Nitrification Inhibitor Nitrapyrin Research Articles

Comparison of early season stem nitrate and leaf total nitrogen concentrations across corn hybrids

Abstract Basal stem nitrate‐N concentration in young maize plants has been proposed as a method to evaluate soil nitrogen (N) adequacy for near maximum yields. While plants are usually considered good integrators of soil N availability, adoption of tissue testing procedures to evaluate crop N status may depend on metabolic differences between maize cultivars. Research was initiated to evaluate if there are cultivar induced differences in basal stem nitrate‐N concentration and total N concentration in maize leaves at the V6 growth stage. A nitrification inhibitor (nitrapyrin) was incorporated into split plots at planting to create two inorganic N regimes. Large variations in basal stem nitrate concentration within hybrids precluded detection of differences between hybrids for either year of the study as a result of the nitrification inhibitor. In contrast, leaf N concentration was different between hybrids for both years, but was not affected by nitrapyrin treatment. Cultivar selection based on leaf N conc...

Reducing gaseous losses of nitrogen from cattle slurry applied to grassland by the use of additives

AbstractLosses of nitrogen (N) through ammonia (NH3) volatilisation and denitrification were determined following the application of cattle slurry to grassland in autumn or spring. Denitrification was examined on two contrasting soils. A system of small wind tunnels was used to measure NH3 loss and an acetylene inhibition technique for denitrification. Between 31 and 84% of the ammonium N (NH‐N) applied in slurry was lost through NH3 volatilisation. Acidifying the slurry to pH c 5.5 prior to application reduced these losses to between 14 and 57%. On a freely drained loam soil, denitrification from unacidified slurry applied in the autumn at 80 m3 ha−1 was continuous throughout the winter, with the maximum rate of 0.91 kg N ha−1 day−1 occurring a few weeks after slurry application. The total denitrification losses were equivalent to about 29% of the NH‐N applied for this treatment and 41% for the acidified slurry. The nitrification inhibitor dicyandiamide reduced the amount of N lost through denitrification by 70% when applied with the slurry at 25 kg ha−1, by 55% at 20 kg ha−1 and by 30% at 15 kg ha−1. The nitrification inhibitor nitrapyrin did not appreciably reduce denitrification. Denitrification losses were consistently small from slurry applied to the freely drained loam soil in spring, or to a poorly drained, silty clay in autumn or spring. Neither nitrification inhibitor was of benefit in these situations.

Response of grain sorghum to enhanced-ammonium supply

Two greenhouse experiments were conducted to examine the effects of increased levels of soil NH4+ on the growth and yield of grain sorghum (Sorghum bicolor (L.) Moench). Nitrogen was supplied as urea plus the nitrification inhibitor nitrapyrin (enhanced-NH4+ supply) or as a 4∶1 molar ratio of CA(NO3)2 and Mg(NO3)2 at rates of 0 to 450 mg N kg−1 soil in 37.5 mg N increments. Enhanced-NH4+ supply, in comparison to the NO3 treatment, increased grain yield 15 and 18% in the two experiments. In one experiment this yield increase occurred through increased number of kernels and in a second experiment, through increased weight of kernels. During the first 28 days after plant emergence, the number of leaves, stalk width, plant weight, and plant N content were greater with enhanced-NH4+ supply than with NO3−. However, at harvest total plant weight and plant N content were minimally affected by enhanced-NH4+ supply.

Tests of nitrification and of urease inhibitors, when applied with either solid or aqueous urea, on grass grown on a light sandy soil

