Nitrogen

Editorial

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3 pages, 196 KiB

Open AccessEditorial

Soil Nitrogen Supply: Linking Plant Available N to Ecosystem Functions and Productivity

by Jacynthe Dessureault-Rompré

Nitrogen 2022, 3(3), 455-457; https://doi.org/10.3390/nitrogen3030030 - 10 Aug 2022

Cited by 2 | Viewed by 1961

Abstract

Nitrogen (N), a common chemical element in the atmosphere (78% of our atmosphere) yet less common within the Earth’s crust (less than 2%), is a crucial nutrient for life [...] Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

Research

Jump to: Editorial

16 pages, 1095 KiB

Open AccessArticle

An Original Experimental Design to Quantify and Model Net Mineralization of Organic Nitrogen in the Field

by Thierry Morvan, Laure Beff, Yvon Lambert, Bruno Mary, Philippe Germain, Benjamin Louis and Nicolas Beaudoin

Nitrogen 2022, 3(2), 197-212; https://doi.org/10.3390/nitrogen3020015 - 15 Apr 2022

Cited by 3 | Viewed by 2589

Abstract

Improving the assessment and prediction of soil organic nitrogen (N) mineralization is essential: it contributes significantly to the N nutrition of crops and remains a major economic and environmental challenge. Consequently, a network of 137 fields was established in Brittany, France, to represent [...] Read more.

Improving the assessment and prediction of soil organic nitrogen (N) mineralization is essential: it contributes significantly to the N nutrition of crops and remains a major economic and environmental challenge. Consequently, a network of 137 fields was established in Brittany, France, to represent the wide diversity of soils and cultivation practices in this region. The experimental design was developed to measure net N mineralization for three consecutive years, in order to improve the accuracy of measuring it. Net N mineralization was quantified by the mineral N mass balance, which was estimated from March to October for a maize crop with no N fertilization. The effect of climate on mineralization was considered by calculating normalized time (ndays) and, then, calculating the N mineralization rate (Vn) as the ratio of the mineral N mass balance to normalized time. Strict screening of the experimental data, using agronomic and statistical criteria, resulted in the selection of a subset of 67 fields for data analysis. Mean Vn was relatively high (0.99 kg N ha⁻¹ nday⁻¹) over the period and varied greatly, from 0.62 to 1.46 kg N ha⁻¹ nday⁻¹ for the 10th and 90th percentiles, respectively. The upper soil layer (0–30 cm) was sampled to estimate its physical and chemical properties, particulate organic matter carbon and N fractions (POM-C and POM-N, respectively), soil microbial biomass (SMB), and extractable organic N (EON) determined in a phosphate borate extractant. The strongest correlations between Vn and these variables were observed with EON (r = 0.47), SMB (r = 0.45), POM-N (r = 0.43), and, to a lesser extent, the soil N stock (r = 0.31). Vn was also strongly correlated with a cropping system indicator (r = 0.39). A modeling approach, using generalized additive models, was used to identify and rank the variables with the greatest ability to predict net N mineralization. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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11 pages, 823 KiB

Open AccessArticle

Autumn Tillage Reduces the Effect of Plant Cover on Topsoil Nitrogen Leaching

by Jorge F. Miranda-Vélez and Iris Vogeler

Nitrogen 2022, 3(2), 186-196; https://doi.org/10.3390/nitrogen3020014 - 13 Apr 2022

Cited by 1 | Viewed by 2168

Abstract

Keeping cover crops to reduce nitrogen leaching often conflicts with timing tillage operations before the soil becomes un-trafficable during winter, while leaving cover crops in the field until spring raises concerns over pre-emptive competition with the following crop. Therefore, farmers may resort to [...] Read more.

