Tag: SoilHealth

Soil to Substrate: Key Irrigation and Fertigation Ideas for Long Cane Raspberries

Posted on | by Josh Mays

The Comparison

Traditional soil production for soft fruit crops is a buffered system that is slow to change, whether good or bad. Fertigation mistakes in a traditional soil system isn’t necessarily going to be detrimental, or result is major pH or nutrient changes. For the same reasons, soil deficiencies or incorrect pH ranges are more difficult to correct in traditional systems.

The difference in a substrate system is significant. It is a low volume potted container area that is essentially fed by an IV nutrient solution, so fertigation changes can result in major nutrient or pH shifts within a matter of hours. So, this situation is both good and bad – you can correct your mistakes very quickly and you can make mistakes very quickly. Think of substrate as a high risk, high reward type system where your attention to detail is very important.

Moving forward with those differences in growing systems pointed out let’s lay out some key ideas for growing.

Substrate System
Soil System under Polytunnel

Plant Nutrition and PH

Starting with the right pH is key in a soil system for berries, or you’ll be fighting it all season long, but impact in season is minimal with the right fertility program. Most soil systems are high volume of fertilizers and water, with low frequency of runs for irrigation and fertigation. Fertility in soil systems are referred to in terms of pounds per acre. The southeast typically has programs of 150-30-200#/acre NPK with 30-50# S and 40-50# Ca. Fertigation is supplied commonly with potassium nitrate/calcium nitrate/UAN style blends (a 5-1-7 with 2% Ca for example). We do a lot of these type blends in traditional soil production of soft fruit, with sulfur being supplied as a supplement.

In a substrate system, the program is the opposite of a soils system. Low volume and high frequency systems run typically for 2-3 minutes at a time 20-30 times daily. Fertigation is driven by PPM (parts per million) to target crops by each stage every irrigation cycle. Fertility isn’t driven by pounds of nutrient applied per acre, but crop demand of a balanced nutrient solution based on irrigation needs. It is also critical to realize that rapid pH manipulation is possible through water treatment and fertilizer selection. Just think about the size of the pot and the tight area the plant is in. So, as a grower, you have to re-calibrate yourself in this type of system to be more targeted and understand how quickly changes can be made.

Water Quality

Water quality is the first factor in determining a proper nutrient and irrigation plan for a substrate crop. Well, municipal, and surface water is variable and should be regularly tested for pH, EC, and iron. Managing pH is very important particularly in substrate systems as highlighted earlier. Making assumptions about your source water can lead to big mistakes, test first.

Injection Systems and Fertilizer Sources

When you look at injection systems to create a fertility base like we’ve been discussing it is generally a two-stage injection system that will allow growers to run one tank that is calcium based and another being sulfur based. Calcium and sulfur don’t play nice as fertilizer concentrates, so this split is the most natural way to begin your fertility program. Both tanks can be run as a diluted mix simultaneously, pending quality and dilution rate.

Nutrient form matters! The form you choose to use can have a large impact on your pH (especially nitrogen). Water-soluble blends are the recommended best option for a substrate system due to the ability for customization. Drip grade liquid fertilizers are an option with reduced labor, but it can’t be customized as much, as the scale for drip fertigation is much larger and is made in greater quantities typically. There are many options to find the same end goal for nutrition, as long as the product form/ratios are correct.

Last Thoughts

There are a lot of factors that need to be monitored in both substrate and soil systems. You can go from a very simple, labor intensive style to monitor pH, water quality, nutrients, and E/C which does work or you can start adding layers of sensors and automation. To learn more you can reach out to our team and they can help you research solutions that will work best for you and your substrate production needs.

Happy National Ag Day!

Posted on | by triestag1

We’re proudly celebrating this year’s National Ag Day. Farmers and our ag communities are the backbone of our country. So much of what we eat, use, or wear every day is provided by agriculture.

We at TriEst Ag Group, a TriCal Group company, celebrate our farmers and are proud to be helping to create sustainable ag practices. We believe in functional sustainability and we define functional sustainability as helping growers reach both their financial and regenerative agriculture goals. It all starts with healthy soil.

Healthy soils lead to healthier plants that produce higher quality harvests. Ground-breaking information and new studies can be found at our new AgHub. https://tricalgroup.com/aghub/

So today let’s all celebrate agriculture and thank all of the people who work hard to feed the world, look after crops and livestock, and contribute to agricultural production. 

Green Beans: Low Rate Fumigation Trial

Posted on | by Josh Mays
Green Beans

Building off of our traditional success in tobacco and our more recent watermelon results in 2020-2021, we wanted to trial our low rate system in another crop that fit the specifications outlined earlier; 60-120 day crop, high value, not currently being fumigated as a standard practice. An opportunity was found in Florida with fresh market green beans. After reviewing the economics of green bean production in this region and considering the chloropicrin rate ranges we had seen increased vigor/yields in other crops, the following protocol was set for the trial:

  • Evaluate 85# broadcast (25# BER) and 130# broadcast (40# BER) on fresh market green bean
  • Fumigation was applied bare-ground with a single application shank at a 6” depth while stacking a 12” bed at application. The grower followed this by double bedding immediately following the fumigation pass to increase stack from 12” to 15-18”, resulting in a final application depth of 21-24”. At planting, the bed is knocked down to an 8-10” pressed bed that’s prepared for direct seeding. This results in seed being planted directly into the fumigated zone.

The results of this study were very successful. The crop vigor and uniformity were significantly better in fumigated treatments and had a direct correlation to rate. Both rates resulted in better seed germination, larger root systems, uniform plant populations and enhanced growth versus non-fumigated. Yield results were the following:

The results of this study are quite drastic, but this work was done in a heavily cropped system in tight rotations.  This project was in the third rotation of green bean on this farm, with no previous fumigation on that specific crop and grower standard yields were below average. With that said, we’ve drawn the following conclusions and thoughts:

  • Chloropicrin has the potential to maintain higher than average yields in multiple cropping cycles of green bean
  • Consistent emergence and uniform growth resulted in more yield bearing plants per acre and harvest efficiency
  • Future projects will focus on fresh rotations in both Fall and Spring, to determine ideal timing of applications and efficient use of Chloropicrin

We hope you continue with us on our low rate trial journey. Sign-up for our blogs today to keep up.

To learn more about what soil fumigation can do in your fields contact a sales rep in your area by clicking here.