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2027 Product Guide
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Products
39 readable product entriesproduct
ACTIVE PRIME
Seed nutrient dressing analysis, directions, compatibility matrix, multi-year yield, germination, disease-reduction and vigour tables reconstructed from printed pages 37–41.
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ACTIVE PRIME DRY
EARLY ROOT SUPPORT Delivers micronutrients at planting to support strong root establishment.
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ACTIVE PLS
Supplies seeds with essential micronutrients and trace elements to improve germination rates.
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STABILIZER PLUS
SLOWS DOWN THE N CYCLE Inhibits nitrogen loss processes, keeping nitrogen available to plants longer.
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ARM U 18% NBPT
BEST INDUSTRY VOLATILIZATION PRODUCT Leads the industry in preventing nitrogen loss via ammonia volatilization.
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ARM U 30% NBPT
BEST FOR HIGH NITROGEN LOSS SITUATIONS High concentration of NBPT is effective with high pH soils and low moisture.
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ARM U 15% DMPP
SLOWS DOWN THE N CYCLE Slows the conversion of ammonium to nitrate, enhancing the efficiency of nitrogen fertilizers.
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ARM UAN
ARM UAN is a dual-action nitrogen stabilizer engineered for UAN. It protects against both above-ground and below-ground nitrogen losses by slowing urea hydrolysis and inhibiting microbial conversion of ammonium to nitrate. With ARM UAN, more of your applied ni…
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FERTILITY
Our granular fertility portfolio is built around seed safety, low salt, nutrient efficiency, and measured nutrient release, giving the crop access to nutrition as it grows rather than delivering a large concentration of soluble nutrients to the soil all at onc…
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TSN
With TSN, you’re not applying more, you’re applying agronomics that your accountant can get behind:
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TAPP 2X
Taurus Ag Poly Phosphate (TAPP) 2X is a unique source of seed safe essential plant nutrients.
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About OSTARA
Conventional phosphorus fertilizers can quickly become tied up in the soil after application, reducing efficiency and increasing nutrient losses. Crystal Green™ uses a purified, root-activated form of phosphorus that releases nutrients only in the presence of…
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CG P2X
APPLY LESS, GET MORE – Twice the efficiency of MAP allows you to cut your phosphorus rates without sacrificing yield.
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CG SYNCHRO 50 MAX
STEADY RELEASE PATTERN – Reduces the risk of early tie-up and ensures phosphate is available across critical growth stages.
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CG PEARL
Crystal Green Pearl analysis, physical/logistics properties, manufacturing description and three Pearl-versus-MAP trial cards reconstructed from printed pages 83–84.
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About ICL
Agronomic Advantage. Logistical Simplicity. Cost Effective for Broad-Acre.
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POLYSULPHATE®
A naturally plant-available, gradual release fertilizer with S, K, Mg and Ca
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POLYSULPHATE PREMIUM®
Four-nutrient Polysulphate Premium analysis, handling properties and source-described product positioning reconstructed from printed page 87.
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ICL PKPLUS®
The power of Polysulphate with a boost of P for season-long nutrition.
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ABOUT SUL4R-PLUS®
• HANDLING CHARACTERISTICS Great handling, blending and storage qualities with a dust free design.
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SUL4R-PLUS®
Traditional fertilizers can release nutrients too quickly, leading to inefficiencies, soil acidification, and handling challenges. SUL4R-PLUS® uses patented calcium-sulfate technology to provide extended-release sulfur and calcium in a durable, low-salt pellet…
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PEA & LENTIL
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 2750 viable spores/g
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SOYBEAN
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 2750 viable spores/g
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CHICKPEA
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 2750 viable spores/g
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CANOLA-CORN-CEREAL
SERENDIPITA – PTB299 Technology Serendipita indica: 2 x 106 viable spores/g
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FERTILIZER ADDITIVE
BACTERIA – PTB101 Technology Bacillus velezensis: 5 x 108 viable spores/g
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FIELD CROPS
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 8000 viable spores/g
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SPECIALTY CROPS
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 178 viable spores/g
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POTATO
MYCORRHIZAE – PTB297 Technology Rhizophagus irregularis: 10 500 viable spores/g
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Active BUILD
DRIVES ROOT GROWTH Provides essential nutrients for young plants to establish strong, healthy root systems.
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Active VPR PLUS
TAILORED FOR PULSE CROPS Formula customized for peas, soybeans, and other dry edible beans.
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ACTIVE GFB
ENHANCED FLOWERING High boron promotes nutrient movement and healthy flowering.
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ACTIVE PODFILL X
EXTENDS POLLINATION Extends the pollination window giving plants a greater opportunity for successful fertilization.
