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Canola (Brassica napus L.) is a nitrogen (N)-demanding crop, so tissue N analysis should be related to soil N supply. We evaluated canola N uptake in relation to soil N pools in plots receiving 0, 50, 100, and 150 kg N·ha−1 from urea at three sites in eastern Canada in 2012. Soil N pools varied significantly at the rosette, flowering, pod filling, and maturity stages, but responded less predictably to urea. Canola N uptake was inconsistently related to soil N pools and urea input. This confirms the importance of site-specific N fertilizer management when growing canola in eastern Canada.

Effective nitrogen (N) management strategies are important for ensuring a balance between optimizing plant growth and minimizing disease damage. A field experiment was conducted for three years to (i) assess the effects of N fertilizer application on the growth and seed yield of canola and severities of Sclerotinia stem rot (SSR), and (ii) to determine a reasonable N-rate for optimizing plant growth and minimizing the loss from SSR in eastern Canada. The experiment was designed with factorial combinations of eight N treatments and two canola hybrids. All N treatments reduced canola emergence with increasing preplant N application rates above 100 kg ha−1, but had a positive impact on plant height, fresh weight, dry weight, and seed yield. The development of SSR showed differential responses to N application rates. Of all the treatments, the split application (50 kg N ha−1 at preplant plus 100 kg N ha−1 side-dressed at the 6-leaf stage) increased canola growth and often produced the highest or similar seed yields to those of equivalent N rate applied as preplant. At the 150 kg ha−1 N rate, no severe development of SSR was observed in either preplant-only or split application. Overall, this study demonstrates that the split-N management strategy (50 + 100 kg ha−1) maintained a balance between enhancing plant growth and mitigating the negative impacts of SSR on canola.

Predicting the soil-available nitrogen (N) to grain corn over a growing season in humid temperate regions is the key for improving fertilizer N recommendations. The objective of this study was to evaluate a suite of soil-N tests to predict soil N availability to grain corn over two growing seasons at 13 individual sites with long-term history of synthetic N fertilization in Ontario, Canada (13 site-years). At each site, fertilizer N was applied at various rates (0–224 kg N·ha−1) to determine the crop response to N fertilizer, relative yield (RY), and the most economic rate of N (MERN). Across the entire dataset, water-extractable mineral N (WEMN) was the only soil test that strongly correlated to both RY (r = 0.74**) and MERN (r = −0.56*) indicating that in grain corn fields with long-term history of N fertilization, mineral forms of N in soil solution can be used for fertilizer N recommendations in southern and eastern Ontario. We also provide evidence that grouping soils based on clay content could further refine fertilizer-N recommendations for grain corn in Ontario. A multi-year validation of the WEMN test with more field sites and development of a fertilizer recommendation table for this soil test are recommended.

The objective of this study was to explore the changes in leaf nitrogen (N) and phosphorus (P) content, physiological processes, growth, and resource-use efficiency in a rapeseed cultivar under drought and (or) high temperatures. The two-wk-old plants were grown under controlled growth chamber conditions and subjected to individual or combined water (well-irrigated, 88% ± 4% field capacity vs. drought, 46% ± 5% field capacity) and temperature (control, 23 °C/17 °C vs. high temperatures, 26 °C/25 °C) regimes for 10 d. The measured response parameters were [N], [P], and their total content in leaves, photosynthetic rate (Asat), stomatal conductance (gs), intercellular CO2 concentration (Ci), mitochondrial respiration (R), intrinsic water use efficiency (WUEi), photosynthetic N use efficiency (PNUE), relative growth rate of the root (RGRr) and shoot (RGRs), leaf area, and dry matter accumulation in the plant. Drought significantly decreased [N], [P], and their total content in leaves, Asat, gs, Ci, RGRr, RGRs, leaf area, dry matter accumulation in the root, shoot, and whole plant, and PNUE, but significantly increased R and WUEi. Drought-induced reduction in growth or Asat was mainly attributed to a decreased Ci due to stomatal closure, while reduction in gs and leaf area appeared to be a drought-adaptive mechanism. High temperature stress alone had no negative impact on physiological and growth parameters, indicating an enhanced thermal stability of the cultivar, which was diminished at combined drought and high temperature stresses. We therefore conclude that the thermal stability of the cultivar in terms of growth was compromised under simultaneous occurrence of drought and high temperature stresses.

