The 12 days of Crop Nutrients

Day 4 

Since I have already lost the theme of this thread (being a tie with the beloved carol, The 12 Days of Christmas), I won’t try to draw a connection between four calling birds and potassium – although I’m sure I could if I tried hard enough.

 

Potassium in one of the primary plant nutrients. It is essential for the transport of sugars and the formation of starches and oils. Potassium helps to regulate the opening and closing of a leaf’s stoma which are important for the efficient use of water by the crop.

Potassium deficiency in almonds
Apple with a potassium deficiency
Potassium deficiency in grapes

 

 

 

 

 

 

Potassium also promotes root growth, increases a plant’s resistance to disease and cold temperatures. It improves the size and quality of fruits, nuts and grains, and is essential in high-quality forage. Crops that produce large amounts of carbohydrates (sugars) require large amounts of potassium – sometimes even more th an nitrogen! Cotton, almonds, alfalfa, grapes, cherries, and peaches are all especially fond of potassium.

 

Common symptoms of potassium deficiency:

  • Slow growth
  • Tip and marginal leaf burning
  • Burning of older leaves
  • Weak stems and stalks causing lodging
  • Low fruit sugar content and shriveled seeds
Corn with a potassium deficiency

The 12 days of Crop Nutrients

Day 2

Welcome to our second day of the crop nutrients post. Hopefully you caught our first day – where we focused on phosphorus. In the traditional Christmas carol, the second day is two turtle doves. Since I don’t have any clever alliteration ideas for this one, I am going to talk about a secondary nutrient: calcium.

 

Calcium (Ca)

Calcium is a secondary plant nutrient that stimulates root and leaf development, activates several plant enzymes, and is required by nitrogen-fixing bacteria. In the soil, calcium indirectly influences yield by reducing soil acidity. It also helps improve root growth conditions, molybdenum availability, and uptake of other nutrients. In the soil, calcium indirectly influences yield by reducing soil acidity, which in turn lowers the solubility and toxicity of manganese, copper, and aluminum.

Alfalfa calcium deficiency comparison. (Left has deficiency, right does not)

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, soil calcium is usually found in a form that is not easily taken up by plants.

 

Calcium deficiency in an apple

As an example, in an apple tree, the leaves, new shoots, and fruit all take calcium. 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 in fruit trees, it is important to test the fruit, rather than relying solely on leaf or soil tests. Signs of calcium deficiency common in all crops include abnormal dark green foliage, premature shedding of blossoms and buds, and weakened stems.

 

Further problems with the calcium levels in the plant, and therefore in the fruit, are often caused by changes in the weather. In high temperature, low humidity conditions, for example, transpiration will increase dramatically, causing the plant to use more water. In irrigated crops, if watering has not been well scheduled, even soils with good levels of calcium can have problems in the fruit caused by calcium deficiency, such as blossom-end rot in tomatoes. This is the time when we need a fast calcium fertilizer that can be applied by foliar.

 

Common symptoms of calcium deficiency:

  • Death of growing points
  • Abnormal dark green foliage
    Example of calcium deficiency in lettuce
  • Premature shedding of blossoms and buds
  • Weakened stems
  • Tip burn of young leaves (primarily in vegetable crops)
    Calcium deficiency in corn
  • Water soaked, discolored areas on fruits
    Canola with a calcium deficiency

The 12 days of Crop Nutrients

Is anyone else missing the Christmas carols? Because we’re in the midst of the 12 Days of Christmas, and because the lack of seasonal music has me feeling a little deflated, I’m going to borrow the theme of the beloved Christmas carol “The 12 Days of Christmas,” and turn it into the 12 days of crop nutrients.

Partridge in a Pear Tree – or Phosphorus (P)

The alliteration here demands that we feature phosphorus first.

Phosphorus is an essential plant nutrient and very important for numerous plant processes and crop production. It is a vital component of DNA and RNA, the building blocks of proteins and protein synthesis. The adenosine triphosphate molecule (ATP) molecule is responsible for storing and transferring all of the energy produced and needed by the plant. At the core of this ATP molecule are phosphates, responsible for all of the activity of ATP. Phosphorus also plays a major role in the stimulation of new root growth.

