Pulse Cereal Mixtures for Improved Forage Production

Funded by the Canadian Agricultural Partnership

(Government of Canada and Government of Alberta)

There are numerous annual forage crops available, each crop has its own strengths and weaknesses, and should be compared to your own situation and requirements. Results obtained from the Regional Silage Trials over the past 10 years have shown that the inclusion of pulses in a silage mixture can increase protein contents on average by 2 - 5 %. Also, intercropping cereals with peas can potentially help curb the lodging of pea varieties with no or short vines. Much of the work was done with field peas but producers are also taking an interest in the use of faba bean varieties as a potential silage option. In addition, newer forage-type peas with greater forage potential have recently been released warranting their assessments with cereal crops for forage production and feed quality. This study evaluates forage yield and quality of pulse-cereal mixtures with pea and faba bean varieties.

What we did

The trial was carried out at the Fairview Research Farm (NW-5-82-W6M) on RR #35, MD of Fairview. The field soil information from the surface (0-6" soil depth) before seeding: pH = 6.1 and organic matter = 6.6 %. The site was summer fallowed the year before this trial was established. Before seeding, the site was tilled with a plot cultivator followed by harrowing.

A randomized complete block design was used in 4 replications in small plots measuring 8 m x 1.14 m. For this trial, the following 24 treatments in total, consisting of 16 pulse/cereal mixtures, 4 monoculture spring cereal varieties, 4 monoculture pulses were seeded:

AAC Awesome SWW 1.16 bu/ac + AAC Aberdeen peas 2.45 bu/ac
AAC Awesome SWW 1.16 bu/ac + DL Delicious peas 2.16 bu/ac
AAC Awesome SWW 1.16 bu/ac + DL Tesoro faba beans 150 lb/ac
AAC Awesome SWW 1.16 bu/ac + Snowbird faba beans 159 lb/ac
CDC Austenson barley 1.55 bu/ac + AAC Aberdeen peas 2.45 bu/ac
CDC Austenson barley 1.55 bu/ac + DL Tesoro faba beans 150 lb/ac
CDC Austenson barley 1.55 bu/ac + DL Delicious peas 2.16 bu/ac
CDC Austenson barley 1.55 bu/ac + Snowbird faba beans 159 lb/ac
CDC Baler Oats 1.86 bu/ac + Snowbird faba beans 159 lb/ac
CDC Baler Oats 1.86 bu/ac + AAC Aberdeen peas 2.45 bu/ac
CDC Baler Oats 1.86 bu/ac + DL Delicious peas 2.16 bu/ac
CDC Baler Oats 1.86 bu/ac + CDC Tesoro faba beans 150 lb/ac
Taza Triticale 1.56 bu/ac + AAC Aberdeen peas 2.45 bu/ac
Taza Triticale 1.56 bu/ac + DL Delicious peas 2.16 bu/ac
Taza Triticale 1.56 bu/ac + DL Tesoro faba beans 150 lb/ac
Taza Triticale 1.56 bu/ac + Snowbird faba beans 159 lb/ac
AAC Awesome SWW monoculture 2.31 bu/ac
CDC Austenson barley monoculture 3.11 bu/ac
CDC Baler Oats monoculture 3.40 bu/ac
Taza Triticale monoculture 3.11 bu/ac
DL Delicious peas monoculture 2.8011 bu/ac
DL Tesoro Faba beans monoculture 200 lb/ac
AAC Aberdeen peas monoculture 3.17 bu/ac
Snowbird Faba beans monoculture 211 lb/ac

Seeding

Target seeding rates were 75% for each of the cereal crops in the mixture and 50% of the pulse crop in a mixture.
- The 75% for the cereals was based on:

300 plants/m2 (28 plants/ft2) for oats and barley

370 plants/m2 (34 plants/ft2) for spring triticale and winter wheat

250 plants/m2 (23 plants/ft2) for fall rye

The 50% for pulses was based on:

88 plants/m2 (5.15 plants/ft2) for peas

44 plants/m2 (4.07 plants/ft2) for faba beans

The target seeding rate calculation for small plots was based on 1,000 kernel weight, germination, plot area and 5% mortality rate.
Seeding was done on May 27, 2022 with a 6-row Fabro plot drill equipped with disc-type openers on 23 cm row spacing. The seeding depth was 0.75". The soil temperature at seeding was 11.7 °C.

