APP “Institute of Agricultural Resources and Economics”
STENDE RESEARCH CENTRE
„Evaluation of the efficacy of ChitoHumus in the covered areas of lettuce and pea pot trials”
Researchers:
MSc in Agriculture, Solveiga Maļecka,
Research assistant Margita Damškalne
APP “Institute of Agricultural Resources and Economics”
Stende Research Centre
Dižstende, 2025
The purpose of the trial:
To compare the effects of bioproduct doses on lettuce and pea green mass and its quality in greenhouse conditions.
Test methodology and conditions
| Test site | Stende Research Centre, Institute of Agricultural Resources and Economics, “Dižzemes”, Dižstende, LV-3258 | Stende Research Centre, Institute of Agricultural Resources and Economics, “Dižzemes”, Dižstende, LV-3258 |
| Commissioning client | SIA JIKO Ent | SIA JIKO Ent |
| Trial started | 2025.g. | 2025.g. |
| Trial finished | 2025.g. | 2025.g. |
| Name of the trial | Evaluation of the efficacy of ChitoHumus in the areas covered in the lettuce and pea pot trial. | Evaluation of the efficacy of ChitoHumus in the areas covered in the lettuce and pea pot trial. |
| Trial environment | Greenhouse | Greenhouse |
| Growing method | Pots | Pots |
| Series 1 | Series 1 | Series 1 |
| Crop | Lettuce (Lettuce) | Peas (Pisum sativum) |
| Variety | ‘Lollo Bionda’ | ‘Casablanca’ |
| Type of substrate | Peat substrate KKS , neutralized peat finely sifted, fraction, mm:0-7mm, moisture max. 60%, peat decomposition degree according to von Post scale: H2-H5, SIA Laflora, Kaigu peat bog, guaranteed volumetric density of substrate 140-180 kg m3, 250L | Peat substrate KKS , neutralized peat finely sifted, fraction, mm:0-7mm, moisture max. 60%, peat decomposition degree according to von Post scale: H2-H5, SIA Laflora, Kaigu peat bog, guaranteed volumetric density of substrate 140-180 kg m3, 250L |
| Characteristics of the substrate | pHKCl 5.1-6.1 EC (mS/cm: 0.10. Calcium, Ca: 1.16%; Magnesium, Mg: 0.07%.) | pHKCl 5.1-6.1 EC (mS/cm: 0.10. Calcium, Ca: 1.16%; Magnesium, Mg: 0.07%.) |
| Date of sowing/planting | August 7 | August 7 |
| Sizes of pots | 1.47 L pots | 5.7 L pot |
| Type of planting / sowing | 1 piece in a pot | 6 peas in a pot |
| Added to the substrate | substrate | sand 0.5 : 4 substrate |
| Added to the substrate | complex fertilizer + trace elements YaraMila Cropcare N:P:K(S) 11-11-21 (26), Mg, B, Cu, Mn 100g on 4 buckets of peat | complex fertilizer + trace elements YaraMila Cropcare N:P:K(S) 11-11-21 (26), Mg, B, Cu, Mn 100g on 4 buckets of peat |
| Added to the substrate | No added wetting agent | No added wetting agent |
| Treatment | Control without NPK; ChitoHumus 0.1 L ha-1 without NPK (C1); ChitoHumus 0.2 L ha-1 without NPK (C2); control with NPK; ChitoHumus 0.1 L ha-1 with NPK (C1); ChitoHumus 0.2 L ha-1 with NPK (C2) | Control without NPK; ChitoHumus 0.1 L ha-1 without NPK (C1); ChitoHumus 0.2 L ha-1 without NPK (C2); control with NPK; ChitoHumus 0.1 L ha-1 with NPK (C1); ChitoHumus 0.2 L ha-1 with NPK (C2) |
| Harvesting | Fresh biomass at market maturity | Fresh biomass at the start of flowering |
| 6.09.2025. | 26.-27.09.2025. | |
