Seasonal denitrification rates under corn ( Zea mays L.) in two Quebec soils

. 1999. Seasonal response of denitrifiers to temperature in a Quebec cropped soil. Can. J. Soil Sci. 79: 551-556. While some studies indicate no denitrification activity in early spring, others have demonstrated that denitrifiers from temperate region soils can adapt to low temperatures. The aim of the present paper was to study how seasonal changes in temperature affect denitrifying enzyme activity (DEA) in a cropped humic gleysol located in a cold temperate climate (Quebec). Soil was sampled monthly during a 16-mo period and DEA was measured at nine temperatures from 2 to 35°C. A seasonal effect of temperature on DEA was significant at all incubation temperatures and was more important in November and in May-June. The effect of temperature on DEA was better fitted with the square root model of Ratkowsky than with the Arrhenius equation. The regression coefficient b (Ratkowsky parameter) varied seasonally with a trend similar to that of DEA. These results show that the Ratkowsky model should be used instead of Arrhenius equation to describe the effect of cold temperature on denitrification.Key words: Denitrification, temperature, cold, Arrhenius equation, Ratkowsky model Pelletier, F., Prévost, D., Laliberté, G. et van Bochove, E. 1999. Activité saisonnière des dénitrificateurs en fonction des températures dans un sol cultivé du Québec. Can. J. Soil Sci. 79: 551-556. Certaines études affirment que la dénitrification dans les sols est négligeable au printemps, alors que d'autres ont démontré que les dénitrificateurs des sols des régions tempérées peuvent s'adapter aux basses températures. Le but de cette étude a été de déterminer l'effet des températures saisonnières sur la dénitrification dans un gleysol humique cultivé sous un climat froid tempéré (Québec). Des échantillons de sol ont été prélevés mensuellement pendant 16 mois et l'activité de dénitrification a été mesurée à neuf températures variant de 2 à 35°C. Un effet saisonnier de température sur l'activité de dénitrification a été observé pour toutes les températures d'incubation mais a été plus important en novembre et en mai-juin. L'effet de la température sur la dénitrification a été mieux ajusté au modèle "racine carrée" de Ratkowsky qu'à l'équation d'Arrhénius. En effet, la variation saisonnière du coefficient de régression b (paramètre de Ratkowsky) a été similaire à celle de l'activité de dénitrification. Ces résultats suggèrent l'utilisation du modèle Ratkowsky pour décrire l'effet des basses températures sur la dénitrification.

Section: Discussionsupporting

confidence: 76%

mentioning

confidence: 99%

Seasonal response of denitrifiers to temperature in a Quebec cropped soil

Prévost¹,

Laliberté²,

Bochove³

1999

“…Malhi and Nyborg (1986) reported loss of 44 kg N ha -1 under conditions prevailing in early spring for soils of north-central Alberta. Liang and MacKenzie (1997) found that for a sandy clay loam in the St. Lawrence lowlands losses of NO 3 -by denitrification were related to soil moisture in April and May. Chantigny et al (1999) reported that denitrification rates were inversely related to air-filled porosity.…”

Section: Discussionmentioning

confidence: 99%

“…Release of N 2 O, a greenhouse gas that depletes ozone layer, via denitrification was also reported for soils receiving excess fertiliser N (Liang and MacKenzie 1997). The presence of NO 3 -in soils after harvest and in early spring was associated with a risk of both leaching (Chichester 1977;Malhi and Nyborg 1986;Liang et al 1991) and denitrification (Goodroad and Keeney 1984;Liang et al 1991;Liang et MacKenzie 1997). Therefore, the reduction of the risk of air and water pollution from agricultural soils implies that the soil residual NO 3 content in fall and early spring should be kept at a minimum.…”

mentioning

confidence: 90%

Underseeded clover as a nitrogen source for spring wheat on a Gleysol

Garand¹,

Simard²,

MacKenzie³

et al. 2001

. 2001. Underseeded clover as a nitrogen source for spring wheat on a Gleysol. Can. J. Soil Sci. 81: 93-102. Although there is a potential to substantially reduce N fertiliser inputs by cropping spring cereals with an interseeded legume, the agronomic value and the nitrate catch-crop effect associated with this practice are not documented under the conditions of eastern Canada. This 3-yr study estimated N credits and non-N nutritional effects for interseeded clover (Trifolium pratense L. 'Arlington') in spring wheat production (Triticum aestivum L. 'Algot') and assessed fall and spring nitrate (NO 3 -) in soil. The soil is a St. Urbain clay (Orthic Gleysol) located in the St. Lawrence lowlands. Ammonium nitrate (NH 4 NO 3 ) was applied at 0, 40, 80, 120 and 160 kg N ha -1 with or without red clover as a companion crop. Clover was incorporated as a green manure crop in mid-November. Clover significantly (P ≤ 0.05) influenced wheat yield response to N fertilisation for 2 of the 3 yr. Clover did not reduce wheat grain yield through competition between the two plant species. Higher wheat yields with clover were attributed to N supplied by clover through mineralisation of residues incorporated in the soil the previous fall. Nitrogen fertiliser replacement value of clover was approximately 80 kg N ha -1 for 1994 and 1995. Clover occasionally increased NO 3 --N measured in the soil profile in late fall and in spring. Interseeded red clover may provide most of the N needs of a companion spring wheat crop in fine-textured gleysolic soils, but is an inefficient N catch-crop.

“…The experimental design, method and timing of fertilizer N application, and the management of field plots have been reported previously (Liang and MacKenzie 1997). Corn was grown continuously on the Chicot soil since 1984, and on the Ste.…”

mentioning

confidence: 99%

Nitrate leaching from residual fertilizer N after spring thaw in two corn agro-ecosystems

Zhang¹,

MacKenzie²,

Liang³

2004

Self Cite

--N at previous fertilizer N rates of 0 and 170 kg ha -1 in both soils. However, NO 3 --N concentrations of the leachates from soils receiving 285 and 400 kg N ha -1 yr -1 varied from 1.4 to 80 mg L -1 , depending on the initial levels of soil residual NO 3 --N and the supply of percolation water. When the initial levels of soil NO 3 --N were relatively high and percolation of water was relatively slow in 1993, NO 3 --N concentrations of the leachates ranged from 20 to 80 mg L -1 . Nitrite-N concentrations were from 1.4 to 15.6 mg L -1 when the initial levels of soil residual NO 3 --N were relatively low and percolation was relatively fast in 1994. The occasional higher NO 3 --N concentrations in the leachate from the previous higher N applications indicated a potential for contaminating surface and ground waters as a result of NO 3 --N leaching in the early spring.