The trade-off between crop production and weed control is a fundamental scientific issue, as it is frequently influenced by individual crop competitive ability, population density, and planting pattern. A 2 yr field study was conducted to examine the relationship between planting density and row spacing, using two contrasting oat varieties. On average, high planting density (480 plants m−2) reduced weed biomass at oat maturity by 59% in 2012 and by 56% in 2013, when compared with a low density (120 plants m−2). The droopy-leaf variety suppressed weed biomass by up to 69% and weed density up to 72%, compared with the erect-leaf variety. In a drier year, the greatest grain yield was achieved with the droopy-leaf variety under the intermediate density, while in 2013, the erect-leaf variety under the high density had similar yield to the droopy-leaf variety at the intermediate density. A general trend was that increasing plant density suppressed weed infestation, and promoted crop biomass and yield. The droopy-leaf variety exhibited a strong competitive ability under the intermediate planting density, while the erect-leaf variety had a strong competitive ability under the high density. Taken together, there was a complex variety-by-environment interaction to achieve the balance between crop production and weed suppression, which was mediated by growing-season conditions.

The understanding of plant nutrient uptake and dynamics is a necessary step to develop site-specific, economically viable, and environmentally responsible management practices. A field study on canola (Brassica napus L.), treated with preplant and sidedress nitrogen (N) applications under ample phosphorus (P) supply conditions, was conducted to determine seasonal plant dry matter (DM) and N and P uptake patterns. We found that periodic DM measured at 20% flowering (FL), from FL to 50% pods reaching maximum size (FL-RI), and from RI to physiological maturity (RI-PM) contributed to 30%, 57%, and 14% of total DM, respectively. Yields ranged from 111 to 447 g m−2 with a sharp decline in 2012 induced by heat and drought. The crop took up about 58%–71% of total plant N by FL, whereas up to 42% of total plant P was assembled during the RI-PM. Canola seed accounted for 60%–66% of total plant N and 59%–63% of total plant P. Accumulation of DM and N post-FL, and of P during RI-PM could explain 69%, 43%, and 55%, respectively, variations in yield, seed N, and seed P. Our data indicated that plant P uptake under adequate P supply conditions in canola was largely enhanced by N application.

A two-year (2010–2011) field experiment was undertaken to examine the effect of nitrogen (N) rate (0, 100, 150, and 200 kg N ha−1) and N source (urea, calcium ammonium nitrate; ammonium sulphate) on canopy reflectance, chlorophyll pigments, photosynthesis, yield, grain quality, and N-use efficiency in corn. However, the physiological observations were made only in 2011. We found that stover biomass was unaffected by higher N rate beyond 150 kg N ha−1 in both years. Higher N rates did not provide a yield advantage as compared to 150 kg N ha−1 in 2010, but the highest grain yield was produced with 200 kg N ha−1 in 2011. The higher grain yield by N application was attributed to a greater kernel size in both years. Corn stover [N] was found to increase with increasing N rates in both years. Kernel [N] only responded to the high N rate in 2010. There was no change in the kernel density as affected by N rate in both years. An increased N addition resulted in a decrease in both N-uptake efficiency and agronomic-N use efficiency in both years. There was an inconsistent effect of N source on yield and N use efficiency indices in the corn over two years.

Understanding the spatial variability of soil mineral nitrogen (SMN) and crop growth is an important step for implementing precision nitrogen (N) management technologies for canola production. A 3 ...

Farmers in Canada are adopting no-till (NT) production at a high frequency. Conventional tillage (CT) was compared to no till (NT) with corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and whe...

Fusarium head blight is a common disease of oat and resistant cultivars are not available in Canada. The effect of nitrogen (N) fertilization on the incidence of seed-borne Fusarium spp. was evaluated under natural field conditions in three locations (Ottawa, ON; Melfort, SK; and Normandin, QC) in Canada in 2013 and 2014. At each site, oat cultivars CDC Morrison, AAC Nicolas, and AAC Noranda were used under four levels of N fertilization (0, 50, 100, and 150 kg N ha−1). Of the seven Fusarium spp. recovered, F. poae, F. equiseti, F. graminearum,F. sporotrichioides, and F. avenaceum were the most common species and were isolated from 9.6%, 1.3%, 1.1%, 1.0%, and 0.3% of the harvested grain, representing 72%, 10%, 8%, 7%, and 3% of the pathogen population, respectively. The remaining species, F. acuminatum and F. oxysporum, were each recovered from a single seed only. A significant N treatment effect (P

The boron concentration in soil extracts and ashed plant tissue was quantified with a rapid and reproducible microplate assay. The microsized azomethine-H method required adjustment to reduce pH and chemical interferences in soil and plant tissue samples. Microplate spectrophotometry permits replication and quality control and is suitable for high-throughput analysis.