Keeping cover crops to reduce nitrogen leaching often conflicts with timing tillage operations before the soil becomes un-trafficable during winter, while leaving cover crops in the field until spring raises concerns over pre-emptive competition with the following crop. Therefore, farmers may resort to tilling their fields in autumn after letting cover crops remain in the fields for only a short period of time. We explore the effects of this practice in a laboratory lysimeter setting by analyzing the leaching of nitrate from intact topsoil cores. Cores were extracted from no-till (NT) plots and plots tilled in autumn (AuT), in areas kept bare (B) and with volunteer winter rye plant cover (V) after harvest. Nitrate breakthrough curves show that V significantly reduced N leaching by 61% relative to B in NT, but did not have a significant effect in AuT. Dissection of leached cores and undisturbed reference cores indicated a significant removal of mineral N from the soil during the lysimeter experiment for all treatments except V in NT. This indicates that volunteer cover removed a crucial amount of leachable N and suggests that tillage counteracted the effect of V in AuT, likely due to a combination of reduced uptake and re-mineralization of N in cover crop residue. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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9 pages, 1056 KiB

Open AccessArticle

Degradation of N-(n-butyl) Thiophosphoric Triamide (NBPT) with and without Nitrification Inhibitor in Soils

by Ahmed A. Lasisi and Olalekan O. Akinremi

Nitrogen 2022, 3(2), 161-169; https://doi.org/10.3390/nitrogen3020012 - 2 Apr 2022

Cited by 8 | Viewed by 3712

Abstract

Recent studies have shown that nitrification inhibitor (NI) impairs the efficacy of urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT), in reducing ammonia volatilization and urea hydrolysis rate. A laboratory study was conducted to evaluate the influence of NI (specifically 3,4-dimethyl pyrazole [...] Read more.

Recent studies have shown that nitrification inhibitor (NI) impairs the efficacy of urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT), in reducing ammonia volatilization and urea hydrolysis rate. A laboratory study was conducted to evaluate the influence of NI (specifically 3,4-dimethyl pyrazole phosphate) on the degradation of NBPT in six soils. Soils were amended with either NBPT (10 mg NBPT kg⁻¹ soil) or NBPT plus NI (DI; 10 mg NBPT + 2.5 mg NI kg⁻¹ soil), incubated at 21 °C, and destructively sampled eight times during a 14-day incubation period. The degradation of NBPT in soil was quantified by measuring NBPT concentration with high-performance liquid chromatography-mass spectrometry, and the degradation rate constant was modeled with an exponential decay function. The study showed that the persistence of NBPT in soil was not influenced by the presence of NI, as the NBPT degradation rate constant across soils was 0.5 d⁻¹ with either NBPT or DI. In contrast, the degradation rate constant was significantly dependent on soils, with values ranging from 0.4 to 1.7 d⁻¹. Soil pH was the most important variable affecting the persistence of NBPT in soils. The half-life of NBPT was 0.4 d in acidic soil and 1.3 to 2.1 d in neutral to alkaline soils. The faster degradation of NBPT in acidic soils may explain its reduced efficacy in such soils. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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12 pages, 1079 KiB

Open AccessArticle

Simulated Cropping Season Effects on N Mineralization from Accumulated No-Till Crop Residues

by Rashad S. Alghamdi, Larry Cihacek and Qian Wen

Nitrogen 2022, 3(2), 149-160; https://doi.org/10.3390/nitrogen3020011 - 31 Mar 2022

Cited by 2 | Viewed by 2474

Abstract

The adoption of no-till management practices has increased in the United States over the last decade. In the state of North Dakota, approximately 5.7 million hectares of cropland is managed under no-till or conservation tillage management practices. Even though conservation tillage is known [...] Read more.

