scholarly journals Biological and synthetic approaches to inhibiting nitrification in non-tilled Mediterranean soils

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Adrián Bozal-Leorri ◽  
Mario Corrochano-Monsalve ◽  
Luis Miguel Arregui ◽  
Pedro M. Aparicio-Tejo ◽  
Carmen González-Murua
Keyword(s):  
Root Exudates ◽  
Agricultural Soils ◽  
Green Revolution ◽  
N Fertilization ◽  
Control Treatment ◽  
Nitrification Inhibitors ◽  
Ammonia Oxidizing Bacteria ◽  
N Losses ◽  
Mineral N ◽  
N Pollution

Abstract Background The increasing demand for food production has led to a tenfold increase in nitrogen (N) fertilizer use since the Green Revolution. Nowadays, agricultural soils have been turned into high-nitrifying environments that increase N pollution. To decrease N losses, synthetic nitrification inhibitors (SNIs) such as 3,4-dimethylpyrazole phosphate (DMPP) have been developed. However, SNIs are not widely adopted by farmers due to their biologically limited stability and soil mobility. On the other hand, allelopathic substances from root exudates from crops such as sorghum are known for their activity as biological nitrification inhibitors (BNIs). These substances are released directly into the rhizosphere. Nevertheless, BNI exudation could be modified or even suppressed if crop development is affected. In this work, we compare the performance of biological (sorghum crop) and synthetic (DMPP) nitrification inhibitors in field conditions. Results Sorghum crop BNIs and DMPP prevented an increase in the abundance of ammonia-oxidizing bacteria (AOB) without affecting the total bacterial abundance. Both nitrification inhibitors maintained similar soil NH4+ content, but at 30 days post-fertilization (DPF), the sorghum BNIs resulted in higher soil NO3− content than DMPP. Even so, these inhibitors managed to reduce 64% and 96%, respectively, of the NO3−-N/NH4+-N ratio compared to the control treatment. Similar to soil mineral N, there were no differences in leaf δ15N values between the two nitrification inhibitors, yet at 30 DPF, δ15N values from sorghum BNI were more positive than those of DMPP. N2O emissions from DMPP-treated soil were low throughout the experiment. Nevertheless, while sorghum BNIs also maintained low N2O emissions, they were associated with a substantial N2O emission peak at 3 DPF that lasted until 7 DPF. Conclusions Our results indicate that while sorghum root exudates can reduce nitrification in field soil, even at the same efficiency as DMPP for a certain amount of time, they are not able to prevent the N pollution derived from N fertilization as DMPP does during the entire experiment. Graphic Abstract

Influence of nitrification inhibitor (Nitrapyrin) on winter wheat yield 

2021 ◽  
Author(s):  
Rayehe Mirkhani ◽  
Mohammad Sajad Ghavami ◽  
Elnaz Ahmadi ◽  
Ebrahim Moghiseh
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Stem Elongation ◽  
Block Design ◽  
Wheat Yield ◽  
Nitrification Inhibitor ◽  
Control Treatment ◽  
Nitrification Inhibitors ◽  
Ammonia Oxidizing Bacteria ◽  
Winter Wheat Yield

