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Growing Pulse Crops - Pulse Crops Working Group EPISODE 5, 12th May 2020
Pulse Crop Fertility
00:00:00 00:24:43

Pulse Crop Fertility

Mark Schmidt, a North Dakota Farmer, joins us to share the steps he is taking to improve the fertility of his pulse crops. Dr. Dave Franzen from the NDSU extension also chimes in to share what current research and recommendations are available for pulse growers. 

Mark discusses his thought process in working through what crops to plant this season especially in the current global climate that is “just unlike any other year that I’ve farmed.” His persistent battle with root rot has led to planting more rotations as a form of mitigation. He now grows “two or three different crops in between (his) pulse crops.” Like many, Mark mentions that ongoing research and recommendations can at times seem like they contradict previous recommendations making it difficult to always know the best course of action. We visit with Dr. Dave Franzen to provide some direction with pulse crop fertility.


“Inoculation with proper inoculant is just really important….So that’s a big thing in the area where the pulse crops are grown.” - Dr. Dave Franzen


According to Dr. Franzen, Potassium, Phosphorus and Sulfur are not needed in large quantities in the North Dakota area. Monitoring the type of soil you have is much more beneficial than trying to assess these levels as you can predict what is needed. He typically suggests a small amount of Phosphorus and soluble Sulfur if the soil type suggests it.  Potassium is rarely needed and Nitrogen only required depending on the crop. “In the absence of any diagnosis, putting a little bit on is probably not a bad plan,” says Dr. Dave Franzen. Micronutrients like “Zinc, Manganese, Iron, Molybdenum” are generally of little concern in his experience and not worth the added expense. 


“We are having an emerging problem with acid pH in the west where most of these pulse crops are grown in long term, no till in particular.” - Dr Dave Franzen


Acidity is observed from the bacterial process when “ammonia goes to nitrate.” A lot of crops cannot be successful in an acidic environment and will require an additive to help neutralize the pH. The sugar beet industry and municipal drinking water facilities produce a byproduct that can serve to neutralize the pH but is difficult to transport and spread. With limited limestone sources, using these byproducts may become more significant and a higher priority if the pH continues to drop. 


Dr. Franzen also helps us understand the calculation and use of Nitrogen credit. Pulse crops provide opportunity for nitrogen fixing bacteria to replenish nitrogen stores in the soil. The credit represents the “nitrogen that we know is going to be available probably in the first month or two after the next crop is planted.” Unfortunately this value is not represented in any soil tests so a calculation based on a store of data and the type of crop previously used is referenced. “Credit is something that you don’t see in the soil test but you know is going to happen.”


“The (Nitrogen credit) doesn’t come because it’s released in the nodules. It doesn’t come because it’s released in the residue. It comes because the residue is not tying up as much Nitrogen as what other choice crops might be.” - Dr. Dave Franzen


This Week on Growing Pulse Crops:


  • Meet Mark Schmidt, a pulse crop farmer in North Dakota
  • Hear about the difficulty he has in determining the best planting practices for his pulse crop rotations
  • Also meet Dr. Dave Franzen an NDSU Extension Soil Specialist 
  • Explore the significance of different micronutrients in regards to pulse growers and their effects on fertility in pulses
  • Learn about the Nitrogen Credit and how it is calculated


Growing Pulse Crops Podcast is hosted by Tim Hammerich of the Future of Agriculture Podcast.