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Active KONNECT
ENHANCED FRUIT & GRAIN GROWTH Supports fruit, grain, and nut growth, improving yield and size.
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Proform N
DUAL-ACTION NITROGEN Delivers both quick and slow-release nitrogen for steady, balanced nutrition.
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ACTIVE MICROMATRIX
STRONGER ROOT GROWTH IBA aids cell division and expansion, enhancing root initiation and growth.
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Micronutrients
Rapid Rapid correction correction of in-season of in-season nutrient deficiencies nutrient deficiencies.
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EDTA Micros
Optimized for Optimized for starter starter and and liquid fertilizer liquid fertilizer blends. blends.
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Cal-Mag-Bor
Five Cal-Mag-Bor formulations and their separate nutrient analyses reconstructed from printed page 167.
Independent agronomy articles
98 panels split at the gold divideragronomy
GERMINATION TRIO
A dormant seed needs three things to wake up: water to swell and activate it, oxygen to power respiration, and warmth to drive the process. Waterlogged soil is a common trap, it drives out oxygen, so a moist but not saturated seedbed germinates best.
agronomy
COLD LIMITS
Seeds won’t start growing until soil at seeding depth hits a minimum temperature, and it differs by crop. Cool-season Prairie crops (barley, wheat, peas, canola) start at 3-5C; warm-season crops (corn, soybeans, beans) need about 10C. Plant colder than the crop’s limit and emergence is slow and patchy.
agronomy
SHALLOW SEEDING
Small seeds carry little stored energy, so a seed placed too deep can run out of fuel before the shoot reaches the surface. In an AAFC study, canola emergence under moist soil nearly doubled at 1 cm versus 4 cm. Shallow, uniform placement into moisture gives faster, more even emergence.
agronomy
FERTILIZER BURN
Fertilizer placed right with the seed can injure it, especially in dry soil. Salts and ammonia pull moisture away from the germinating seed and can damage the seedling, thinning the stand. Risk climbs when soil is dry, rates are high, and seed and fertilizer are concentrated in a narrow band.
agronomy
FEED FIRST ROOTS
Phosphorus barely moves in soil, so a tiny seedling with a small root system can struggle to reach enough, even where soil tests high. A little phosphorus near the seed row gives young roots easy access and vigorous early growth. It matters most in cold, wet soils where roots grow slowly.
agronomy
BIGGER SEED
Larger seed carries bigger cotyledons and more stored energy, giving seedlings a faster start and steadier emergence. But bigger seed also means fewer seeds per pound, so the same seeding weight puts fewer seeds in the ground. Size boosts vigor, but it doesn’t replace a real seeding rate calculation.
agronomy
SEED BY COUNT
A pound of seed can hold very different seed counts depending on thousand kernel weight (TKW). Setting a seeding rate means combining TKW with germination percentage and expected survival to hit a target plant stand, not just a flat weight per acre. Without those calculations, differences in seed size can lead to underseeding or overseeding.
agronomy
FREE NITROGEN
Legumes such as peas, lentils and beans partner with Rhizobium bacteria in root nodules that turn nitrogen from the air into a form the plant can use. The bacteria barely move in soil, so inoculant must contact the seed or seed row. Each legume needs its matching type; nodules form within about three weeks.
agronomy
PLANT ON TIME
Many crops have a best planting window, and yield potential slips a little for each day past it. In corn, roughly 0.3%/day in early May, rising to about 1%/day by mid-May. Planting date matters, but it’s only one of many yield factors, so mudding in a crop just to beat the calendar usually backfires.
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EVEN BEATS UNEVEN
When some plants come up days late, bigger early neighbors shade and out-compete them, leaving low-yielding runts. In corn, if half or more of the stand emerges three weeks late, replanting an even stand can lift yield up to about 10%. Even emergence comes from uniform depth, good seed-to-soil contact, and steady moisture.
agronomy
FIRM THE SEEDBED
Seeds pull most of their water as vapor, not liquid. Soil air stays near 100% humidity across almost any moisture level you’ll plant into. What actually slows emergence is distance: loose, cloddy soil and air pockets widen the gap vapor has to cross to reach the seed. Firming the seedbed closes that gap and holds humidity in the seed zone.
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THE FIRST DRINK
In the first hours after planting a seed rapidly soaks up water, a step called imbibition. Good moisture lets this happen fast and evenly, which lowers the chance of chilling injury in cold soils. That’s why corn and soybeans are safest once soil at seed depth is about 10C (50F) with moisture present.
