Renewable Farming

Foliar feeding can add bushels to beans during pod fill

One of the most profitable farming inventions since the combine is the high-clearance, GPS-equipped field sprayer. 

But we’re surprised at how early in the season many sprayer owners park their big spray rigs in the machine shed. That doesn’t happen in Europe. Small grains, corn and soybeans typically get foliar-fed through the summer, increasing seed fill and density. If it’s green, they keep spraying.

The threat of fungal disease or aphid invasions brings out the big sprayers, but “foliar feeding” to add three to six bushels to the bottom line is an unfamiliar decision.

Here are a few points we’ve learned by late-season foliar feeding soybeans since 2012. Of course we use WakeUP Summer to intensify foliar nutrient absorption, so our yield results will usually be higher than spraying with an NPK or trace element blend alone. We also use water structured with a Pursanova system: That also drops surface tension of the spray solution about 10%.

Our first test case was in 2012. The neighboring 20 acres belonging to a retired couple was rented to a nearby farmer, who planted Roundup Ready soybeans and sprayed them twice with glyphosate. This patch had been mostly in pasture for many years and tested very low in fertility. Potassium was extremely deficient, and that showed up through the season.  

We asked the tenant if we could foliar feed some strips across his field of beans to see if we could create visual and yield differences. With that permission, we sprayed a broad-spectrum trace element mix.  The photo below shows what the beans looked like in mid-July.  Severe potassium deficiency created splotchy yellow patches across the field.

Here’s how soybeans looked on the best soil in the field on July 16, 2012, when we started foliar feeding.

Just over a month later on August 18, we flew over the field with a powered parachute and took photos. You can see how the soybeans are darker green on the sprayed strips. Most of the chlorotic appearance had faded out; new growth was stronger where the crop had foliar-fed nutrients to enhance its health.

Aerial view shows foliar-fed strips 60 feet wide

A Google Earth image taken about the same time as our aerial photo showed the same striped pattern; we couldn’t help but marvel that our foliar feeding evidence was visible from space.

The summer of 2012 brought severe drought to our area in July and August. Even so, we raised yields 15% with two foliar feedings and 27% with five foliar feedings, We created a summary of this experiment after the 2012 harvest to show our WakeUP clients.  You can download the full report at this link.


The following spring, 2013,  we rented the 20 acres. Spring brought incessant rains, and we were forced to put one wet-laying field back into soybeans.  

As expected, the potassium deficiency showed up again despite a spring broadcast application of potassium. So we took this as another opportunity to see what foliar feeding could do. This time we applied foliars in alternating six-row strips. You can see the visual difference in the photo below, taken August 25.

Alternating six-row strips were foliar fed. Yield benefit: 8 bu. per acre.

All the statistics for that experiment are compiled in a PDF summary you can download at this link.

Our 2013 season brought another dry summer. We offset that challenge by spraying in the early morning, when a little dew was on the leaves.

We planted corn in this field in 2014, and came back to soybeans this year, 2015. One of the main fertility elements was applying 2,000 lbs. per acre of calcium sulfate sold by one of our WakeUP distributors, BRT of Ladora, IA.

We’ve seen significant gains in soil condition since beginning that program.  So finally, here’s a photo of part of our 2015 soybeans on the same field as in the 2013 photo above.

2015 soybeans at Renewable Farming
Here’s how our soybeans look as of August 10, 2015

The beans are about five feet high. Packed with pods and blooms as of August 10. We’ve given these beans two foliar treatments so far this season. Likely now, we will follow with three more foliars — two with Seed Set from BRT to encourage more blooming, then a final with Rondo from BRT to increase seed bulking and test weight.