Salt stress increases the accumulation of toxic ions in chloroplasts of higher plants and is associated with decreased photosynthesis. A pot experiment was conducted to investigate the effect of fo...

Field trials were conducted with soybean at two sites each year from 2001 to 2003 in Ottawa, ON, to determine the effect of seed treatments with various combinations of seven formulated fungicides and the bioagent Yield Shield (Bacillus pumilus GB34) under Rhizoctonia solani inoculated conditions. Controls were untreated seed planted into both non-inoculated (natural) soil and soil inoculated with R. solani. Compared with the non-inoculated control, inoculation significantly increased root rot severity and reduced emergence by 27%, and yield by 31%. Under the inoculated conditions, none of the seed treatments significantly increased emergence or yield in all of the six trials when compared with the control. Allegiance (metalaxyl) plus Vitaflo-280 (carbathiin plus thiram) and Vitaflo-280 alone were the most effective seed treatments, increasing emergence in by 20 and 19% and yield by 21 and 26%, which were significantly better than the control in four and five trials for emergence and three and four trials for yield, respectively. Allegiance plus HEC5725 (HEC5725), Apron Maxx RTA (fludioxonil plus metalaxyl), and Maxim 480FS (fludioxonil) increased both emergence and yield in two trials and TFL RTU (metalaxyl plus triflox ystrobin) plus Yield Shield in one trial. There was no difference between seed treatment with Allegiance and the untreated control for all parameters, confirming that metalaxyl is ineffective to R. solani. It is concluded that carbathiin, thiram, HEC5725, fludioxonil an trifloxystrobin are effective active ingredients protecting soybean from soil-borne R. solani and increasing plant emergence and yield. Key words: Rhizoctonia solani, seed treatment, soybean, Glycine max, fungicide, bioagent

Screening of cold-tolerant genotypes is hampered by the lack of a reliable field-evaluation method. A study was conducted to develop a field screening method for cold tolerance by recreating seedbed conditions limiting seed growth and quantifying the effect of those limiting parameters on the germination and emergence of two maize hybrids. By comparing maize germination and emergence in uncovered control plots with those covered with reflective insulation, differences were monitored in soil temperature, soil water content, oxygen and air content. Maize germination and emergence were monitored, and rate of radicle and coleoptile growth was measured. Soil temperature was significantly reduced by covering with reflective insulation. The average soil temperature at 5 cm depth was 5.5 and 7.4°C in late April, 11.0 and 16.0°C in May and 14.0 and 16.6°C in early June for the covered and uncovered treatments, respectively. In addition, day-to-day fluctuation in maximum and minimum temperatures was much smaller under covered than uncovered conditions. Although air content was maintained (about 34% on average), seedbed oxygen content dropped tremendously three times during the growing period. Reflective insulation cover caused a 5-d delay in germination and emergence for both hybrids. On average, across hybrids, the daily growth rate of radicle and coleoptile was 50% and 22% higher in uncovered than in covered treatments. Reflective insulation cover created adverse growth conditions and reduced seed germination, which suggests that it could be used to create uniform cold seedbed conditions for screening maize cold tolerant lines under field conditions. Key words: Soil temperature, soil water content, germination, emergence, Zea mays L.

