Phosphorus (P) is considered a primary crop nutrient, along with nitrogen and potassium. Phosphorus is involved in photosynthesis, respiration, energy storage and transfer and many other processes in the plant. Phosphorus improves the quality of fruit, vegetable, and grain crops, and is vital to seed formation. Phosphorus uptake is a continuous process during the active growth period of plants. Phosphorus is absorbed by plants throughout the growing season, with much of the plant’s phosphorus need occurring during periods of fast vegetative growth and fruit production. Since phosphorus is needed at all stages of plant growth it is imperative that the nutrient be in a plant available form throughout the growing season.
Most phosphate fertilizers combine, or complex, with other minerals in the soil to create compounds that are not usable to plants. This can happen in as little as 4 to 8 days. Pro-Germinator™ contains both orthophosphate, which is immediately available to the plant, and long-chain polyphosphates that are protected by flavonol chelation technology resulting in season long phosphorus availability.
The combination of ortho- and polyphosphates, along with its flavonol chelation technology allows Pro-Germinator™ to provide more nutritional performance per gallon than conventional fertilizers. That results in having excellent crop nutrition at lower application rates than other phosphate products. When applied at recommended rates, Pro-Germinator™ is cost effective, on a per acre basis. Pro-Germinator™ should be the backbone of all crop fertility programs, potentially providing the greatest return on phosphorus investment.
An experiment was conducted at the AgroLiquid North Central Research Station to determine phosphate availability of Pro-Germinator™ compared to other liquid phosphate fertilizers. Pro-Germinator™, 9-18-9 orthophosphate, and 10-34-0 ammonium polyphosphate were applied at 20 lb P2O5 per acre. Plant usable phosphorus in soil solution was measured at various times throughout the growing season.
AgroLiquid’s goal is to prosper the farmer while safeguarding the environment. Learn how they are different from any other fertilizer company in the industry today as experts discuss details about their line of high-performance fertilizers formulated with scientifically based recommendations to help growers achieve the best possible production yields while employing sustainable agricultural practices.
If salt index isn’t a good predictor of fertilizer injury to many crops — what should be considered when selecting a fertilizer?
There has been a lot of discussion about the term “salt index” and what it means with regard to crop safety for fertilizers. When synthetic fertilizers were first becoming prominent in the marketplace one of the concerns was the crop safety that each product provided and how that related to where a product should or shouldn’t be placed. The term “salt index” was used to help describe the relative safety of fertilizer products – both liquid and dry. Over the years, the term salt index has been used for a variety of things, some that make sense, and some that were, perhaps, not technically accurate.
In order to understand salt index it is important to understand what is meant by the term “salt.” A salt is any chemical compound that is composed of a positively charged ion and a negatively charged ion. When most of us hear the word salt we tend to think of sodium chloride, or table salt. Sodium chloride is a salt, but it is not a common component of fertilizers.
The question is often asked about how much salt fertilizers have. In strict chemical terms fertilizers ARE salts. One of the more recognizable fertilizer formulas is K-Cl, or potassium chloride. That compound is 0-0-60 potash. The potassium component is a positive ion and the chloride component is a negative ion. That fertilizer, along with all others, are salts.
Why was the concept of salt index developed? The original intent was to develop a scale, or index, of the potential for a fertilizer to cause crop injury. The actual numbers reported can be measured values using electrical conductance tests, or can be calculated values based on product components. It is easy to see how different analysis methods can give different index values, so comparing the salt index of various products is problematic unless the products were all measured (not calculated) using the exact same methods.
Is the salt index number of any value when describing the potential for fertilizer injury? Not as much as it used to. Some literature suggests that fertilizers with salt indexes above 20 should not be applied near the seed of sensitive crops. Commodity fertilizer products such as potash or DAP are well known to cause crop injury when placed too close to a sensitive seed. Some liquid fertilizers, such as 10-34-0 or 6-18-6, can be applied in-furrow to certain crops but with significant rate restrictions. Newer technology products – including many AgroLiquid products – are safe for in-furrow application to many crops, including some products that have salt index values higher than 20.
If salt index is not a good predictor of fertilizer injury to many crops what should be considered when selecting a fertilizer? First and foremost, crop safety and performance of AgroLiquid products should be the focus of any discussion. AgroLiquid product crop safety and performance claims are backed up by over 20 years of research and field experiences, and don’t need to be justified by a laboratory value.
