Maize roots enhance wheat yields through chemical Influence

Aug 14, 2023

Unlocking Maize's Secret to Wheat Growth

Researchers from the University of Bern have uncovered a fascinating link between maize and wheat yields through their recent study. Maize plants secrete unique chemicals from their roots that influence the quality of soil. These chemicals, known as benzoxazinoids, have the remarkable ability to increase wheat yields by over 4% in fields where wheat follows maize cultivation. Although the effects are variable, this discovery holds promise for sustainable grain farming without the need for extra fertilizers or pesticides.

Agricultural Chemistry and Soil Enhancement

Plants release a variety of special chemicals into the soil that can alter its properties. The Institute of Plant Sciences (IPS) at the University of Bern conducted field experiments to explore the potential of utilizing these excreted chemicals for improved agricultural productivity. Their findings, published in the journal eLife, reveal that maize root metabolites can indeed boost wheat yields under real-world farming conditions.

The Power of Benzoxazinoids

Earlier studies had shown that benzoxazinoids released by maize roots influence the soil's microbial composition and subsequently affect the growth of following plants. Recent research aimed to determine if these plant-soil interactions hold true in practical agricultural settings. Through a two-year field experiment, maize lines were cultivated, with only one-line releasing benzoxazinoids into the soil. Subsequent wheat crops were then grown on these differently conditioned soils, demonstrating improved germination, tillering, growth, and yield.

Promising Implications for Sustainable Farming

Beyond yield enhancement, the study also observed reduced pest infestations in the treated fields. While a 4% yield increase might not seem substantial, considering the challenges in boosting wheat yields, it is indeed a significant step. The researchers, led by Professor Matthias Erb from the Institute of Plant Sciences and Klaus Schläppi from the University of Basel, acknowledge that the study's broader impact on overall agricultural productivity and sustainability needs further exploration.

Valentin Gfeller, who contributed to the study as a doctoral student at IPS, emphasizes the potential of utilizing specialized plant compounds like benzoxazinoids to enhance crop productivity through targeted rotations. Additionally, the study found no negative impact on wheat grain quality due to the increased harvest.

Sowing the Seeds of Sustainable Agriculture

The research sheds light on the intricate relationship between maize root chemicals, soil, and subsequent wheat growth. The persistent presence of benzoxazinoids in the soil highlights the potential for long-term benefits. Further investigations will delve into the indirect effects of these chemicals on wheat growth through soil microorganisms.

As soil properties play a pivotal role, additional experiments explored how these interactions vary in heterogeneous fields. This insight contributes to understanding the effects of soil properties on plant-soil feedbacks, a crucial step towards sustainable agriculture.

Video: Turning Plant Defense Into a Management Strategy

Turning Plant Defense Into a Management Strategy

Understanding how a plant responds to stress is one thing.

Using that knowledge to make better management decisions is another.

Systemic acquired resistance, or SAR, is the plant's more direct defense response. When stress or infection occurs, the plant begins signaling throughout its system and preparing defensive compounds.

But if we know that response exists, can we help prepare the plant before the stress arrives?

The answer starts with understanding what triggers the response and what the plant needs to carry it out.

The Trigger and the Fuel

Salicylic acid plays an important role in triggering the SAR pathway.

Think of it as turning the truck on.

The engine may be running, but it still needs fuel to do the work.

In this case, manganese plays an important role in supporting the enzyme systems involved in the plant's defensive response.

This makes manganese status an important part of the conversation. Whether a producer is using tissue testing, sap analysis, or simply scouting for visible deficiency symptoms, the goal is to make sure the plant has adequate manganese available.

Manganese is required in relatively small amounts, but that does not make its role small.

If the plant receives a signal to defend itself but lacks the nutrition needed to support that response, it may struggle to carry out the process efficiently.

The trigger matters.

The fuel matters too.

Prepare Before the Stress Arrives

The best time to think about stress management is before the plant is overwhelmed.

Once a crop is already struggling, management can quickly turn into a game of catch-up.

This is similar to nitrogen management. Once a plant becomes severely deficient, correcting the problem does not necessarily erase the time and yield potential already lost.

Plant defense can work the same way.

Low-rate, targeted approaches designed to support the SAR pathway may fit best ahead of an expected stress event rather than after significant damage has already occurred.

That requires producers to think about predictable stress.

We may not know exactly what the weather will do tomorrow, but we generally know summer heat is coming. We know certain field conditions increase disease pressure. We know a herbicide application can temporarily stress a crop as the plant processes the chemistry.

Even a properly timed and labeled herbicide application can create a temporary response in the plant.

That does not mean the herbicide is bad.

Weeds can create significantly more yield loss than the temporary stress caused by controlling them.

The question is not whether we should eliminate every stressor.

The question is whether we can better prepare the plant to manage necessary and predictable stress.

Not All Stress Is Bad

Stress is a normal part of plant growth.

A perfectly stress-free environment does not exist in the field.

In fact, some stress is necessary for normal plant development. A plant responds to wind, temperature, moisture, sunlight, and countless other environmental signals throughout the season.

The environment is stress.

The plant's job is to manage it.

Problems begin when the stress load becomes greater than the plant's ability to respond.

Extreme heat, drought, high salt concentrations, disease pressure, and even certain management practices can add to that load.

This is where understanding SAR becomes useful.

Instead of waiting until the plant is visibly struggling, producers can begin identifying periods when stress is likely and make management decisions around those windows.

ISR Starts With the Soil

While SAR is a more direct defense response, induced systemic resistance, or ISR, brings the conversation back to soil health.

The longevity of a farm is closely connected to the health of its soil.

Carbon plays a major role because it supports biological life within the soil. Bacteria, fungi, and other organisms interact with plant roots and influence how the plant grows, accesses nutrients, and prepares for stress.

This is why soil health cannot be reduced to one product or one application.

It is a system.

Keeping living plants in the field longer can support biological activity. Cover crops may fit some operations. Better water management can improve soil conditions.