Fertility

Soil test results from 0-6" before seeding were used to determine fertilizer rates for N, P, K and S. For both cereal monocultures and mixtures, the actual nutrients applied were: 30 lbs/acre P, 17 lbs/acre K, and 8 lbs/acre S.

Spraying

In-crop spraying was with Basagran Forte at 0.81 L/acre for mixtures and monocultures.

Harvest

Plots were harvested based on crop development and this was when most of the spring cereals were in the appropriate growth stage for silage:

Milk stage for oats monoculture and pulse/oats mixtures
Soft dough stage for mixtures with barley and pulse/barley monocultures
Late milk stage for mixtures with spring triticale and soft white wheat and their monocultures with pulses

The three middle rows were harvested using a plot-type forage harvester on August 8th for barley and August 16 th for oats. Forage samples for each treatment were sent to A & L Lab in Ontario for quality analysis.

Results

Forage DM yield

From the forage DMY and quality in Table 7, yields varied significantly and ranged between 2,784 to 6,146 lbs/acre amongst treatments with all pulse monocultures yielding comparatively lower to pulse cereal mixtures and cereal monocultures. A closer look reveals that both faba bean varieties yielded lowest as monocultures and in mixtures with triticale and oats but not with barley and wheat. Amongst the cereal monocultures, Awesome soft white wheat was the highest yielder; with 1,373-2,047 lbs/acre more forage DM yield than other cereal monocultures. No obvious forage DM yield advantages were produced by any of the pulse/cereal mixtures over the respective cereal monocultures.

Forage quality

The forage CP varied significantly and ranged 6.9 to 16.6% CP between treatments. Despite the higher CP values of pulse monocultures (especially the faba bean varieties), seeding them with cereals did not result in any significant changes in the protein content of pulse cereal mixtures.

Fibre did not vary significantly between treatments and ranged from 24.0 to 34.5 % (ADF) and 37.5 to 51.3 % (NDF).

Energy (TDN) varied significantly between treatments and ranged between 65.3 to 71.9% TDN with pulse cereal mixtures having CDC Austenson barley consistently showing a TDN > 71.0%.

The Ca content also varied significantly between treatments, with pulses having significantly higher Ca values compared to pulse cereal mixtures and cereal monocultures. Ranges of 0.16 to 0.34%, 1.14 to 1.91%, and 0.17 to 0.25% were noted for P, K, and Mg respectively. The P contents of pulse monocultures, just like the Ca contents reported earlier, were also higher than their respective pulse cereal mixtures and cereal monocultures.

Implication of Results

No forage DM yield advantage was produced by the pulse/cereal mixtures over their respective monoculture cereals.

Interestingly, protein contents of forage mixtures were not improved despite the higher protein contents of monoculture pulses. In general, pulse cereal mixes would meet the nutritional requirements of dry gestating cows at mid and last trimester. The energy contents of the cereal pulse mixtures were mostly above 65% and will constitute a high energy diet. Calcium levels of pulse cereal mixes were generally high and would meet the requirements of gestating and lactating cattle but some form of supplementation would be needed for growing and finishing calves. Pulse monocultures proved to be really high in Ca and P and will make for good Ca supplementation in diets deficient in Ca and P. The phosphorus levels in treatments were adequate for a dry gestating beef cow, but short of the 0.26% P needed by lactating beef cows.

Forage peas are a valuable crop for forage. Older forage peas tended to have long vines, normal leaf-type, purple flowers, and produced a lot of biomass. An older variety call 40-10 which is still grown today - has a very small seed size and produces a lot of biomass. However, 40-10 has an indeterminate growth habit and tends to lodge and fall over at the flowering stage, making it more difficult to handle at harvest. The newer forage varieties produce as much or more biomass as 40-10, but are easier to manage and have better lodging resistance. Generally, newer forage pea varieties tend to be semi leafless, have more basal branching, a determinate growth habit, and increased biomass. In peas/cereal intercrops, the cereal component prevents the pea component from lodging. Intercrops can contribute to low input systems in particular. We observed that in terms of lodging, spring triticale and semi-leafless forage are ideal intercropping partners; with no lodging expected even with strong winds.