SummaryIn 1984 and 1985 a field experiment on a grass ley on a light sandy soil at Woburn Experimental Farm, Bedfordshire, tested injected aqueous urea and broadcast prilled urea, applied alone or with a nitrification or urease inhibitor. Aqueous urea, prilled urea and ‘Nitro-Chalk’ were applied as a single 375 kg N/ha dressing, and prilled urea and ‘Nitro-Chalk’ also as three 125 kg N/ha dressings. The nitrification inhibitor nitrapyrin or a mixture of sodium trithiocarbonate (STC) plus potassium ethyl xanthate (KEtX) was injected with aqueous urea. The nitrification inhibitor dicyandiamide (DCD) or the urease inhibitor phenyl-phosphorodiamidate (PPDA) was broadcast with prilled urea.The nitrification inhibitors significantly retarded nitrification of both aqueous and prilled urea. PPDA reduced ammonia volatilization from 375 kg N/ha broadcast as urea, and hence losses to the atmosphere, which otherwise ranged from 13 to 33 kg N/ha.Nitrapyrin or STC and KEtX increased yield and nitrogen uptake in both years when urea was injected in January. Nitrapyrin also increased yield and nitrogen uptake in 1985, but not in 1984, when urea was injected in March, whereas the STC and KEtX mixture was then either detrimental or ineffective. DCD increased yield and nitrogen uptake from a single dressing of broadoast urea only in 1985. PPDA increased yield and nitrogen uptake from a single broadcast dressing of urea in both years, but had little effect when applied with divided dressings.In 1984 a divided broadcast dressing of ‘Nitro-Chalk’ gave the largest yield and nitrogen uptake, but in 1985 aqueous urea injected with nitrapyrin in January or without or with a nitrification inhibitor in Maroh and prilled urea broadcast as a divided dressing all gave a larger yield. Similarly, a single application was generally more effective as ‘Nitro-Chalk’ in 1984, but as urea in 1985.

Der Einfluß von 1-Carbamoyl-3(5)-methylpyrazol (CMP) auf die Nitrifikation und bodenbiologische Kennwerte im Vergleich zu Nitrapyrin (NP) und Dicyandiamid (DCD)

Summary A new compound that retards the microbially induced process of nitrification, 1-carbamoyl-3(5)-methyl-pyrazole (CMP), is described and its influence on soil organisms, in comparison with the well-known nitrification inhibitors dicyano diamide (DCD) and nitrapyrin (NP) is discussed. This examination was carried through (i) by testing pure cultures of microorganisms, (ii) in the laboratory using two different soils, and (iii) by field experiments in different locations.

Biological nitrogen transformations in soil after repeated application of nitrification inhibitors

Summary The nitrification inhibitors dicyandiamide (DCD), nitrapyrin or etridiazole were applied to different plots of a field experiment on sandy soil each autumn for 4 years, immediately prior to sowing a winter cereal. Laboratory determinations of biological nitrogen transformations were made on soils sampled 6 months after the last inhibitor application. Nitrogenase activities, nitrogen mineralisation and denitrification capacities of soils were unaffected by pretreatment in the field with an inhibitor, compared with soil that had never received an inhibitor. Nitrification of ammonium was slightly depressed in soil that had received an annual application of nitrapyrin, but was unaffected in soils pretreated with DCD or etridiazole.

Nitrification and organic nitrogen formation in soils

The formation of mineral nitrogen species and of organic nitrogen was studied in three different types of soils in relation to the application of the nitrification inhibitor nitrapyrin. The results indicate that nitrification brings about a deficit in total mineral nitrogen and a concomitant surplus in non biomass organic nitrogen. This phenomenon increases with increasing levels of applied ammonium nitrogen and soil organic matter. The phenomenon is considered to be due to the reaction of the transient nitrite formed with soil phenolic compounds and appears to be of significance in all soils in which nitrification occurs, even neutral to alkaline and low carbon soils.

Comparison of the effects of aqueous and of prilled urea, used alone or with urease or nitrification inhibitors, with those of ‘Nitro-Chalk’ on ryegrass leys

