Funder: Results Driven Agriculture Research (RDAR)
By Chelsey Hostettler
Background
Perennial cereal grain crops (PCGC) are grain crops that live and remain productive in the field for more than two growing seasons. PCGCs can produce grain every year, have no requirements for annual tillage, pre-pass, seed and seeding costs, which are in most cases required for annual cropping systems. PCGCs can provide producers. with mixed farming enterprises. the flexibility of using a grain crop or a forage crop for their farm needs.
Information on PCGC adaptation, intercropping systems, grain and forage productivity, ecological stability, and agroecosystem services, as well as economic viability, will assist producers in making future decisions on which PCGCs to use in their farming systems. Our hypotheses, on this project, are that: 1) PCGC productivity can be maintained by including a forage legume component, 2) PCGC/legume intercropping will provide ecosystem functions, soil health benefits and offer opportunity for integrated crop-forage-livestock production, and 3) PCGC/legume intercropping will reduce annual fertility and production costs, as well as insight into cost benefit analysis.
Objective
The 2022 crop year is considered an establishment year for the PCGCs and legume-cereal mixtures. A collection of baseline data was completed for soil chemical and physical characteristics, and biological activities to enable proper assessments of soil health indicators including mycorrhizal root colonization under different soil types and ecozones in Alberta. Plant count establishment was a key indicator in the plant populations following first year seeding at each project site.
Potential Benefits to Agricultural Industry
The benefits of any PCGC/legume intercrop system will depend on establishment, management, and harvesting factors. The project will provide information on management practices in order to optimize production potential of PCGCs and PCGC intercropping systems. One crucial goal is to inform farmers throughout Alberta about the potential of a perennial cereal crop when it’s planted with a nitrogen-fixing legume. There is opportunity to reduce fertility inputs while also utilizing multi-year harvesting strategies. There is additional industry potential for continued work on perennial cereal crop seed breeding in Alberta.
Methods
PCBFA seeded a site at the Fairview Research Farm along with project partners from five other agricultural organizations from across the province. They are: GRO at Westlock, MARA at Fort Vermillion, University of Alberta at Breton, BRRG near Forestburg and CARA at Oyen.
At the Fairview Research Farm, we are testing the resiliency and productivity of two PCGCs: ACE-1 and Kernza®. ACE-1 perennial rye was developed by Agri-Food Canada Research Centre in Lethbridge. This particular cultivar was developed for silage and greenfeed. ACE-1 establishes quickly and competes well with weeds. It produces more biomass than barley and fall rye and the forage quality was found to be similar to barley. A drawback is that it has shown to produce less seed than high yielding fall rye, however improvement through breeding continues. Kernza® is a type of intermediate wheatgrass, which was further developed by the Land Institute. It serves a dual purpose as a crop, with some farmers choosing to let livestock graze on the remaining leaves and stems after harvesting the grain using a combine.
What we are testing:
Spring forage harvest production then fall grain yield
Summer grain yield then fall forage harvest production
Soil health metrics
Forage legume fixation
Water use efficiency
Treatments |
Perennial Wheat Mono |
Perennial Wheat + Alfalfa |
Perennial Wheat + White Clover |
Perennial Wheat + Sainfoin |
Perennial Rye Mono |
Perennial Rye + Alfalfa |
Perennial Rye + White Clover |
Perennial Rye + Sainfoin |
Year 1 – All sites were established except CARA’s site at Oyen (due to drought conditions). Plans to re-establish this site in 2023 are underway.
Years 2 & 3 – Evaluate forage and grain production, take plant and soil measurements for nutrient analysis. Complete an economic analysis. Employ two masters students to assist with project analysis and evaluation.
Seeding
Seeding was completed on June 15. Seed treatment was applied on the cereals and an inoculant was applied on the legumes. PCGC monocultures were at 100% normal seeding rates, while the intercropping treatments were seeded at 100% PCGC and 50% legume. The seeding rate calculations were based on normal seeding rates for the various crop types provided in Table 43.
Table 43. Normal Seeding Rates
Crop Type | Plant Population (m2) |
Perennial Wheat | 320 |
Perennial Rye | 260 |
Alfalfa | 300 |
White Clover | 350 |
Sainfoin | 125 |
Seeding was completed in 6 rows with row spacing at 9” and plot size of 11.7 m2. The site was tilled and harrowed prior to seeding, allowing a uniform, shallow coverage of the seed and preventing the seedbed from drying out. Seed placement for the legumes was at 0.5” and for the cereals was 1”.
Fertility
A blended fertilizer of N-P-K-S was applied based on the fertilizer recommendations from soil reports obtained from conducting a composite soil sample. Fertilizer recommendations for grass-legume mixture was 56-35-21-10 lb/acre for an average yielding forage crop.
