Nitrogen source and placement effects on stand density, pasmo severity, seed yield, and quality of no-till flax

Abstract

Field studies were conducted at two locations in western Manitoba over three years to evaluate the impact of rate, source, and placement of nitrogen (N) fertilizer on seedling emergence, disease severity, crop yield, and seed quality of flax (Linum usitatissimum L.). Urea, urea ammonium nitrate (UAN), and ammonium nitrate (AN) fertilizers were applied at 0, 30, 60, and 90 g N ha −1 , pre-plant banded or side-banded 2.5 m to the side and 2.5 m below the seed-row, using a hoe-type opener with 20 m row spacing. Differences in stand emergence occurred from year to year, depending on the moisture conditions after seeding. Nitrogen fertilizer occasionally decreased stand density when side-banded, with effects being greatest with urea and UAN. The magnitude of stand decrease was generally low, although it may have restricted seed yield with high rates of urea fertilization in some years. Nitrogen applications frequently increased leaf and stem pasmo, but the effects of fertilizer source and placement were variable. Seed yield increased with N application except at a single site where soil N levels were high. Where differences existed among sources, yield was generally lower with urea than with the other sources, possibly related to seedling damage from the urea at higher rates of application, or to physiological effects of high ammonia:nitrate ratio nutrition during early growth. Seed quality for oil production tended to decline with increasing N applications due to lower oil concentration, lower iodine number, and a decrease in the concentration of high-quality linolenic and linoleic fatty acids. However, seed protein concentration increased with increasing N concentration. While risk of seedling damage and pasmo may increase with increasing levels of N fertilizer, either side-banded or pre-plant banded N applications still resulted in increased flaxseed yield. However, increasing N rate slightly decreased quality for oil production.Key words: ammonia toxicity, linseed, fatty acid profile, ALA.Résumé : Trois années durant, les auteurs ont poursuivi une étude sur le terrain à deux endroits, dans l'ouest du Manitoba, en vue d'évaluer les répercussions du taux d'application, de la nature et de la méthode d'application des engrais azotés (N) sur la levée, la gravité de la maladie, le rendement et la qualité des semences du lin (Linum usitatissimum L.). Des engrais à base d'urée, d'urée combinée au nitrate d'ammonium (UNA) et de nitrate d'ammonium (NA) ont été appliqués à raison de 0, 30, 60 et 90 kg de N par hectare en bande avant les semis ou en bande latérale, 2,5 cm à côté de la planche de semis et 2,5 cm sous celle-ci, au moyen d'un traceur de sillon à disque, sur des rangs espacés de 20 cm. La levée varie d'une année à l'autre, selon le degré d'humidité relevé après les semis. Lorsqu'on l'applique en bande latérale, l'engrais azoté diminue parfois la densité du peuplement, l'effet étant plus important avec l'urée et l'UNA. L'importance de cette baisse demeure néanmoins généralement faible, même si elle a pu...

Cultivars Response of Flax ( Linum usitatissimum L.) to Different Nitrogen Sources in Dry Environment

“…The increase in flax straw yield and its attributes due to AN followed by AS form might be attributed to its increased the availability of nutrients and efficiency improved uptake, thus increased growth rate resulted in raising plant height and straw yield plant -1 which led to increasing straw yield fed -1 , also the increase in straw yield might be attributed to the main role of N in stimulating and raising plant growth and productivity, therefore increased straw yield. Under different soil type conditions, the same trend was found by Soethe et al (2013) and Grant et al (2016) Figure 1 illustrated that a significant effect due to the interaction between flax cultivars and nitrogen sources for stem diameter in the 1 st growing season and straw yield plant -1 and straw yield fed -1 in the 2 nd one was found. It is clearly observed that the highest values for most studied characteristics of straw yield and its components were obtained from Sakha-1 fertilized by ammonium nitrate or ammonium sulfate.…”

“…In the same soil condition, Soethe et al (2013) found that urea significantly exceeded ammonium sulfate on number of branches plant -1 , dry weight plant -1 , seed index and seed yield ha -1 . Grant et al (2016) tested N fertilizers of urea and urea ammonium nitrate (UAN), as well as ammonium nitrate (AN) on flax and they reported that seed yield was higher with AN than urea. In loamy sand, Zaki et al (2018) investigate four forms of nitrogen (olive pomace 1.54% N, ammonium nitrate 33.5% N, ammonium sulfate 20.6% N and urea 46.5% N) on sugar beet, and they mentioned that ammonium nitrate and ammonium sulfate surpassed urea for most studied traits.…”

Performance of Fertilizer Metering Mechanisms of Planters as a Function of Longitudinal Inclination

“…Weirich Neto et al (2013) studied fertilizer positioning at sowing, Lu et al (2014) worked on a planter project, and Grant et al (2016) assessed the influence of fertilizer sources on the crop installation. However, these authors did not find in the literature scientific studies examining the horizontal toothed rotor performance of planters as a function of longitudinal inclination to the metering mechanism.…”

Response of Flax Plant to Foliar Spray by Urea and Some of Micronutrients Mixture under Different Nitrogen Levels

“…Such finding, consequently, leads to a decrease of unsaturated / saturated fatty acids ratio with increasing nitrogen fertilizer rate. In this connection Grant et al (2016) reported that seed quality for flax oil tended to decline with increasing N application due to lower iodine number which revel the increase of saturated fatty acids was in account of unsaturated fatty acids.…”