So, P is Important

Our crops clearly need phosphorus to thrive. So, what do we need to worry about when supplying P? “Tie up” within the soil is the primary concern with phosphorus fertilizers. In acidic soil conditions, P will tend to get tied up by iron, aluminum, and manganese. In basic soil conditions, calcium will be the major component of phosphorus tie up.

Phosphorus deficiency symptoms in corn
Phosphorus deficiency in corn

Phosphorus is most available to the plant in a soil pH range of 6.3-6.8. Common liquid fertilizers, such as ammonium polyphosphate (10-34-0) and orthophosphate (9-18-9), applied in the early spring will also have a likely chance of being tied up if a gypsum application was made in the fall.

Choosing a phosphorus fertilizer that is protected from tie up will ensure that you get the most out of your fertilizer investment and that your crop will receive the required amount of phosphorus needed.

Available P versus Usable P

Not to mention, applying phosphorus as a crop nutrient can be tricky. Just because phosphorus was applied to the soil does not mean that it is doing what you want it to do: feed the plant!  AgroLiquid founder, Douglas Cook, was known to say that all applied fertilizer is available, but not all applied fertilizer is usable. Sounds funny, but it’s true. What’s the difference? All fertilizer is available to plants — it’s right there for the taking. But it may not be usable. In order for a nutrient to be usable, it must be close to the roots and it must be in a form that the plant can absorb.

Nutrients like nitrogen can be lost to leaching or volatility before absorption. Potassium can be strongly held by clay in the soil and not able to be taken up by roots since it is not in the soil solution. Phosphorus can also become unusable. Phosphate is negatively charged and can react with, or be fixed, by positively charged elements in the soil (cations). Plants cannot take up these compounds of calcium phosphate, aluminum phosphate or iron phosphate. Estimates are that the crop will utilize only around 20% of applied phosphate fertilizer during the season after application, and in following years, the amount becomes progressively less as it reverts to mineral forms. Again, the nutrients are there and available, but they are not always usable.

Out of Sight, Out of Mind

You cannot actually see the fate of phosphate molecules in the soil, so it’s not necessarily something growers are thinking about. If only a small percentage of your planted seed came up, you would probably be mad because you can see that loss. Similarly, only a small percentage of the applied phosphate is usable. However, you cannot see this, so it is not a concern.  But it should be.

Placement is Key

Phosphate fertilizer works best if it is placed close to the seed at planting. In the picture at the left, it is apparent that phosphate fertilizer placement is affecting growth. Five rows of the plot had 5 gal/A of Pro-Germinator applied through the planter, and the sixth row had no planter fertilizer.

Phosphorus source comparison in field corn
Fertilizer placement comparison using Pro-Germinator in corn

The rows with the In-furrow placement are tasseling, whereas the 2×2 placement has yet to tassel. Close inspection shows that the corn with the 2×2 placement is taller than the row with no fertilizer, but it is behind the rows with the in-furrow placement. This shows that phosphorus placement for earliest root access affects plant growth and yield. Additional testing at the North Central Research Station has shown that in furrow placement can out-yield 2×2 placement by almost 5 bu/A.

In order for phosphorus fertilizer to be most effective, it needs to be usable. Usability is increased by placement close to the seed row and protection from fixation losses. Pro-Germinator is the only fertilizer that does both.

 

 

 

Common phosphorus deficiency symptoms:

  • Stunted plants
  • Leaves may be darker green or begin purpling
  • Leaves may curl upward
  • Maturity can be delayed
  • Poor seed set
  • Poor fruit quality
Phosphorus deficiency in citrus fruit
Phosphorus deficiency in citrus fruit can result in poor fruit quality.
Purpling leaves, like those in this canola plant, can be a symptom of phosphorus deficiency
Purpling leaves, like those in this canola plant, can be a symptom of phosphorus deficiency

 

 

Building and Managing Soil Phosphorus

By: Dr. Jerry Wilhm, Senior Research Manager

Clearly, phosphorus is important for growing crops. It is involved in many functions within a plant like energy storage and transfer (ATP/ADP), protein synthesis, photosynthesis, nucleic acid (DNA/RNA) synthesis, nutrient movement through cell walls and many more processes. Therefore, it pays to make sure phosphorus does not become deficient in plants.