SummaryField experiments on ryegrass leys at Rothamsted in 1981, 1982 and 1983 examined the eifects of injected aqueous urea and of broadcast prilled urea applied alone or with one of several nitrification or urease inhibitors, on yields and N, K, Ca and Mg uptakes. Aqueous urea, prilled urea or ‘Nitro-Chalk’ were applied as single 375 kg N/ha dressings, and prilled urea or ‘Nitro-Chalk’ as three 125 kg N/ha dressings. The nitrification inhibitors etridiazole or nitrapyrin were injected with aqueous urea, but dicyandiamide (DCD) was broadcast with prilled urea. Neither the urease inhibitor hydroquinone nor the nitrification inhibitors slowed the rate of urea hydrolysis. Neither hydroquinone nor DCD diminished volatilization losses of ammonia from broadcast urea which ranged from 8 to 25 kg N/ha; they were less than 4 kg N/ha from injected urea or broadcast ‘Nitro-Chalk’. Nitrapyrin, etridiazole and DCD effectively inhibited nitrification. DCD, and to a lesser extent hydroquinone, increased yields and nitrogen uptakes from a single broadcast application of prilled urea given either in winter or in spring. However, these yields were still smaller than those given by injected urea or by divided dressings of urea, whether or not an inhibitor was used. The inhibitors did not increase yields with divided broadcast dressings of urea, which were slightly smaller than those with equivalent dressings of ‘Nitro-Chalk’. Inhibitors did not consistently increase yield when injected with aqueous urea. Inhibitors applied with injected or broadcast urea slightly increased K uptakes, and slightly decreased Ca and Mg uptakes.

Nitrate Leaching as Influenced by Water Application Level and Nitrification Inhibitors

AbstractThe effects of water application level and nitrification inhibitors on NO3−‐N leaching from a sandy loam soil were evaluated using soil columns and nonweighing field lysimeters. In soil columns (297 mm diam by 1.2 m deep) fertilized with 224 kg N ha−1, addition of the nitrification inhibitor nitrapyrin [2‐chloro‐6‐(trichloromethyl)pyridine] reduced NO3−‐N leaching losses by 51 and 30 kg ha−1, respectively, for the 12.7‐ and 38.1‐mm weekly water application levels. Both nitrapyrin and Terrazole (5‐Ethoxy‐3‐trichloromethyl‐1,2,4‐thiadiazole) (Olin Corp., Little Rock, Ark.) inhibitors were equally effective in reducing total NO3−‐N leaching losses from soil columns after 100 d for the 38.1‐mm water application level. The change in flow‐weighted NO3−‐N concentration due to use of nitrification inhibitors was about −0.4 to −1.0 mmol L−1.Annual NO3−‐N leaching losses measured at the 1.2‐m depth in field lysimeters cropped with corn (Zea mays L.) over a 3‐yr period averaged about 12 kg ha−1 less (7%) for nitrapyrin‐coated urea. The results were not consistent since nitrapyrin reduced NO3−‐N leaching during the growing season by 12 and 17% for 2 of the 3 yr and post season leaching by 35% for 1 yr. The change in flow‐weighted NO3−‐N concentration (3‐yr avg) due to nitrapyrin was −0.4, −1.5, and +0.9 mmol L−1, respectively, for the growing season, post season, and preemergence periods. Nitrification inhibitors may help to minimize nonpoint‐source pollution on sandy soil where supplemental irrigation is used by reducing and/or delaying NO3−‐N leaching particularly during the growing season when N is utilized by plants.

Measurement of nitrification rates in lake sediments: Comparison of the nitrification inhibitors nitrapyrin and allylthiourea

A method for measuring rates of nitrification in intact marine sediment cores has been modified and adapted for use in freshwater sediments. The technique involves subsampling a sediment core into minicores. Half of these cores are treated with an inhibitor of chemolithotrophic nitrification and, after incubation, differences in ammonia and nitrate concentration between inhibited and uninhibited systems are calculated. The within-treatment variability of ammonia and nitrate concentrations could be reduced by storing the cores overnight prior to subsampling. Estimates of the nitrification rate using the difference in ammonia concentrations between the inhibited and uninhibited mini-cores were always greater than the rate estimate using the difference in nitrate concentrations. Comparison between the results using the nitrification inhibitors allylthiourea (ATU) and nitrapyrin (N-Serve) indicated that the former appeared to give larger values for the nitrification rate than did the latter. Differences in the efficiency of these inhibitors in the control of nitrification under the conditions used partly explain these results. Data are also presented on the effect of N-Serve and ATU on some other nitrogen transformations affecting ammonia and nitrate concentrations.

