Cecil Vera

Seasonal biomass accumulation and nutrient uptake of wheat, barley and oat on a Black Chernozem soil in Saskatchewan

Dry matter and nutrient accumulation in the growing season are the main factors in the determination of seed yield and nutrient use efficiency. Field experiments were conducted with spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.) in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine the biomass accumulation and plant nutrient uptake at different growth stages, and their relationship with days after emergence (DAE) and growing degree days (GDD). All crops generally followed a similar pattern of biomass and nutrient accumulation in the growing season, which increased continuously with growing time, with much faster increase at early growth stages than at late growth stages. Maximum biomass accumulation rate and amount usually occurred at late boot stage (46–47 DAE or 443–460 GDD) and ripening stage (89–90 DAE or 948–1050 GDD), respectively. Maximum rate of nutrient uptake occurred at tillering to stem elongation stages (22–36 DAE or 149–318 GDD). Maximum ...

Seasonal Biomass Accumulation and Nutrient Uptake of Canola, Mustard, and Flax on a Black Chernozem Soil in Saskatchewan

ABSTRACT Seed yield and nutrient use efficiency are related to biomass accumulation and nutrient uptake in the growing season. Biomass accumulation and nutrient uptake of canola (Brassica napus L. and Brassica rapa L.), mustard (Brassica juncea L.) and flax (Linum usitatissimum L.) and the relationship to days after emergence (DAE) or growing degree days (GDD) were determined during the 1998 and 1999 growing seasons in field experiments at Melfort, Saskatchewan, Canada. In general, biomass accumulation and nutrient uptake increased with time at early growth stages and reached a maximum at late growth stages. Significant R2 values for both biomass accumulation and nutrient uptake indicated that a cubic polynomial type equation was suitable to represent these parameters as a function of DAE. All oilseed crops maximized biomass at mid way to the end of pod forming stages (74–84 DAE or 750–973 GDD). Maximum biomass accumulation rate occurred at the early to late bud forming stage (42–49 DAE or 390–498 GDD), and it was 146–190 kg ha−1d−1 for canola, 158–182 kg ha−1d−1 for mustard, and 174–189 kg ha−1d−1 for flax. Maximum nutrient uptake occurred during flowering to early ripening (59–82 DAE or 597–945 GDD). Maximum nutrient uptake rate normally occurred at branching to early bud formation (21–42 DAE or 142–399 GDD). There was a close correlation between biomass accumulation and nutrient uptake, and among nutrients, suggesting interrelated absorption. For nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and boron (B), respectively, maximum nutrient uptake rate was 2.3–4.5, 0.3–0.5, 2.5–5.7, 0.7–1.1, and 0.005–0.008 kg ha−1d−1 for canola; 2.3–3.9, 0.4–0.5, 2.6–4.9, 1.2–1.4, and 0.006–0.008 kg ha−1d−1 for mustard; and 3.2–4.0, 0.3–0.4, 2.9–4.1, 0.3–0.5, and 0.004–0.009 kg ha−1d−1 for flax. In general, maximum nutrient uptake rate and amount occurred earlier than maximum biomass accumulation rate and amount, and maximum rates of both nutrient uptake and biomass accumulation occurred earlier than their maximum amounts. The findings suggest that for high seed yields, there should be adequate supply of nutrients for plants, particularly to sustain high nutrient uptake rate at branching to bud forming stage and high biomass accumulation rate at early to late bud forming stage.

Seasonal Biomass Accumulation and Nutrient Uptake of Pea and Lentil on a Black Chernozem Soil in Saskatchewan

