三种吡唑类硝化抑制剂在潮棕壤中的垂直和水平迁移

分别利用土柱淋溶试验和水平扩散试验研究了3种吡唑类硝化抑制剂[3-甲基吡唑(MP)、3,4-二甲基吡唑磷酸盐(DMPP)和4-氯-3-甲基吡唑(ClMP)]随水在潮棕壤中垂直和水平迁移及与NH4+移动的同步性。结果表明,淋溶试验结束后(总淋洗量700 mm),各土层(0、10、20 cm)MP含量与NH4+-N含量的比值未发生变化,而DMPP和ClMP含量与NH4+-N含量的比值随土层深度增加显著降低。扩散试验结束后,在距圆心40 mm范围内,MP和DMPP含量与NH4+-N含量的比值均未发生较大变化,而ClMP含量与NH4+-N含量比值显著减小。研究结果说明,MP随水沿垂直和水平方向移动的速率几乎和NH4+一样,不存在同NH4+脱离风险,而DMPP和ClMP随水移动的速率比NH4+慢。     

Modes of action of nitrification inhibitors

 In recent years, substantial progress has been made towards understanding the modes of action for the specific inhibition of autotrophic NH₃ oxidation. This has included demonstrating that NH₃ monooxygenase (AMO) has a broad substrate range for catalytic oxidation, and the inhibitory effects of many compounds are due to competition for the active site. Other compounds, such as acetylenes, are oxidized by the normal catalytic cycle of AMO to highly reactive products which covalently bind the enzyme causing irreversible inhibition. Substantial evidence has shown the important role of Cu in the activity of AMO, and indicated that a large class of compounds containing thiono-S inhibit AMO activity by binding with Cu within the active site. Heterocyclic N compounds form another important class of nitrification inhibitors with little known about their mode of action, although evidence suggests that their inhibitory influence is closely related to the presence of ring N. Received: 21 July 1998     

几种吡啶类化合物对土壤硝化的抑制作用比较

为了探明吡啶类化合物对土壤硝化作用的抑制效应,采用室内微宇宙试验,研究了2-氯-6(三氯甲基)硫酸盐、2-氯-6(三氯甲基)盐酸盐、吡啶混合物和吡啶X类化合物对潮土、红壤和水稻土中铵态氮硝化的抑制作用。结果表明,在35 d培养期内,吡啶类化合物处理土壤硝态氮含量明显低于对照(未添加吡啶类化合物),吡啶类化合物对土壤中铵态氮的硝化抑制率介于2.91%~91.92%,抑制强度先逐渐升高后降低,在培养21 d时抑制强度达到峰值。不同类型吡啶类化合物对土壤中铵态氮的硝化抑制效果存在差异,吡啶盐酸盐类化合物优于其他几类化合物;吡啶类化合物对土壤中铵态氮的硝化抑制作用与土壤类型有关,对3种土壤中铵态氮的硝化抑制作用表现为潮土>水稻土>红壤。就同一土壤而言,硝化抑制强度随着吡啶类化合物用量的增加而增加。     

Influence of moisture regime on inhibition of nitrification by DCD

A laboratory study at the Indian Agricultural Research Institute, New Delhi showed that DCD was an efficient nitrification inhibitor under field capacity moisture (???30 kPa) but not so under submerged soil conditions. Nitrification inhibition by DCD was 79.6% after 1 week of incubation and decreased to 59.3% after 3 weeks of incubation under field capacity moisture, while it was only 19.3% after 1 week of incubation and 10.6% and 18.4% after 2 and 3 weeks of incubation under submergence, respectively. DCD can play an important role in reducing N losses from agricultural fields.     