Effects of Nitrogen and Phosphorus Application Method and Nitrogen Source on Winter Wheat Grain Yield and Leaf Tissue Phosphorus

AbstractThe positive effect of placing N (especially NH+4‐N) with P on crop growth has been demonstrated many times in short‐term greenhouse studies. Under field conditions, however, the effect has not been well defined. The present objective was to evaluate N and P placement methods on the P nutrition and final grain yield of wheat (Triticum aestivum L.) grown in the field and greenhouse. Anhydrous ammonia (NH3), urea‐ammonium nitrate solution (UAN), and sodium nitrate (SN) were N sources while liquid ammonium polyphosphate (APP) was the P source. Methods of N‐P application included: knife N‐knife P (‘dual knife’), knife N‐hroadcast P, broadcast N‐knife P, and broadcast N‐broadcast P. Two nitrification inhibitors were included in some studies. In the greenhouse, APP was labelled with 33P orthophosphate and 32P pyrophosphate to examine P uptake of its ortho‐ and polyphosphate fractions with different N‐P‐K application methods each with either a NH+4‐N or NO‐3‐N source.Dual knife N‐P applications gave higher leaf P concentrations and grain yields than other N‐P application methods in many of the field studies when ammoniacal N sources were used. Sodium nitrate dual knife applications were not as effective as dual knife applications of UAN or ammonia. The inclusion of the nitrification inhibitor nitrapyrin to dual knife treatments increased grain yield and/or leaf tissue P level in two 1978 studies, but had no effect in 1979. In the greenhouse the highest leaf P levels resulted from the banded NH3‐APP application. The banded SN‐APP application gave the second highest P uptake. This study also demonstrated that the N and APP need to be placed together, not separately in the soil. The amounts of the initial ortho‐ and polyphosphate portions of the APP absorbed by the plants seemed to be a function of fertilizer P demand and not related to fertilizer N in the same band. Including KCl in a band of APP did not affect leaf tissue P concentrations.

Increase in Cabbage Yield by Fenamiphos Treatment of Uninfested andHeterodera schachtii-Infested Field Soils

N-Serve) was applied similarly at 2,337 Abawi, G. S., and Mai, W. F. 1983. Increase in cabbage yield by fenamiphos treatment of ml of 24E formulation per hectare. uninfested and Heterodera schachtii-infested field soils. Plant Disease 67:1343-1346. In some treatments, soil was autoclaved 3 of each Applications of fenamiphos did not significantly affect the final population of H. schachtii. The soil was added to the appropriate tiles. influence of fenamiphos on cabbage yield was minimal when field soils were pretreated with Telone The center of each microplot was C-I17 at 374 L/ ha or by autoclaving. Increase of cabbage yield by fenamiphos, however, occurred in planted with three seeds of the cabbage field soils previously pasteurized for 30 min at 50 C. Intermediate increases with fenamiphos were cultivar Roundup and later thinned to also obtained in soils previously pasteurized at 60, 70, or 80 C. A similar effect on cabbage yield was one seedling. When needed, extra seeds obtained with aldicarb at 6.7 kg a.i./ ha. Control of foliar insects by fenamiphos and aldicarb did were also planted at the edges of tiles for not explain the observed increase in cabbage yield. Soil treatment with the miticide propargite, the ealso plantedttvtheaedgesof tilesrfo nitrification inhibitor nitrapyrin, and the fungicide metalaxyl (selectively active against early destructive sampling. Cultural pythiaceous fungi) did not increase cabbage yield. These data indicate that higher yields of cabbage practices rilizerbicid insecand obtained by treating soil with fenamiphos or aldicarb are due to control of soilborne biological planting, fertilizers, and insect and