The adoption of no-till management practices has increased in the United States over the last decade. In the state of North Dakota, approximately 5.7 million hectares of cropland is managed under no-till or conservation tillage management practices. Even though conservation tillage is known for building soil health, increasing soil organic matter, capturing soil moisture, and reducing wind and water erosion, it also presents a unique best management practice since an increased mass of crop residue remains on the soil surface. Producers are concerned about whether plant needs are being met by nitrogen fertilizer that is currently being applied based on current North Dakota recommendations for long-term no-till systems. A Forman clay loam soil (fine-loamy, mixed, superactive, frigid Calcic Argiudolls) was used in this study, as it represented glacial till soils of the region. We examined whether N mineralization from surface-applied crop residue would result in similar or different results when compared to crop residue mixed into the soil. Soil freeze-thaw contribution to soil N mineralization was also evaluated. Six residue treatments with different C/N ratios including corn (Zea mays L.), soybean (Glycine max L.), forage radish (Raphanus sativus L.), winter pea (Pisum sativum L.), spring wheat (Triticum aestivum L.), and winter wheat (Triticum aestivum L.) were used. Five 10–14-week cycles with a three-week freeze period between each cycle at 0 ºC were evaluated for NO₃-N production. Crop residues with a narrow C/N ratio contributed to greater instances of N mineralization during each incubation cycle, and the accumulation of crop residues with a wide C/N ratio over each incubation cycle following the first incubation did not offset the immobilization trends observed in the first incubation. A change in N mineralized in the untreated control soil during the last two incubation cycles may have been caused by freeze-thaw effects or a shift in microbial population due to a lack of fresh C inputs. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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10 pages, 3095 KiB

Open AccessArticle

Spatial Variability in Inorganic Soil Nitrogen Production in a Mixed-Vegetation Urban Landscape

by Juma Bukomba and Mary G. Lusk

Nitrogen 2022, 3(1), 118-127; https://doi.org/10.3390/nitrogen3010009 - 11 Mar 2022

Cited by 2 | Viewed by 2788

Abstract

Urban landscapes are not homogeneous, and small-scale variations in plant community or management inputs can give rise to a large range of environmental conditions. In this paper, we investigated the small-scale variability of soil nitrogen (N) properties in a single urban landscape that [...] Read more.

Urban landscapes are not homogeneous, and small-scale variations in plant community or management inputs can give rise to a large range of environmental conditions. In this paper, we investigated the small-scale variability of soil nitrogen (N) properties in a single urban landscape that has distinctly different patches or types of cover. We specifically measured soil net N mineralization, nitrification, and exchangeable forms of inorganic N for patches with traditional turfgrass versus patches with common turfgrass alternatives such as ornamental grasses, groundcovers, and mulches. All soil N properties were variable among landscape patches, showing that soil N processing can vary on scales of a few meters. Notably, both mineralization and nitrification were the highest in a patch covered with perennial peanut, but exchangeable nitrate (NO₃⁻) was low for the same soil, indicating that soils under perennial peanut may be producing high levels of inorganic N but that the produced N does not stay in the soil, possibly leaching to underlying groundwater. We recommend future studies on the mechanisms that drive the variable N properties seen under distinct urban landscape patches, with special emphasis on potential patterns in N losses for mixed-vegetation landscapes. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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11 pages, 1751 KiB

Open AccessArticle

Biochar Applied with Inorganic Nitrogen Improves Soil Carbon, Nitrate and Ammonium Content of a Sandy Loam Temperate Soil

by Peter Omara, Lawrence Aula, Fred Otim, Alfred Obia, Joao Luis Bigatao Souza and Daryl Brain Arnall

Nitrogen 2022, 3(1), 90-100; https://doi.org/10.3390/nitrogen3010007 - 23 Feb 2022

Cited by 1 | Viewed by 2953

Abstract

Biochar is suggested to improve soil properties. However, its combination with inorganic nitrogen (N) fertilizer in temperate soils is not well understood. This study compared the effect of fertilizer N-biochar-combinations (NBC) and fertilizer-N (FN) on total soil N (TSN), soil organic carbon (SOC), [...] Read more.