Relying less on fertilizer N and more on crop residual and biological N2 fixation by legume crops has been suggested as an effective way to meet the challenge of maximizing economic return while minimizing environmental pollution. A field study was conducted on a Brandon loam soil (Orthic Humic Gleysol) to determine the effects of crop rotation and N amendments on grain yield, crop growth, N uptake and use efficiency (NUE) of maize ( Zea mays L.) and fertilizer replacement values of legume. The rotations included maize in annual rotation with soybean [Glycine max (L.) Merrill], alfalfa ( Medicago sativa L.) or continuous maize. The soil N amendments included no amendment, NH4NO3 at 100 kg N ha-1, stockpiled or rotted dairy manure at 50 Mg ha-1 (wet weight). Averaged across 4 yr, increases in maize grain yield, total plant N uptake, and NUE ranged from 13 to 35% in the maize-soybean and maize-alfalfa rotations compared to continuous maize monoculture. During the study, total dry matter production was 15 to 35% higher and crop growth rate was 13 to 23% higher for maize following alfalfa than for continuous maize monoculture. The effect of legumes on the subsequent growth of maize (i.e., total dry matter production a n d crop growth rate) was most apparent during the grain filling period. Total maize dry matter production was similar up to silking stage for all three rotation systems; however, the difference in total dry matter between maize monoculture and maize in rotation with legume continued to increase after this stage so that the greatest differences were observed at physiological maturity. Grain yield was 19% higher in the 100 kg N ha-1 treatment and 23% higher in the repeated manure amendment than in the unfertilized treatment. Fertilizer N replacement values were on average, 68 kg ha-1 for soybean and 133 kg ha-1 for alfalfa. Our results indicate that maize in annual rotation with legume crops could increase the maize yields by as much as 20% and reduce the amount of chemical fertilizer N by as much as 180 kg N ha-1. The effect of legume preceding crop on maize dry matter production and N uptake is expressed mostly in the later stages of crop growth in this mid- to short-growing- season region. Key words: Rotation, Zea mays, dry matter accumulation, crop growth rate, manure, nitrogen use efficiency

The ability of arbuscular mycorrhizal (AM) fungi to help their host plant absorb soil P is well known, but little attention has been paid to the effect of AM fungi on soil P depletion capacity. A greenhouse experiment was conducted to assess, under different P levels, the effects of mycorrhizae on extractable soil P and P uptake by maize hybrids with contrasting phenotypes. The experiment had three factors, including two mycorrhizal treatments (mycorrhizal and non-mycorrhizal), three P fertilizer rates (0, 40, and 80 mg kg-1) and three maize hybrids [leafy normal stature (LNS), leafy reduced stature (LRS) and a conventional hybrid, Pioneer 3979 (P3979)]. Extractable soil P was determined after 3, 6 and 9 wk of maize growth. Plant biomass, P concentration and total P content were also determined after 9 wk of growth. Fertilization increased soil extractable P, plant biomass, P concentration in plants and total P uptake. In contrast to P3979, the LNS and LRS hybrids had higher biomass and total P content when mycorrhizal. Mycorrhizae had less influence on soil extractable P than on total P uptake by plants. The absence of P fertilization increased the importance of AM fungi for P uptake, which markedly reduced soil extractable P under AM plants during growth. This effect was strongest for LNS, the most mycorrhizae-dependent hybrid, intermediate for LRS, and not significant for the commercial hybrid P3979, which did not respond to AM inoculation. Key words: Arbuscular mycorrhizal fungi, extraradical hyphae, maize hybrid,plant biomass, P uptake, soil extractable P

Conflicting reports have led to a renewed interest in the effects of narrow row spacing and high plant population densities on maize (Zea mays L.) grain yield. Field experiments were conducted to evaluate maize response to row spacing and N fertility over a 4-yr period (1997–2000). A randomized complete block design, arranged in a split plot was used with four replications each year with modifications of treatments over years. Row spacings of 0.51 m, 0.76 m and 0.76 m paired row alone or in combination with hybrid were tested in the subplot whereas combination of fertilizer N by population density (1997 and 1998) or N alone was assigned to the main plot. In 1997 and 1998, combinations of N by density consisted of 0 , 60, 120, 180 and 240 kg N ha-1 at 89 000 plants ha-1, and 60 and 180 kg N ha-1 at 69 000 plants ha-1 using a single hybrid, Pioneer 3893. In 1999 and 2000, N fertility levels of 0, 80 and 180 kg N ha-1 >were the main plots and six combinations of hybrids (Pioneer 3893 and Pioneer 38P06 Bt) by row spacing were grown in the subplots at 69 000 plants ha-1. Row spacing and fertility levels showed no significant interaction for any parameter at any developmental stage. In both 1997 and 1998, row spacing had no significant effect on yield (yield differed by 5% among row spacing treatments) or harvest index (varied from 0.45 to 0.53). For Pioneer 38P06 Bt in 1999, grain yield of the 0.51 m row spacing with the 80 kg N ha-1 fertilizer rate was 14.6% higher than the conventional 0.76 m row spacing. In 2000, the substantially lower (11%) yield of the 0.76 m paired row spacing than the other row spacing treatments was more likely the result of an exceptionally cool and wet season. In 1997 and 1998, plant density showed no effect on shoot or root DM. The lower density (69 000 plants ha-1) did, however, show a higher root to shoot ratio than the higher density. Shoot DM, root DM and root to shoot ratio did not differ between the 60 and 180 kg N ha-1 fertility treatments. While higher N levels increased above- and below-ground crop N contents, row spacing showed no consistent effects on maize plants at the early stages. Under the conditions of this study, narrow rows did not result in higher yield or N use efficiency even plant density and N fertility varied. Key words: Maize (Zea mays L.), nitrogen use, population density, root/shoot ratio, row spacing