Some furfural derivatives as nitrification inhibitors

Three series of furfural derivatives, namely N-O-furfural oxime ethers, furfural Schiff bases (furfurylidene anilines), and furfural chalcones, have been synthesized and evaluated for nitrification inhibition activity in laboratory incubation studies in typic Ustocrept soil. Furfural oxime ethers and furfural Schiff bases showed potential activity, but furfural chalcones were only mildly active. N-O-ethyl furfural oxime among the oxime ethers, and furfurylidine-4-chloroaniline among the furfural Schiff bases, performed the best. These two compounds showed more than 50% nitrification inhibition on the 45th day at 5% dose as compared to 73% inhibition by nitrapyrin. Activity of furfural oxime ethers decreased with an increase in carbon atoms in the N-O-alkyl side chain. Introduction of a chlorine atom in the phenyl ring of furfurylidene anilines increased the persistence of their activity. N-O-Ethyl furfural oxime and furfurylidine-4-chloroaniline coated urea performed at par with their application in solution form. Ethyl and N-O-isopropyl oxime, as well as chloro- and nitro- substituted Schiff bases, did not reveal any phytotoxicity (adverse effect on germination) on chickpea seeds (Cicer arietinum) even at the highest dose (40 ppm, soil basis).     

Effect of nitrification inhibitors on rice protein

Abstract

The effects of ammonium sulfate and urea nitrogen (150 kg N/ha) applied with three levels (5, 10 and 15% of N) of the nitrification inhibitors karanjin and nitrapyrin on grain protein of rice (Oryza sativa L. cv. Bala) were studied in pot experiment. Karanjin at the 10 and 15 per cent levels and nitrapyrin at the 10 per cent level significantly increased grain protein. Rice protein levels were highest at the 15 per cent karanjin level.     

Decomposition rate of dicyandiamide and nitrification inhibition

Abstract

Degradation of dicyandiamide (DCD) was assayed in laboratory studies at 8, 15, and 22 C in a Decatur silt loam and in a Norfolk loamy sand. Dicyandiamide was very short lived at 22 C, with half‐lives of 7.4 and 14.7 days in the Decatur and Norfolk soils, respectively. In the Norfolk soil at 8 C, half‐life increased to 52.2 days. In a nitrificaton study of both soils at 22 C, 80 mg (NH₄)₂SO₄‐N kg^‐1 of soil was applied with 20 mg DCD‐N kg^‐1 of soil and 100 mg kg^‐1 (NH₄)₂S0₄‐N was added with 5% nitrapyrin. Distinct lag phases preceded zero order nitrification with the inhibitor treatments. Lag periods were 2 and 2.6 times the half life of DCD in the degradation study for Decatur and Norfolk soils, respectively. Like most nitrification inhibitors, the effectiveness of DCD decreases with increasing temperature. In the Norfolk loamy sand, nitrification inhibition by DCD was equal to nitrapyrin for up to 42 days, but in Decatur silt loam, DCD was less potent to nitrapyrin as a nitrification inhibitor.     

Growth of comammox Nitrospira is inhibited by nitrification inhibitors in agricultural soils

Purpose

The discovery of comammox Nitrospira being capable of complete oxidising ammonia to nitrate radically challenged the conventional concept of two-step nitrification. However, the response of comammox Nitrospira to nitrification inhibitors (NIs) and their role in soil nitrification remain largely unknown, which has hindered our ability to predict the efficiency of NIs in agroecosystems.

Materials and methods

We evaluated the effect of four NIs, 2-chloro-6-(trichloromethyl) pyridine (nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP), allylthiourea (ATU) and dicyandiamide (DCD) on the growth of comammox Nitrospira, ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB) in two pasture and arable soils.

Results and discussion

The amendment of nitrogen fertiliser significantly increased soil nitrate concentrations over time, indicating a sustaining nitrification activity in both soils. The addition of all the four NIs effectively reduced the production of nitrate in both soils, but to varying degrees during incubation. The abundances of comammox Nitrospira clade A were significantly increased by addition of nitrogen fertilisers and significantly impeded by the four NIs in the pasture soil, but their abundances were only remarkably hindered by nitrapyrin in the arable soil. All the four NIs obviously inhibited the AOB abundances in both soils. Except for DMPP, the other three NIs effectively suppressed the AOA abundances in both soils.

Conclusions

We provided new evidence that growth of comammox Nitrospira clade A can be stimulated by nitrogen fertilisers and inhibited by various nitrification inhibitors, suggesting their potential role in nitrification of agricultural soils.

