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The Cropwalker - Volume 2 Issue 6

Always read and follow label directions.


Red Clover Seeding

Normal seeding rate is 6-10 lbs/ac. Each pound of red clover seed equates to 6-7 seeds/sq. ft. So even 5 lbs should give lots of seeds/sq. ft. CCA Ryan Benjamins once seeded red clover January, February, March, and April. The January seeding was not quite as good as the other dates. Once snow leaves you can start. Suggest you get your red clover seed ordered and home. If you are concerned about too much red clover top growth, use single cut (I would strongly consider this on late planted wheat). It has as much or more root mass than double cut. Red clover gives 50+ lb./ac N ($25-30value) for the next crop and 20-25 bu/ac more corn ($75-$100 value) plus will increase soil OM levels. The root portion of cover crops is more valuable than the top portion.

How to get 90% of the benefits of Variable Rate with 10% of the cost

I have been working through a few variable rate scenarios on how to get most of the benefits with minimal investment. Here is one client’s example;

Customer has the capability to do VR seeding and planting, as they operate newer drills and planters. They wanted to also have the capability to do VR fertility. In this situation they hire the local retailer to spread the 3 year p&k and in-season nitrogen.

  • Corn; VR seed with their equipment, retailer bulk spreads VR p&k the fall before on winter wheat stubble, flat rate starter on the planter, flat rate nitrogen with herbicide up front, retailer VR applies in-season nitrogen
  • Soybeans; VR seed with their equipment, flat rate starter on drill with phosphorus
  • Wheat; still working on this one, but likely VR seed, flat rate starter and then possibly VR nitrogen.

So if you are thinking of trying VR on your operation, or recommending it to a customer, I suggest starting with the equipment that puts the seed in the ground. It has one of the fastest paybacks,  and is used on 100% of the acres every year. There are many people you can hire to spread VR fertilizer as you figure this out.

Controlling Glyphosate Resistant Fleabane in Soybeans

Every soybean field, (I do mean every) must have a fail proof strategy for controlling this weed. If you are growing dicamba tolerant soybeans, that is a good strategy. If not, there are some options. The ones I like include using metribuzin (active in Sencor). In Peter Sikkema’s research, when he used Eragon plus Sencor he got 98% control. Eragon burns off the live ones and Sencor gives some residual. Another option includes using 2,4-D before planting. NuFarm is promoting Blackhawk plus Sencor. Pointing out that in Dr Sikkema’s research it is giving 98% control.  Corteva is suggesting that you use their Elevore and Canopy Pro (Classic plus metribuzin). (All combinations are made believing you will be adding glyphosate)

More on Liquid Starters

One reader said “I liked your article on liquid starters but you missed some points on others like 10-34-0. There is also a good product from Helena 8-24-4 and other products from Cangrow and Agroliquid” Last issue we showed how 5 gallons 6-24-6 would be equivalent to 100 lbs /ac of 3-14-3. So really not much N or K but significant P.

1) There is no difference in the plant availability of P whether liquid or dry. Lots of discussion of ortho vs. poly phosphates in liquid starters. To the plant there is no difference.

2) Liquid pop up has the advantage of being right on the seed. Hard to get enough dry fertilizer at significant rates right on the seed. But not impossible. Just not worth the trouble.

3) You do get a starter effect by placing dry in a 2 X 2.

4) Zinc, if needed, you need at least 1-pound per acre. Liquid starters at most probably can only get 10% of that amo­­unt.

5) Other liquid starters such as 10-34-0 are missing K. Long ago research by Dr Jay Johnston, Ohio, showed the importance of K in a no till starter. I think sometimes conventional tilled fields experience no till conditions, so I like to have K in a starter, unless K levels are high.

6) There is a difference in the quality of liquid starters. At one time there was an inexpensive 10-34-0, which was made from “spent acid” This was acid that had been used to clean metals in factories. This product had other heavy metals which caused some seed safety issues on light soils under dry conditions. Buy from a reputable dealer.

7) Salt index – 10-34-0 does have a higher P value, but in discussion with the Anderson’s territory rep, you need to watch rates on lighter soils. The Salt Index per Plant Nutrient, takes the Salt Index and divides it by the total actuals nutrients in the formulation. So even though 10-34-0 has a higher analysis, it also has a higher salt index and higher salt index per unit of plant nutrient than 6-24-6. Also, 100% orthophosphate starters are made with potassium hydroxide, where as a blend or 100% polyphosphate may be made with potassium chloride, which also leads to a higher salt index.

Table 1 - Anderson's Liquid Starter Salt Index Chart

Phosphates in Liquid Starters

For phosphorous to be taken up by the plant it must be in one of the ortho phosphate ion forms either H2PO4-, or HPO4--. Liquid fertilizers have a certain % of their phosphate in the ortho and a certain % in the poly form. Poly phosphates are long chains of ortho phosphates. With time (dependent on moisture and temperature), these poly phosphate ions break down to form ortho ions. The theory is that it is not good to have all your phosphate in the ortho form. Why? Because ortho phosphates can be tied up in the soil, especially by Calcium.

