Soil inorganic nitrogen content in commercial potato fields in New Brunswick

Abstract

. 2003. Soil inorganic nitrogen content in commercial potato fields in New Brunswick. Can. J. Soil Sci. 83: 425-429. Information on inorganic N content in commercial potato fields in Atlantic Canada is limited. Soil inorganic N measurements were collected from 228 commercial potato fields from 1999 to 2001. Soil NO 3 content to 30 cm depth at planting ranged from 2 to 124 kg N ha -1 , and was generally higher for preceding potato, red clover, or hay crops compared to preceding cereal or other crops. Soil NH 4 content to 30 cm depth measured at planting ranged from 3 to 64 kg N ha -1 , indicating that both soil NO 3 and NH 4 need to be measured to assess plant-available soil N content in spring. Soil NO 3 content to 30-cm depth at tuber harvest ranged from 3 to 250 kg N ha -1 , generally increased with increasing fertilizer N application rate, and differed among different potato cultivars. Soil NO 3 content measured to 30-cm depth in spring ranged from 3 to 100% of soil NO 3 at harvest in the preceding fall, indicating that highly variable losses of soil NO 3 from the root zone occur between growing seasons. La concentration est généralement plus élevée si les terres ont précédemment servi à produire des pommes de terre, du trèfle rouge ou du foin plutôt que des céréales ou d'autres cultures. À la même profondeur, la concentration de NH 4 fluctue de 3 à 64 kg de N par hectare, égale-ment à la plantation. Il convient donc d'établir la quantité de NO 3 et de NH 4 pour évaluer la concentration de N disponible dans le sol au printemps. À la récolte, la concentration de NO 3 se situe entre 3 et 250 kg de N par hectare, toujours à la profondeur de 30 cm. Elle augmente généralement avec le taux d'application des engrais azotés et varie avec le cultivar. La quantité de NO 3 mesurée au printemps à la même profondeur s'établit entre 3 et 100 % de celle relevée à la récolte, l'automne précédent, signe que la quantité de NO 3 perdue au niveau des racines varie considérablement d'une période végétative à l'autre.

Effect of fertilizer nitrogen management on N2O emissions in commercial corn fields

“…(1 , including starter fertilizer (Zebarth et al 2006a). These treatments are also higher than the 60 and 150 kg N ha…”

“…(1 , including starter fertilizer, recommended based on the PSNT values for the 2004 and 2005 sites, respectively (Zebarth et al 2006b). …”

“…Corn (Zea mays L.) is a crop of increasing importance in Atlantic Canada, and is one that receives relatively high fertilizer N inputs (Zebarth et al 2006a). Current grower practice in New Brunswick is to band starter fertilizer at planting, and to apply additional N as a preplant broadcast application of fertilizer or manure.…”

“…Current grower practice in New Brunswick is to band starter fertilizer at planting, and to apply additional N as a preplant broadcast application of fertilizer or manure. New fertilizer N recommendations based on the Pre-sidedress soil nitrate test (PSNT) have been developed for the region (Zebarth et al 2006b). The PSNT is based on a soil test taken when the corn is at approximately the sixleaf stage (Magdoff 1991).…”

Changes in Bacterial Denitrifier Community Abundance over Time in an Agricultural Field and Their Relationship with Denitrification Activity

“…The potato represents the dominant arable crop in Atlantic Canada. Potato cropping systems, which commonly receive high N fertilizer inputs (40), frequently have high N 2 O emissions compared with those of other typical arable crops (31,34). High spatial and temporal variation in N 2 O emissions has been documented in potato fields, particularly in relation to the row structure (i.e., the potato "hill" and the "furrow") (4,31).…”