Walley, F. L., Kyei-Boahen, S., Hnatowich, G. and Stevenson, C. 2005. Nitrogen and phosphorus fertility management for desi and kabuli chickpea. Can. J. Plant Sci. 85: 73-79. Chickpea (Cicer arietinum L.) is a relatively new crop in Saskatchewan and acreage has undergone a rapid expansion during the past decade. However, uncertainty remains regarding growth and yield responses of this grain legume to N and P fertilization under the semiarid environment of Saskatchewan. Field experiments were conducted at various locations in Saskatchewan to investigate chickpea response to starter N (0, 15, 30, and 45 kg N ha -1 ) and P (0, 20 and 40 kg P 2 O 5 ha -1 ) using desi cv. Myles and kabuli cv. Sanford. Starter N was side banded (2.5 cm to the side and 4 cm below the seed) and the P was placed in the seed row or side banded. Starter N promoted early vegetative growth of both desi and kabuli chickpea, but kabuli seed yield was unaffected by N application. Application of 30 or 45 kg N ha -1 enhanced desi yield by as much as 221 kg ha -1 . Starter N reduced N 2 fixation by kabuli chickpea whereas N 2 fixation by desi apparently was not as sensitive to inorganic N. Phosphorus (40 kg P 2 O 5 ha -1 ) enhanced chickpea vegetative growth, although only desi seed yield was significantly enhanced (121 kg ha -1 ). Shoot N and P accumulation in both chickpea types generally increased with P application, but N 2 fixation was unaffected. The results suggest that although N and P application had no effect on kabuli seed yield, desi yields may be optimized by the application of low rates of starter N (i.e., 30 kg N ha -1 ) and P (20 kg P 2 O 5 ha -1 ). L'engrais de démarrage azoté a été appliqué latéralement (bandes de 2,5 cm, à 4 cm sous la semence) alors que l'engrais P a été appliqué avec la semence ou sur le côté. L'engrais de démarrage azoté accélère la croissance des deux types de pois chiche en début de saison, mais le rendement grainier du cultivar kabuli n'est pas affecté par ce traitement. L'application de 30 ou de 45 kg de N par hectare accroît le rendement du pois chiche desi de jusqu'à 221 kg par hectare. L'engrais de démarrage azoté ralentit la fixation de N 2 par le pois chiche kabuli, mais la fixation de cet élément par le pois chiche desi n'est apparemment pas aussi sensible à l'azote minéral. Le phosphore (40 kg de P 2 O 5 par hectare) favorise la croissance végétative du pois chiche, quoique le rendement du pois desi soit le seul à connaître une hausse significative (121 kg par hectare). L'accumulation de N et de P dans les pousses des deux types de pois chiche est généralement plus élevée après l'application d'un engrais phosphaté, sans que la fixation de N 2 en soit touchée. Bien que les engrais N et P ne semblent pas modifier le rendement grainier du pois kabuli, les résultats indiquent qu'on pourrait optimiser celui du pois desi en appliquant une petite quantité d'engrais de démarrage azoté (à savoir, 30 kg de N par hectare) et d'engrais phosphaté (20 kg de P 2 O 5 par hectare).

Although the relevance of biological N nutrition of soybean [Glycine max (L.) Merr.] is recognized worldwide, inoculation with Bradyrhizobium japonicum shows variable results and the benefi t needs to be validated under current crop production practices. We conducted statistical analysis of soybean fi eld trial data to provide insight into factors aff ecting the effi cacy of soybean inoculation under contrasting crop production conditions. Most experimental sites, 187 trials in the United States and 152 trials in Argentina, were in soils with soybean history and naturalized B. japonicum strains. Yield increases were greater in Argentina (190 kg ha -1 equivalent to 6.39%) than in the United States (60 kg ha -1 equivalent to 1.67%). Tillage methods did not aff ect inoculant performance. In the United States, inoculation was more eff ective in soils with higher pH (>6.8) while in Argentina the greatest inoculation eff ect on crop production occurred in soils with a lower pH (<5.5). In the United States, where most of the trials were in rotation with corn (Zea mays L), the greatest positive eff ect of inoculation was observed in late planted soybean crops and independent of soil organic matter (SOM). In Argentina, the inoculant had its greatest eff ect in soils with no soybean history, a relatively high SOM, higher levels of soil extractable P and S, and in areas with greater precipitation during early reproductive growing stages. In both regions, the yield increases due to B. japonicum inoculation support the regular use of this practice to help provide adequate conditions for soybean production.M. Leggett, Novozymes BioAg, Research and Development, 3935 Th atcher Ave.,

