak ◽

Kurt S. Pregitzer ◽

James A. Teeri

Keyword(s):

Atmospheric Co2 ◽

N Availability ◽

Soil N ◽

Soil N Availability ◽

Elevated Atmospheric Co2 ◽

Populus Grandidentata

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Carbon Mineralization in a Soil Amended with Sewage Sludge-Derived Biochar

Applied Sciences ◽

10.3390/app9214481 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4481 ◽

Cited By ~ 3

Author(s):

Figueiredo ◽

Coser ◽

Moreira ◽

Leão ◽

Vale ◽

...

Keyword(s):

Sewage Sludge ◽

Co2 Emissions ◽

Nitrogen Availability ◽

Carbon Mineralization ◽

Environmental Benefits ◽

N Availability ◽

Soil N ◽

Total N ◽

Soil N Availability ◽

Organic Matter Stabilization

Biochar has been presented as a multifunctional material with short- and long-term agro-environmental benefits, including soil organic matter stabilization, improved nutrient cycling, and increased primary productivity. However, its turnover time, when applied to soil, varies greatly depending on feedstock and pyrolysis temperature. For sewage sludge-derived biochars, which have high N contents, there is still a major uncertainty regarding the influence of pyrolysis temperatures on soil carbon mineralization and its relationship to soil N availability. Sewage sludge and sewage sludge-derived biochars produced at 300 °C (BC300), 400 °C (BC400), and 500 °C (BC500) were added to an Oxisol in a short-term incubation experiment. Carbon mineralization and nitrogen availability (N-NH4+ and N-NO3−) were studied using a first-order model. BC300 and BC400 showed higher soil C mineralization rates and N-NH4+ contents, demonstrating their potential to be used for plant nutrition. Compared to the control, the cumulative C-CO2 emissions increased by 60–64% when biochars BC300 and BC400 were applied to soil. On the other hand, C-CO2 emissions decreased by 6% after the addition of BC500, indicating the predominance of recalcitrant compounds, which results in a lower supply of soil N-NH4+ (83.4 mg kg−1) in BC500, being 67% lower than BC300 (255.7 mg kg−1). Soil N availability was strongly influenced by total N, total C, C/N ratio, H, pore volume, and specific surface area in the biochars.

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