Young corn plants do not need phosphate until about 4 weeks after planting. During this time plants are either sitting in the soil un-germinated, or living off the phosphate in the seed. If all of the phosphorous is in the readily available ortho form during this first 4 weeks it could be tied up by calcium. That’s the theory. In reality, according to Ontario researchers, there is no difference in anticipated yields between liquid fertilizers if the only thing different between them is % ortho and polyphosphate.

4R Chart – revisited

I was asked a few questions on last week’s 4R chart. Here are some additional thoughts. As I had worked through the chart, I asked myself the question, if I adjusted only this one parameter and got it wrong, what would the effect be?

Nitrogen – the nutrient impacted the greatest by rate (you have to apply it every year).

Rate – If you have too little, the rest doesn’t matter, you have given up yield. If you have too much, there is extra cost, you have the risk of lodging in cereals, or groundwater contamination.

Source – Different products have different strengths. So it depends on what you want to do. For instance urea containing products can volatilize. Ammonium nitrate (CAN) or ammonium sulphate are not prone to volatilization and do not have the incorporation requirement that urea containing products do.

You may have a preference due to price point or operational capabilities. However, if applied properly, the risks with a particular product can be mitigated.

Timing – Slightly important to get the product applied prior to the right growth stage. Research is suggesting that on some soil types, there is no benefit to split applying N in corn provided you have the right rate up front.

Place – Since nitrogen is a mobile nutrient, placement is  the least critical of all factors.

Phosphorus – the nutrient impacted the greatest by placement.

Rate – Ontario data shows a response to many rates of phosphorus. Rate is dependent on soil test P, and as result proper placement will depend on soil test levels. At low testing levels you need some P close to the seed. At high levels of soil P, seed placed P does not give the response that it gets at low soil test leves.

Source – Really are only 3 phosphorus products widely available in Ontario. MAP and Microessentials SZ (MESZ), which also contains phosphate derived from MAP and P in liquid starters.

Timing – Whether applied in the fall or in the spring, it is not as critical as being close to the seed during early growth. If you could apply a 2x2 band in the fall and then come back and plant corn in the spring, you would get a similar response.

Place – By placing P close to place at emergence, you get up to 1.5 to 3 times more effective response than if you had broadcast it. (IPNI). In all cases P must be incorporated to reduce the chance of offsite movement

Potassium – the nutrient impacted the greatest by timing.

Rate – You can apply potassium and get a yield response bigger than what you would have expected for the rate applied. The key part is to ensure you are applying enough to get a plant response.

Source- All sources of potash are more or less equal when it comes to supplying elemental K. You may choose a different source for other reasons (magnesium requirements, salt toxicity, sulphur requirements, etc).

Timing – One grower asked why timing was the most critical part of potassium. My response is that it should be applied to the soil prior to crop growth to get a response. Not as critical on how it is applied, what product is used, and to some extent what the rate was. If you surface applied potash in corn close to tasseling, you are likely to get little benefit from it. It will leach in lighter soil types (provided you had enough rainfall); however, it still needs to be applied prior to crop requirements.

Place – There is a slight benefit to banding K in low testing soils, but the response is muted compared to phosphorus.

Table 2 - 4R Nutrients by most important factor

Should I do variable rate starter fertilizer?

My quick answer is no. There is still some variability within the field, even with high intensity soil testing, so I like to use the starter as a means of reducing some of this variability that we are unable to measure. Thus you will still get a response in those areas and protect the downside risks from our soil sampling limitations.

Now here is a few scenarios I would consider having VR capabilities;

1) You apply all of your cropping system P requirements as starter fertilizer (i.e. in a notill system). In this situation you would want the ability to VR based upon crop requirements and soil test needs, while still applying an amount that would provide crop response on low testing areas. The downside is that you will be placing a high rate of P in a zone. P does not move. so this high rate of P could be inefficient

2) You run enough acres that it provides savings due to section control capabilities. Perhaps you have Precision Planting v-Drives to reduce seed overlap and point rows. In some situations, it may make sense to have something comparable for the fertilizer due to the number of acres and shape of the fields.

3) You want to run on-farm trials. If you do, please share the data!

Too Many Soybeans not the only Cause of OM Levels Dropping

One of our readers suggested there are other reasons for Ontario’s dropping OM levels. Mainly too much tillage. I agree. In a lot of areas there is no reason for fall tillage, even corn stalks going into soybeans. You can use spring conservation tillage on these fields, and get the same yield as if there was fall conservation tillage. It does mean more spring work. But on some light and rolling land, we have to reduce the amount of tillage. We need more “smart tillage”

Wrong Seed is Costly

June 12th 2017. Call from my brother-in-law. “Pat you have to come and look at my corn. It is all dead.” Desperation in his voice meant I better get there right away. “Wayne what was sprayed.” “Roundup” he said. I asked was it Roundup Ready seed. “Yes”, he said. We checked his order and his dealer. His dealer put in an order for Roundup Ready seed. Another farmer planted it. Another farmer sprayed the Roundup. We found some tags. It was not Roundup Ready corn. This happens every year. What is ordered is not always what is received. Once your seed comes in, check ALL tags to be sure you got what you thought. Then figure out where what seed will be planted. Even write on the bags. Check the seed size of all bags. Check seed count on soybeans. And write everything down. Then make provision for saving tags. Or take pictures of tags.

“What’s not going to change in the next ten years?” - Shane Parrish