Optimal seeding rate for organic production of lentil in the northern Great Plains

Abstract

northern Great Plains. Can. J. Plant Sci. 89: 1089Á1097. Organic lentil (Lens culinaris Medik.) producers must rely upon the recommended rate for conventional production of 130 plants m (2 , but this seeding rate may not be suitable, as organic and conventional production systems differ in management and inputs. The objective of this study was to determine an optimal seeding rate for organic production of lentil considering a number of factors, including yield, weed suppression, soil nitrogen and phosphorus concentrations, plant uptake of phosphorus, and economic return. A field experiment was conducted for 4 site-years at locations near Saskatoon, SK. Treatments included seeding rates of 15, 38, 94, 235 and 375 seeds m (2 . Seed yield increased with increasing seeding rate up to 1290 kg ha (1 . Weed biomass was reduced by 59% at the highest seeding rate as compared with the lowest seeding rate. Post-harvest soil phosphorus and nitrogen levels were similar between seeding rate treatments. Economic return was maximized at $952 ha(1 at the highest density of 229 plants m (2 , achieved with a seeding rate of 375 seeds m (2 . Organic farmers should increase the seeding rate of lentil to achieve a plant density of 229 plants m (2 to increase profitability and provide better weed suppression. , mais une telle densite´pourrait ne pas convenir, car les intrants et les pratiques diffe`rent pour les syste`mes de culture biologique et traditionnel. L'e´tude devait e´tablir la densite´de semis optimale pour la culture biologique de la lentille en fonction de plusieurs facteurs, notamment le rendement, le de´sherbage, la concentration d'azote et de phosphore dans le sol, l'absorption de phosphore par la plante et le rendement e´conomique. Pendant quatre anne´es-sites, les auteurs ont proce´deá`u ne expe´rience sur le terrain a`plusieurs endroits pre`s de Saskatoon (Saskatchewan). Les traitements consistaient en une densite´de semis de 15, 38, 94, 235 et 375 graines par m 2 . Le rendement grainier augmente aves la densite´de semis jusqu'aù n maximum de 1 290 kg par hectare. La densite´de semis la plus e´leve´e re´duit la biomasse des adventices de 59 % comparativement a`la densite´la plus basse. La concentration de phosphore et d'azote dans le sol apre`s la re´colte e´tait analogue, peu importe la densite´des semis. Le meilleur rendement e´conomique s'e´tablit a`952 $ par hectare, a`la plus forte densite´de peuplement, soit 229 plants par m 2 , obtenue avec une densite´de semis de 375 graines par m 2 . Ceux qui pratiquent l'agriculture biologique devraient augmenter la densite´de semis de la lentille pour obtenir un peuplement de 229 plants par m 2 en vue d'en rehausser la rentabilite´et de mieux lutter contre les mauvaises herbes.

Effect of sowing date and variety on yield and weed populations in a lentil–barley mixture

“…Early sowing of lentil was found to be a good strategy for better weed control and seemed to be superior to the ‘stale-seedbed’ technique followed by farmers. It had a similar effect to the strategy of increasing lentil competitiveness by higher sowing density (Ball et al 1997; Paolini et al 2003; Baird et al 2009): robust and big plants resulted from early sowing, which could better compete with emerging weeds. It is not clear, however, whether this effect was caused by the lentil crop, or by the companion barley crop, or by both.…”

“…One of the main challenges for lentil cultivation is increasing its yield, which in Germany currently ranges from 0·5 to 0·8 t/ha under farmers’ practices. This is much lower than the 1–2 t/ha in, for example, Turkey, Canada and Australia (Tepe et al 2005; McDonald et al 2007; Baird et al 2009).…”

Pulse Crops Improve Energy Intensity and Productivity of Cereal Production in Montana, USA

“…There was no difference between pulses and wheat in energy inputs attributed to herbicide or seed. Although pulse seed is assumed to be less energy intensive to produce than wheat (Table 1), more pea seed is required because the seeds are larger (Gan et al 2003) and recommended seeding rates for lentil are for higher plant density than for pea (Baird et al 2009). …”

The Sustainability of Organic Grain Production on the Canadian Prairies—A Review

“…A farm-scale, Canada-wide trial of different seeding rates in organically managed spring wheat suggested that a 1.25x seeding rate was nearly as effective as 1.5x or 2x seeding rates for increasing grain yield [48], and would likely make the economic return even more favourable. In organically managed pulses in Saskatchewan, increasing the seeding rate substantially above the conventional recommendation led to weed biomass reductions of up to 59% and 68% for lentil and field pea, respectively [49,50]. In lentil, economic returns were positive at the highest recommended seeding rate of 375 viable seeds m -2 [49], while in pea, an intermediate seeding rate (200 seeds m -2 ) provided the best compromise between weed biomass reductions, yield gains, and input costs [50].…”