Spraying
At the Fairview site, Startup was applied at 0.67 L/acre on May 30 and Basagran Forte was applied on July 22 with a rate of 910 mL/acre. To reduce the volunteer canola from setting seed, the plots were mowed on August 22 at an increased height so as not to harm the vegetative undergrowth of the PCGC and cereal-legume mixtures.
Data Collection
Baseline infield measurements were taken for soil compaction, soil infiltration, soil temperature and moisture
Bi-weekly monitoring: NDVI, soil moisture and temperature. The four lowest readings (between 0.32 and 0.39) were measured in plots with perennial wheat, perhaps further indicating the slow establishment of perennial wheat at the Fairview site.
Establishment plant counts were conducted 30 days and 45 days after seeding. Same row seeding of perennial cereal with legumes provided very low to no plant counts of legumes. Generally, the plant counts decreased between the 30 day and 45-day count. This may have been due to plant mortality, lack of moisture and the cereals out-competing the legumes.
ACE-1 Rye
Mycorrhizal root colonization (MRC) samples were taken and submitted to AAFC for analysis.
2022 Field Observations
Four of the six group sites experienced similar difficulties with same row legume and perennial cereal establishment versus alternate row.
Kernza® wheat’s first year heading was evident in plot sites from all the project groups.
Overall, ACE-1 rye performed better than wheat for all project group sites.
Thicker leaves when both perennial cereal crops where tillering was evident on the ACE-1 rye. Kernza Wheat
Results
Plant Establishment Counts
To determine plant stand viability, plant establishment counts were conducted on 4 rows at 50 cm in length. These counts were conducted 45 days after seeding.
Table 44. Variations amongst project sites for top performing plant establishments
Top Performing Establishment (plants/ft2) | |||
Project Location | |||
PCBFA, Fairview | rye/clover (AR) | wheat/clover (AR) | wheat/alfalfa (AR) |
MARA, Fort Vermillion | rye/alfalfa (SR) | wheat/sainfoin (SR) | wheat/alfalfa (SR) |
GRO, Westlock | wheat/clover (AR) | rye/clover (AR) | rye/alfalfa (AR) |
BRRG, Forestburg | wheat/clover (SR) | rye/sainfoin (AR) | wheat/clover (AR) |
U of A, Breton | wheat/clover (AR) | rye/clover (AR) | wheat/alfalfa (AR) |
AR – alternate row seeding
SR – same row seeding
The plant counts observed for alternate row and same row seeded plots provided results where the same row seeded plots were generally less than the plant stands that were seeded in alternate rows. Alfalfa and clover were generally in the top 3 when interseeded with wheat or rye. Table 45 outlines the legume and cereal plant count percentages within each plot.
Table 45. Percentage of legume and cereal within each plant stand
Seeding Method | Crop Name | %Cereal | %Legume |
Mono | Rye | 100% | |
Wheat | 100% | ||
Same row | Rye-Clover | 98% | 2% |
Rye-Alfalfa | 91% | 9% | |
Rye-Sainfoin | 87% | 13% | |
Wheat-Clover | 96% | 4% | |
Wheat-Alfalfa | 93% | 7% | |
Wheat-Sainfoin | 94% | 6% | |
Alternate row | Rye-Clover | 44% | 56% |
Rye-Alfalfa | 60% | 40% | |
Rye-Sainfoin | 63% | 37% | |
Wheat-Clover | 54% | 46% | |
Wheat-Alfalfa | 61% | 39% | |
Wheat-Sainfoin | 67% | 33% |
Preliminary Metrics for Soil Biomass
Baseline data from bulk soil samples were analyzed at AAFC Lethbridge. DNA concentrations can be used as a preliminary metric of biomass in soils but the project groups will be considering a multitude of other parameters to determine beneficial microbial activity.
The highest DNA concentrations were observed at U of A, Breton and PCBFA plots while the lowest DNA concentrations are in Westlock. DNA concentrations below 10 ng/ul are generally considered problematic, suggesting that some Westlock samples may be difficult to sequence.
DNA quality is assessed through 260/280 ratios with optimal readings between 1.8 and 2.0. All sample averages were within this acceptable range with the lowest being 1.8 at the MARA site and the highest at GRO, Westlock and BRRG at 2.0.
The initial analysis is outlined for all groups in Figure 8.
Conclusion
Overall, the perennial rye proved to have good establishment with a lot of tillering for weed suppression potential. Same row seeded plots had less legume plant counts than alternate row plots. Although alternate row seeding may prove to be difficult to complete on-farm as seed drill implements are not designed for alternate row seed placement, the plant counts observed within small plots were generally higher for legume survivability.
Unseasonably hot and dry fall weather conditions may have impacted the perennial stands' continuation of establishment. Plant stands will be assessed in the spring of 2023.
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