<p>Nitrogen (N) is a crop nutrient that is commonly applied as fertilizer, however the dynamic nature of N and its propensity for loss from soil‐plant systems creates a unique and challenging environment for its efficient management. Nitrification inhibitors (NIs) are compounds that can reduce the bacterial oxidation of NH<sub>4</sub><sup>+</sup> to NO<sub>2</sub><sup>−</sup> by inhibiting the activity of ammonia-oxidizing bacteria and maintaining a higher proportion of applied nitrogen in the soil by preventing nitrate loss from leaching and gaseous N losses from nitrification and denitrification. The organic compound 2-chloro-6-(tri-chloromethyl) pyridine, commonly known as nitrapyrin (NP), is such a nitrification inhibitor that is used in agriculture. The objective of this study was to investigate the effect of NI (NP) on winter wheat yield compared to farmers practice without NI at a given N rate and same number of N split applications.</p><p>A randomized complete block design in five replications was used in this study. Treatments were: T<sub>1</sub> (control treatment - without urea), T<sub>2</sub> (farmers practice - 300 kg urea/ha), and T<sub>3</sub> (urea+NP - 300 kg urea/ha). Urea was applied in three split applications at tillering, stem elongation and booting stages in treatments T<sub>2</sub> (farmers practice) and T<sub>3</sub> (urea+NP). The average grain yield of winter wheat was 8.7 t ha<sup>-1</sup> for the farmers practice (T<sub>2</sub>) and 9.1 t ha<sup>-1</sup> for the urea+NP treatment (T<sub>3</sub>) at the same number of split fertilizer applications.</p><p>The crop yield data showed that urea applied with NP (T<sub>3</sub>) did increase only slightly grain yield, as compared to farmers practice (T<sub>2</sub>). The grain yield increase with NP was about 4%, however the statistical analysis showed that this increase due to the application of urea with NP was not significant. Further research is needed to investigate additional nitrification inhibitors and their effect on wheat production.</p>

Influence of different nitrogen inhibitors on maize yield

2021 ◽  
Author(s):  
Maria Heiling ◽  
Mahdi Shorafa ◽  
Rayehe Mirkhani ◽  
Elden Willems ◽  
Arsenio Toloza ◽  
...  
Keyword(s):  
Block Design ◽  
Nitrification Inhibitor ◽  
Maize Yield ◽  
N Fertilizer ◽  
Control Treatment ◽  
Nitrification Inhibitors ◽  
Stable Form ◽  
N Losses ◽  
N Fertilizers ◽  
Significant Difference

<p>Nitrogen (N) fertilizer management is challenging due to the many factors and have low N use efficiency (NUE). Heavy N losses from soil reduce plant yield and have negative impacts on the environment. Nitrogen processes inhibitors, such as urease and nitrification inhibitors (UI and NI), are chemical compounds which reduce urea hydrolysis and nitrification respectively. By coating ammonium based chemical fertilizers with N process inhibitors allows N to stay in a more stable form of ammonium (NH<sub>4</sub><sup>+</sup>) thus minimising N losses as well as improving NUE and consequently enhancing crop yield.</p><p>A field experiment was established at the Soil and Water Management and Crop Nutrition Laboratory (SWMCNL) in Seibersdorf, Austria to determine the effect of different N fertilizers coated with N process inhibitors on maize yield in summer 2020. The field site is characterised by a moderately shallow Chernozem soil with significant gravel content. Three combinations of N fertilizer (urea or NPK) with N process inhibitors (UI and/or NI)) were tested and compared with a control treatment (without N fertilizer) and a urea application without any inhibitor. All treatments received 60 kg ha<sup>-1</sup> P<sub>2</sub>O<sub>5</sub> and 146 kg ha<sup>-1</sup> K<sub>2</sub>O. The amount of N added to each treatment receiving N fertilizer was 120 kg N ha<sup>-1</sup>. The inhibitors used were (i) UI (2-NPT: N-(2-nitrophenyl) phosphoric acid triamide), (ii) NI-1 (MPA: N-[3(5)-methyl-1H-pyrazol-1-yl) methyl] acetamide), and (iii) NI-2 (DMPP: 3,4-dimethylpyrazole phosphate). DMPP, a nitrification inhibitor, was used in combination with NPK fertilizer. A randomized complete block design with four replications was used in this study. Treatments were: T<sub>1</sub> (control treatment - without N fertilizer), T<sub>2</sub> (Urea only), T<sub>3</sub> (Urea + UI), T<sub>4</sub> (Urea + UI + NI-1), and T<sub>5 </sub>(NPK + NI-2). Urea was applied through two split applications in the T<sub>2</sub> treatment. In T<sub>3</sub>, T<sub>4</sub>, and T<sub>5</sub> treatments, N fertilizers were applied only once. Supplemental irrigation was only applied in the early stages of growth, to ensure that the crop could establish. Harvest was carried out at 98 days after planting.</p><p>The yield data showed that different fertilizer treatments had a significant (p ≤ 0.01) effect on maize yield (dry matter production). There was no significant difference between treatments 4 and 5, which had the highest yield followed by treatments 2 and 3. The comparison between T<sub>2</sub> and T<sub>3</sub> showed that the application of a urease inhibitor avoids the need for a split application of urea, which decreases labour costs. Adding NI-1 (under T<sub>4</sub>) further increases the yield. Also, the package of NPK, a common choice by farmers in Austria, in combination with the nitrification inhibitor NI-2 showed equally good results as urea combined with two inhibitors. Based on the yield results, it can be concluded that N process inhibitors play a significant role in enhancing maize yields.</p>