Effect of Nitrapyrin on N Response of Corn on Sandy Soils1

AbstractPreplant N fertilizer applications on sandy Coastal Plain soils are often less efficient than sidedress N applications due to leaching of NO−3 from the rhizosphere. Preplant‐incorporated broadcast applications of ammoniacal N fertilizers containing the nitrification inhibitor nitrapyrin [2‐chloro‐6(trichloromethyl)pyridine] should increase utilization of the exchange capacity of sandy soils to retain NH+4 and increase preplant N fertilizer efficiency. The effects of N rate, N source, and nitrapyrin on inorganic soil N form, soil N content, and corn (Zea mays L.) growth were investigated in 1977 on a Marlboro sand (Typic Paleudult) and a Varina loamy sand (Plinthic Paleudult) and in 1978 on a Wagram sand (Arenic Paleudult). Nitrogen treatments consisted of a zero‐N check, preplant broadcast applications of 56, 112, 168, and 224 kg N/ha as urea, 112 kg N/ha as NaNO3, and 112 kg N/ha as urea plus 1.12 kg nitrapyrin/ha dissolved in water.Soil N measurements at 34, 40, and 48 days after N treatment application on the Marlboro, Varina and Wagram soils, respectively, showed that nitrification was suppressed by nitrapyrin. The lack of significant differences in inorganic soil N contents in the 0 to 15 cm depth among 112 kg N/ha supplied as urea with and without nitrapyrin and NaNO3 indicated that little leaching occurred in 1977. Leaching conditions in 1978 resulted in large losses of inorganic N from the rooting zone; however, when nitrapyrin was added with urea, losses of N were significantly reduced. High N rates from urea decreased the pH in all soils except when nitrapyrin was included. In 1977, inclusion of nitrapyrin with urea had little effect on leaf N, grain yields, plant N accumulation or N fertilizer recovery due to small losses of soil inorganic N. However, in 1978 when leaching conditions occurred, nitrapyrin with urea decreased soil N losses, significantly increased leaf N concentration, grain yields, plant N accumulation and N fertilizer recovery.

Inhibitory Effect of Nitrapyrin on Three Genera of Ammonia-Oxidizing Nitrifiers

Five strains of Nitrosomonas and one each of Nitrosospira and Nitrosolobus were examined for sensitivity to the nitrification inhibitor nitrapyrin. Considerable variation in sensitivity was observed, with some strains about five times more resistant than others. Sensitivity to nitrapyrin varied more with strain than with genus.

COMPARISON OF THE EFFECT OF NO3- AND NH4-N ONGROWTH, YIELD, AND YIELD COMPONENTS OF MANITOU SPRING WHEAT AND CONQUEST BARLEY

The objective of this study was to compare the effects of NO3 and NH4 forms of nitrogen on the growth and yield of spring wheat and barley. Two growth-room experiments were carried out using spring wheat (Triticum aestivum L. ’Manitou’) in both experiments and barley (Hordeum vulgare L. ’Conquest’) in the second. NO3 or NH4-N plus the nitrification inhibitor nitrapyrin were applied at rates from 23 to 360 kg N/ha. Temperatures were 27/12 °C (day/night) and soil moisture was maintained at between −0.05 and −1.0 bars by frequent watering. NO3-N-treated plants were taller, and had thicker stems and more spikelets/spike than NH4-N-treated plants. The NH4-N-treated plants produced more spikes and matured faster initially, although by anthesis stage there was little difference in maturity between the NO3- and NH4-N-treated plants. There was no differential effect of nitrogen source on total dry matter at maturity, although dry matter increased in proportion to nitrogen rate. Grain yield of the NH4-N-fed plants was higher than that of the NO3-N-fed plants, especially at the higher nitrogen rates. This was due primarily to the effect on number of spikes produced and secondarily on seed set. It is suspected that denitrification losses of nitrogen from the NO3-N-treated soil contributed to the differential response to the two sources, but there was circumstantial evidence to suggest that some of the difference may have been due to the inherent nature of the two sources which might have affected their ease of metabolism by the plant.

THE EFFECT OF THE NITRIFICATION INHIBITOR NITRAPYRIN ON YIELD AND ON NITROGEN FRACTIONS IN SOIL AND TISSUE OF CORN (ZEA MAYS L.) GROWN IN THE ANNAPOLIS VALLEY OF NOVA SCOTIA

The application of fertilizer (10-10-10) treated with the nitrification inhibitor nitrapyrin [2-chloro-6-(trichloromethyl) pyridine] was generally not effective in increasing the yields of grain corn, although at one location the addition of stabilized fertilizer increased the yield (P = 0.25) by 660 kg/ha over that from plots receiving non-stabilized N fertilizer. Nitrapyrin did not affect the levels of the N fractions in corn tissue but it did inhibit nitrification of soil NH4-N. As might be expected, the addition of fertilizer and increasing fertilizer rates increased yields and levels of N in tissue and soil.