When selecting fertilizer products and application placement it is important to use the best agronomic practices for the product, crop, and row spacing. Corn and soybeans, for example, have different limitations on what rates certain AgroLiquid products can be applied in-furrow or as a foliar spray. Some of the vegetable crops, on the other hand, should not have in-furrow applications of AgroLiquid products at planting. In addition to the product itself there are several environmental conditions that need to be taken into account when determining crop safety risks. Soil environmental conditions play a large role in crop response to fertilizer products, with colder, dryer soil conditions having a higher potential for adverse crop response compared to a warmer, moist soil. Foliar applications have additional issues to consider with regard to crop safety and performance. Crop growth stage is a very important factor in the safety and performance of foliar fertilizer applications. Tank mix partners and surfactants may also play a role in safety and performance. When tank mixing with crop protection products it is important to READ AND FOLLOW LABEL DIRECTIONS of the pesticides. Pay special attention to tank mix restrictions and compatibility testing instructions on the pesticide label.
Reminders about salt index
How it relates to AgroLiquid products:
Don’t worry about absolute numbers. Methodology, test conditions, and the products tested all influence the index value that is reported. Also, don’t get caught up in salt index comparisons with other products.
Do consider the safety, flexibility and performance of AgroLiquid products, and the research plus field experiences that prove performance.
Do select and apply fertilizers based on sound agronomic practices. Consider what crops, application methods, tank mix partners, and environmental conditions are present when making fertilizer decisions.
Calcium is the third most important element in a plant. And, calcium is the fifth most abundant element on the planet. It makes sense that traditionally, growers don’t apply much calcium, because they assume the plant will get what they need from the soil. But, calcium is usually found in a form that is not easily taken up by plants.
In an apple tree, the leaves, new shoots, and fruit all take calcium and the nutrient will be found in the tissues and the root, but, the fruit cannot compete with the other parts of the plant hence why the fruit often doesn’t get enough calcium. That is why calcium deficiencies are evidenced on the fruit, rather than the rest of the tree. In apples, a calcium deficiency causes a disorder known as bitter pit. Bitter pit is a physiological breakdown of the cell walls in the fruit that occur below the skin of the fruit. For that reason, when scouting for calcium deficiencies, it is important to test the fruit, rather than relying solely on leaf or soil tests.
In this particular trial, Horticulturists were testing for fruit firmness, how many apples produced on each tree, and how much the fruit weighs. At the North Central Research Station High-Density Apple Orchard, researchers test approximately 10 apples per experimental plot for firmness. They use a pentameter, which measures the pressure needed to break the cell part inside the apple. They test four spots on each apple, as research has shown there is a difference in firmness between the side of the apple exposed to sun, versus the shade-side. The average fruit firmness is reported.
A trial of the effects of LiberateCa™ in 2015 at the NCRS High-density Apple Orchard in Michigan showed that the apples treated with LiberateCa™ fall close to the preferred range of 14.5 lb – 17.5 lb for fruit firmness, while the untreated trees’ fruit firmness was significantly higher than desired. In addition, the treated trees had more apples per tree, and overall yield per tree increased as well. These trees were planted at 3 ½ feet between trees, 11 feet between rows, with a planting density of 1,100 trees per acre.
“If you can hang two more apples per tree, with 1,100 trees, you have 2,200 more apples – and that means more money in your pocket.” Horticulturist Jacob Emling
Senior Research Manager, Dr. Jerry Wilhm discusses how and why the lower applied rates of AgroLiquid nutrients are sustainable and more efficient in feeding the plant the nutrients it needs to thrive. In this short video, Dr. Wilhm further demonstrates this through a four-year sustainability study from the North Central Research Station (NCRS).
In grapes, a combination of variety, management, and training system dictates how much quality fruit the plant can produce. One of the best options is using fertilizer applied in the spring that can be easily taken up by the vine. Over the last four years, we have been looking at what AgroLiquid products can do on grapes. All fertilizer is soil applied in the spring underneath the vines.
Conventional Program: 12 gallons of 28%UAN + 12.9 gallons of 10-34-0 + 100 lbs. of sulfate of potash.
Dr. Joel Gruver of Western Illinois University has found some compelling evidence of nutrient banding, much like you might find with band-application of commercial fertilizer, with the use of cover crops. Learn more in the video above.
In the newest, installment of video from the North Central Research Station, Dr. Jerry Wilhm provides a comprehensive harvest re-cap, giving a glimpse into the harvest process that make AgroLiquid plot work possible.
Dr. Brian Levene also makes an appearance. Brian addresses grower questions from George McDonald of Catesa Farms in Riddleton, TN. Catesa Farms is a producer of high quality plasticulture strawberries and George is looking for the best step-by-step fertility program to bring sweet, firm berries with a good shelf life to market.