Little attention has been paid to the effect of arbuscular mycorrhizal (AM) fungi on the uptake of nutrients that move mainly by mass flow. The objective of this study was to assess the possible contribution of indigenous AM fungi to the K, Ca and Mg nutrition of maize (Zea mays L.) as influenced by soil P levels and its impact on plant dry mass. The field experiment had a split plot design with four replicates. Treatments included soil fumigation status (fumigation and non-fumigation) and three levels of P fertilization (0, 60 and 120 kg P2O5 ha-1) in a loamy sand soil in 1997 and a fine sandy loam soil in 1998. Soil fumigati on with Basamid® was used to suppress indigenous AM fungi. Plants were sampled at four different growth stages (6-leaf stage, 10-leaf stage, tasseling and silking). Soil fumigation decreased shoot dry weight, but P fertilization increased shoot dry weight at most sampling times. When no P fertilizer was added, fumigation in the loamy sand soil reduced shoot K and Ca concentrations while, in contrast, in the fine sandy loam soil only Mg concentration was reduced by soil fumigation. The concentration of K in maize shoots was positively correlated (P < 0.05) with extraradicular hyphal length in both soils. The correlation between the abundance of extraradicular hyphae and the concentrations of Ca and Mg in maize shoots was significant only for soils where available Ca or Mg was relatively low. Arbuscular mycorrhizal fungi could increase corn biomass production and K, Ca and Mg uptake in soil low in these elements and low in P. These results indicate that the contribution of mycorrhizae to maize K, Ca and Mg nutrition can be significant in a field situation and that the extent of this contribution depends on the availability of these nutrients and of P in soils. Key words: Arbuscular mycorrhizal fungi, soil fumigation, extraradicular hyphae, uptake of K, Ca, and Mg, soil P levels, maize

There is an increased interest in developing high-yielding hulless feed barley (Hordeum vulgare L.) with low fibre content for swine rations. However, little information on physiological basis to select for high-yielding hulless barley was available. Approximately 400 double haploid barley lines were derived from a Kunlun No. 1/CIMMYT No. 6 cross using the bulbosum method. Both parental lines were six-row feed barley types differing in seed type, leaf type, leaf area distribution, tillering, time to heading and maturity and grain yield. Although Kunlun No. 1 yielded abou t 66% of CIMMYT No. 6, its seed was hulless with a grain weight 21% larger than covered CIMMYT No. 6 seed. Hulless barley, with its reduced fibre content, is desirable in swine rations. Selected double haploid lines (100 covered lines in 1995 and 100 hulless lines in 1996), parental lines and an adapted check, Chapais were evaluated at Ottawa, ON, and Charlottetown, PEI. We found that grain yields were significantly correlated with leaf area index (LAI), dry matter (DM), length and width of flag leaves, and plant height. All of the highest yielding lines in both hulless and covered populations common to both sites were similar to the parent Kunlun No. 1 with broader, shorter and greener leaves than the parent, CIMMYT No. 6. The best covered lines yielded more than the check cv. Chapais and some of the hulless lines were similar to the check. This study suggests that selection of high-yielding low fibre double haploid barley lines based on physiological traits has potential to increase grain yield for feed barley. Key words: Hulless barley, physiological traits, yield, feed quality, double haploid