Biochar is suggested to improve soil properties. However, its combination with inorganic nitrogen (N) fertilizer in temperate soils is not well understood. This study compared the effect of fertilizer N-biochar-combinations (NBC) and fertilizer-N (FN) on total soil N (TSN), soil organic carbon (SOC), soil nitrate (NO₃⁻–N), and ammonium (NH₄⁺–N). Soil samples were taken from experiments at Efaw and Lake Carl Blackwell (LCB), Oklahoma, USA with ten treatments consisting of three N rates (50, 100, and 150 kg N ha⁻¹) and three biochar rates (5, 10, and 15 t ha⁻¹). Results at Efaw showed greater TSN and SOC under NBC compared to FN by 3 and 21%, respectively. No percentage difference was observed for NH₄⁺–N while NO₃⁻–N was lower by 7%. At LCB, TSN, SOC, NO₃⁻–N, and NH₄⁺–N were higher under NBC by 5, 18, 24, and 10%, respectively, compared to FN. Whereas application of biochar improved SOC at both sites, NO₃⁻–N and NH₄⁺–N were only significant at LCB site with a sandy loam soil but not at Efaw with silty clay loam. Therefore, biochar applied in combination with inorganic N can improve N availability with potential to increase crop N uptake on coarse textured soils. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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16 pages, 2708 KiB

Open AccessArticle

Combination of Inorganic Nitrogen and Organic Soil Amendment Improves Nitrogen Use Efficiency While Reducing Nitrogen Runoff

by Ian Phillips, Chanyarat Paungfoo-Lonhienne, Iman Tahmasbian, Benjamin Hunter, Brianna Smith, David Mayer and Matthew Redding

Nitrogen 2022, 3(1), 58-73; https://doi.org/10.3390/nitrogen3010004 - 20 Jan 2022

Cited by 9 | Viewed by 3458

Abstract

Improved nitrogen fertiliser management and increased nitrogen use efficiency (NUE) can be achieved by synchronising nitrogen (N) availability with plant uptake requirements. Organic materials in conjunction with inorganic fertilisers provide a strategy for supplying plant-available N over the growing season and reducing N [...] Read more.

Improved nitrogen fertiliser management and increased nitrogen use efficiency (NUE) can be achieved by synchronising nitrogen (N) availability with plant uptake requirements. Organic materials in conjunction with inorganic fertilisers provide a strategy for supplying plant-available N over the growing season and reducing N loss. This study investigated whether a combined application of inorganic N with an organic soil amendment could improve nitrogen use efficiency by reducing N loss in runoff. Nitrogen runoff from a ryegrass (Lolium multiflorum) cover was investigated using a rainfall simulator. Nitrogen was applied at low, medium and high (50, 75 and 100 kg/ha) rates as either (NH₄)₂SO₄ or in combination with a poultry manure-based organic material. We showed that the NUE in the combination (58–75%) was two-fold greater than in (NH₄)₂SO₄ (24–42%). Furthermore, this combination also resulted in a two-fold lower N runoff compared with the inorganic fertiliser alone. This effect was attributed to the slower rate of N release from the organic amendment relative to the inorganic fertiliser. Here, we demonstrated that the combined use of inorganic and organic N substrates can reduce nutrient losses in surface runoff due to a better synchronisation of N availability with plant uptake requirements. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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17 pages, 5066 KiB

Open AccessArticle

Nutrient Availability for Lactuca sativa Cultivated in an Amended Peatland: An Ionic Exchange Study

by Jacynthe Dessureault-Rompré, Alexis Gloutney and Jean Caron

Nitrogen 2022, 3(1), 26-42; https://doi.org/10.3390/nitrogen3010002 - 14 Jan 2022

Cited by 4 | Viewed by 2773

Abstract

Few conservation strategies have been applied to cultivated peatland. This field study over one growth cycle of Lactuca sativa examined the effect of plant-based, high-C/N-ratio amendments in a real farming situation on peatland. Plant Root Simulator (PRS^®) probes were used directly [...] Read more.

