Research Coordinator: Dr. Akim Omokanye
Location: Fairview Research Farm
From: Peace Country Beef & Forage Association 2020 Annual Report
Intercropping is the growing of two or more crops simultaneously on the same field. For producers who are not accustomed to intercropping, the system can look complicated. Carefully designed intercropping systems can have many advantages in comparison to monocropping, such as increased forage yield, enhanced weed control, reduced soil erosion and, in the case of legumes, improved soil fertility due to their symbiosis with nitrogen-fixing bacteria. This report examines forage production and quality of intercropping involving canola, wheat, and flax with peas.
Methods
Experimental Site: Fairview Research Farm (NW-5-82-3-W6M) on RR #35, MD of Fairview.
Site soil information from 0-6” depth at seeding: pH = 6.2, organic matter = 4.7% and electrical conductivity = 0.21 (dS/m).
Cropping history: Before the fall of 2018, when the site was sprayed out with Roundup at 1.0 L/acre and tilled, the previous crop was alfalfa hay for over 15 years.
Experimental design: A randomized complete block design was used in 3 replications in small plots measuring 8 m x 1.8 m. Each plot was subsequently divided into halves, one half for forage production and feed quality, and the other half was for seed production. The report on seed production is not included here. This will be available later.
Treatments: 4 monocultures (canola, flax, peas, and wheat) were compared to 6 intercrops of wheat, flax, and canola with peas.
The intercrops were seeded in mixed and alternate rows.
The cash crops (wheat, canola, and flax) have been seeded at 100% of their recommended seeding rates. Each crop in the intercrops has been seeded at 75% of its recommended seeding rates.
Crop varieties and monoculture seeding rates:
1. Canola - CS2500CL at 7.0 seeds per square foot
2. Flax- CDC Plava at 32 seeds per square foot
3. Pea - CDC Meadow at 8 seeds per square foot
4. Wheat - AAC Brandon at 33 seeds per square foot
Seeded on May 29 with a 6-row plot drill, which is equipped with disc-type openers into 9” rows.
The peas were inoculated at seeding with granular inoculant.
Pre-emergent was with StartUp glyphosate + LI surfactant. Hand weeding of plots was done twice.
Forage dry matter (DM) yield and feed quality were determined for different monocrops and intercropping.
Intercropping is the growing of two or more crops simultaneously on the same field. For producers who are not accustomed to intercropping, the system can look complicated. Carefully designed intercropping systems can have many advantages in comparison to monocropping, such as increased forage yield, enhanced weed control, reduced soil erosion and, in the case of legumes, improved soil fertility due to their symbiosis with nitrogen-fixing bacteria. This report examines forage production and quality of intercropping involving canola, wheat, and flax with peas.
Methods
Experimental Site: Fairview Research Farm (NW-5-82-3-W6M) on RR #35, MD of Fairview.
Site soil information from 0-6” depth at seeding: pH = 6.2, organic matter = 4.7% and electrical conductivity = 0.21 (dS/m).
Cropping history: Before the fall of 2018, when the site was sprayed out with Roundup at 1.0 L/acre and tilled, the previous crop was alfalfa hay for over 15 years.
Experimental design: A randomized complete block design was used in 3 replications in small plots measuring 8 m x 1.8 m. Each plot was subsequently divided into halves, one half for forage production and feed quality, and the other half was for seed production. The report on seed production is not included here. This will be available later.
Treatments: 4 monocultures (canola, flax, peas, and wheat) were compared to 6 intercrops of wheat, flax, and canola with peas.
The intercrops were seeded in mixed and alternate rows.
The cash crops (wheat, canola, and flax) have been seeded at 100% of their recommended seeding rates. Each crop in the intercrops has been seeded at 75% of its recommended seeding rates.
Crop varieties and monoculture seeding rates:
1. Canola - CS2500CL at 7.0 seeds per square foot
2. Flax- CDC Plava at 32 seeds per square foot
3. Pea - CDC Meadow at 8 seeds per square foot
4. Wheat - AAC Brandon at 33 seeds per square foot
Seeded on May 29 with a 6-row plot drill, which is equipped with disc-type openers into 9” rows.
The peas were inoculated at seeding with granular inoculant.
Pre-emergent was with StartUp glyphosate + LI surfactant. Hand weeding of plots was done twice.
Forage dry matter (DM) yield and feed quality were determined for different monocrops and intercropping.
Results and Implications
Forage Production
Looking at the monoculture crops - peas, canola, and flax respectively produced 7941, 6265 and 5143 lbs/acre forage DM yield (Figure 1). Peas had 1676 and 2798 lbs/acre more forage DM yield than canola and flax respectively. Both mixed and alternate rows, when pooled across intercropping produced very similar forage DM yield (5727 vs 5744 lbs DM/acre). Pea/wheat from both mixed and alternate rows had more forage DM yield than pea/canola and pea/flax in both seeding methods (mixed and alternate rows). In general, the order of forage DM yield values for both mixed and alternate rows was: pea/wheat > pea/canola > pea/flax.
Forage Quality
Forage protein was lowest for wheat monoculture (9.28% CP) and highest for flax monoculture (13.2% CP) (Table 1). All intercropping treatments (except for pea/wheat) had 11% CP or more. All monocrops and intercropping had sufficient protein for a dry gestating beef cow, which needs 9% CP. Only wheat monoculture and pea/wheat mixed intercropping were short of providing adequate protein for a nursing beef cow that needs 11% CP.
In terms of energy (total digestible nutrients, TDN), monoculture wheat and intercropping of pea/wheat with 63-67% TDN generally had higher forage energy than other monocultures and intercropping (Table 1). This shows that the requirements of a dry gestating cow have been met by pure or monoculture wheat and pea/wheat mixture. Monoculture canola and pea/canola intercropping in mixed and alternate rows generally had lower TDN than other monocultures and intercropping, and consistently fell short of meeting the TDN requirements of a dry gestating beef cow, which needs 55% TDN in mid-pregnancy and 60% TDN in late-pregnancy.
All monocultures and intercropping would be able to provide sufficient Ca, P, and Mg for a dry gestating beef cow (Table 1). Only canola and flax monocultures, and pea/flax in alternate row showed inadequate levels of K for a dry gestating beef cow. Sodium was generally low for all monocultures and intercropping.
Going by the lower TDN values and mineral content (particularly K and Na) of some monocultures and intercropping, it is important to feed test monocultures and intercropping to be sure of what is needed for supplementation.
Looking at the NDF digestibility (NDFD) for monocultures, only monoculture peas and wheat had up to the suggested preferred minimum of 40% after 24-hr of NDF digestibility (NDFD 24-hr) (Table 1). For the intercropping methods (mixed and alternate), only mixed pea/flax and pea/wheat, alternate seeding of pea/wheat could reach the 40% following NDFD 24-hr. Wheat monoculture had a higher digestibility of 61% than others after NDFD 48-hr. Of all the monocultures and intercropping, peas appeared to have a faster NDF disappearance rate with 5.62% per hr, while flax showed the slowest NDF disappearance rate with 3.52% per hr.