| Observations and accounting for harvest | Fresh biomass, g (weighed on OHAVS Scout laboratory scales: 620 g, d = 0.01 g). Dry matter, % (Cabinet Regulation No. 518). Leaf length, cm. Number of leaves, pcs. Root collar diameter, mm (with calipers). Root length, cm (difficult to wash out of peat; some parts break off). Leaf quality: protein in dry matter, % (elemental analysis, dry combustion); crude fibre in dry matter, % (insufficient material from unfertilised plants) (ISO 5498:1981); potassium in dry matter, % (LVS EN ISO 6869:2002); calcium in dry matter, % (GOST 26570-95); magnesium in dry matter, % (GOST 26570-95). | Plant green mass, g (weighed on laboratory scales OHAVS Scout (620 g, d= 0.01g) Dry matter, % (Ministry of the Interior Regulation No.518) Root length, cm Green mass quality: protein in dry matter, % (Element analysis, dry combustion); crude fibre in dry matter, %(ISO 5498:1981); potassium in dry matter, %, (LVS EN ISO 6869:2002); phosphorus in dry matter, g kg-1 (ISO 6491:1998); NDF dry, % (LVS EN ISO 16472:2006); ADF dry, % (ISO 13906 : 2008) |
| Test reports | TN-103/25, 07.10.25 | TN-125/25, 08.10.25. |
| Area to be counted | 10 plants per treatment | 60 plants per treatment |
| Number of variants | 6 | 6 |
| Number of replicates | 10 | 10 |
| Total number of variants | 12 | 12 |
| Total number of pots | 120 | 120 |
| The watering mode | As needed | As needed |
| Series 2 | Series 2 | Series 2 |
| Crop | Peas (Pisum sativum) | Peas (Pisum sativum) |
| Variety | ‘Salamanca’ | ‘Salamanca’ |
| Date of sowing/planting | 14 October | 14 October |
| Soil | field soil | field soil |
| Sizes of pots | 1.47 L pots | 1.47 L pots |
| Type of planting / sowing | 1 pea in a pot | 1 pea in a pot |
| Soil characteristics | pH 5.81, org.v. 2.03%, movable phosphorus 355.2 mg kg-1, movable potassium 236.5 mg kg-1, total nitrogen 0.81 mg g-1 | pH 5.81, org.v. 2.03%, movable phosphorus 355.2 mg kg-1, movable potassium 236.5 mg kg-1, total nitrogen 0.81 mg g-1 |
| Nitrogen fertilizer | YaraBela Axan N27-S4, applied at a dose of N30 kg ha-1 | YaraBela Axan N27-S4, applied at a dose of N30 kg ha-1 |
| Control without NPK; ChitoHumus 0.1 L ha-1 without NPK; ChitoHumus 0.2 L ha-1 without NPK; ChitoHumus 0.1 L ha-1 with NPK; ChitoHumus 0.2 L ha-1 with NPK | Control without NPK; ChitoHumus 0.1 L ha-1 without NPK; ChitoHumus 0.2 L ha-1 without NPK; ChitoHumus 0.1 L ha-1 with NPK; ChitoHumus 0.2 L ha-1 with NPK | |
| Harvesting | Fresh biomass at the start of flowering | Fresh biomass at the start of flowering |
| 25.11.2025. | 25.11.2025. | |
| Observations and accounting for harvest | Plant fresh biomass, g (weighed on OHAVS Scout laboratory scales: 620 g, d = 0.01 g). Dry matter in aboveground parts, % (Cabinet Regulation No. 518). Plant length, cm. Root mass, g (weighed on OHAVS Scout laboratory scales: 620 g, d = 0.01 g). Root dry matter, % (Cabinet Regulation No. 518). Root length, cm. Number of tendrils, pcs. | Plant fresh biomass, g (weighed on OHAVS Scout laboratory scales: 620 g, d = 0.01 g). Dry matter in aboveground parts, % (Cabinet Regulation No. 518). Plant length, cm. Root mass, g (weighed on OHAVS Scout laboratory scales: 620 g, d = 0.01 g). Root dry matter, % (Cabinet Regulation No. 518). Root length, cm. Number of tendrils, pcs. |
| Test reports | TA-59/25, 23.10.2025; TN-166/25, 28.11.25.; TN-167/25, 28.11.25. | TA-59/25, 23.10.2025; TN-166/25, 28.11.25.; TN-167/25, 28.11.25. |
| Area to be counted | 4 plants per treatment (series 2) | 4 plants per treatment (series 2) |
| Number of variants | 5 | 5 |
| Number of replicates | 4 | 4 |
| Total number of variants | 5 | 5 |
| Total number of pots | 20 | 20 |
| The watering mode | As needed | As needed |
| Data processing | Using Microsoft Excel | Using Microsoft Excel |
