Building the Capacity of an Immerging Hydroponic Farm in Guyana

By Andrew Blunk, F2F Volunteer in March 2022

This blog was taken with permission from his blog on YOOMBEEKINBARACHUUGUBACHUU. It has been edited for length.

About the Assignment: Andrew Blunk supported CV Farms as a Hydroponics Expert. Mr. Blunk assessed the operations of CV Farms, focusing on yield and shelf life of their crops. Mr. Blunk is a Plant Science Consultant for Grateful Greens Microgreens in Vermont.

A little history about hydroponics in Guyana.

In 2005 there was a bad flood in Guyana that caused crop failures across the country and 40% of the country to lose personal possessions and property 2005 Georgetown flood – Wikipedia. Consequently, the agricultural sector looked to options that could withstand extreme rainfall events. This is pretty common everywhere in the world currently- farmers are very aware/experiencing that climate change is affecting weather, especially rain, and are looking at how to grow food when the rainy season is less predictable. Less predictable means, more instances of extreme rain events and also more periods of extended drought. 

A common sense answer to this dilemma of ‘how to grow food with unreliable rain?’, is to opt out of the rain, and instead grow under a roof supplying one’s own water (Of course a more-common-sense answer is to not do all that stuff that causes the unpredictable rain in the first place, but that one’s a bit more challenging!) A way to do this is hydroponics- growing plants without soil, in water and nutrient solutions. Guyana had an initiative after the flood to educate farmers on hydroponics so that they could make the transition away from dependence upon the weather, to avoid crop failures like the 2005 flood; and be more resilient generally going forward. Additionally, by not being dependent upon rain, hydroponics allows for year-long production which can greatly improve the amount a farm can produce.

While growing hydroponically can be understandably attractive, it offers many challenges. Many of the functions of a natural farm now have to be managed by the farmer. The function of soil to act as a substrate for the plant to hold itself up, supply nutrients to the plant roots, and hold water and air for the roots, now has to be recreated by the farmers. Farms that use hydroponics need containers for the plants, pumps for water, air pumps to aerate the water, and nutrients to supply to the plants. Its a complete “systems change” and greatly changes the roles of the farmers. 

Some would say- why would you change so much and make your job so technical when you can just grow in soil? And to that question farmers have many different answers- they want to save time on weeding/soil management, they had a huge crop failure one year from rain and don’t want to risk that anymore, they want to grow during seasons when there is no rain, it allows them to grow a crop that can’t grow as easily in their climate otherwise, it’s interesting, and others too. In my short time in Guyana, many people that I talked with outside of the farm, were questioning why one would grow in hydroponics when soil grown is so much easier; it’s not a bad question and highlights the impressive commitment to a change that a farmer needs to make if they are wanting to grow this way.

For two weeks I worked with an impressive farm called CV Farm that is growing diverse vegetables in hydroponics. They grow many things- spinach, mint, parsley, lettuce, kale, peppers, tomatoes and more all year long and grow them very well! However, they were experiencing some crop issues that they wanted to improve. Amazingly, the farm owner was not a farmer before being introduced to hydroponics by the Partners of America hydroponic program and he continued his hydroponic education through YouTube, to now be managing a large impressive partially indoor farm. He wants to start cultivating mushrooms and fruit soon.

Do you want to know what we actually did? 

The main issues that CV farm was experiencing were nutrient-affected disorders found in tomato (blossom end rot), lettuce (tip burn) and arugula (light-colored leaves- interveinal chlorosis). 

In my time at the farm, we first identified the main issues and then went over all management practices to try and determine where the issues could be coming from. In hydroponics, a nutrient issue could simply be from an inefficient ratio of nutrients added to the water, but it could also be caused by environmental conditions especially humidity, heat and sun exposure, management practices that don’t thoroughly mix the nutrients in the water or create nutrient solution (water mixed with nutrients) environments that are not ideal plants (low oxygen, high algae for example) or even more simple mechanical failures. Just like human health, are we getting the right nutrients? Are we in an environment that’s okay? Is our management (exercise, hygiene, self-talk, etc) okay?

Basically, we did an audit of the practices to see if there was anything that could be improved, and also explained the issues being faced. We then began to trial the different changes to see which one was likely the main contributor to the issues being seen. There were some environmental changes we did, and some management of pruning and mixing of nutrients we changed as well. But to make the story shorter, I’ll just write about the overarching issue we found.

Generally, our overall findings were that the source that the farm was using for the recommended concentration of nutrients to be provided to plants was not reliable and because of this the concentration of nutrients being used on the farm were much too high. Return to human analogy, we were feeding the plants too many things, leading to health issues.

So the problem wasn’t too little nutrients, causing nutrient disorders, it was that there were too many nutrients being provided to the plants, that they were having a harder time taking up nutrients. This can be an issue because of something that is called “ionic competition” and also too many nutrients can cause the water to be more difficult for the plant to take up, leading to nutrient and water issues called “osmotic stress”. A way to think about this issue is, if you want 5 people (desired nutrient) to enter through a human sized doorway (pore for nutrients to enter on a root), but you filled the room with some elephants, horses, cow and maybe a few giraffes that all want to enter the doorway too; its going to be much harder for those 5 people to ever enter the doorway. In a way, this is what happens to calcium (the nutrient issue of our lettuce and tomato) when there are too many nutrients in solution- too much competition for that doorway entrance. Notably this issue doesn’t as easily happen in the soil, because when nutrients are at “too high” concentrations, the soil acts as a buffer and can mediate the availability to the plant, reducing the ionic competition and potential for osmotic stress.

We changed some of the nutrient solution calculations and re-filled the reservoirs for the crops with the new solution. The arugula quickly saw improvements; and we started a new crop of lettuce and changed our nutrient solution for tomato as well. While my time at the farm is finished, the farmer and I plan to be in contact throughout this growing season to continue to monitor the changes that we made.

In most places around the world, hydroponics production is expected to become more and more popular, as farms adjust to the changing climate, and also demands for crops increases with an ever-increasing population. This is partially what makes working in this indoor/hydroponics agriculture industry so interesting to me- it’s a very visible response being made to the changes in our world.