Few conservation strategies have been applied to cultivated peatland. This field study over one growth cycle of Lactuca sativa examined the effect of plant-based, high-C/N-ratio amendments in a real farming situation on peatland. Plant Root Simulator (PRS^®) probes were used directly in the field to assess the impacts of incorporating Miscanthus x giganteus straw and Salix miyabeana chips on nutrient availability for lettuce. The results showed that lettuce yield decreased by 35% in the miscanthus straw treatment and by 14% in the willow chip treatment. In addition, the nitrogen flux rate was severely reduced during crop growth (75% reduction) and the plant N uptake index was much lower in the amended treatments than in the control. The phosphorus supply rate was also significantly lower (24% reduction) in the willow treatment. The influence of sampling zone was significant as well, with most macro-nutrients being depleted in the root zone and most micro-nutrients being mobilized. Additional work is needed to optimize the proposed conservation strategy and investigate the effects of consecutive years of soil amendment on different vegetable crops and in different types of cultivated peatlands to confirm and generalize the findings of this study. Future field studies should also explore the long-term carbon dynamics under plant-based, high-C/N-ratio amendments to determine if they can offset annual C losses. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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15 pages, 2758 KiB

Open AccessArticle

Oilseed Rape Cultivars Show Diversity of Root Morphologies with the Potential for Better Capture of Nitrogen

by László Kupcsik, Claudia Chiodi, Taraka Ramji Moturu, Hugues De Gernier, Loïc Haelterman, Julien Louvieaux, Pascal Tillard, Craig J. Sturrock, Malcolm Bennett, Philippe Nacry and Christian Hermans

Nitrogen 2021, 2(4), 491-505; https://doi.org/10.3390/nitrogen2040033 - 14 Dec 2021

Cited by 6 | Viewed by 2836

Abstract

The worldwide demand for vegetable oils is rising. Oilseed rape (Brassica napus) diversifies cereal dominated crop rotations but requires important nitrogen input. Yet, the root organ is offering an untapped opportunity to improve the nitrogen capture in soil. This study evaluates [...] Read more.

The worldwide demand for vegetable oils is rising. Oilseed rape (Brassica napus) diversifies cereal dominated crop rotations but requires important nitrogen input. Yet, the root organ is offering an untapped opportunity to improve the nitrogen capture in soil. This study evaluates three culture systems in controlled environment, to observe root morphology and to identify root attributes for superior biomass production and nitrogen use. The phenotypic diversity in a panel of 55 modern winter oilseed rape cultivars was screened in response to two divergent nitrate supplies. Upon in vitro and hydroponic cultures, a large variability for root morphologies was observed. Root biomass and morphological traits positively correlated with shoot biomass or leaf area. The activities of high-affinity nitrate transport systems correlated negatively with the leaf area, while the combined high- and low-affinity systems positively with the total root length. The X-ray computed tomography permitted to visualize the root system in pipes filled with soil. The in vitro root phenotype at germination stage was indicative of lateral root deployment in soil-grown plants. This study highlights great genetic potential in oilseed rape, which could be manipulated to optimize crop root characteristics and nitrogen capture with substantial implications for agricultural production. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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13 pages, 2762 KiB

Open AccessArticle

Surface Properties and Adherence of Bradyrhizobium diazoefficiens to Glycine max Roots Are Altered When Grown in Soil Extracted Nutrients

by Armaan Kaur Sandhu, Senthil Subramanian and Volker S. Brözel

Nitrogen 2021, 2(4), 461-473; https://doi.org/10.3390/nitrogen2040031 - 15 Nov 2021

Cited by 4 | Viewed by 3730

Abstract

Soybean roots are colonized and nodulated by multiple strains of compatible nitrogen-fixing rhizobia primarily belonging to the Genus Bradyrhizobium. Motility towards the root and attachment to root hairs are key determinants of competitive colonization and subsequent nodulation. Bacterial surface properties and motility [...] Read more.