     

Effect of urease inhibitors on nitrification in soil

Abstract. This paper describes experiments on the inhibitory effects of hydroquinone (HQ), phenylphos-phorodiamidate (PPDA) and N-butyl phosphorothioic triamide (NBPT) on the nitrification in soil. Incubations were carried out at 2/3 field capacity at 25°C of soil samples to which either ammonium or nitrite was added together with inhibitors. Addition of PPDA or NBPT did not influence the oxidation of ammonium. HQ. however, retarded the process significantly, and also the accumulation of nitrite. This was confirmed in experiments whereby added nitrite was followed. Some of the differences could be explained by changes in the soil pH. During incubation the evolution of the total mineral nitrogen was not importantly altered by addition of the inhibitors.     

Effects of urease inhibitors on nitrification in soils

The effects of 10 urease inhibitors on nitrification in soils were studied by determining the effects of 10 and 50 parts/10⁶ (soil basis) of each inhibitor on the amounts of nitrate and nitrite produced when soils treated with ammonium sulfate (200 μg of ammonium N/g of soil) were incubated (30°C) under aerobic conditions for 14 days. The urease inhibitors used (catechol. hydroquinone, p-benzoquinone, 2,3-dimethyl-p-benzoquinone, 2,5-dimethyl-p-benzoquinone. 2,6-dimethyl-p-benzoquinone. 2,5-dichloro-p-benzoquinone, 2,6-dichloro-p-benzoquinone. sodium p-chloromercuribenzoate, and phenylmercuric acetate) were those found most effective in previous work to evaluate more than 130 compounds as soil urease inhibitors. Their effects on nitrification were compared with those of three compounds patented as soil nitrification inhibitors (N-Serve. AM. and ST).Most of the urease inhibitors studied had little effect on nitrification when applied at the rate of 10 μg/g of soil. but had marked inhibitory effects when applied at the rate of 50 μg/g of soil. None inhibited nitrification as effectively as N-Serve. but phenylmercuric acetate inhibited nitrification more effectively than did AM or ST when applied at the rate of 10 μg/g of soil. Phenylmercuric acetate, 2,5-dimethyl-p-benzoquinone, and 2,6-dimethyl-p-benzoquinone had very marked effects on nitrification when applied at the rate of 50 μg/g of soil.     

Potentials of nitrification inhibitors in modern N-fertilizer management

Modern agricultural practices require a new concept of N-fertilizer management in order to optimize N-utilization and avoid N-losses. Nitrification inhibitors or ?N-stabilizers”? fit very good into this conception. Dicyandiamide (DCD) is an efficient nitrification inhibitor and blocks the first step of nitrification for 1–3 months (depending on temperature). This effect is bacteriostatic (not bactericidal) and does not affect other (esp. C-heterotrophic) soil microorganisms (?biological activity”?). DCD is a non-toxic, water soluble compound and will be degraded to CO₂, NH₃ and H₂O without any residues. There are various possibilities to use DCD: addition to liquid manure temporarily prevents oxidation of ammonium nitrogen e.g. of slurry or waste water from potato starch production. In combination with inorganic fertilizers like ammonium sulfate or urea (with 10% of total-N) it enables the farmer to control NH₄-supply to crop plants in certain stages of growth and to gain certain operational advantages by less frequently split applications of N especially on sand and rendzina soils. Thus, the systematic use of nitrification inhibitors not only represents a progress in agricultural technique but also helps to substantially reduce risks concerning pollution of surface and ground waters that are sometimes inevitable consequences of agricultural production.     