| Special requirements | - | - |
Biological product treatments: lettuce
| Treatment | 1., 4. | 2., 5. | 3., 6. |
| Product | Untreated | Biological product | Biological product |
| Name | - | ChitoHumus | ChitoHumus |
| Dose, L ha-1 | - | 0.1 | 0.2 |
| Time of use | - | 22.08.2025. 29.08.2025. | 22.08.2025. 29.08.2025. |
| Method of processing | - | spraying | spraying |
| Water consumption, L ha-1 | - | 200 | 200 |
| Equipment | - | Hand sprayer | Hand sprayer |
Biological product treatments: peas
| Treatment | 1., 4 | 2., 5. | 3., 6. |
| Product | Untreated | Biological product | Biological product |
| Name | - | ChitoHumus | ChitoHumus |
| Dose, L ha-1 | - | 0.1 | 0.2 |
| Time of use | - | Series 1 22.08.2025. 13-14 AE 29.08.2025. 06.09.2025. | Series 1 22.08.2025. 13-14 AE 29.08.2025. 06.09.2025. |
| Treatment | 1. | 2., 5. | 3., 6. |
| Series 2 01.11.2025. 13-14 AE 07.11.2025. | Series 2 01.11.2025. 13-14 AE 07.11.2025. | ||
| Method of processing | - | spraying | spraying |
| Water consumption, L ha-1 | - | 200 | 200 |
| Equipment | - | Hand sprayer | Hand sprayer |
Results
Lettuce
Variety characteristics - medium-early variety forms thick, pronouncedly curly bright green leaves. Weight of the head 300 g. For early harvest in greenhouses, 20-30-day-old seedlings are exhibited at a distance of 20-25 cm. In open ground sown in May, June 0.5-1 cm depth, the spacing between plants 10-12 cm. Grows in 53-60 days. After ingestion, it regrowth. Plants high frost resistance - to -5oC. Variety resistant to bloom. Not bitter. Not demanding to heat, likes light. Lettuce leaves contain proteins, carbohydrates, minerals, various vitamins.
Lettuce in unfertilized variants after planting grew very slowly and did not form green mass, it was 1-2% of the green mass of fertilized variants. Two times ChitoHumus was applied (C1 and C2) at doses - 0.1 l ha-1 and 0.2 l ha-1, harvested at market maturity in fertilized version, but unfertilized were undeveloped and weight negligible.
Table
Lettuce green and dry, Stendes PC, 2025.
| Designation of the variant | Green mass per plant, g | against K, % | Dry matter of one plant, % (Cabinet Regulation No.518) | % of K | Length of the leaf, cm | Number of leaves, pcs. |
| K | 1.17 | 13.19 | 4.4 | 5 | ||
| C1 | 1.35 | 115.0 | 14.12 | 107.1 | 4.6 | 5 |
| C2 | 1.36 | 116.1 | 13.19 | 100.0 | 4.5 | 5 |
| NPK | 70.21 | 5.45 | 18.5 | 12 | ||
| NPK C1 | 65.07 | 92.7 | 5.24 | 96.3 | 18.1 | 12 |
| NPK C2 | 77.41 | 110.3 | 5.01 | 92.0 | 20.5 | 13 |
The number of pages did not differ significantly in the variants. The leaf length only in the variant - NPK C2 was 2 cm longer lettuce. Green mass was also higher by 10.3% in the variant - NPK C2 compared to the control. Dry higher was under control.
The roots were difficult to wash out in the peat substrate, so some of the roots may have broken and the mass cannot be objectively determined due to peat particles that are tightly attached to the roots. Therefore, the determined root length is not accurate (biased). The root collar diameter was equivalent in all fertilized varieties.
The quality of lettuce. The protein content in the fertilized varieties was 138-144%. In the unfertilized ones, crude fibres could not be determined because the dry matter was insufficient. The amount of wood fibre in the fertilized was equivalent in the variants. Potassium and magnesium were more in the fertilized variants, and calcium in the unfertilized variants.