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COLD LOCKS P
Phosphorus barely moves in cold soil, and roots take it up slowly until soils warm past roughly 12 to 15C. Since Prairie crops are often seeded into cold spring ground, seedlings can go short of P right when they need it for early root and shoot growth. A small amount of readily available starter phosphate near the seed bridges that gap.
agronomy
HOW LIME WORKS
Ag lime is finely ground limestone (mostly calcium carbonate) that neutralizes acidity: the carbonate reacts with acidic hydrogen ions to form CO2 and water, raising pH. It dissolves slowly, months to start, years to fully react, and finer grinds act faster. Dolomitic lime also supplies magnesium.
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P PEAKS NEUTRAL
The guide says phosphorus is most available around pH 6.0 to 7.5 and that availability falls below about pH 5.5 as phosphorus becomes tied up and root growth is restricted. Its cited USDA-NRCS source supports that qualitative pH range and decline, but it does not provide the quantitative percentage curve shown in the guide; treat that graph as the guide’s illustration rather than source data. Liming decisions should follow a soil test and local agronomic guidance.
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METALS LOVE ACID
Most micronutrients behave opposite to what you’d expect. Iron, manganese, zinc, copper and boron become more available as soil turns acidic and less as pH climbs; molybdenum does the reverse. For the metals the effect is dramatic, availability can fall ~100-fold per one-unit pH rise, so high-pH fields can show deficiency even when the nutrient is present.
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TWO P TRAPS
Phosphorus gets locked up at both ends of the pH scale, by different culprits. In acid soils, iron and aluminum bind it into insoluble compounds; in alkaline or calcareous soils, calcium does. That’s why availability peaks in the middle, and why just adding more P to a very acid or calcareous field is inefficient without managing pH and placement.
agronomy
LIME RATES VARY
Two fields at the same pH can need very different amounts of lime, because soil holds a hidden reserve acidity that resists change. Clay-rich and high-organic-matter soils have a large reserve and need much more lime; sandy soils change fast but re-acidify sooner. That’s why labs run a separate buffer-pH test to set the rate.
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WHAT CEC MEANS
Cation exchange capacity (CEC) is the soil’s ability to hold positively charged nutrients, calcium, magnesium, potassium, on clay and organic matter surfaces, keeping them available instead of leaching away. It’s reported in meq/100g. Sandy soils are low (~1-5); clay-or organic-rich soils are much higher (~20-40+).
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CLAY & HUMUS
A soil’s CEC comes almost entirely from clay minerals and organic matter, both carry negative charges that grab positively charged nutrients. Organic matter has a very high charge per unit weight, so building it (and having more clay) raises CEC. Low-CEC sandy soils leach easily, which is why lighter soils benefit from smaller, split applications.
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BASE SATURATION
Base saturation is the share of a soil’s CEC occupied by base cations, calcium, magnesium, potassium and sodium. The rest is held by acidic cations (hydrogen and aluminum), so base saturation tends to rise as pH rises. A base saturation of 75% means three of every four exchange sites are filled by base cations.
agronomy
THE RATIO MYTH
Some soil-balancing programs claim a fixed ideal ratio of calcium to magnesium to potassium is needed for top yields. Peer-reviewed reviews don’t support this: within ranges normally found in soils, yield generally isn’t controlled by the ratio. What matters is that each nutrient is present in sufficient amount. Chasing a ratio often means buying inputs the crop doesn’t need.
agronomy
THE SALT INDEX
The salt index measures how much a fertilizer raises the salt concentration of the soil solution, compared with sodium nitrate set at 100. Highly soluble sources (some N and K fertilizers) tend to run higher; phosphates like MAP are lower. A high salt index near the seed can pull water away from seedlings and cause fertilizer burn.
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SAFE SEED RATES
Too much fertilizer with the seed can injure or kill seedlings through ammonia and salt effects, cutting your stand. Safe rates depend on crop, source, soil moisture, and how widely seed and fertilizer are spread. On the Prairies canola is far more sensitive than cereals, roughly 20 lb/ac seed-placed phosphate for canola versus 50 for cereals.
agronomy
MEASURING SALT
Electrical conductivity (EC) measures how well soil solution carries a current, which rises as dissolved salts increase, a direct read on salinity, reported in dS/m. By the common standard a soil is saline at 2 dS/m or more. High salt makes it harder for roots to pull in water, stressing crops even when moisture is present.
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SODIUM DAMAGE
Sodicity is a sodium problem, not just a salt problem. It’s measured by exchangeable sodium percentage (ESP) or sodium adsorption ratio (SAR); soil is generally sodic at ESP ~15+. Too much sodium makes clay disperse, destroying structure and creating dense, crusted, poorly draining soil. Unlike a saline soil, a sodic soil’s main damage is physical.