However, applying phosphorus as a crop nutrient can be tricky. Like all nutrients, phosphorus must be managed. In other words, just because phosphorus was applied to the soil does not mean that it is doing what you want it to do: feed the plant!  AgroLiquid founder, Douglas Cook, was known to say that all applied fertilizer is available, but not all applied fertilizer is usable. Sounds funny, but it’s true. What’s the difference? All fertilizer is available to plants — it’s right there for the taking. But it may not be usable.

In order for a nutrient to be usable, it must be close to the roots and it must be in a form that the plant can absorb. Nutrients like nitrogen can be lost to leaching or volatility before absorption. Potassium can be strongly held by clay in the soil and not able to be taken up by roots since it is not in the soil solution. Phosphorus too can become unusable. Phosphate is negatively charged and can react with, or be fixed, by positively charged elements in the soil (cations). Plants cannot take up these compounds of calcium phosphate, aluminum phosphate or iron phosphate. Estimates are that the crop will utilize only around 20% of applied phosphate fertilizer during the season after application, and in following years, the amount becomes progressively less as it reverts to mineral forms. Again, the nutrients are there and available, but they are not always usable.

This may not be a concern to growers because you cannot actually see the fate of phosphate molecules in the soil. If only a small percentage of your planted seed came up, you would probably be mad because you can see that loss. Similarly, only a small percentage of the applied phosphate is usable. However, you cannot see this, so it is not a concern.  But it should be.

 

 

 

 

Phosphate fertilizer works best if it is placed close to the seed at planting. In the picture at the left, it is apparent that phosphate fertilizer placement is affecting growth. Five rows of the plot had 5 gal/A of Pro-Germinator applied through the planter, and the sixth row had no planter fertilizer. The rows with the In-furrow placement are tasseling, whereas the 2×2 placement has yet to tassel. Close inspection shows that the corn with the 2×2 placement is taller than the row with no fertilizer, but it is behind the rows with the in-furrow placement. This shows that phosphorus placement for earliest root access affects plant growth and yield. Additional testing at the North Central Research Station has shown that in furrow placement can out-yield 2×2 placement by almost 5 bu/A.

Pro-Germinator has carbon encapsulation for protection against fixation losses that affect other forms of phosphate fertilizer. This is the  Flavonol Polymer Technology that AgroLiquid developed to prevent fixation losses and enable extended nutrient release into the growing season. This also increases crop safety and can be effective at lower rates than those of conventional fertilizer like 10-34-0. In this experiment from the North Central Research Station, the lower rate of Pro-Germinator enabled a higher corn yield than that with the higher rate of 10-34-0. Closer inspection shows larger ear size and the darker yellow corn indicates advanced maturity.

In order for phosphorus fertilizer to be most effective, it needs to be usable. Usability is increased by placement close to the seed row and protection from fixation losses. Pro-Germinator is the only fertilizer that does both.

 

Kentucky Corn Looking Great with AgroLiquid

So last week, Senior Sales Manager Galynn, SAM Rob and I went down to Hopkinsville, KY to visit the Security Seed & Chemical Research Farm.  It is a large facility where fertilizer plots are established each year to test different program, both old and new.  Fertilizer Agronomist Lang French met us at the plots to show us around.  AgroLiquid has been a standard program there for quite a few years now.  But that is challenged each year.  They do have really good looking corn down there.

inspecting corn

 The corn is in the silking stage now.  Here is a plot that received a preplant application of dry fertilizer (9-23-30).

corn in silking stage

 And right next to it is a plot that instead received a planter application of Pro-Germinator + Micro 500.  Notice that the silks are turning brown indicating that it is farther along in maturity.

corn silk turning brown

Lang said that they often see tassel emergence at least seven days earlier with AgroLiquid compared to dry treatments.  One of the many features explaining the high performance of AgroLiquid.  Go to their upcoming field day if you are in the neighborhood.

And if you want to see a video discussion of these plots (and who doesn’t?) go to @DrJerryCropDoc on Facebook.

Fast-Growing Corn (LAND OF LIQUID Blog)

So how fast does corn grow anyway?  I recently read an article in a Pioneer update that told about spraying a stalk with paint and then checking it the next day.  I shared this my friend Chris Cook who farms in SE Wyoming and thought it would be a good project for his young boys Brady and Matt.

how fast does corn grow?

