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.
The Effect of Liquid and Conventional Fertigation Treatments on Commercial Tomato Production
Researchers compare liquid and conventional fertigation treatments for impact on yields of ‘Roma’ and ‘Beefsteak’ tomatoes.
Customized products work better for consumers because they meet their specific needs. Tomato nutrition is no different. Customized fertility programs are effective because they meet the specific nutrient requirements of the tomato crop. Fertigation is a good way to implement a customized nutrition program for commercial tomato production, especially when liquid fertilizers are used.
Many tomato growers use drip systems to provide plant nutrition through irrigation water, a process known as fertigation. Drip systems can accommodate both water-soluble granules and liquid fertilizers, but there are some definite advantages to using liquid over water-soluble granular formations. This article will discuss three of them.
According to a study performed by AgroLiquid, fertigation treatments using liquid fertilizer have a greater impact on tomato yields than conventional treatments. For the experiment, researchers compared the effects of liquid and conventional fertigation treatments on the yield of fresh market ‘Beefsteak’ and ‘Roma’ type tomatoes.
Materials and Methods
Soil preparation included banding liquid fertilizer down the center of the plots or broadcasting dry fertilizer into the area. A swath of plastic mulch covered the center 2 ft. of each 5 ft. wide plot.
Growers doused the soil around each transplant with approximately 4.2 oz. of transplant solution (~300 GPA) which contained the fertilizers described in Table MT1. The rest only had water. For early season disease and insect management, Ridomil and Admire were added to the transplant water.
Drip applications started at early bloom and continued until mid-September. Eight weekly treatments occurred during the season. Upon maturity, ripe fruits were counted and weighed to determine yields. Spring rains delayed planting and harvesting, so a majority of the yields for all treatments occurred during the final portion of the season. Six harvests took place throughout the season; the initial harvest occurred on Aug. 13 and the last on Oct. 18.
When 100% of the fertilizer was applied pre-plant, the AgroLiquid base program (Trt. #2, See Figure MT1) surpassed the conventional program (Trt. #1) for the yield of ‘Beefsteak’ and ‘Roma’ type tomatoes.
During the growing season, drip applications (Trt. #4-#6) supplied 40% of total nitrogen, and in some cases (Trt. #5 and #6), nearly half of the potassium. These changes in the application timing improved tomato yields without using any additional fertilizer when compared to the Agro-Liquid base program (Trt. #1). Table MT1 shows these changes in application timing and volumes.
Kalibrate, listed here as K-10 (Trt. #3 and #6), matched the performance of Sure-K® (Trt. #2 and #5) when it was used in a similar manner. Kalibrate has some winter storage advantages over Sure-K®.
Flexibility and Uniformity
Fertigation allows the grower to apply smaller applications on a frequent basis with greater uniformity. Conventional fertilizer programs can be hit or miss because they usually consist of two or three applications per season. Depending on a plant’s stage of development, it may receive too much or too little fertilizer, or it may not be able to utilize the nutrients at all.
Fertigation improves nutrient uptake because it targets the active root zone; plants have easy access to the nutrients they need. Application rates can also coincide with a crop’s nutrient needs at different growth stages. For instance, growers can start with smaller doses at planting, increase the dose during the vegetative stage, and then decrease the dose as the crop nears the fruiting stage and maintain crop health at the end of a plant’s lifecycle.
To observe the comparison between a conventional dry program and a complete AgroLiquid program. Long term averages are a great way to see how fertilizer programs affect yields. By averaging yield results over several years it takes into account different soil types that the experiments were conducted on and the different weather conditions that exist from year to year. Each year all Agro-Culture Liquid Fertilizer programs placed phosphorus, potassium and micro nutrients in a 2×2 band with the planter. High NRG-N was used as the nitrogen source and applied as a surface broadcast after planting. Conventional programs placed phosphorus as DAP (dry spread) or 10-34-0 (2×2) and potassium as potash along with micro nutrients as a broadcast spread and tilled into the soil ahead of planting. Urea (applied the same as other dry materials) or 28% UAN (broadcast after planting) was used as the nitrogen source. All programs matched fertility needs of the test area for that particular year. The North Central Research Station uses a Gandy Orbit Air spreader to accurately spread dry materials across the entire 15’ plot width. (Note: Prior to 2007 the above planter 2×2 applications were applied 1 inch to the side of the seed and at an even depth.)