scholarly journals Microbial N Transformations and N2O Emission after Simulated Grassland Cultivation: Effects of the Nitrification Inhibitor 3,4-Dimethylpyrazole Phosphate (DMPP)

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Yun-Feng Duan ◽  
Xian-Wang Kong ◽  
Andreas Schramm ◽  
Rodrigo Labouriau ◽  
Jørgen Eriksen ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Ammonia Oxidation ◽  
Nitrification Inhibitor ◽  
Transcript Abundance ◽  
N Leaching ◽  
Ammonia Oxidizing Bacteria ◽  
N Losses ◽  
Mineral N ◽  
N Transformations ◽  
Ammonia Oxidizing Archaea

ABSTRACT Grassland cultivation can mobilize large pools of N in the soil, with the potential for N leaching and N2O emissions. Spraying with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) before cultivation was simulated by use of soil columns in which the residue distribution corresponded to plowing or rotovation to study the effects of soil-residue contact on N transformations. DMPP was sprayed on aboveground parts of ryegrass and white clover plants before incorporation. During a 42-day incubation, soil mineral N dynamics, potential ammonia oxidation (PAO), denitrifying enzyme activity (DEA), nitrifier and denitrifier populations, and N2O emissions were investigated. The soil NO3 − pool was enriched with 15N to trace sources of N2O. Ammonium was rapidly released from decomposing residues, and PAO was stimulated in soil near residues. DMPP effectively reduced NH4 + transformation irrespective of residue distribution. Ammonia-oxidizing archaea (AOA) and bacteria (AOB) were both present, but only the AOB amoA transcript abundance correlated with PAO. DMPP inhibited the transcription of AOB amoA genes. Denitrifier genes and transcripts (nirK, nirS, and clades I and II of nosZ) were recovered, and a correlation was found between nirS mRNA and DEA. DMPP showed no adverse effects on the abundance or activity of denitrifiers. The 15N enrichment of N2O showed that denitrification was responsible for 80 to 90% of emissions. With support from a control experiment without NO3 − amendment, it was concluded that DMPP will generally reduce the potential for leaching of residue-derived N, whereas the effect of DMPP on N2O emissions will be significant only when soil NO3 − availability is limiting. IMPORTANCE Residue incorporation following grassland cultivation can lead to mobilization of large pools of N and potentially to significant N losses via leaching and N2O emissions. This study proposed a mitigation strategy of applying 3,4-dimethylpyrazole phosphate (DMPP) prior to grassland cultivation and investigated its efficacy in a laboratory incubation study. DMPP inhibited the growth and activity of ammonia-oxidizing bacteria but had no adverse effects on ammonia-oxidizing archaea and denitrifiers. DMPP can effectively reduce the potential for leaching of NO3 − derived from residue decomposition, while the effect on reducing N2O emissions will be significant only when soil NO3 − availability is limiting. Our findings provide insight into how DMPP affects soil nitrifier and denitrifier populations and have direct implications for improving N use efficiency and reducing environmental impacts during grassland cultivation.

scholarly journals Nutritional status and fruit production of Carica papaya as a function of coated and conventional urea