Suppression of methane oxidation in aerobic soil by nitrogen fertilizers,nitrification inhibitors,and urease inhibitors

Concentrations of CH₄, a potent greenhouse gas, have been increasing in the atmosphere at the rate of 1% per year. The objective of these laboratory studies was to measure the effect of different forms of inorganic N and various N-transformation inhibitors on CH₄ oxidation in soil. NH ₄ ⁺ oxidation was also measured in the presence of the inhibitors to determine whether they had differential activity with respect to CH₄ and NH ₄ ⁺ oxidation. The addition of NH₄Cl at 25 g N g^-1 soil strongly inhibited (78–89%) CH₄ oxidation in the surface layer (0–15 cm) of a fine sandy loam and a sandy clay loam (native shortgrass prairie soils). The nitrification inhibitor nitrapyrin (5 g g^-1 soil) inhibited CH₄ oxidation as effectively as did NH₄Cl in the fine sandy loam (82–89%), but less effectively in the sandy clay loam (52–66%). Acetylene (5 mol mol^-1 in soil headspace) had a strong (76–100%) inhibitory effect on CH₄ consumption in both soils. The phosphoroamide (urease inhibitor) N-(n-butyl) thiophosphoric triamide (NBPT) showed strong inhibition of CH₄ consumption at 25 g g^-1 soil in the fine sandy loam (83%) in the sandy clay loam (60%), but NH ₄ ⁺ oxidation inhibition was weak in both soils (13–17%). The discovery that the urease inhibitor NBPT inhibits CH₄ oxidation was unexpected, and the mechanism involved is unknown.     

Nanoclay polymer composites loaded with urea and nitrification inhibitors for controlling nitrification in soil

Nanoclay polymer composites (NCPCs) were synthesized with partially neutralized acrylic acid and bentonites and loaded with urea and nitrification inhibitors (NIs) to act as a slow release carrier of nitrogen (N). The resulting product was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD of NCPCs revealed that the bentonite layers were completely exfoliated and dispersed in the composite after the polymerization. The water absorbency of pure polymer (Acrylic acid + Acrylamide) was 197.53 g g^?1 and 137.75 g g^?1 by nanocomposite (8% nanobentonite) in distilled water. The nitrification inhibition ability of these NCPCs was evaluated by incubation study for 60 days in laboratory at 28°C and 50% water-holding capacity. The Schiff base -NCPCs were most effective at inhibiting nitrification (30–87%) compared to dicyandiamide and Neem oil. A column study was performed to know the movement of NH₄-N and NO₃-N at three different depths. Result showed that the Schiff base -NCPC decreased nitrate movement by 78.5% at the depth of 5 cm in soil column. The slow release of nitrogen and good water retention capacity confirmed that these NCPCs can be viably exploited for application in agriculture.     

Persistence of effects of nitrification inhibitors added to soils

Abstract

The persistence of the effects of four nitrification inhibitors (2‐ethynylpyridine, nitrapyrin, etridiazole, 3‐methylpyrazole‐l‐carboxamide) on nitrification in soil was assessed by measuring the ability of two soils to nitrify NH₄ ⁺ [added as (NH₄)₂SO₄] after they had been treated with 5 μg inhibitor g^‐1 soil and incubated at 10, 20, or 30°C for 0, 21, 42, 84, 126, or 168 days. The soils used differed markedly in organic‐matter content (1.2 and 4.2% organic C). The data obtained showed that the persistence of the effects of the inhibitors studied decreased markedly with increase in soil temperature from 10 to 30°C and that, whereas the initial inhibitory effects of the test compounds on nitrification were greatest with the soil having the lower organic‐matter content, the persistence of their effects at 20 or 30°C was greatest with the soil having the higher organic‐matter content. The inhibitory effects of 2‐ethynylpyridine and etridiazole on nitrification were considerably more persistent than those of nitrapyrin or 3‐methylpyrazole‐l‐carboxamide and were significant even after incubation of inhibitor‐treated soil at 20°C for 168 days.     

三种硝化抑制剂在石灰性土壤中的应用效果比较

在人工气候室内采用25℃黑暗培养法研究双氰胺(DCD)、3,4-二甲基吡唑磷酸(DMPP)及2-氯-6-三氯甲基吡啶(Nitrapyrin)在石灰性土壤中的硝化抑制效果。结果表明:施用DCD、DMPP、Nitrapyrin的土壤NH4+-N含量较单施硫酸铵的土壤(对照)分别提高228.45~244.85 mg/kg(砂土)、209.75~254.79 mg/kg(黏土),NO3--N含量较对照分别降低93.85%~94.99%(砂土)、91.82%~95.38%(黏土)。表观硝化率随培养进程增加缓慢,培养期间只增加了1.28%~2.09%(砂土)、2.72%~8.40%(黏土),而对照增加了86.00%(砂土)、80.89%(黏土)。3种硝化抑制剂均显著抑制了石灰性土壤中硫酸铵水解铵硝化作用的进行,并且在砂土中的硝化抑制率高于黏土,硝化抑制效果最好的为DMPP处理,0.54%Nitrapyrin处理次之但用量最小,0.27%Nitrapyrin和10.8%DCD处理抑制效果相对较弱。     