For an objective evaluation of the bioproduct, the trial must be repeated, because single results give an incomplete picture of the effects of the investigated products.
Table
Lettuce roots characteristics, Stendes PC, 2025.
| Designation of the variant | Root collar diameter, mm | % of K | Root length, cm* | % of K |
| K | 0.22 | 12.8 | ||
| C1 | 0.21 | 95.5 | 11.6 | 90.6 |
| C2 | 0.21 | 95.5 | 14.65 | 114.5 |
| NPK | 1.04 | 20.8 | ||
| NPK C1 | 0.99 | 95.2 | 18.15 | 87.3 |
| NPK C2 | 0.96 | 92.3 | 20.65 | 99.3 |
*peat is difficult to wash out, so some of the roots may have broken and the mass cannot be determined objectively due to peat particles.
Table
Lettuce quality, Stendes PC, 2025.
| Designation of the variant | Protein in dry matter, % (Element analysis, dry combustion) | % of K | Crude fibre in dry matter, % (ISO 5498:1981) | Potassium in dry matter, % (LVS EN ISO 6869:2002) | Calcium in dry matter, % (GOST 26570-95) | Magnesium in dry matter, % (GOST 26570-95) |
| K | 15.74 | Not available | 3.42 | 1.32 | 0.23 | |
| C1 | 14.93 | 94.9 | Not available | 2.98 | 1.32 | 0.3 |
| C2 | 16.12 | 102.4 | Not available | 3.21 | 1.28 | 0.31 |
| NPK | 37.39 | 12.79 | 7.70 | 0.52 | 0.68 | |
| NPK C1 | 39.59 | 105.9 | 12.57 | 7.27 | 0.45 | 0.74 |
| NPK C2 | 36.64 | 98.0 | 12.96 | 7.92 | 0.6 | 0.79 |
Peas - 1st series
Peas ‘Casablanca’ is a yellow pea variety with good yields and high protein content in the seeds. It has been grown in Latvia for several years, obtaining stable harvests. Forms medium-high plants with good stem stability. Representative of breeder rights: KWS Lochow GmbH.
ChitoHumus (C1 and C2) at doses of 0.1 l ha-1 and 0.2 l ha-1, applied 3 times during growth.
The green mass was harvested at the beginning of flowering, because due to high humidity there was a strong spread of mildew and further cultivation would not be productive. The mass of the fertilized varieties was about 4 times higher than that of the unfertilized ones. The use of ChitoHumus (C1) provided 9.7% green mass increase and ChitoHumus (C2) 33.9% green mass increase.
The roots were difficult to wash out in the peat substrate, so some of the roots may have broken and the mass cannot be objectively determined due to peat particles that are tightly attached to the roots. Therefore, the determined root length data were subjective.
Protein, potassium and phosphorus contents in the unfertilized varieties were increased with ChitoHumus, while in the fertilized varieties they were reduced. Crude fibre content on the contrary. Minimum criterion for quality feed > 14% dry matter.
For an objective evaluation of the bioproduct, the trial must be repeated, because single results give an incomplete picture of the effects of the investigated products.
ADF (associated with the structural components of the plant, in particular the cell walls) and NDF determine digestibility - the quality of peas as feed. Low NDF values are generally desirable as the NDF value increases as the feed ripens.
Table 2.1
Peas green and dry, Stendes PC, 2025.
| Designation of the variant | Green mass of plant from pot, g | % of K | Avg. green mass per plant, g | % of K | Average root length, cm * | % of K | Aboveground dry matter, % (Cabinet Regulation No.518) | % of K |
| K | 18.85 | 3.28 | 34.7 | 25.91 | ||||
| C1 | 19.83 | 105.2 | 5.54 | 169.0 | 34.4 | 99.2 | 25.13 | 97.0 |
| C2 | 18.57 | 98.5 | 3.10 | 94.7 | 35.9 | 103.6 | 24.51 | 94.6 |
| NPK | 76.55 | 13.86 | 33.6 | 19.82 | ||||
| NPK C1 | 83.95 | 109.7 | 23.99 | 173.2 | 31.6 | 94.2 | 16.70 | 84.2 |
| NPK C2 | 102.51 | 133.9 | 31.08 | 224.3 | 32.1 | 95.5 | 14.52 | 73.3 |
*peat is difficult to wash out, so some of the roots may have broken and the mass cannot be determined objectively due to peat particles.