A gronomy J our n al • Volume 10 0 , I s sue 2 • 2 0 0 8 285 ABSTRACT Nitrogen accounts for the largest energy input in oilseed production. Understanding N use characteristics of oilseed crops will help improve N use effi ciency and minimize production costs. Th is study determined nitrogen use effi ciency (NUE, defi ned as seed yield produced per unit of N supply), nitrogen fertilizer use effi ciency (NFUE, defi ned as seed yield produced per unit of fertilizer N), and crop N uptake for oilseed crops under diverse environments. Five oilseed crops, namely Brassica juncea, B. napus, and B. rapa canolas, and B. juncea and Sinapis alba mustards, were grown at seven rates of N fertilizer (0, 25, 50, 100, 150, 200, and 250 kg N ha -1 ), at 11 sites (year × location combinations) in Saskatchewan from 2003 to 2005. At sites with low soil N supply or low rainfall, alba mustard, juncea canola, and rapa canola had lower NUE and NFUE than juncea mustard and napus canola.At sites with high soil N supply or rainfall, napus canola had the greatest NUE and was the most sensitive to the gradient of productivity among the fi ve oilseeds. All oilseed species responded to N fertilizer rates in a similar manner; both NUE and NFUE decreased as N fertilizer rate increased. Th e minimum NUE and NFUE were obtained with N fertilizer rate greater than 150 kg N ha -1 . At sites with low soil N supply or rainfall, alba mustard had the least NUE or NFUE response to increasing N fertilizer rates and napus canola the greatest. At sites with high soil N supply or rainfall, juncea mustard had the least NUE and NFUE response to increasing N fertilizer rates and rapa canola the greatest. On average, seed N uptake was greatest for juncea canola and juncea mustard and least for alba and rapa canola. Th e fi ve oilseed species had similar response patterns of seed N uptake to N fertilizer rates, while the magnitude of response varied among species. Improving NUE in oilseed production systems requires optimizing rates of N fertilizer which vary depending on environmental conditions, and soil N supply and rainfall during the critical growth period of the oilseed crops play an important role in aff ecting NUE.

Grazing swathed, small‐grain crops can reduce costs of overwintering beef cows (Bos taurus) by 40%. However, the late planting required to target mid‐September harvest may be associated with low yield and carrying capacity. The objective was to compare whole‐plant yield, nutritive value, and potential carrying capacity in relation to beef cow requirements for spring barley (Hordeum vulgare L.), oat (Avena sativa L.), and triticale (X Triticosecale Wittmack) when planted on seven weekly intervals (10 May–23 June) over 3 yr at Lacombe, AB; whole‐plant material was harvested at soft dough (barley and triticale) or milk stages (oat). Data were analyzed relative to planting date delay as an independent variable. Barley matured more rapidly than oat and triticale, with the latest planting date harvested on 27 August for barley, 8 September for oat and 25 September for triticale. Nutritive value for barley and triticale was unaffected by planting date, but neutral (NDF) and acid detergent fiber (ADF) concentrations increased quadratically with delay in planting for oat. In vitro true digestibility (IVTD) was lower for oat than barley and triticale. Yield declined linearly with planting delay for barley (35–39%), but increased (quadratically) as planting was delayed from late May to early June for oat (8%) and triticale (10%). Consequently, the potential carrying capacity for triticale was 1.6 and 1.8 times greater than barley and oat, respectively when planted for swathing in late August or early September.