Digging up the truth about soil health

When the Soil Conservation Council of Canada challenged everybody to ‘soil your undies’, the move sparked a lot of interest as farmers and gardeners buried clean underwear in the soil and then dug them up 2 months later to assess soil health. Those whose soils were healthy dug up little else besides elastic waistbands, while those with unhealthy soils dug up dirty but intact underwear. You could say that’s the soil health story in briefs.

The soil is not a lifeless mixture of sand, silt and clay. It is a living system buzzing with billions of bacteria, fungi, and other micro and macro organisms that are critical to the soil’s functions of providing and recycling nutrients for plant growth, detoxifying pollutants, retaining water for use during drier periods, and serving as a firm structure for agricultural activities. Soil health has been concisely defined as the continued capacity of the soil to function as a vital living system that sustains plants, animals and humans. Two elements in this definition are key. First, ”the continued capacity of” reflects the soil’s resilience and ability to regenerate and function well for future generations. Second, recognition of soil “as a vital living system” highlights the importance of soil biota.

The role of soil biota in the soil system was largely neglected in the past because it was poorly understood and difficult to measure. Today, however, with advanced analytical techniques, soil biota can be better studied, and its importance in the sustenance of life is gradually taking center stage.

So, how can we improve soil health? Research has shown that reducing the level of soil disturbance, diversifying the species of plants grown, keeping the soil covered all the time, keeping living plants in the soil as often as possible, and adding organic or biological soil amendments all have beneficial effects on soil health.

Recent studies warning that we are losing topsoil a lot faster than it can be replenished through natural processes should indeed make us pay attention and stop treating soil like dirt. And by the way, if you want to ‘soil your undies’ this year, now is a great time to start.  You can find the protocol for the experiment here: http://www.soilcc.ca/soilyourundies/2017/Soil-Your-Undies-Protocol.pdf

-Ikenna Mbakwe, PhD, PAg
Head of Research
SynergyAG

 

The rise and rise of biological seed treatment

When treating seeds with biological organisms was first suggested many years ago, the idea seemed like something out of a sci-fi comic book. But today, just like how these organisms proliferate in plant systems, the idea has proliferated in the R&D departments of top agricultural companies as research scientists join the race to find the best ways to unleash the powers of these microscopic creatures. Indeed, the future of agriculture is looking more likely to be defined not necessarily by huge machinery, massive satellites and big data, but by the tiny organisms whose potentials we are just beginning to unmask.

There are billions of microbes in the soil around plant roots. Some are friends, some are enemies. The person who said ‘Keep your friends close, and your enemies closer’ wasn’t talking about crop production… not literally anyway. In farming, you’d want to keep your friends close and your enemies far, far away. Keeping the very beneficial soil microbes close is key, and forms the core of biological seed treatment.

But how do these beneficial organisms work? Farmers all over the world are familiar with Rhizobia used to inoculate legumes such as soybean, peas and lentils. These bacteria were discovered more than a century ago. When applied on seeds of legumes, the bacteria penetrate the root, resulting in the formation of root nodules that fix nitrogen from the air and make it readily available to the plant. Another bacterium, Azospirillum brasilense, in addition to fixing nitrogen, also produces plant hormones which help important plant processes such as germination, stem elongation, flower development and leaf and fruit senescence. Penicillium bilaiae, a naturally-occurring soil fungus excretes organic acids that solubilize phosphorus tied up in the soil, making the nutrient available for uptake by plant roots.  Some biological seed treatments also contain natural compounds which encourage the colonization of roots by mycorrhizal fungi thereby increasing the surface area of roots and enabling them take up more water and nutrients. There is indeed, a wide range of biologicals and at SynergyAG we are committed to ensuring that growers use the products best suited to their needs.

Science has shown that seed treatments are advantageous. The return on investment will be more apparent when growing conditions are poor. For example, if a treatment is designed to help seeds thrive during periods of moisture stress, its efficacy cannot be assessed if the soil is sufficiently moist. However, treating seeds offers insurance against unexpected crop challenges or when the weather throws us a curve ball – which seems to happen far too often these days.

-Ikenna Mbakwe, PhD, PAg
Head of Research
SynergyAG

Staying ahead of the game – Why seed treatment is vital for a successful cropping season

If seeds could talk, they’d probably tell you they agree with Mike Tyson when he said ‘everyone has a plan until they get punched in the mouth’. Every seed has a plan – a plan to push roots down, send shoot up and yield a bumper crop. That plan is the seed’s genetic yield potential. But a seed hardly actualizes its plan.  As soon as you put that seed in the ground, it gets…well, sort of punched in the mouth by a host of soil and environmental conditions. That is why protecting your seeds is definitely one of the best decisions you’d make early in the season.

