Fighting Kochia in Saline & Marginal Areas

By Tatum Adair

Farming Smarter’s Field Tested crew adds to the integrated weed management conversation with a new three-year kochia salinity study.

The study tests 10 common integrated weed management strategies to control herbicide-resistant kochia in marginal, saline areas. The team, led by Lewis Baarda, works directly with commercial farmers to evaluate the performance of each strategy and fill the knowledge gap of kochia management in the areas where it thrives.

Undertaking a new trial requires rigorous planning and significant preparation to ensure consistency in the results. A key component of this planning is implementing a research design that is replicated and randomized. Small-plot trials are heavily relied upon in agricultural research as they minimize variability from uncontrollable factors -- like weather and soil.  

The 10 experimental factors (treatments) in this trial are replicated four times across four rows (replicates) (See photo 1). These factors are then arranged in a unique random order in each replicate. This ensures that the inconsistent weed pressure will not have a systematic impact on the trial’s results.  

Additionally, the research design must determine the size of the trial. Its plots must be large enough to meaningfully capture the existing weed populations since no weed seed was introduced. Plot sizes were standardized to 6x6-metres to allow for enough weed presence to be studied at each site in this project. 

Furthermore, the pathways need ample room to allow for equipment maneuverability since certain treatments require mowing or tillage. A secondary mechanic of pathways is to ensure treatments are separated enough they do not influence each other. 

Once the research design is complete, two things must still occur before trial execution can begin: seeding preparation and location selection.  

Seeding preparation includes calibrating equipment and calculating different seeding rates for each crop. This year, three crops will be evaluated for their competitiveness with kochia – Saltlander, a salt-tolerant grass; ESMA Barley, a salt-tolerant annual crop; and Oakman Spring Wheat. Wheat will be tested at a normal seeding rate of 300 seeds/m2 and a double seeding rate. Barley is seeded at a normal seeding rate of 300 seeds/m2 and Saltlander is seeded at 15-20 lbs/ac. 

Lentils and canola will replace wheat in the study over the next two years, respectively. 

Locations were selected based on their applicability to the trial criteria – the presence of kochia patches in saline and low-lying regions. Farming Smarter is partnering with four different farmers to develop site-specific guidelines for kochia management.  

Ultimately, the success of the trial is still dependent on the farmers – in their partnership, interest, and willingness to prioritize the integrity of the trial amid all their other commitments. 

For Farming Smarter, a successful trial is one that provides farmers with easily applicable knowledge. While there is undoubtedly a large amount of work required to successfully maintain a trial – from seeding, applying treatments or weeding – a lot of the work begins before data collection ever begins.