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THE VITAL 5%
Organic matter is usually just a few percent of soil by weight, but it punches far above that. It releases nutrients as it breaks down, binds particles into crumbs that resist erosion, improves water infiltration and holding capacity, and feeds the organisms that keep soil functioning.
agronomy
A NUTRIENT BANK
Soil organic matter is roughly half carbon and about 5% nitrogen by weight, with a carbon-to-nitrogen ratio near 10:1, and it holds most of the soil’s reserve sulfur. Because these nutrients are locked in organic form, microbes release them slowly as they decompose the material: a steady trickle rather than a quick dose.
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BUILD IT SLOWLY
Organic matter rises when you return more carbon than is lost, through residue, cover crops, forages in rotation, reduced tillage and manure. The catch is time: it can take around 20 years of good management to raise organic matter by one percentage point. The goal is steady maintenance and gradual gain, not a quick fix.
agronomy
TAURUS FERTILITY
Traditional fertilizer programs can deliver a large nutrient flush early in the season, followed by a rapid decline. Taurus fertility technologies are designed to promote a more balanced release pattern, helping maintain nutrient availability during key growth stages and supporting season-long crop performance. Go to page 7 in the Agronomy section to compare salt content in fertilizers.
agronomy
pH SETS THE TABLE
Soil pH controls how easily nutrients dissolve into the soil water where roots can reach them. Drift too low or too high and nutrients lock into forms plants can’t absorb, so a fertilized field can still show hidden deficiencies. Most nutrients are most available from slightly acidic to neutral.
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AIM SIX TO SEVEN
There’s no single perfect pH, but most field crops take up what they need at roughly pH 6.0 to 7.5. A few differ: potatoes tolerate more acidic soil (~5.5), while alfalfa prefers the upper end (6.5+). A soil test tells you where a field sits.
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SAND, SILT, CLAY
Soil texture describes the proportion of three mineral particle sizes. Sand is largest (0.05-2.0 mm) and feels gritty; silt is medium (0.002-0.05 mm) and feels smooth; clay is smallest (under 0.002 mm) and feels sticky when wet. Texture is set by the parent material and doesn’t change with management.
agronomy
READING TEXTURE
Because the three particle percentages always add to 100%, any soil can be plotted on a triangular chart to find its class. You read percent sand, silt and clay along the three sides; where they cross names one of 12 classes, from sand to clay, with loams in the middle. Loams are prized for blending the strengths of all three.
agronomy
LOAM WINS WATER
Sandy soils drain fast and hold little water for plants. Clay soils hold a large total amount but grip much of it too tightly for roots to pull out. Medium-textured soils like loams and silt loams strike the best balance, holding the most water plants can actually use.
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CRUMBS BREATHE
Aggregates are small clumps where sand, silt, clay and organic matter are glued together by roots, fungal threads and microbial secretions. The spaces between and within them let water soak in, air reach roots, and roots grow freely. Well-aggregated soil resists erosion and crusting; compacted soil chokes off water and air.
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COMPACTION
Compaction from equipment or livestock, especially on wet soil, packs particles together and raises bulk density (dry soil weight per unit volume). Past a threshold, roots can no longer push through, cutting off water and nutrient uptake and lowering yield. That threshold is lower for clay-rich soils than for sandy ones.
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USABLE WATER
After soil is soaked and free water drains by gravity, the moisture left is field capacity, the full tank. As plants and evaporation draw it down they reach the permanent wilting point, where the rest is held too tightly for roots. The water between those two points is the plant-available water, the part farmers manage.
agronomy
GETTING RAIN IN
Infiltration is how fast water enters the soil surface, usually in inches per hour. Coarse sandy soils take water quickly through large pores; dense or crusted clay soils take it slowly. Good structure, surface residue and higher organic matter all speed infiltration, bare ground, crusting and compaction slow it and send water off as runoff.
agronomy
THE 4RS
4R Nutrient Stewardship is a science-based framework for managing fertilizer: the Right Source at the Right Rate, the Right Time, and in the Right Place. The goal is to match nutrient supply to what the crop needs while protecting air and water. It’s site-specific, so the right choices change from field to field.
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MOVE OR STAY
Nutrients travel through soil at very different speeds. Nitrate is highly mobile and moves with soil water, so it can leach below the root zone in wet conditions. Phosphate is nearly immobile, it binds tightly to soil minerals and stays put, while potassium sits in between, held on soil but somewhat leachable in sandy, low-CEC soils.
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RELEASE & TIE-UP
Soil organic matter is a big nitrogen reservoir, but plants can’t use it directly. Mineralization is when soil microbes break down organic N and release plant-available ammonium. Immobilization is the reverse, microbes tie up available N as they decompose high-carbon residues like straw, temporarily making it unavailable to the crop.
agronomy
HOW N IS LOST
Once nitrogen is in the soil, several processes move it out of reach. Nitrification converts ammonium to nitrate, which is plant-available but leachable. Denitrification turns nitrate into nitrogen gases in waterlogged soils, and volatilization releases ammonia gas from surface-applied urea or manure that isn’t incorporated.