2016 ◽  
Vol 20 (4) ◽  
pp. 322-328 ◽  
Author(s):  
Gabriel B. da Silva Júnior ◽  
Eduardo M. dos Santos ◽  
Roberto L. Silva ◽  
Ítalo H. L. Cavalcante
Keyword(s):  
Fruit Production ◽  
N Fertilization ◽  
Soil Mineral ◽  
Experimental Conditions ◽  
N Losses ◽  
Mineral N ◽  
N Sources ◽  
N Release ◽  
Coated Urea ◽  
Polymer Coated Urea

ABSTRACT As a strategy to minimize N losses in the soil, mineral N sources, such as polymer-coated urea, have been studied as possibility to increase the synchronization of N release by the fertilizer and its absorption by plants. Thus, this study aimed to evaluate the contents of macronutrients and the production of Formosa papaya as a function of sources and doses of N fertilizer applied as top-dressing in the region of Bom Jesus-PI, Brazil. The treatments were arranged in a 2 x 4 factorial scheme corresponding to N sources (coated urea and conventional urea) and N doses (350, 440, 530 and 620 g plant-1 of N), with four replicates and four plants per plot. The contents of macronutrients in the leaf dry matter and fruit production were evaluated. The sources and doses of top-dressing N fertilization incremented the leaf contents of macronutrients and the production of Formosa papaya hybrid Caliman 01. Under the experimental conditions and based on the macronutrient contents considered as adequate for crop nutrition, associated with maximum fruit production (8.08 kg plant-1), the supply of 525 g of N plant-1 is recommended in the form of coated urea.

scholarly journals Carbon dynamics in a biochar-amended loamy soil under switchgrass

2015 ◽  
Vol 95 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Suzanne E. Allaire ◽  
Benjamin Baril ◽  
Anne Vanasse ◽  
Sébastien F. Lange ◽  
John MacKay ◽  
...  
Keyword(s):  
Block Design ◽  
Carbon Dynamics ◽  
C Sequestration ◽  
N Fertilization ◽  
Control Treatment ◽  
Mineral Fertilizers ◽  
Soil Parameters ◽  
Loamy Soil ◽  
Mineral N ◽  
The Impact

Allaire, S. E., Baril, B., Vanasse, A., Lange, S. F., MacKay, J. and Smith, D. L. 2015. Carbon dynamics in a biochar-amended loamy soil under switchgrass. Can. J. Soil Sci. 95: 1–13. The environmental impacts of switchgrass production for bioenergy could be reduced through the use of biofertilizers rather than mineral fertilizers and through soil amendment with biochar. The objectives of this study were: (1) to assess the impact of biochar and biofertilizer on switchgrass (Panicum virgatum L.) yield and parameters related to carbon dynamics, (2) to correlate carbon parameters with soil physico-chemical properties over the first two growing seasons, and (3) to develop a C budget. A complete randomized block design was installed in a sandy loam with split plot treatment design, the main plots receiving 0 or 10 t ha−1of biochar and the sub − plots receiving no fertilization, mineral N fertilization, or biofertilizers. Biofertilizers had no significant impact on plant and soil. Biochar increased yield relative to the control treatment by about 10% during the first year and root biomass by up to 50% after 2 yr (P>0.1). Mineral N fertilization also increased yield resulting in higher plant C sequestration after 2 yr. Biochar increased CO2soil concentration (CO2-soil) by up to 50% but its impact on CO2emission flux (CO2-flux) changed over time. The impact of mineral fertilization on CO2-fluxalso varied with time. Soil CO2dynamics was mostly influenced by temperature, N and water content. Biochar and fertilization treatments showed interactions on some plant and soil parameters. The highest C sequestration budget was obtained with a combination of biochar and mineral N fertilization. The equivalent of about one-third of the increase in soil C content associated with biochar treatments was respired away by soil microorganisms. Nearly one-fourth of C sequestered by plants remained in or at the soil surface (root and crop residues).