And it was!  I got this pic right back from them showing the amount of growth overnight.  Pretty phenomenal.  Of course this corn had the advantage of using AgroLiquid.  But I’m pretty sure corn with other fertilizer would grow at least some in the same test.  Maybe.

Summary of Fertilizer Placement Options for Corn

Experiment Info

305/309/512/719
Planted:5/14,19,16,25
Variety:DKC46-07
DKC53-78
DKC46-07
DKC48-12
Population:38,000
36,000
38,000
31,000
Row Spacing:30″
Previous Crop:Corn/Soys/Soys/Soys
Plot Size:15’x210’/180’/240’/210’
Replications:1/5/1/4
Harvested:10/22,26,29

Soil Test Values (ppm)

pH:7.2/7.3/6.9/3.8
CEC:7.2/6.5/10.6/12.3
% OM:1.5/1.8/2.0/3.0
Bray P1:26/26/34/20
K:136/76/60/121
S:21/11/8/16
% K:4.8/3.0/1.5/2.5
% Mg:18.4/16.4/20/21.7
% Ca:15.8/79.6/77.2/75.5
% H:0
% Na:1.0/1.0/0.9/0.3
Zn:0.8/1.0/1.4/0.3
Mn:5/4/7/2
B:0.5/0.6/0.7/0.6
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Objective:

To determine yield response for fertilizer placed either 2×2 or in-furrow during corn planting.

The table below summarizes four locations across the North Central Research Station were Pro-Germinator, Sure-K and Micro 500 were applied either in-furrow or 2×2 at planting. Within each experiment the fertilizer applications were the same and applied according to soil test recommendations and all treatments were sidedressed with the same rate of nitrogen. Nitrogen only applications were done to show the benefits of planter time fertilizer. Experiment and average overall yield appear on the table below.

Summary of Fertilizer Placement Options for CornConclusions:

  • At all four locations, the nitrogen only treatment yielded lower than the other treatments. An average of over 11 bu/A was achieved with the addition a 2×2 planter applied fertilizer.
  • At half the locations, in-furrow applications yielded much higher than 2×2 fertilizers. In the other locations there was little difference between the two methods of application.
  • On average over all locations, planter fertilizer applied in-furrow yielded almost 5 bu/A higher than 2×2.
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“Permanent Plots”: Program Components in Corn

Experiment Info

Planted4/25/12
Variety:DKC48-12
Population:31,000
Row Spacing:30″
Previous Crop:Soybeans
Plot Size:15’ x 210’
Replications2
Fall BC10/28
Spring BC4/13,23
Sidedress5/24/12
Harvested:10/29/12

 

Soil Test Values (ppm)

 pH7.0
CEC12.4
%OM3.4
Bicarb P17
K111
S5
%K2.3
%Mg21.4
%Ca75.9
%H0
% Na0.4
Zn1.5
Mn4
B0.7
Yield Goal:180 bu
Target Fertilizer Rate:180-30-60-2Zn
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Objective:

Evaluate the yield effects of the different AgroLiquid program components.

This experiment is intended to follow similar fertilizer programs over time in a corn-soybean rotation. Based on soil test, a corn fertilizer program of 180-30-60-2 Zn was implemented for a 200 bu/A yield goal. This is a very productive soil, where yields the past two seasons have exceeded expectations. As such, and based on previous results, the recommended 215 lb-N/A recommendation was reduced to 180 lb/A. Within this experiment there were program source comparisons. It should be mentioned that due to a fast and heavy rain event on May 7 that two of the replications of plots were damaged from water runoff and not harvested. However, the
remaining two replications were unscathed and provided good data.

In this part of the experiment, the yield of the total AgroLiquid planter program of 3 gal/A of Pro-Germinator + 5 gal/A of Sure-K + 2 qt/A of Micro 500 was compared to that of the Pro-Germinator or Sure-K alone (although still with Micro 500). These were all compared to a nitrogen only treatment. It is hoped that the highest yield is obtained with the whole program, but research will find out. Treatment yields appear in the following chart.

liquidfert

Conclusions:

  • The highest yield was obtained with the total program.
  • The single component treatment yields were closer to that of the total program than perhaps would be desired. But there was a numerical additive effect none-the-less.
  • The yields of the individual components still out-yielded that of either conventional complete program (see that report).