Seedbed temperature and moisture conditions affect crop emergence rate and stand establishment. A 4 × 4 factorial experiment arranged in a split plot design with four replications was conducted for 3 yr at four sites to measure corn emergence rate and stand establishment while monitoring seedbed temperature and soil water content in situ. Four planting dates, beginning as early as the soil could be worked and every 10 d thereafter, were the main plots and four corn (Zea mays L.) hybrids the subplots. Volumetric soil water content in the top 0.10 m was measured a minimum of two times per week using time domain reflectometry (TDR) and estimated daily using a budget model. Measured and estimated soil water contents were similar (R2 = 0.73) and daily estimated values were used in the analysis. Stand establishment for most planting date-site-years ranged from 80 to 99%. Less than 15% of planting date-site-years had stands below 80%, and they were characterized by soil temperatures at or below 12.5°C combined with high soil water contents (>90% available water). Rate of emergence was not associated with stand establishment (P > 0.10) and could not be predicted from soil temperatures below 12.5°C. Results suggest that reduction in stand establishment under conditions of low (12.5°C) soil temperature and high (>field capacity) soil water content may be a factor in corn yield reductions associated with reduced or no tillage. Key words: Time domain reflectometry, soil water content, soil temperature, maize

Tillage effects on the soil environment suggest that it may influence rooting depth and root distribution. In this study, corn (Zea mays L.) rooting depth and root mass distribution were compared under conventional and conservation (chisel, ridge, no-) tillage on sandy loam and clay loam soils at Ottawa, Ontario. Root depth and distribution in 0.10-m vertical increments during vegetative growth were estimated using a combination of excavation of the surface horizon (0–0.10 m) and 0.05-m diameter cores obtained in the row and midway between two rows over a 3-yr period. An exponential model was used to fit root mass distribution data normalized with respect to total root density summed over all increments and maximum rooting depth in the profile. Soil moisture, temperature, mechanical resistance and bulk density varied with tillage treatment, but differences were not associated with root mass distribution. Rooting depth varied with soil texture, year and tillage, with increased rooting depth associated with increased tillage and decreased moisture in surface soil layers. In contrast, a common exponential model was found to fit normalized root mass distribution data under all tillage treatments. Our data suggest that simulation of root mass distribution under all tillage practices is possible if rooting depth and root mass density of the surface soil layer are known. Key words: Corn, model fitting, root distribution, tillage, Zea mays

Chlorophyll meters have been used to provide a rapid non-destructive method to estimate corn leaf nitrogen (N) concentration, although meter readings plateau at high leaf N levels. Paired chlorophyll meter and leaf N concentration data were obtained for ear level leaves at growth stages ranging from 3 wk before anthesis to 5 wk after anthesis over a 2-yr period at Ottawa, Ontario. Separate quadratic-plus-plateau models best represented chlorophyll meter response to leaf N concentration for pre-anthesis, early grain-fill and late grain-fill stages; chlorophyll meter readings corresponding to the beginning of the plateau increased at later growth stages. Leaf N concentration was estimated well from chlorophyll meter readings up to the plateau range using growth stage specific functions (R2 ≥ 0.77) but chlorophyll meter readings beyond the plateau should not be used to estimate leaf N concentration. Key words: Chlorophyll meter calibration, maize

There may be potential to increase grain yield and/or quality of barley (Hordeum vulgare L.) under the short crop-growing season conditions of Southwestern Quebec with intensive cereal management (ICM) practices similar to those used successfully in Europe. A field experiment was conducted for 4 yr (1987–1990) at the Macdonald Campus of McGill University to evaluate the applicability of ICM (140 kg N ha−1, 480 g a.i. ethephon ha−1, 70 g triadimefon ha−1 and 10-cm row spacing) vs. conventional cereal management (CCM) (70 kg N ha− and 20-cm row spacing) on spring barley. Four barley cultivars (Cadette, Joly, Laurier and Leger) were grown on three soil types: Bearbrook clay, St. Bernard loam and Chicot loamy sand. Grain yields of most cultivars were either unchanged or decreased 5–30% by ICM whereas Laurier occasionally yielded better under ICM than CCM. A general increase in spikes m−2 that resulted from ICM was largely offset by a reduction in grains per spike. Although ICM increased crude protein concentrations in grain and straw, use of 15N-labelled fertilizer showed a lower N recovery rate. The results indicated that yield response to ICM was inconsistent and was influenced to a large extent by prevailing weather and soil conditions. The ICM package tested is not applicable in this region. Key words: Conventional cereal management (CCM), intensive cereal management (ICM), 15N, nitrogen recovery, protein, soil type, spring barley