Effect of slurry application and mineral nitrogen fertilization on N leaching in different crop combinations

1997 ◽  
Vol 128 (1) ◽  
pp. 79-86 ◽  
Author(s):  
K. SIELING ◽  
O. GÜNTHER-BORSTEL ◽  
H. HANUS
Keyword(s):  
Winter Wheat ◽  
Oilseed Rape ◽  
N Uptake ◽  
N Fertilization ◽  
N Leaching ◽  
Pig Slurry ◽  
N Losses ◽  
Mineral N ◽  
Soil System ◽  
Preceding Crop

Nitrogen (N) fertilizer not used by the crop can increase the risk of nitrate leaching into the groundwater. In two growing seasons, 1990/91 and 1991/92, the relationships between N fertilization and yield, N uptake by the grain and the N leaching in the subsequent percolation period were investigated in a multifactorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape – winter wheat – winter barley, and effects of soil tillage (minimum tillage without ploughing, conventional tillage), application of pig slurry (none, application in autumn, application in autumn and in spring), mineral N fertilization (none, 80 or 200 kg N ha−1 to oilseed rape and 120 or 240 kg N ha−1 to cereals) and application of fungicides (none, intensive) were all tested. In each year, the rotation and the treatments were located on the same plots. Mineral N fertilization and fungicide application increased yield and N uptake by grain or seed in all crops. In contrast, the application of slurry, especially in autumn, had only small effects on yield and N uptake. Nitrogen losses by leaching (measured using porous ceramic cups) were affected mainly by the year and the crop. In 1992/93, averaged over all factors, 80 kg N ha−1 was leached compared with 28 kg N ha−1 the previous year. Oilseed rape reduced N losses, whereas under winter wheat up to 160 kg N ha−1 was leached. Due to a lower N-use efficiency, autumn applications of slurry increased N leaching, and mineral N fertilization of the preceding crop also led to higher N losses.Since the amount of leached N depends both on the nitrogen left by the preceding crop (unused fertilizer N as well as N in residues) and on N uptake by the subsequent crop, it is not possible to apportion the N losses to any particular crop in the rotation. The cropping sequence, together with its previous and subsequent crops, must also be considered.To minimize leaching, N fertilization must meet the needs of the growing crop. In order to improve the efficiency further, investigations must be conducted in order to understand the dynamics of N in the plant–soil system in conjunction with the weather and crop management practices.

scholarly journals Ammonia-oxidizing bacterial communities are affected by nitrogen fertilization and grass species in native C4 grassland soils

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12592
Author(s):  
Jialin Hu ◽  
Jonathan D. Richwine ◽  
Patrick D. Keyser ◽  
Lidong Li ◽  
Fei Yao ◽  
...  
Keyword(s):  
Panicum Virgatum ◽  
Fertilization Rate ◽  
N Fertilization ◽  
Perennial Grasses ◽  
Grass Species ◽  
Ammonia Oxidizing Bacteria ◽  
Big Bluestem ◽  
Grassland Soils ◽  
N Losses ◽  
Nitrification Potential

Background Fertilizer addition can contribute to nitrogen (N) losses from soil by affecting microbial populations responsible for nitrification. However, the effects of N fertilization on ammonia oxidizing bacteria under C4 perennial grasses in nutrient-poor grasslands are not well studied. Methods In this study, a field experiment was used to assess the effects of N fertilization rate (0, 67, and 202 kg N ha−1) and grass species (switchgrass (Panicum virgatum) and big bluestem (Andropogon gerardii)) on ammonia-oxidizing bacterial (AOB) communities in C4 grassland soils using quantitative PCR, quantitative reverse transcription-PCR, and high-throughput amplicon sequencing of amoA genes. Results Nitrosospira were dominant AOB in the C4 grassland soil throughout the growing season. N fertilization rate had a stronger influence on AOB community composition than C4 grass species. Elevated N fertilizer application increased the abundance, activity, and alpha-diversity of AOB communities as well as nitrification potential, nitrous oxide (N2O) emission and soil acidity. The abundance and species richness of AOB were higher under switchgrass compared to big bluestem. Soil pH, nitrate, nitrification potential, and N2O emission were significantly related to the variability in AOB community structures (p < 0.05).

scholarly journals Direct and Indirect Effects of Urease and Nitrification Inhibitors on N2O-N Losses from Urea Fertilization to Winter Wheat in Southern Germany