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SULFUR LEACHES
Plants take up sulfur mainly as sulfate, which behaves much like nitrate: mobile and able to leach below the root zone, especially in sandy, low-organic-matter soils. Sulfur deficiency has grown as atmospheric sulfur deposition has declined. On the Prairies, canola has a high sulfur demand and is very sensitive to shortages.
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EIGHT MICROS
Plants need eight micronutrients in very small quantities: iron, manganese, zinc, copper, boron, molybdenum, chlorine and nickel. Micro refers to the amount, not the importance, a shortage of any one can limit yield. For scouting: chlorine and molybdenum move readily (deficiency in old leaves), while the others are immobile (deficiency in new growth).
agronomy
HARVEST TAKES
The original Taurus crop-removal figure is retained above for provenance. It shows canola removal of 2.1 lb N, 1.2 lb P2O5, 0.62 lb K2O and 0.32 lb S per bushel, and single wheat values, but its crop labels and values need source reconciliation before operational use. The cited 2025 OMAFRA table identifies the wheat values as winter wheat and gives ranges of 1.15–1.25 lb N, 0.55–0.63 lb P2O5, 0.35–0.37 lb K2O and 0.08 lb S per bushel at marketing moisture. It gives canola sulfur removal as 0.33 lb/bu, while the Taurus figure shows 0.32 lb/bu. Do not silently substitute either value or use this panel alone for a fertility recommendation; confirm the intended crop category and values with Taurus and the source table.
agronomy
EXCESS BLOCKS
Nutrients don’t act alone, an excess of one can interfere with a plant’s uptake of another, a relationship mapped in Mulder’s Chart. For example, very high potassium can reduce magnesium and calcium uptake, and high soil phosphorus can trigger zinc deficiency. Balance matters: piling on one nutrient can accidentally create a shortage of another.
agronomy
COVER CROPS
Cover crops are fast-growing plants, rye, clover, radish, grown when a cash crop isn’t in the ground. They shield soil from erosion, scavenge leftover nitrogen so it isn’t lost to water, and add organic matter that feeds soil life. Their living roots also loosen compaction and build structure, often more effectively than tillage.
agronomy
RESIDUE GUARDS
Crop residue left on the surface absorbs the impact of raindrops and slows runoff, so soil stays put instead of washing or blowing away. Keeping at least 30% of the field covered after planting cuts soil erosion by at least half compared with bare, tilled ground. More cover means more protection.
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LESS TILLAGE
Intensive tillage breaks down structure, speeds organic-matter loss and leaves soil bare to erosion. Reducing tillage keeps residue on top, lets carbon build and holds soil in place. On the Prairies, less tillage plus less summerfallow helped Canada’s farm soils shift from a net carbon source in 1981 to a net sink capturing 22.4 Mt CO2/yr by 2021.
agronomy
WARM & MOIST
Soil life runs on warmth and moisture. Microbial activity, and the nutrient release it drives, roughly doubles for each 10C rise until it gets too hot, and slows to a crawl in cold or bone-dry soil. That’s why nitrogen mineralized from organic matter shows up mainly once soils warm and stay moist in spring.
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PROTECT WATER
Nutrients that leave the field can end up in water. Nitrate leaches into groundwater, while phosphorus attached to eroding soil runs off into surface water and can fuel algae blooms. Matching rate and timing to crop need, keeping soil covered, and placing nutrients below the surface all keep fertility in the field and out of the water.
agronomy
FIVE FORCES
Every soil is the product of five factors, remembered as CLORPT: Climate, Organisms, Relief (slope), Parent material and Time. That’s why two fields a mile apart can differ sharply. Knowing these forces explains a soil’s natural texture, depth and fertility before you ever fertilize.
agronomy
SOIL LAYERS
Dig a pit and you see distinct layers, called horizons, that make up the soil profile. From the top: O (organic litter), A (dark topsoil rich in organic matter), B (subsoil where clay accumulates), C (weathered parent material) and R (bedrock). The A horizon is your most productive layer, so protecting topsoil protects yield.
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READ THE COLOR
Soil color is a free diagnostic. Dark brown to black usually signals higher organic matter; red and bright brown mean well-oxidized iron and good drainage; gray, blue-gray or mottled colors (gleying) point to waterlogging and poor aeration. Checking subsoil color helps you judge natural drainage with no special tools.
agronomy
EARTHWORMS
Earthworms are a quick, low-cost indicator of soil health. They shred residue, mix organic matter and create channels that improve air and water movement. A common field check is to dig a cubic foot of moist soil and hand-sort, roughly 5 to 30 worms is typical, with numbers rising under reduced tillage and higher organic matter.
