PSV-24 Forage yield, land equivalent ratio of cereals and pea-cereal intercrops differing in pea to cereal ratio at two sites in western Canada.

Abstract Intercrops of pea (Pisum sativum L.; cv. CDC Jasper) with wheat (Triticum aestivum L.; cv. 15FOR36), barley (Hordeum vulgare L.; cv. CDC Renegade), triticale (Triticosecale Wittmack; cv. Taza) and rye (Secale cereale L. cv. KWS Bono) (binary crops) and their equally composited mixture (poly crops; 12.5% or 18.75% each cereal) in two pea: cereal seeding ratios (25:75 and 50:50) were compared with monocrops of pea and cereals in summer 2024. The experiment was conducted at the Lethbridge Research and Development Centre at Lethbridge, AB, Canada and at the Goodale Farm University of Saskatchewan at Saskatoon, SK, Canada. Monoculture seeding rates were 135, 123, 90, 163, and 129 kg/ha for wheat, barley, rye, triticale, and pea, respectively. The intercrop seeding ratio was calculated as a percentage of full seeding rate of individual monocrop. The experimental design was a RCBD with replicated (n = 4) 15 treatments (5 monocrops, 8 binary crops, and 2 poly crops). Plot size was 6×1.8 m, and plots were seeded at 3.75 cm depth (on 11 and 15 June for Lethbridge and Saskatoon, respectively) at row spacing of 30 cm and harvested on 9 and 30 August for Saskatoon and Lethbridge, respectively. Forage yield (DMY), land equivalent ratio (LER), and competitive ratio (CR) were determined. The DMY ranged from 2.3 to 6.6 t/ha at Saskatoon and 3.2 to 11.2 t/ha at Lethbridge. Pea was similar (P > 0.05) with rye but was lower (P < 0.05) than wheat, barley, and triticale monocrops in DMY. The cereal monocrops, excluding rye, had comparable (P > 0.05) DMY within the two sites (6.0 ± 0.7 and 10.9 ± 1.2 t/ha for Saskatoon and Lethbridge, respectively). The rye monocrop and intercrop with pea yielded lower (P < 0.05) than other cereal monocrops and their respective intercrops at both sites. The DMY of pea and –wheat, –barley, –triticale intercrops were not different (P > 0.05); 5.5 ± 1.0 and 10.2 ± 2.1 t/ha for Saskatoon and Lethbridge, respectively. Cereals were dominant in the pea–cereal 50:50 intercrops accounting for 55–93% of DMY. The intercrops did not vary (P > 0.05) in DMY due to seeding ratios. However, the contribution of pea in combined DMY of intercrops was greater (P < 0.05) in 50:50 mixtures than in 25:75 mixtures (29.6 vs. 15.6%). The intercrops in Saskatoon did not differ in LER (0.89 ± 0.06; P > 0.05). In contrast, there was a cereal by seeding ratio interaction (P < 0.05) for LER at Lethbridge. At Saskatoon, cereal and pea CR were 4.9 ± 2.17 and 0.42 ± 0.25, respectively. Overall, pea intercropped at either seeding ratios with wheat, barley, triticale, and rye showed no yield benefits compared to the corresponding monocrops.