• Over 9 years, there has been an average 1 Ton/A yield advantage using Agro-Culture Liquid Fertilizers compared to a conventional fertilizer program.
• AgroLiquid nutrients provide all of the necessary nutrition needed for a great sugarbeet crop.
To compare broadcast Nitrogen sources on sugarbeets. One of the major nutrient needs of sugarbeets is nitrogen. However, adding more nitrogen than is needed will encourage leaf growth and decrease sucrose content of the root. Nitrogen should be applied to achieve optimum canopy development for the beginning of the growing period. Then soil nitrogen levels should back off toward the end of the season to acquire the highest sucrose yield. Recoverable white sugar per acre (RWSA) is the term for sucrose yield and the major factor for quality payments to growers. In this experiment High NRG-N was compared to 28% UAN + eNhance and 28% UAN. The rates used were 28, 32 and 40 GPA respectively. Treatments were broadcast applied after planting.
• No significant difference in yield was observed between the 4 comparisons.
• The higher amount of 28% UAN did have the lowest recoverable white sugar per acre. It has been seen in the past that higher nitrogen applications can result in less recoverable white sugar per acre possibly because of the excess nitrogen.
• High NRG-N and 28% UAN + eNhance can provide the same yield as higher rates of 28% alone while applying fewer pounds of nitrogen. Efficiency of the nutrients is the key to using less total pounds of N.
• A rate of 32 gal of 28% + eNhance provided the highest recoverable white sugar per acre.
Step-up Almond Yields with Effective Nitrogen Management
Proper nitrogen management enhances almond yields, promotes healthy tree growth and benefits the environment.
The key to nitrogen management for almonds is to meet crop demand without going overboard. This involves timing nutrient applications to meet the needs of the crop so nutrients are not lost to leaching and denitrification. Nitrogen is essential to the healthy growth and development of almond trees and has a direct impact on yields. In the end, proper management of this essential element pays handsome rewards, both in yields and in preservation of the environment.
Crop Demand Guides Nutrient Applications
Effective nitrogen management for almonds involves letting crop demand guide the timing of applications to ensure nitrogen is present in the root zone when the crop uptake will be most efficient. Split applications work well because growers can time them to match high uptake periods.
“Almond trees use a majority of their nitrogen from leaf-out to kernel fill. We recommend applying 80 percent of the total nitrogen budget by that point,” says David Doll, University of California Cooperative Extension nut pomology farm advisor for Merced County. “After leaf expansion, the nitrogen growers apply goes into the developing kernel. Once kernel fill is complete, it is best to back off on applications until the post-harvest period, and then apply another 20 percent of the nitrogen budget post-harvest.”
Doll cautions that growers should not exceed 50 pounds of nitrogen in the fall because the crop can’t effectively use more than that amount and the excess can be lost to leaching.
Nut Yield Influences the Nitrogen Budget
Nut yield is a major determinant of nitrogen demand in mature almond trees. Depending on yield, a large portion of the total nitrogen a tree takes up in a given year goes into the nuts, while a much smaller amount fuels tree growth. According to Doll, 65 pounds of nitrogen are removed with every 1,000 kernel pounds.
To be accurate, growers must base nitrogen budgets for the current crop year on expected yield, minus additional inputs such as nitrogen-rich cover crops, compost and nitrogen in the irrigation water. Growers also need to look at the efficiency of the nutrient.
“Nitrogen has an efficiency factor of 70 percent,” says Doll. “This means that you have to apply around 85 pounds of it in order to get 65 pounds into the ground. Growers need to make sure they are figuring this into their nitrogen budgets.”
Agro-Culture Liquid Fertilizers Offers Solutions with Advanced Nitrogen Products
Balancing crop demands with increased accountability over the uncertain fate of nitrogen makes is imperative that growers constantly evaluate their nitrogen management. Agro-Culture Liquid Fertilizers recognizes the challenges almond growers face when managing nitrogen inputs. Their N-Suite™ of products offers solutions with greater nitrogen efficiency as well as a way to improve the efficacy of many conventional materials.
Three powerhouse products, High NRG-N™, NResponse™ and eNhance™, provide greater nitrogen efficiency and application flexibility, while still maintaining the overall health and yields desired from your almond trees.