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BELOW 5.5
When soil pH drops below about 5.5, aluminum and manganese become far more soluble and can reach levels toxic to roots. Toxic aluminum prunes roots, stunting them so plants can’t take up water and nutrients, often mimicking a phosphorus shortage. It’s a key reason to monitor and lime strongly acid soils.
agronomy
LEGUME BONUS
A legume in the rotation leaves nitrogen behind for the next crop, so you can cut fertilizer accordingly. Guidance credits corn after soybean roughly 45 lb N/ac on medium-to-fine soils (about 25 on sandy), while a good alfalfa stand can credit 90 lb N/ac or more. Taking the credit saves money and avoids over-applying.
agronomy
CARBON TIES N
How fast residue breaks down depends on its carbon-to-nitrogen ratio. Microbes need roughly 24 parts carbon to 1 part nitrogen; residues above that (wheat straw ~80:1, corn stalks ~57:1) decompose slowly and temporarily tie up soil nitrogen, while low-C:N legume residue breaks down fast and releases nitrogen.
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HALF IS EMPTY
In an ideal topsoil about half the volume is solid (roughly 45% mineral, 5% organic matter) and half is pore space split between water and air (about 25% each). Those pores are where roots breathe and where water moves and is stored. Big pores drain and let air in; small pores hold water for plants.
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ROOTS NEED AIR
Roots respire, they use oxygen to make the energy needed to take up water and nutrients. Oxygen reaches them through air-filled pores, and soils generally need at least about 10% air-filled pore space for good growth. Because oxygen moves roughly 10,000 times slower through water than air, waterlogged or compacted soil quickly starves roots.
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WET SOIL LOSES N
When soil stays saturated, pores fill with water and oxygen runs out. Bacteria then strip oxygen from nitrate and release nitrogen to the air as gas, denitrification, permanently losing it from the field. In warm soils (above about 18C / 65F), an estimated 4 to 5% of nitrate-nitrogen can be lost per day of saturation.
agronomy
17 ELEMENTS
Every crop needs 17 essential nutrients to complete its life cycle. Carbon, hydrogen and oxygen come from air and water; the other 14 come from the soil. The ones used in large amounts are macronutrients (N, P, K, plus secondary S, Ca, Mg); the ones used in tiny amounts are micronutrients. Essential means the plant can’t finish growing without each one.
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OLD OR NEW?
Some nutrients move freely inside the plant and some don’t, which tells you where to look for trouble. Mobile nutrients (N, P, K, Mg) get pulled from older leaves to feed new growth when supply is short, so deficiency shows in the lower, older leaves first. Immobile nutrients (Ca, S, B, Fe, Mn, Zn) stay put, so deficiency shows first in the newest top leaves.
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N BUILDS GREEN
Nitrogen is a building block of chlorophyll, the green pigment that captures sunlight, and of the proteins and enzymes that run the plant’s machinery. That’s why a nitrogen-short plant turns pale green to yellow and grows slowly. Because nitrogen is mobile, yellowing appears on the older, lower leaves first.
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P POWERS ENERGY
Phosphorus is central to ATP, the molecule plants use to store and move energy, and it’s part of the DNA and RNA copied every time a cell divides. That makes it especially important for early root growth, seedling vigor and reproduction. Demand is highest during rapid early growth and again during grain and seed formation.
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K MANAGES WATER
Potassium doesn’t build tissue, it regulates water and activates dozens of enzymes. It controls the guard cells that open and close leaf pores (stomata), so the plant can take in carbon dioxide while limiting water loss. Well-supplied plants hold turgor and handle heat and drought better; potassium-short plants wilt sooner and are more stress-prone.
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SECONDARY THREE
Sulfur, calcium and magnesium are secondary only because plants use less of them than N, P and K, not because they matter less. Sulfur is part of proteins and enzymes; calcium builds and stabilizes cell walls; magnesium sits at the center of the chlorophyll molecule and activates many enzymes. A shortage of any one can cap yield.
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TINY DOSES
Plants need micronutrients, iron, manganese, zinc, copper, boron, molybdenum, chlorine, nickel, in very small amounts, yet each does a job no other element can fill. Most act as helpers inside enzymes or as catalysts for reactions like photosynthesis, hormone production and nitrogen use. Because so little is needed, over-applying one can trigger a shortage of another.