ABSTRACT Close relationships usually exist among biomass accumulation, nutrient uptake, and seed yield during the growing season. Field experiments with pea (Pisum sativum L.) and lentil (Lens cultinaris L.) were conducted in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine relationships of biomass accumulation and nutrient uptake with days after emergence (DAE) or growing degree days (GDD). For both biomass accumulation and nutrient uptake, maximum rates and amounts increased with time at early growth stages and reached a maximum value at late growth stages. The R2 values for cubic polynomial regressions were highly significant, indicating their suitability to estimate the progression of biomass accumulation and nutrient uptake as a function of days after emergence (DAE). Both pulse crops followed a similar pattern in biomass accumulation and nutrient uptake, which increased in the early growth stages and reached a maximum late in the growth cycle. Pulse crops usually reached their maximum biomass accumulation rate and amount at early to late bud formation (42–56 DAE or 390–577 GDD) and at medium pod formation to early seed filling (75–82 DAE or 848–858 GDD) growth stages, respectively. Maximum biomass accumulation rate was 175–215 kg ha− 1d−1 for pea and 109–140 kg ha− 1d− 1 for lentil. Maximum nutrient uptake rate and amount usually occurred at branching to early bud formation (28–49 DAE or 206–498 GDD) and at the flowering to seed filling (66–85 DAE or 672–986 GDD) growth stages, respectively. Maximum uptake rate of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S), respectively, was 4.6–4.9, 0.4–0.5, 5.0–5.3 and 0.3 kg ha− 1d− 1 for pea, and 2.4–3.8, 0.2–0.3, 2.0–3.4 and 0.2 kg ha− 1d− 1 for lentil. In general, maximum nutrient uptake rate and amount occurred earlier than maximum biomass accumulation rate and amount, respectively; and the maximum accumulation rates of both biomass and nutrients occurred earlier than maximum amounts. The findings suggest that adequate supply of nutrients from soil and fertilizers at early growth stages, and translocation of biomass and nutrients to seed at later growth stages are of great importance for high seed yield of pulse crops.

Effects of Water Deficit and Supplemental Irrigation on Winter Wheat Growth, Grain Yield and Quality, Nutrient Uptake, and Residual Mineral Nitrogen in Soil

Abstract Water deficit (WD) is a primary factor that limits winter wheat (Triticum aestivum L.) production in the Loess Plateau of China, as rainfall during the growing season is usually low and erratic in this region. Supplemental irrigation (SI) in early winter and/or early spring has been widely practiced to mitigate this problem. However, the timing at which WD and SI occur can influence grain yield and quality. A simulation pot experiment was conducted from October 1999 to June 2000 to determine the effects of WD and SI applied at different stages on winter wheat growth, grain yield and quality, nutrient uptake, and residual mineral nitrogen (N) in soil. The results showed that wheat at tillering, stem elongation, and grain‐filling growth stages was more sensitive to WD than at dormant stage. Water deficit at stem elongation or grain‐filling stage not only decreased biomass, but it also appeared to have inhibited the translocation of assimilates from the vegetative plant parts to the heads, especially when WD occurred during grain‐filling stage. Water deficit at dormant stage had no significant effect on biomass production, but it may have hindered the allocation of assimilates to the heads. Water deficit at tillering tended to increase grain harvest index but decreased biomass. Grain yield was significantly decreased (15–91%) by WD at all four growth stages. Translocation of N, phosphorus (P), and potassium (K) also appeared to have been pronouncedly impeded by WD. This inhibitory effect was more apparent at the advanced growth stages of winter wheat. Supplemental irrigation applied at dormant or grain‐filling stage increased grain yield (12% and 35%, respectively). Of the nutrients uptake, only N uptake in grain was increased (21%) when SI occurred at grain‐filling stage. Application of SI at tillering stage significantly decreased grain yield and N and P uptake in the grain, possibly due to decreased biomass and nutrient uptake in the whole plant. Supplemental irrigation at elongation stage increased biomass and N, P, and K uptake in the whole plant, but it appeared to have decreased translocation of assimilates and nutrients to the heads. Supplemental irrigation decreased or had no effect on N, P, and K concentration in grain. The main form of residual mineral N in soil was nitrate‐N, and it was markedly increased when WD was applied at all growth stages or when SI was applied at tillering stage. Supplemental irrigation at elongation or grain‐filling stage significantly decreased residual soil nitrate‐N.