Efficiency of Urea, Nitrification Inhibitor treated Urea and Slow Release Nitrogen Fertilizers for Sugarcane

AbstractA field experiment conducted for two crop seasons (1976‐77 and 1977‐78) showed that the treatment of urea with nitrification inhibitor Nitrapyrin (also refered as ‘N‐Serve’) or neem (Azadirachta indica A. Juss) cake increased its efficiency by preventing N losses and produced significantly more cane. In one of the years sulphur coated urea (Gold N) at lower rate (75 kg N/ha) gave higher sucrose content in juice and significantly more commercial cane sugar (CCS) than uncoated urea. Considering both the cane yield and CCS production mixing or coating of urea with neem cake holds considerable promise and needs wider testing along with and in comparison to nitrification inhibitors and sulphur coated urea and other slow release fertilizers for increasing the efficiency of nitrogen applied to sugarcane.

Inhibition of nitrification by nitrapyrin, carbon disulphide and trithiocarbonate

AbstractWe have studied the behaviour of the nitrification inhibitors nitrapyrin (2‐chloro‐6‐trichloromethyl pyridine) and carbon disulphide (CS2), and of trithiocarbonate ion (CS32−). Solutions of Na2CS3 in water or aqueous NH3 are stable but when added to soil they decompose with evolution of CS2, which in laboratory tests was complete within hours. In field experiments each material was injected simultaneously with aqueous NH3 or aqueous urea. Nitrapyrin was held strongly on soil near the centre of the injected band of fertiliser N. It became fully effective only approximately two months after injecting grassland in November (1974 and 1975) with 375 kg N/ha, but approximately one month after injecting winter wheat with 100 kg N/ha in March (1976). In contrast CS2 itself, or CS2 generated by CS32−, diffused rapidly from the injected band and markedly inhibited nitrification for up to three months after injecting grassland and up to one month after injecting winter wheat, but had no effect on nitrification later. The main practical implication of the work is that liquid fertilisers supplying NH4‐N may, if mixed with a trithiocarbonate, be injected into grassland in autumn, without risk of substantial nitrate leaching during winter. This extends the period suitable for injection and eases congestion of work normally done in spring.

Influence of some biologically active compounds on microbial activity and on the availability of plant nutrients in soils. II. Nitrapyrin, dazomet, 2‐chlorobenzamide and tributyl‐3‐chlorobenzylammonium bromide

AbstractThe effect of the nitrification inhibitor nitrapyrin (2‐chloro‐6‐trichloromethylpyridine), the soil partial sterilant dazomet (tetrahydro‐3,5‐dimethyl‐1,3,5‐thiadiazine‐2‐thione), the quaternary ammonium growth retardant tributyl‐3‐chlorobenzylammonium bromide, and the pre‐emergent herbicide 2‐chlorobenzamide on total microbial activity and available plant nutrient content of an acid and an alkaline soil during an incubation period of 6 weeks under aerobic conditions has been studied in comparison with untreated soils. The compounds were incorporated with the soils at normal application rates. At intervals determinations were made of carbon dioxide liberated, the content of ammonium and nitrate nitrogen and of some available plant nutrient mineral elements. All four compounds were found to influence these quantities. Nitrapyrin increased carbon dioxide production throughout and dazomet did so after initial depression. 2‐Chlorobenzamide and the growth retardant reduced carbon dioxide liberation especially in the early stage of incubation. All the compounds retarded nitrification in both soils; an increase in ammonium nitrogen resulted in treated soils except in the alkaline soil containing the growth retardent, where ammonification was also reduced. A reduction in the content of available mineral nutrient elements was usually found suggesting interference with the biological oxidation of these elements to less available forms. However, available manganese was increased by dazomet, as were available iron and manganese by the growth retardent and 2‐chlorobenzamide.