 
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Nitrogen Source and Method of Application Comparison in Corn

Experiment Info

Planted:4/25
Variety:DKC48-12
Population:31,000
Row Spacing:30″
Previous Crop:Soybeans
Plot Size:15′ x 530′
Replications:3
Broadcast:4/26
Sidedress:4/25
Harvested:10/29

 

Soil Test Values (ppm)

pH:6.1
CEC:10.8
% OM:2.4
Bray P1:24
K:128
S:10
% K:3.0
% Mg:18.5
% Ca:63.7
% H:14.4
% Na:0.4
Zn:0.9
Mn:9
B:0.4
Yield Goal:180
Target
Fertilizer Rate:
175-22-29
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Objective:

To compare different nitrogen sources and application methods for corn.

There are many options for nitrogen placement when it comes to fertilizing a corn crop. In this experiment two nitrogen sources were used: High NRG-N and 28% + eNhance. Methods of application included: PRE emergence broadcast treatment, sidedress application 30 days after planting and a split application where 15 gallons per acre was applied 2×2 at planting with the remainder at sidedress. An additional treatment of 28% UAN applied PRE broadcast and was tested as a standard comparison. Yields appear on the chart below.

Nitrogen Source and Method of Application Comparison in CornConclusions:

  • There was no significant difference in yield amongst methods of application for both of the nitrogen sources. Numerically, the sidedress applications yielded slightly higher than either the broadcast or split applications.
  • At broadcast, 28% yielded slightly higher than High NRG-N but there was no significant difference between it and 28% + eNhance.
  • The sidedress treatments showed no statistically significant difference in yield between the two nitrogen sources.
  • There was no difference in nitrogen sources with the split applications. However, by using High NRG-N at plating and sidedressing with 28% UAN there was a yield increase. This warrants further testing in the future as there may be advantages to using two products with different nitrogen-release curves.
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Corn planter fertilizer placement

Experiment Info

Planted:5/9/2011
Variety:Pioneer 9807
Population:36,000
Previous Crop:Soybeans
Plot Size:15′ x 115′
Replications:4
Sidedress:6/8/2011
Harvested:10/25/2011

Soil Test Values (ppm)

pH:7.0
CEC:7.5
% OM:1.6
Bicarb:18
K:71
S:6
% K:2.4
% Mg:24.8
% Ca:71.8
% H:0
% Na:1.0
Zn:1.5
Mn:8
B:0.6
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Objective:

Compare different placements of Liquid fertilizer (3 gal/A Pro-Germinator + 7 gal/A Sure-K + 2 qt/A Micro 500) for effects on corn yield.

There are various placement options for liquid fertilizers such as (1) 2×2 placement and in-furrow placement. In-furrow also presents some options, such as on a (2) seed fi rmer/cover with the fertilizer tube split into a Y at the end (3) an in-furrow tube that places the fertilizer in the bottom of the furrow prior to seed drop. An issue that can arise in wet spring conditions like this year is that some growers get concerned about just fi nishing planting before more rain occurs and don’t bother putting on any planter fertilizer. Then after emergence they become concerned about lack of fertilizer and wonder if they should put some on at sidedress (4), or just do nothing (5). An experiment was conducted to evaluate these five different placement options. (Note: sidedress fertilizer for all was 21 gal/A High NRG-N + 28 gal/A 28% + eNhance.) Pictures of fertilizer placement and average placement yield appear in the following picture.

 

Corn Planter Fertilizer PlacementConclusions:

  • All fertilizer applications resulted in a yield increase over no P and K fertilizer.
  • The highest yield was with the tube and the seed firmer.
  • The application with sidedress was lower than the planter-time applications, but was much better than forgoing application due to it being 30 days after planting.
Some of the planter-applied treatments from 2011 were also applied in a similar experiment in 2010 (10-710a). The two-year average would suggest an advantage for the tube in-furrow placement. But both the tube and the seed firmer resulted in a better overall yield than that of the 2x2 placement, likely due to the earlier access to the row-placed crop nutrition.
Some of the planter-applied treatments from 2011 were also applied in a similar experiment in 2010 (10-710a). The two-year average would suggest an advantage for the tube in-furrow placement. But both the tube and the seed firmer resulted in a better overall yield than that of the 2×2 placement, likely due to the earlier access to the row-placed crop nutrition.
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