Table 2.2
Pea dry quality, Stendes PC, 2025.
| Designation of the variant | Protein in dry matter, % (Element analysis, dry combustion) | % of K | Crude fibre in dry matter, % (ISO 5498:1981) | % of K | Potassium in dry matter, % (LVS EN ISO 6869:2002) | Phosphorus in dry matter, g/kg (ISO 6491:1998) |
| K | 17.82 | 30.99 | 1.97 | 1.59 | ||
| C1 | 25.04 | 140.5 | 22.95 | 74.1 | 4.60 | 6.73 |
| C2 | 22.22 | 124.7 | 24.44 | 78.9 | 4.28 | 5.98 |
| NPK | 22.81 | 26.10 | 4.35 | 6.67 | ||
| NPK C1 | 17.61 | 77.2 | 29.93 | 114.7 | 1.97 | 1.54 |
| NPK C2 | 18.60 | 81.5 | 30.36 | 116.3 | 2.08 | 1.51 |
Table 2.3
| Designation of the variant | NDF dry, % (LVS EN ISO 16472:2006) | % of K | ADF dry, % (ISO 13906 : 2008) | % of K |
| K | 46.33 | 41.41 | ||
| C1 | 38.41 | 82.9 | 31.40 | 75.8 |
| C2 | 39.25 | 84.7 | 35.66 | 86.1 |
| NPK | 42.20 | 35.35 | ||
| NPK C1 | 47.45 | 112.4 | 43.37 | 122.7 |
| NPK C2 | 46.18 | 109.4 | 39.70 | 112.3 |
Peas — series 2
Pea variety ‘Salamanca’ is a high yield potential, early, protein pea variety, with good resistance to diseases, easy to pluck, high to very high resistance to mildew. Country of origin Germany, breeder representative Saaten-Union GmbH, quality group – food.
ChitoHumus (C1) and (C2) were applied twice and the peas were grown in soil harvested from the seed crop succession field No. ICC 1, the results of the analysis reflected in the methodology. For comparison, nitrogen fertilizer was used in two variants - dose N30 kg ha-1.
Table
Peas green and dry, Stendes PC, 2025.
| Designation of the variant | Green mass per plant, g | % of K | Dry matter, % | Plant height, cm | % of K | Number of tendrils, pcs. |
| K | 10.33 | 18.14 | 58.0 | 15 | ||
| C1 | 12.48 | 120.8 | 18.32 | 68.8 | 118.5 | 16 |
| C2 | 12.24 | 118.5 | 21.3 | 68.6 | 118.3 | 16 |
| N C1 | 13.10 | 126.8 | 19.51 | 66.7 | 115.0 | 17 |
| N C2 | 13.18 | 127.6 | 16.84 | 67.6 | 116.5 | 16 |
Table
Pea root mass, length length and dry, Stendes PC, 2025.
| Designation of the variant | Root length, cm | % of K | Root mass, g | % of K | Dry matter, % |
| K | 22.95 | 7.68 | 10.64 | ||
| C1 | 23.78 | 103.6 | 8.15 | 106.1 | 11.24 |
| C2 | 26.03 | 113.4 | 9.27 | 120.8 | 11.79 |
| N C1 | 22.88 | 99.7 | 9.20 | 119.9 | 13.35 |
| N C2 | 27.68 | 120.6 | 11.06 | 144.0 | 16.32 |
The green mass in the treated varieties was 18.8-27.6% higher than in the control. Plant length in the treated varieties was also 15-18.5% longer than in the control, so the peas had one string more. The soil separates from the roots more easily than peat substrate, so it was possible to determine the root mass and it was 6.1-44% higher in the treated variants compared to the control. Root length is also more objective and was 3.4-3.6% without fertilizer, but with fertilizer was equivalent or 20.6% greater.
Person responsible for the tests
Solveiga Maļecka
09.01.2026.