Why is crop rotation considered a good agricultural practice?
Increase Soil Fertility
Get Better Nitrogen Use
Improve Soil Structure
Prevent Soil Erosion
Increase Crop Yields
Crop Rotation: a good agricultural practice
In Western Canada, "our natural mycorrhizal populations have been depleted. Reintroducing them gives other crops a chance to regain that value, access nutrients and water more efficiently, and reach their genetic potential,” mentions Craig Davidson, from Taurus Agricultural Marketing.
Watch the complete interview with Craig explaining canola rotation impact on plants and soil biology in Western Canada:
In this article, discover why crop rotation is important, and how adding the beneficial mycorrhizal inoculant is one of the key solutions!
1. Increase Soil Fertility
Soil is fertile when it provides all the favorable conditions for plant growth. One of these conditions is the balanced intake of nutrients. When the same crop is grown each year in a field, the soil runs out of essential nutrients for this crop type. Since each crop doesn't have the same nutrient requirements,crop rotation supports the use of different nutrients from year to year depending on the crop grown.
Each plant has its microbiological preferences (living organisms in the soil), so crop rotation allows better diversity of the microflora. On their side, mycorrhizae, with their hyphae, will provide carbohydrates (sugars) to beneficial soil microbes. In other words, mycorrhizae will deliver sunlight energy packaged as liquid carbon to a vast array of soil microbes involved in plant nutrition and disease suppression.1
2. Get Better Nitrogen Use
Incorporating a legume crop inside the rotation will improve the non-fertilizing nitrogen supply through its symbiosis with rhizobium-type bacteria. In addition, pea crops will put back a portion of nutrients, including nitrogen, in the soil for the next crop grown in the rotation.
"Pulses or legumes can fix up to 80 percent of the nitrogen they need from the air, which reduces the amount of nitrogen removed from the soil. […] Pulse or legume residue has a significant amount of nitrogen in it, which then will become available to future crops as it decomposes." 2
3. Improve Soil Structure
A good soil structure (arrangement of soil particles in various aggregates differing in shape, size, stability, and degree of adhesion to one another) is important for water and air infiltration and erosion control. Growing different species of plants in a rotation, each with distinct root systems, helps create a more varied and functional soil structure that supports better water infiltration.
4. Prevent Soil Erosion
Adding mycorrhizae will clearly improve soil quality by building a better soil structure. Knowing that 40 to 50% of the soil is made of pores (holes), it's great to know that mycorrhizal hyphae will create a path through this soil, and thus increase water infiltration. By allowing better interconnections between the soil pores, the micro-channels (tunnels) created by the mycorrhizal hyphae will also delay the formation of a water layer on the soil surface.
Listen to Adam Smith, from Taurus Agricultural Marketing, sharing his top solution when doing crop rotation:
5. Increase Crop Yields
Taken together, these four benefits help explain why crop rotation can contribute to improved yields and is considered a good agricultural practice. With that being said, concrete data are always the best to confirm the theory.
Manitoba Agriculture published in 2018 a complete and very informative table in The Manitoba Co-operator showing the Yield response of Manitoba crops sown on large fields of various previous crops (stubble) in rotation3
And what about AGTIV® mycorrhizae efficacy data?
AGTIV® inoculants help crops establish effective mycorrhizal colonization early in the season, supporting crop health and yield. Consult our Efficacy Report for all details and third-party reports.
While AGTIV® supports crop performance across different rotation systems, some situations highlight its value even more clearly. Canola stubble is one of them.
A Special Case in Crop Rotation: Canola Stubble
Growers and researchers have long observed that crops seeded after canola often deliver lower yields than crops seeded after other field crops. One of the key reasons lies in the relationship between canola and mycorrhizal fungi, which play an important role in plant nutrition and soil biology.
Unlike most field crops, canola (Brassica napus) does not form a symbiotic relationship with mycorrhizae. In fact, canola roots exude a toxic compound4 that actively reduces populations of these beneficial microorganisms in the soil. As a result, the next crop may start the season with lower mycorrhizal activity, limiting its early ability to access nutrients and water efficiently.
That delay can matter. In a study examining mycorrhizal development in corn following canola, Gavito and Miller5 found that it took 62 days for the mycorrhizae population to return to its pre-canola level. In Western Canada’s short growing season, that can represent a critical part of early crop development, especially when phosphorus uptake is essential to strong establishment and growth.
The Solution: AGTIV® Mycorrhizal Inoculant at Seeding
Adding AGTIV® mycorrhizal inoculant at seeding following a canola crop is a simple and effective tool to reintroduce beneficial soil biology at the start of the season.
Mycorrhizal hyphae extend beyond the root zone to explore a greater volume of soil and help the crop access more:
phosphorus (P)
copper (Cu)
zinc (Zn)
water
This added support can help the crop establish more efficiently and perform better under challenging conditions.
Be sure to AGTIV-ate your crops
Increasing soil fertility, improving soil structure and preventing soil erosion are just some of the reasons to include AGTIV® mycorrhizal inoculant in your crop rotation farming practices.
Growing canola? Have a look at the Canola Council tips and details to help you plan your canola rotation.
Sources: 1 Jones, C. E. 2014. Nitrogen: the double-edge sword. Amazing Carbon. pp. 8. 2 Phelps, S. 2017. Crop rotations: 8 things to consider. https://www.topcropmanager.com/crop-rotation-considerations-11370/ 3 Kubinec Anastasia, Manitoba Agriculture. 2018. Building a ‘better’ crop rotation Understand all the interactions within a rotation and their effect on yield. The Manitoba Co-operator. https://masc.mb.ca/masc.nsf/mmpp_crop_rotations_2010_2016.pdf
4 Ryan, M. H. (2001). The effect of Brassica crops on the level of mycorrhizal inoculum in soil. Proceedings of the Australian Society of Agronomy.
5 Gavito, M. E. and M. H. Miller, 1998. Changes in mycorrhizal development in maize induced by crop management practices. Plant Soil. 198: 185–192.