Soybean roots are colonized and nodulated by multiple strains of compatible nitrogen-fixing rhizobia primarily belonging to the Genus Bradyrhizobium. Motility towards the root and attachment to root hairs are key determinants of competitive colonization and subsequent nodulation. Bacterial surface properties and motility are known to vary with chemical composition of the culture medium, and root adhesion and nodulation occur in a soil environment rather than laboratory medium. We asked whether the nodulation-promoting factors motility, surface hydrophobicity and surface adhesion of Bradyrhizobium are affected by growth in a soil nutrient environment. B. diazoefficiens USDA 110, 126, 3384, and B. elkanii USDA 26 were grown in mineral salt medium with peptone, yeast extract and arabinose (PSY), and in a soil extracted soluble organic matter (SESOM) medium. Surface hydrophobicity was determined by partitioning into hydrocarbon, motility by transition through soft agar, and surface-exposed saccharides by lectin profiling, followed by biofilm formation and soybean root adhesion capacity of populations. SESOM-grown populations were generally less motile and more hydrophobic. They bound fewer lectins than PSY-grown populations, indicating a simpler surface saccharide profile. SESOM populations of USDA 110 did not form detectable biofilm, but showed increased binding to soy roots. Our results indicate that growth in a soil environment impacts surface properties, motility, and subsequent soy root adhesion propensity. Hence, evaluation of Bradyrhizobium for nodulation efficiency should be performed using soil from the specific field where the soybeans are to be planted, rather than laboratory culture media. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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17 pages, 3191 KiB

Open AccessArticle

Short-Term Effect of Nitrogen Fertilization on Carbon Mineralization during Corn Residue Decomposition in Soil

by Tanjila Jesmin, Dakota T. Mitchell and Richard L. Mulvaney

Nitrogen 2021, 2(4), 444-460; https://doi.org/10.3390/nitrogen2040030 - 27 Oct 2021

Cited by 10 | Viewed by 6378

Abstract

The effect of N fertilization on residue decomposition has been studied extensively; however, contrasting results reflect differences in residue quality, the form of N applied, and the type of soil studied. A 60 d laboratory incubation experiment was conducted to ascertain the effect [...] Read more.

The effect of N fertilization on residue decomposition has been studied extensively; however, contrasting results reflect differences in residue quality, the form of N applied, and the type of soil studied. A 60 d laboratory incubation experiment was conducted to ascertain the effect of synthetic N addition on the decomposition of two corn (Zea mays L.) stover mixtures differing in C:N ratio by continuous monitoring of CO₂ emissions and periodic measurement of microbial biomass and enzyme activities involved in C and N cycling. Cumulative CO₂ production was greater for the high than low N residue treatment, and was significantly increased by the addition of exogenous N. The latter effect was prominent during the first month of incubation, whereas N-treated soils produced less CO₂ in the second month, as would be expected due to more rapid substrate depletion from microbial C utilization previously enhanced by greater N availability. The stimulatory effect of exogenous N was verified with respect to active biomass, microbial biomass C and N, and cellulase and protease activities, all of which were significantly correlated with cumulative CO₂ production. Intensive N fertilization in modern corn production increases the input of residues but is not conducive to soil C sequestration. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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13 pages, 1907 KiB

Open AccessArticle

Winter Malting Barley Growth, Yield, and Quality following Leguminous Cover Crops in the Northeast United States

by Arthur Siller, Heather Darby, Alexandra Smychkovich and Masoud Hashemi

Nitrogen 2021, 2(4), 415-427; https://doi.org/10.3390/nitrogen2040028 - 8 Oct 2021

Cited by 1 | Viewed by 3007

Abstract

There is growing interest in malting barley (Hordeum vulgare L.) production in the Northeastern United States. This crop must meet high quality standards for malting but can command a high price if these quality thresholds are met. A two-year field experiment was [...] Read more.

