Timing and Level of Nitrogen Fertility Effects on Spring Wheat Yield in Eastern Canada

Abstract

Bread wheat (Triticum aestivum L.) produced in areas of higher rainfall, such as eastern Canada, are often low in protein. Our objective was to determine if N management could be used as a way to produce bread quality wheat in eastern Canada. An experiment was conducted for 2 yr at two Quebec sites. The effects of N fertilizer level and timing on grain yield, yield components, and lodging level of four hard red spring wheat cultivars with breadmaking potential were investigated. The soil type was Ste‐Rosalie clay (fine, non‐acid, frigid, typic Humaquept). The experiment was a four (cultivars) × four (N level) × two (N timing) factorial. Cultivars were Columbus, Katepwa, Max, and Hege 155‐85. In both years, 0, 60, 120, and 180 kg N ha‐1 were applied at seeding or 60% at seeding and 40% at anthesis. Hege 155‐85 had the highest gram yield, responded most to N fertilizer addition, and was the most resistant to lodging. Differences in N management effects and cultivar responses were observed among the four site‐years. Grain yield, plant height, lodging, tillers per square meter, spikes per square meter and kernels per spike increased with increasing N fertility. When compared with application of all the fertilizer N at seeding, split application of N fertilizer (60% at seeding, 40% at heading) had little effect on yield (no effect at three site‐years, small reduction at the fourth), reduced the risk of lodging at one site, caused a reduction in the number of tillers per square meter and spikes per square meter at one site‐year, caused an increase in 1000‐kernel weight at two site‐years, and caused an increase in test weight at three site‐years. Gram yield increases due to greater N application were largely due to increases in kernels per spike and tillers per square meter. The correct combination of N application level and timing of N application can increase yields and reduce the risk of lodging. However, under these experimental conditions, the most important management decision is the choice of cultivar.

Recovery of 15N-labeled fertilizer by spring bread wheat at different N rates and application times

“…The greater precipitation during the 1994 growing season was probably responsible for the greater amount of N fertilizer required for wheat. Our findings in 1994 are supported by the results of Ayoub et al (1994a), as in their study the N rate required to reach the maximum yield of four cultivars of spring wheat in eastern Canada was around 120 kg N ha -1 .…”

“…The wheat yield response to N fertilizer varies with the climatic conditions and soil N supplying power during the growing season (Giroux and Tran 1989;Carr et al 1992) and with cultivar (Ayoub et al 1994a;Tremblay and Vasseur 1994). A significant increase in grain yield has been observed with N fertilization especially when soil N supply was low, but application of very high N rate can reduce grain yield by increasing lodging and disease incidence (Sinclair and Dewit 1975).…”

Spring wheat yield response to variable seeding rates in organic farming systems at different fertility regimes

“…However, other spring wheat research in Que´bec has shown that the addition of N increased test weight in half of the sites studied (Ayoub et al 1994). In our study, the added fertility may have encouraged weed competition and reduced resources available to the crop during grain filling, resulting in lower test weight.…”

Bread wheat varieties as influenced by different nitrogen levels

“…Such response can be attributed to the adequate nitrogen availability which might facilitate the tillering ability of the plants, resulting in a greater spike population. Ayoub et al(1994) also reported that spike population increased with increase in nitrogen level. Table 4 data show that there were no significant differences in spikes weight of the four wheat cultivars.…”

“…Nitrogen comprises 7% of total dry matter of plants and is a constituent of many fundamental cell components such as nucleic acids, amino acids, en-zymes, and photosynthetic pigments (Bungard et al, 1999). Ayoub et al(1994) reported that spilt N application had little effect on yield, but decreased lodging and spike population, while grain weight increased. Nitrogen application at 120 kg/ha for wheat has been recommended by various research workers (Lathwal et al, 1992;Das et al, 1993).…”