Sowing ratio determines forage yields and economic benefits of oat and common vetch intercropping

Mixtures of annual legumes with cereal grasses in forage production are considered to have great advantages and are extensively used in the agro-pastoral region of China. However, the effect of sowing ratio on forage yields and economic benefits of oat (Avena sativa L.) and common vetch (Vicia sativa L.) intercropping remains largely unknown. A 2 yr field experiment was conducted with seven sowing ratios (sowing ratio of oat as 0, 25, 33, 50, 67, 75, and 100%) for oat and common vetch intercropping in northeastern China. Intercropping showed significant advantages in forage yield, land equivalent ratio (LER), and net income in the 2 yr. Oat was the dominant partner in the mixtures, strongly outcompeting common vetch. A sowing ratio of oat at 50% produced the highest forage yields of 10.8-11.1 t ha(-1) in spring seeding and 4.9-7.7 t ha(-1) in summer seeding, which were 28.7-66.4% and 12.6-166.9% higher than those in monocultures, respectively, if we considered two years together. In any case, oat forage yield just slightly decreased with a decreasing share in the intercrops, whereas common vetch forage yields strongly decreased. The highest LERs were detected in a sowing ratio of oat at 50%, which was 11-57% higher than other sowing ratios. Similarly, the highest annual net incomes of US$1,336 and $1,088 ha(-1) were also obtained in a sowing ratio of oat at 50% in the 2 yr. In conclusion, oat and common vetch intercropping have greater forage yields and economic benefits compared with the corresponding monocultures in the agro-pastoral region of China, and a sowing ratio of oat at 50% is recommended.

Automated summary

Mixtures of oat and common vetch in forage production in the agro-pastoral region of China showed greater yields and economic benefits compared to monocultures, with a sowing ratio of oat at 50% being recommended for optimal results.