Evaluation of nitrification inhibitors for use under tropical conditions

Abstract

Six simple chemical compounds were evaluated for inhibition of nitrification. The compounds of o‐nitroaniline, m‐nitroaniline, o‐nitrophenol, benzotriazole, and 2,4,6‐trinitrophenol were compared with dicyandiamide by adding 10 μg inhibitor/g of a sandy loam soil, incubating for 30 days at 30°C and analyzing for NH⁺ ₄, NO^‐ ₂, and NO^‐ ₃ formation. The results indicated that benzotriazole, o‐nitrophenol, and m‐nitroaniline were very effective nitrification inhibitors.     

Stimulation of heterotrophic nitrification and N2O production,inhibition of autotrophic nitrification in soil by adding readily degradable carbon

Journal of Soils and Sediments - This study aimed to test the hypothesis that readily degradable Carbon (C) has contrasting effect on soil N autotrophic and heterotrophic nitrification, can...     

Mineralization and nitrification in three Malaysian forest soils

Examination of three forest soils from Malaysia using the soil incubation technique suggests that nitrification was not inhibited in these oligotrophic soils. Nitrification rates were between 40 and 750 ngN produced g^?1 dry weight soil day^?1 of incubation. Addition of phenolic metabolites (tannic acid) and leaf filtrates from hill and lowland forest litter did not significantly inhibit nitrification. Addition of sucrose (1% w/w carbon source) decreased nitrification but not ammonification.     

Effects of nitrification inhibitors on denitrification of nitrate in soil

Summary The influence of 28 nitrification inhibitors on denitrification of nitrate in soil was studied by determining the effects of different amounts of each inhibitor on the amounts of nitrate lost and the amounts of nitrite, N₂O and N₂ produced when soil samples were incubated anaerobically after treatment with nitrate or with nitrate and mannitol. The inhibitors used included nitrapyrin (N-Serve), etridiazole (Dwell), potassium azide, 2-amino-4-chloro-6-methylpyrimidine (AM), sulfathiazole (ST), 4-amino-1,2,4-triazole(ATC),2,4-diamino-6-trichloromethyl-s-triazine (CL-1580), potassium ethylxanthate, guanylthiourea (ASU), 4-nitrobenzotrichloride, 4-mesylbenzotrichloride, sodium thiocarbonate (STC), phenylmercuric acetate (PMA), and dicyandiamide (DCD).Only one of the nitrification inhibitors studied (potassium azide) retarded denitrification when applied at the rate of 10 g g^–1 soil, and only two (potassium azide and 2,4-diamino-6-trichloromethyl-s-triazine) inhibited denitrification when applied at the rate of 50 g g^–1 soil. The other inhibitors either had no appreciable effect on denitrification, or enhanced denitrification, when applied at the rate of 10 or 50 g g^–1 soil, enhancement being most marked with 3-mercapto-1,2,4-triazole. Seven of the inhibitors (potassium azide, sulfathiazole, potassium ethylxanthate, sodium isopropylxanthate, 4-nitrobenzotrichloride, sodium thiocarbonate, and phenylmercuric acetate) retarded denitrification when applied at the rate of 50 g g^–1 soil to soil that had been amended with mannitol to promote microbial activity.Reports that nitrapyrin (N-Serve) and etridiazole (Dwell) inhibit denitrification when applied at rates as low as 0.5 g g^–1 soil could not be confirmed. No inhibition of denitrification was observed when these compounds were applied at the rate of 10 g g^–1 soil, and enhancement of denitrification was observed when they were applied at the rate of 50 or 100 g g^–1 soil.