Reward field pea

Reward, a semi-leafless and powdery mildew resistant yellow cotyledon field pea (Pisum sativum L.) cultivar, has excellent lodging resistance, high yielding ability, round seed shape and medium seed size. It is adapted to field pea growing regions in western Canada. Key words: Pisum sativum L., field pea, powdery mildew resistance, cultivar description

The effect of N and P fertilization on growth, seed yield and quality of industrial hemp in the Parkland region of Saskatchewan

Industrial hemp (Cannabis sativa L.) has sparked renewed interest in western Canada in recent years, and there is very little research information available on its fertilizer requirements. The objective of this study was to determine the effect of surface-broadcast ammonium nitrate and seedrow placed monoammonium phosphate fertilizers on the production and seed quality attributes of industrial hemp (cv. Fasamo and Finola). Field experiments were conducted on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, in 2000, 2001 and 2002. Increasing N rates significantly increased plant height, biomass, seed yield and seed protein content of hemp in all years. Seed-applied P fertilizer increased plant height in all years, and biomass in 2000, but reduced plant density, biomass and seed yield in 2001 and 2002. Finola consistently had lower plant height, earlier maturity, heavier seeds, and higher seed yield, seed protein content and seed oil content than Fasamo. The average amount of nitrate-N in...

Influence of six successive annual applications of sulphur fertilizers on wheat in a wheat–canola rotation on a sulphur deficient soil

A 9-yr (1999–2007) field experiment was conducted on a S-deficient Gray Luvisol (Typic Cryoboralf) loam soil at Porcupine Plain in northeastern Saskatchewan. The objective was to compare the influence of six successive annual applications (1999–2004) and the following residual effects for 3 yr (2005–2007) of elemental S and sulphate-S fertilizers on yield, seed protein and total S concentration, and S uptake of wheat (Triticum aestivum L.) in a wheat–canola rotation. Treatments used were combinations of two application times (preceding autumn and before seeding in spring) with two granular elemental S fertilizers (ES-90 and ES-95), one fertilizer containing both elemental S and sulphate-S (Agrium Plus), ammonium sulphate, and a zero-S control. The S fertilizers were applied annually at a rate of 15 kg S ha–1. From 1999 to 2004, seed yield (3 yr) and straw yield (4 yr), seed protein concentration (3 yr), total S concentration in seed (4 yr), and S uptake in seed (5 yr) and straw (5 yr) of wheat showed sign...

Canstar field pea

Canstar, a yellow cotyledon field pea (Pisum sativumL.) cultivar, has a semi-leafless leaf type, medium maturity, medium-sized and round seeds, good lodging resistance and high yielding ability. Canstar is resistant to powdery mildew and is adapted to the field pea growing regions of western Canada. Key words: Pisum sativum, field pea, powdery mildew resistance, cultivar description

N, P, and S fertilization effects on industrial hemp in Saskatchewan

Industrial hemp (Cannabis sativa L.) has become a well-known crop in western Canada in recent years, but insufficient information is available on its nutrient requirements for optimum yield. Our objective was to confirm the response of two hemp cultivars to increasing levels of nitrogen (N), phosphorus (P) and sulphur (S) in various sites in the province of Saskatchewan, during 2006-2008. Increasing N rates significantly increased plant height, biomass, and seed yield, when data were averaged across all sites (location-years), reaching maximum values at about 150 kg N ha-1 of applied N fertilizer. The cultivar Crag was taller and produced greater biomass than the cultivar Finola over all levels of N fertilizer rate. The minimum rate of N fertilizer to achieve maximum height/biomass for Crag, relative to Finola, was 5 kg N ha-1 lower for height (Finola: 163 kg N ha-1) but 9 kg N ha-1 higher for biomass (Finola: 180 kg N ha-1). Finola seed yield was more responsive to progressively greater rates of N fertil...

Hemp Production in Western Canada

Abstract Hemp production has been successfully adapted to meet local conditions in western Canada. Production has been driven by commercial interest in this species as an oilseed crop. As hemp is a photosensitive plant, the higher latitudes of western Canada appear to contribute to increased levels of essential fatty acids in the seed. Cultivars of shorter stature and early maturity have been imported, or locally bred, for the specific purpose of oilseed production or dual purpose (seed and fiber). Over 2,700 ha were seeded in western Canada in 2003. Research continues in order to improve production practices and optimize seed yield of the crop, under conventional and Certified Organic systems.