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BORON SETS SEED
Boron helps build and cross-link cell walls and is critical for pollen viability and pollen-tube growth, so it has an outsized effect at flowering and seed set. When boron is short during flowering, crops can produce empty pollen, poor pollination and reduced seed. Because boron barely moves in the plant, symptoms appear in the newest growth and flowers.
agronomy
GREEN = WORKING
In photosynthesis, chlorophyll captures sunlight and the plant turns carbon dioxide and water into sugars. Most of a leaf’s nitrogen sits in chlorophyll and photosynthetic enzymes, so leaf greenness closely tracks nitrogen status. That link is why chlorophyll meters can flag nitrogen shortfalls, compared against a well-fertilized reference strip.
agronomy
CORN’S N SURGE
A corn plant takes up very little nitrogen early, then demand surges during rapid vegetative growth. Only about 5% of season-total N is taken up by the V3 stage, but roughly two-thirds is absorbed between V6 and tasseling, with uptake continuing more slowly through grain fill. Matching nitrogen supply to this curve improves efficiency and cuts loss.
agronomy
BUSHELS HAUL
When grain leaves the field, the nutrients stored in it leave too, drawing down soil fertility over time. Ohio on-farm data show corn grain removes about 0.74 lb N, 0.35 lb P2O5 and 0.20 lb K2O per bushel; soybean removes far more per bushel; wheat sits in between. Grain removal is only part of total uptake, but it’s the part you must replace to keep soils in balance.
agronomy
MORE ISN’T BETTER
Excess nitrogen pushes lush, tall growth with longer, weaker lower stem internodes, raising the risk the crop lodges, falls over, before harvest. Over-application can also stretch out vegetative growth and delay maturity. Matching nitrogen rate and timing to crop demand protects both standability and timely ripening.
agronomy
TWO FORMS OF N
Roots take up nitrogen in two forms: nitrate and ammonium. Ammonium is held on soil particles and is used mostly in the roots, while nitrate moves freely with soil water and is easily taken up, but can also leach. In most field soils, microbes steadily convert ammonium to nitrate, so plants often absorb much of their nitrogen as nitrate.
agronomy
SULFUR & OIL
Sulfur is a building block of the amino acids cysteine and methionine, so plants need it to make protein. Canola is especially sulfur-hungry, and on the Canadian Prairies sulfur ranks as the third most limiting nutrient. A short sulfur supply hits canola’s seed set, oil and protein hardest during flowering and pod fill.
agronomy
FOLIAR LIMITS
Leaves can absorb small amounts of nutrients sprayed on them, entering mainly through the waxy cuticle. Foliar feeding is most useful as a quick, short-term fix, correcting a micronutrient shortage when roots can’t keep up during stress or in high-pH soils. Its limit is capacity: the amounts a leaf takes in are far too small to replace a sound soil program for N, P and K.
agronomy
SHORTEST STAVE
Liebig’s Law of the Minimum says yield is limited by whichever essential nutrient is shortest relative to the plant’s need, not the total present. Picture a barrel with staves of different heights: water (yield) spills out at the shortest stave. Adding nutrients that are already adequate won’t raise yield; only fixing the true limiting factor will.
agronomy
REACHING ROOTS
Nutrients get to roots by three routes. Mass flow carries dissolved nutrients along with the water a plant pulls in for transpiration, moving most of the nitrate, sulfate, calcium and magnesium. Diffusion moves nutrients a short distance toward the root when levels there drop, the main route for phosphorus and potassium. Root interception, where a root touches nutrients directly, is minor.
agronomy
GRAIN ROBS LEAVES
Once a crop starts filling grain, the developing seeds become a powerful sink that pulls stored nutrients out of the leaves and stems. Much of the nitrogen and phosphorus in the grain is remobilized from these vegetative parts rather than freshly taken up. This internal recycling drives normal late-season leaf yellowing, and means late-season nutrient status still shapes yield and protein.
agronomy
ASK THE PLANT
Plant tissue analysis measures the nutrient levels actually inside the crop, so it shows what the plant is taking up, not just what’s sitting in the soil. Results are compared against a critical or sufficiency range for that crop and growth stage; below the critical level, yield suffers. Because normal values shift with crop and stage, always record the stage and sample the right plant part.
agronomy
CALCIUM STAYS
Once calcium is built into a cell wall it stays put, the plant can’t pull it out and move it to newer tissue. So when calcium supply or delivery falls short, the youngest, fastest-growing parts suffer first, causing disorders like blossom-end rot and tip burn. Steady water and calcium keep it flowing to growing points.
agronomy
YELLOW VEINS
Magnesium is the central atom in every chlorophyll molecule, and it’s mobile in the plant. When it runs short, the plant moves magnesium out of older leaves to feed new growth, so the classic symptom, yellowing between the veins while the veins stay green, shows up on the lower, older leaves first.
agronomy
PALE NEW LEAVES
Unlike magnesium, iron barely moves within the plant, so a shortage shows up on the youngest leaves first, they turn pale yellow while the veins stay green. In field crops like soybean this iron deficiency chlorosis is most common on high-pH, calcareous soils where iron becomes hard for roots to take up.