There is growing interest in malting barley (Hordeum vulgare L.) production in the Northeastern United States. This crop must meet high quality standards for malting but can command a high price if these quality thresholds are met. A two-year field experiment was conducted from 2015 to 2017 to evaluate the impact of two leguminous cover crops, sunn hemp (Crotalaria juncea L.) and crimson clover (Trifolium incarnatum L.), on subsequent winter malting barley production. Four cover crop treatments—sunn hemp (SH), crimson clover (CC), sunn hemp and crimson clover mixture (SH + CC), and no cover crop (NC)—were grown before planting barley at three seeding rates (300, 350, and 400 seeds m⁻²). SH and SH + CC produced significantly more biomass and residual nitrogen than the CC and NC treatments. Higher barley seeding rates led to higher seedling density and winter survival. However, the subsequent spring and summer barley growth metrics, yield, and malting quality were not different in any of the treatments. There is much left to investigate in determining the best malting barley production practices in the Northeastern United States, but these results show that winter malting barley can be successfully integrated into crop rotations with leguminous plants without negative impacts on barley growth, yield, and grain quality. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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12 pages, 1665 KiB

Open AccessArticle

Comparative Effectiveness of Four Nitrification Inhibitors for Mitigating Carbon Dioxide and Nitrous Oxide Emissions from Three Different Textured Soils

by Yafei Guo, Asif Naeem and Karl H. Mühling

Nitrogen 2021, 2(2), 155-166; https://doi.org/10.3390/nitrogen2020011 - 13 Apr 2021

Cited by 13 | Viewed by 4690

Abstract

Nitrification inhibitors (NIs) can be used to reduce both NO₃⁻-N leaching and N₂O-N emissions. However, the comparative efficacies of NIs can be strongly affected by soil type. Therefore, the efficacies of four nitrification inhibitors (dicyandiamide (DCD), 3, 4-dimethylpyrazole [...] Read more.

Nitrification inhibitors (NIs) can be used to reduce both NO₃⁻-N leaching and N₂O-N emissions. However, the comparative efficacies of NIs can be strongly affected by soil type. Therefore, the efficacies of four nitrification inhibitors (dicyandiamide (DCD), 3, 4-dimethylpyrazole phosphate (DMPP), nitrogenous mineral fertilizers containing the DMPP ammonium stabilizer (ENTEC) and active ingredients: 3.00–3.25% 1, 2, 4-triazole and 1.50–1.65% 3-methylpyrazole (PIADIN)) were investigated in three different textured N-fertilized (0.5 g NH₄⁺-N kg⁻¹ soil) soils of Schleswig-Holstein, namely, Marsch (clayey), Östliches Hügelland (loamy) and Geest (sandy) under a controlled environment. Total CO₂-C and N₂O-N emissions were significantly higher from Marsch than Östliches Hügelland and Geest. In Marsch, DMPP showed the highest inhibitory effect on CO₂-C emission (50%), followed by PIADIN (32%) and ENTEC (16%). In Östliches Hügelland, DCD and PIADIN showed the highest and equal inhibitory effect on CO₂-C emission (73%), followed by DMPP (64%) and ENTEC (36%). In Marsch and Östliches Hügelland, DCD showed the stronger inhibitory effect on N₂O-N emission (86% and 47%) than DMPP (56% and 30%) and PIADIN (54% and 16%). In Geest, DMPP was more effective in reducing N₂O-N emission (88%) than PIADIN (70%) and DCD (33%). Thus, it can be concluded that DCD is a better NI for clay and loamy soils, while DMPP and PIADIN are better for sandy soils to inhibit soil nitrification and gaseous emissions. Full article

(This article belongs to the Special Issue Soil Nitrogen Supply: Linking Plant Available N to Ecosystems Functions and Productivity)

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