Effects of Nitrogen and Sulfur on Canola Yield and Nutrient Uptake

Abstract

at 500, 2000, 3000, and 2500 kg ha Ϫ1 for Sun95, Con95, Con96, and Sun96, respectively. Planting date for Sun95 and Con95 Spring canola (Brassica napus L. var. napus ) is becoming a significant oilseed crop adapted to the western USA. Often N and S limit and for Con96 was 2 May. The cultivar Westar was planted crop growth. Field experiments were established to study the effects at the rate of 7 kg ha Ϫ1 .of N and S fertilization on seed yield, oil content, and N, P, K, and Four N rates (0, 84, 168, and 252 kg N ha Ϫ1 ) and three S S uptake of spring canola. Four N rates in combination with three S rates (0, 22, and 45 kg S ha Ϫ1 ), organized into a randomized rates were evaluated on two irrigated and three rainfed locations in complete block design with a 4 ϫ 3 factorial treatment arrangethe western triangle area of Montana near Conrad. Seed yields ranged ment and four blocks, were applied to plot areas. Plot size from 0.1 to 3.8 Mg ha Ϫ1 . Seed yield and oil content N responses were was six rows wide (30 cm row spacing) and 6 m long. Each closely related to available N (fertilizer N plus soil NO 3 -N in 90 cm research site received 15 kg P ha Ϫ1 as triple superphosphate of soil). Seed oil content varied from 370 to 510 g kg Ϫ1 and was applied with the seed and 34 kg K ha Ϫ1 as KCl broadcast while depressed by increasing N. Optimum seed and oil yield occurred at planting. Nitrogen fertilizer as urea and ammonium sulfate about 200 kg N ha Ϫ1 . Two of the experimental sites responded to S. and S fertilizer as potassium sulfate or ammonium sulfate were About 20 kg S ha Ϫ1 was adequate for optimum seed and oil yields. also applied broadcast while planting. At the optimal N and S levels, total plant N, P, K, and S uptake Irrigated plot sites received enough supplemental water to averaged 140, 25, 170, and 60 kg ha Ϫ1 , respectively. Of the total N, maintain the soil profile (0-90 cm) at about 50% of the avail-P, K, and S accumulation, about 40% of the N, 30% of the P, and able water holding capacity. Growing season precipitation or 85% of the K and S remained in the postharvest residue.precipitation plus irrigation was 24 cm for Sun95, 50 cm for Far95 (flood-irrigated twice at an estimated 15 cm of water per irrigation), 35 cm for Con95, 11 cm for Sun96, and 35 S ince fertilizer programs are a major expense and cm for Con96. Con95 required no supplemental irrigation; profit margins are very small in canola production, however, Con96 required six irrigations, totaling 24 cm of supplemental water.

Genetic and environmental determinants of unreduced gamete production in Brassica napus, Sinapis arvensis and their hybrids

“…Although increases in unreduced gametes were observed for all environmental treatments from 17 to 31 days (Figure 3), the increases were greater in wounded and low-nutrient treatments relative to their less stressful counterparts, although these differences were not strong enough to generate statistical significance. Longer treatment time might have affected meiosis, in particular nutrient limitation, as there may have been nutrients remaining from the nutrient supplementation given before bud formation (Jackson, 2000). With longer or more intense stress treatments, and continuation of the observed trend, we may have observed significant environmental treatment effects.…”

Influence of four successive annual applications of elemental S and sulphate-S fertilizers on yield, S uptake and seed quality of canola

“…Canola is the major cash crop in the Parkland region. Being a high-protein oilseed crop, canola has high requirements for S (Grant and Bailey 1993;Jackson 2000). As S is immobile in plants, deficiency of S can occur at any growth stage and cause considerable reduction in seed yield.…”

Effect of sulphur and micronutrients fertilization on yield and fat content in winter rape seeds (Brassica napus L.)

“…The increase in sulphur dose to 30 kg S/ha did not have a significant impact on the content of oil. Also, McGrath and Zhao (1996), Jackson (2000), Ahmad et al (2005), as well as Malhi et al (2007) in their investigation proved an increased oil concentration in the objects fertilized up to the dose of 40 kg S/ha. As it resulted from the research conducted, the increase in sulphur fertilization dose occurred to be inefficient (Podleśna 2003, Podleśna and Strobel 2009.…”