The International Seed Federation describes seed treatment as the ‘biological, physical and chemical agents and techniques applied to seed to provide protection and improve the establishment of healthy crops’. The practice of seed treatment is very old. One of the earliest references is around 470 B.C. when Pliny proposed that seeds be soaked in wine plus a mixture of bruised cypress leaves to protect them from wheat mildew. I imagine it must have been a sweet proposition (for the treater), but these early methods were crude and coverage was poor. Today, modern seed treatment facilities use sophisticated and precise equipment to coat seeds with a host of active ingredients. Seed treatments can include protectants, nutrients and biologicals.

Treated wheat seeds

Protectants (such as pesticides, fungicides, insecticides, and predator deterrents) are designed to guard seeds from predation and infection by pathogens.  Applying these products directly to the seed is much more efficient and effective than broadcasting crop protection products. Moreover, using protectants in seed treatments is an environmentally more friendly way of using pesticides because the amounts used are very small. Nutrient amendments used in seed treatment have mainly focused on adding micronutrients, such as zinc, boron, manganese, copper, and molybdenum – important nutrients which can easily become deficient because they are often neglected in many fertilizer programs. Treatment with biologicals can deliver natural compounds or microorganisms which proliferate on the seeds, transfer to the root, protect against soil-borne pathogens, and enhance uptake of nutrients. They can also stimulate plants’ natural biological processes to help them cope with abiotic stresses such as cold, heat, drought and salinity.

Studies evaluating seed treatments have shown positive effect on germination, growth, and yield but it is important to use the right product and technique to achieve full coverage when treating seeds. Incomplete coverage will leave some of the crop unprotected, and reduce the effectiveness of the process.

The full potential of crops lies in the seed. Giving a seed every chance to reach that potential starts with a good seed treatment. Be sure to talk to your local SynergyAG rep about the right option for your needs.

 

-Ikenna Mbakwe, PhD, PAg
Head of Research
SynergyAG

 

 

Don’t Let Your Crops Feel ‘Asalted’ – What to Know About Fertilizer Salt Index

Fertilizers are great for boosting crop yield but when someone tries to convince me to add loads of a particular fertilizer to my soil, I take what they say with a pinch of salt. That’s because fertilizers are mostly salts. When they dissolve in soil water, they increase the salt concentration (also called osmotic pressure) of the soil solution. The higher the osmotic pressure of the soil solution, the more difficult it is for plants or seeds to extract the water they need for normal growth.

The fundamental principle is that for plant roots to take in water, the water must pass through the root cell membrane. Water can pass through this membrane only when the osmotic pressure of the solution inside the plant cell is higher than the osmotic pressure of the soil solution outside the cell. If the osmotic pressure of the soil solution becomes higher than that of the solution inside the cell, water cannot enter the cell and may eventually move out of it. With time, the plant tissue dries out and eventually dies. Some people call this phenomenon ‘fertilizer burn’.

Fertilizers differ in their propensity to create salty conditions in the soil. I dare to say that the brilliant scientist who developed the concept of ‘salt index’ to differentiate fertilizers was definitely worth their salt. Salt index is a measure of a fertilizer’s relative tendency to increase the osmotic pressure of the soil solution as compared with the increase caused by an equal weight of sodium nitrate. All fertilizers are compared to sodium nitrate because sodium nitrate is 100% water soluble and it was commonly used when the concept of salt index was developed. A fertilizer with a high salt index has a high tendency to damage crops compared to a fertilizer with a lower salt index. But salt index alone does not predict the amount of material that will cause injury to crops. It only classifies fertilizers relative to each other and shows which is most likely to cause injury.

 

It’s important to note that crops vary in their tolerance to fertilizer salts. Moreover, salt toxicity will be more serious in dry soils (because there is less water to dilute the salts), in coarse-textured soils like sandy soils (because of their low ability to react with the fertilizers), and in cold soils (because root growth in cold soil is slow and thus the root is exposed to the higher concentration of fertilizer for a longer time). Furthermore, the risk of injury is higher where fertilizer is banded close to seed or plants.

So, if your soil or plants are showing signs of nutrient deficiencies, there’s no need to ‘rub salt in the wound’. Talk to your local SynergyAG representative for guidance on the right products and agronomic techniques.

-Ikenna Mbakwe, PhD, PAg
Head of Research
SynergyAG