agronomy
MN SPLITS WATER
Photosynthesis begins by splitting water molecules to release oxygen and the electrons that power the process, and manganese sits at the heart of the enzyme complex that does the splitting. Without enough manganese, that oxygen-evolving step in Photosystem II stalls, so photosynthesis and growth slow down. It’s a tiny requirement with an outsized job.
agronomy
ZINC = GROWTH
Zinc is needed to make tryptophan, the building block the plant uses to produce auxin, the hormone that drives cell division and stem and leaf elongation. When zinc is short, auxin production drops, which is why zinc-deficient plants show stunted growth, shortened stems and small leaves. Small doses of zinc keep the growth signals working.
agronomy
MOLY’S BIG JOB
Molybdenum is needed by two key nitrogen enzymes: nitrate reductase, which lets the plant turn absorbed nitrate into a usable form, and nitrogenase, which lets rhizobia in legume nodules fix nitrogen from the air. So a molybdenum shortage can look like a nitrogen shortage, pale, poor growth, even when soil nitrogen is present. It’s needed in tiny amounts.
agronomy
COPPER FILLS
Cereals, especially wheat, barley, oats and canaryseed, are the crops most sensitive to copper shortage. Copper is important for fertile pollen and grain set, so deficient plants show delayed maturity, prolonged flowering and poorly filled heads. On the Prairies, copper deficiency is most likely on peaty and sandy soils, and it’s linked to more ergot.
agronomy
K HOLDS STALKS
Beyond managing water, potassium strengthens stalks and cell walls, which helps a crop stand and fend off disease. In corn and small grains, low potassium is linked to weaker stalks, more stalk rot and more lodging. Balancing potassium with nitrogen matters: without enough potassium the plant can’t fully use its nitrogen, hurting stalk strength and yield.
agronomy
WATER PUMP
As water evaporates from tiny leaf pores (stomata), it pulls a continuous column of water up from the roots through the plant’s xylem, this is transpiration, and it runs without the plant spending energy. That upward flow is also how many dissolved nutrients ride from soil to leaves. When heat or drought closes the stomata, both water use and that nutrient conveyor slow down.
agronomy
ROOTS HUNT P
Roots don’t grow randomly, their shape adapts to find what’s scarce. Because phosphorus is nearly immobile and concentrates in the topsoil, plants short on phosphorus shift toward shallower, more-branched roots and more root hairs to forage the surface. For nitrate, which leaches deeper, plants instead push roots downward. Healthy root growth is a big part of uptake.
agronomy
DANGER WINDOW
Crops have stages when water and nutrient stress does the most damage, for corn, that’s pollination. Severe drought stress around silking and pollen shed can cut yield by roughly 3 to 8 percent per day, far more than the same stress at other stages. It also throws silk and pollen timing out of sync, leaving kernels unfertilized. This window matters most.
agronomy
FLAX NEEDS FUNGI
Flax removes relatively few nutrients per acre, but it is a poor early forager for phosphorus, especially in cold spring soils, and it depends heavily on mycorrhizal fungi to gather P. Growing flax after a non-mycorrhizal crop like canola weakens that partnership. A modest amount of starter phosphate near the seed helps flax through its slow early growth.
agronomy
PEAS PAY FORWARD
Well-inoculated peas, lentils and chickpeas fix much of their own nitrogen, so they usually need little or no N fertilizer, extra N can actually suppress fixation. They still need phosphorus and sulfur like any crop. And because they leave residual nitrogen behind, Prairie soil-test labs apply a nitrogen credit to the following crop.
agronomy
HEAT, NOT DATES
Crops develop in response to accumulated warmth, not the calendar. Growing degree days (GDD), or heat units, add up each day’s average temperature above a crop’s base. For corn the base is 50F (10C) and daily highs are capped at 86F (30C), because growth doesn’t speed up beyond that. Tracking GDD predicts crop stages better than counting days.
agronomy
LATE N, PROTEIN
In spring and durum wheat, nitrogen taken up after flowering goes largely into building grain protein. Research shows only about 10% of total nitrogen uptake happens after anthesis, yet it can supply roughly 30% of the nitrogen that ends up in the grain. That’s why a late, well-timed N application is used to raise protein, though it’s usually too late to add yield.
agronomy
HUNGRY, BURNABLE
The guide describes canola as a heavy nitrogen and sulfur user and says about 10 lb/ac of seed-placed nitrogen is generally safe. The cited Canola Council guidance is conditional: safe seed-row rates vary with soil texture and moisture, opener spread, row spacing, fertilizer source and crop conditions, and its examples span roughly 5–15 lb/ac. Use the product label, field conditions and local agronomic guidance rather than treating 10 lb/ac as a universal limit.