Peat moss has many reasons to return to professional hydroponics for long-term stay.
The very beginnings of hydroponics.
History.
Peat moss substrates (a completely natural medium, used as a major ingredient in most soilless mixes) were used in hydroponics at least 20 years ago. The cultivation results were very good, but the desire to save on the quality (save costs) of the peat used led to the cultivation containers (growing bags) not being able to hold the required volume, they began to collapse, so that the roots of the plants no longer received the correct water / air ratio. Cultivation results began to deteriorate. At the same time, stone wool producers had run into economic difficulties and were very keen on the idea of starting to use stone wool in hydroponics.
So far, the default problem with the use of stone wool in greenhouses.
EU-regulations state that mineral stone wool (Rockwool) filled with living root mass of the plants may not be dumped in landfill. After one year of usage stone wool containers will be waste, which does not burn or decompose.
Peat moss or stone wool?
New type of Sphagnum peat moss growing bags is the drop-in advanced replacement to stone wool. The best way to test growth efficiency is to make a direct comparison using absolutely the same conditions. So to speak – face to face!
The comparative study was carried out in the greenhouse “Getliņi”, where several cucumber and tomato growing records have already been set.
Unstable structural raw materials.
Using inappropriate fractions and low-quality peat moss, we see that within a few weeks the growing bag begins to lose its volume, the roots are compressed, the air is no longer able to circulate freely. Insufficient irrigation alternates with flooding, where the border can no longer be captured. The soilless substrate begins to look more like a mass of mud, which is not acceptable in professional horticulture.
Resolve the issue of volume stability.
Using new technologies combining with traditional handicrafts, we have the opportunity to reduce the proportion of fine particles in the growth substrate. The role of sod (block) peat is very important. It is able to maintain a stable substrate architecture for many years after development, giving the substrate properties that the milled peat fractions cannot provide. Higher costs are to be expected here, but the results outweigh any investment. Today, the demand for high-quality sod peat is so high that even large producers are no longer able to meet the growing demand.
Cucumber seedlings after 3 weeks on peat moss growing bags
3 weeks after transplanting into growing bags.
After transplanting, the same drip system settings were used as for standard stone wool bags. Both the solution flow rate and the nutrient concentration were identical. Cucumber leaf development parameters were measured and compared with control plants on rock wool. The first results were very gratifying, because even without a special supply system to adapt to the new conditions, cucumbers grew just as well on the control group. The root system quickly spread through the entire volume of the bags, ensuring good fluid uptake conditions. From the beginning, there was some concern that peat could retain more water, thus reducing the amount of minerals ingested, but this was not the case, the drainage was adequate and the EC values at the inlet and outlet met the required values.
Structural stability.
As can be seen in the pictures, the shape of the bags remained very stable, with no signs of shrinkage, which shows that the special peat substrate is doing its job perfectly. In principle, this is also one of the main tasks that had to be dealt with.
Peat moss against stone wool. Just after 3 weeks
The new plant has quickly adapted and managed to fully master its new territory, from which to obtain the necessary nutrients for rapid and successful development. The first harvest of cucumbers is expected very soon.
How did cucumbers develop in 4 months?
It was compared:
1. Productivity. How many kg of cucumber yield was obtained.
2. How well the plant absorbed nutrients and was able to use them.
3. How evenly the plant developed and how it affected the overall yield.
4. Could a common recipe be used for both comparative groups so that no investment is needed in adapting the system.
5. How about peat moss structural stability under weight of huge cucumber plant?
Peat moss against stone wool. Just after 4 months
Cucumber yield in 85 days. Comparative diagram for peat and rock wool
The aim of the study was to prove that peat provides as good plant development conditions as years-tested and very popular rock wool. The diagram shows that the cucumber yields are identical in both groups.
Complete test results. Nutrient uptake rates in cucumber leafs.
Nutrient concentrations were measured in new leafs 6-7 from the top and leaf under cucumber in cigar study. Diagram shows that there is no statistically significant difference between nutrient uptake from peat moss soilless hydroponic growing bags and rock wool growing bags.
Structural stability.
Within 4 months, the specially developed peat moss mixture has fully maintained its stability even under the very heavy weight created by the huge plant. This means that there are no obstacles to the exchange of air and water, the roots of the plant grow freely and receive the necessary nutrients.
Growing bag height and volume.
The height and volume of the peat moss growing bags (right side) did not change, maintaining the initial volume and, above all, the height, which allowed to fully ensure the good development of the root system. On left side is stone wool growing bag. No difference in both height.
Greenhouse experiment demonstrated that plants grown in the pure peat moss substrate rooted more easily than plants grown in the cocos coir substrate or mineral wool.
Utilization.
What happens when the crop is harvested and the greenhouses are prepared for the next one?
One of the biggest reasons why organic (peat moss) substrates are increasing in popularity is due to disposal options, as nearly organic substrates are able to be composted.
The vast amount of solid waste produced each harvesting season is one of the greatest problems associated with greenhouse horticulture. In particular, the disposal of used growing media arising from the soil-less cultivation of vegetables in mineral wool creates serious difficulties. The non-biodegradability of these mainly inorganic substrates causes environmental concern.
It is no longer possible to simply throw out used stone wool bags or scatter them in the field, it is not possible. Used bags have to be disposed of as construction waste and that is very expensive. The bags must be dried after the end of the season so that you do not have to pay for the water left in them. It is estimated that the disposal of stone wool bags entails the same costs as the purchase of the bags themselves.
The results of this study show that organic growing bags are promising and very competitive alternatives to mineral wool. We’re continuing our experiments and looking to expand them significantly. Assessing the economic aspects will play an important role here. There is reason to believe that the use of peat moss growing bags in modern horticulture is much cheaper and more convenient.
LAST REMARKS
The following becomes more interesting
We used double rows to increase plant density per m2. A detailed description will follow.