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 782 ◽  
Author(s):  
Yuncai Hu ◽  
Manuela P. Gaßner ◽  
Andreas Weber ◽  
Martine Schraml ◽  
Urs Schmidhalter
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
N2o Emission ◽  
N Fertilization ◽  
N Fertilizer ◽  
N2o Emissions ◽  
Nitrification Inhibitors ◽  
N Losses ◽  
Calcium Ammonium Nitrate ◽  
Southern Germany

Urea (U) is the most important nitrogen (N) fertilizer in agriculture worldwide, and as N fertilizer can result in large gaseous losses of NH3 and N2O. Thus, urease inhibitors (UIs) and nitrification inhibitors (NIs) have been coupled with U fertilizers to mitigate NH3 and N2O emissions. However, it is still unclear whether adding NIs and/or UIs to U stimulates other pollutants, while reducing one pollutant. Furthermore, part of the NH3 deposition to earth is converted to N2O, leading to indirect N2O emission. To estimate direct and indirect effect of UIs and NIs on the N2O-N and NH3-N losses from U; therefore, we analyzed multi-year field experiments from the same site during 2004 to 2005 and 2011 to 2013. The field experiments with U fertilization with or without UI (IPAT, N-isopropoxycarbonyl phosphoric acid triamide) and NI (DCD/TZ, Dicyandiamide/1H-1, 2, 4-Triazol) in winter wheat and with calcium ammonium nitrate (CAN) were conducted in southern Germany. Fluxes of NH3 or N2O emissions were determined following each split N fertilization in separate experiments on the same site. Our results showed that U with NIs considerably reduced N2O emissions, and adding UIs decreased NH3 emissions. However, the effect on N2O emissions exerted by (U + UIs) or (U + UIs + NIs) was inconsistent. In contrast to the treatment of (U + UIs + NIs), the addition of NIs alone to U stimulated NH3 emission compared to treatment with U. When 1% indirect N2O emission from NH3 (IPCC emission factor (EF4)) was considered to estimate the indirect N2O emission, total N2O emissions from (U + NIs) were approximately 29% compared to that from U alone and 36% compared to that from (U + UI), indicating that indirect N2O emission from NH3 induced by NIs may be negligible.

scholarly journals Ammonia-oxidizing archaea are integral to nitrogen cycling in a highly fertile agricultural soil

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Laibin Huang ◽  
Seemanti Chakrabarti ◽  
Jennifer Cooper ◽  
Ana Perez ◽  
Sophia M. John ◽  
...  
Keyword(s):  
Nitrogen Cycle ◽  
Agricultural Soil ◽  
Agricultural Soils ◽  
Ammonia Oxidizing Bacteria ◽  
Central Process ◽  
Soil Nitrification ◽  
Plant Nitrogen ◽  
Ammonia Oxidizing Archaea ◽  
Activity Measurements ◽  
Nitrite Oxidizing Bacteria

AbstractNitrification is a central process in the global nitrogen cycle, carried out by a complex network of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), complete ammonia-oxidizing (comammox) bacteria, and nitrite-oxidizing bacteria (NOB). Nitrification is responsible for significant nitrogen leaching and N2O emissions and thought to impede plant nitrogen use efficiency in agricultural systems. However, the actual contribution of each nitrifier group to net rates and N2O emissions remain poorly understood. We hypothesized that highly fertile agricultural soils with high organic matter mineralization rates could allow a detailed characterization of N cycling in these soils. Using a combination of molecular and activity measurements, we show that in a mixed AOA, AOB, and comammox community, AOA outnumbered low diversity assemblages of AOB and comammox 50- to 430-fold, and strongly dominated net nitrification activities with low N2O yields between 0.18 and 0.41 ng N2O–N per µg NOx–N in cropped, fallow, as well as native soil. Nitrification rates were not significantly different in plant-covered and fallow plots. Mass balance calculations indicated that plants relied heavily on nitrate, and not ammonium as primary nitrogen source in these soils. Together, these results imply AOA as integral part of the nitrogen cycle in a highly fertile agricultural soil.

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