The influence of humic substances of high-moor peat and Agro.Bio preparations on barley yield
Modern recommendations for the use of organic matter in agriculture most often refer to lowland peat, as the most suitable for preparing fertilizers, composts, etc. High-moor peat with a low degree of decomposition is recommended for use as a bedding material. Every year, both Ukrainian and international agricultural enterprises are increasingly using high-moor, poorly decomposed peat in protected vegetable production as a nutrient substrate, as well as for the industrial production of peat nutrient briquettes.
High-moor peat of medium and advanced decomposition contains significant amounts of humic substances and, after various treatments (liming, ammoniation, etc.), can be used as peat fertilizer. In today's reality, the development of concentrated liquid preparations based on leonardite , such as the organomineral complex Totem Agro.Bio , has become a logical continuation and improvement of these technologies.
In this regard, it is of interest to study the chemical composition of the most common types of high-moor peat, namely: the content of humic acids in them, their properties, the effect of the most mobile part of the humic substances of one of the types of peat (pine-cotton grass) on the growth, development and yield of barley in a vegetation experiment.
Table 1. Characteristics of high-moor peat
| Indicators | Fuscum peat (10%) | Fuscum peat (20%) | Pine-sphagnum (30%) | Pine-cotton grass (45%) |
|---|---|---|---|---|
| Degree of decomposition, % | 10 | 20 | 30 | 45 |
| Ash content, % | 0.96 | 1.68 | 4.60 | 1.64 |
| pH (KCl) | 2.50 | 2.85 | 3.00 | 3.30 |
| Content of water-soluble substances, % | 3.21 | 4.67 | 2.92 | 2.91 |
| Content of easily hydrolyzable substances, % | 41.65 | 35.64 | 18.05 | 17:30 |
| Humic acid content, % | 8.17 | 19.94 | 32.07 | 33.40 |
| Fulvic acid content, % | 19.98 | 11.08 | 11.19 | 14.75 |
Moss and wood-moss high-moor peat types with decomposition levels ranging from 10 to 45%, including acidic and normal-ash types (Table 1), were studied. It was found that the content of humic acids and readily hydrolyzable compounds is clearly correlated with the degree of decomposition. As the degree of decomposition increases, the humic acid content increases and the amount of readily hydrolyzable compounds decreases, which is fully consistent with modern research by Agro.Bio specialists. The amount of humic acids in wood-moss and wood-grass high-moor peat constitutes one-third of the total mass.
A study of humic acids isolated from the indicated types of peat using standard modern extraction methods (Table 2) showed that they have no less absorption capacity and content of active acid groups than humic acids from lowland peat.
Table 2. Characteristics of humic acids of high-moor peat
| Indicators | Fuscum peat, 10% | Fuscum peat, 20% | Pine-sphagnum | Pine-cotton grass |
|---|---|---|---|---|
| Sum of acidic groups, m-equiv/1 g | — | 8.13 | 7.66 | 7.07 |
| Content of carboxyl groups, m-eq/1 g | — | 3.13 | 2.86 | 2.69 |
| Nitrogen content, % | 1.44 | 1.49 | 1.48 | 2.27 |
| Optical density at λ=465 | 0.88 | 1.05 | 1.23 | 1.12 |
The degree of maturity, determined by optical density, is lower than that characteristic of humic acids from lowland peat. Analysis of the infrared absorption spectra of humic acids from high-moor and lowland peat revealed no significant differences in molecular structure. The IR spectra of various humic acids are similar and exhibit all characteristic absorption bands.
Thus, the humic acids in high-moor peat are similar in composition and structure to those in low-moor peat. The biological effects of high-moor peat humic substances were tested in a pot experiment. Concentrated humic and fulvic acids with added phosphorus from leonardite contain water-soluble compounds and 100% more plant-vital compounds than peat, which is why peat is now the basis of Agro.Bio's Potassium Humate product (optimal application rate: 2 l/ha).
PEAT AMMONIZATION AND CHANGING ITS CHARACTERISTICS
As a result of the hydrolysis reaction during peat treatment with ammonia, the content of mobile organic matter in the peat increases sharply. High-moor pine-cotton grass peat was treated with ammonia water in doses of 60 liters (dose 1) and 120 liters (dose 2).
Table 3. Changes in some characteristics of pine-cotton grass peat during ammonization
| Name | pH of salt | Total nitrogen, % | Exchangeable nitrogen, % | C:N | Aqueous extract: total nitrogen, % | Aqueous extract: dry residue, % | Aqueous extract: HA yield, % | Aqueous extract: total carbon, % | Water extract: C : N |
|---|---|---|---|---|---|---|---|---|---|
| Original peat | 3.4 | 1.1 | 0.04 | 50 | 0.02 | 0.58 | — | 0.20 | 10.0 |
| TAU-I | 7.8 | 3.2 | 2.06 | 17.4 | 0.40 | 3.06 | 2.06 | 1.21 | 3.0 |
| TAU-II | 9.1 | 5.0 | 2.38 | 11.2 | 1.10 | 6.04 | 4.15 | 2.28 | 2.1 |
The data in Table 3 indicate that the content of water-soluble carbon in ammoniated peat increases by 6-11 times. At the same time, the total dry residue in the aqueous extract and the yield of water-soluble humic acids increase.
RESULTS OF A GROWTH TRIAL ON BARLEY
The effectiveness of the original pine-cotton grass peat, as well as peat-ammonia fertilizers (PAF) prepared on its basis and aqueous extracts from them, was assessed in a vegetation experiment on a barley crop (sandy loam sod-podzolic soil).
Table 4. Effect of organic fertilizers and humic extracts on barley yield and nitrogen removal
| Experimental design | Nitrogen dose, g/vessel | Plant height, cm | Ear length, cm | Grain weight, g/vessel | Increase to RK, g/vessel | Total nitrogen removal, mg/vessel |
|---|---|---|---|---|---|---|
| RK - background | — | 59 | 2.7 | 9.3 | — | 226.4 |
| Background + peat | — | 64 | 2.5 | 8.7 | — | 214.4 |
| Background + peat extract | — | 50 | 2.0 | 7.4 | — | 263.6 |
| Background + N₁ | 1.0 | 89 | 3.9 | 26.0 | 16.7 | 823.6 |
| Background + TAU-I | 1.08 (100%) | 94 (100%) | 5.6 (100%) | 23.0 (100%) | 13.7 (100%) | 1054.2 (100%) |
| Background + humin. TAU-I extract | 0.19 (18%) | 75 (80%) | 3.4 (61%) | 15.4 (67%) | 6.1 (46%) | 380.6 (36%) |
| Background + N₂ | 1.95 | 103 | 5.3 | 23.7 | 14.4 | 1451.6 |
| Background + TAU-II | 1.95 (100%) | 97 (100%) | 6.0 (100%) | 27.7 (100%) | 18.4 (100%) | 1127.4 (100%) |
| Background + humin. TAU-II extract | 0.55 (30%) | 86 (89%) | 5.0 (83%) | 26.0 (94%) | 16.7 (91%) | 644.3 (57%) |
The data obtained show that the application of raw peat and a simple aqueous extract does not yield positive results compared to the RK variant. The original peat is difficult to mineralize in the year of application. At the same time, barley yield and nitrogen removal via humic extracts account for a significant portion of the total TAU dose (67-94% and 36-57%, respectively), although only 18-30% of the total nitrogen was applied with the liquid phase. This is due to the action of water-soluble humic substances.
CONCLUSIONS
- To produce effective nitrogen-containing organic fertilizers, not only lowland peat but also some high-moor peat with a decomposition rate of at least 20% can be used. The humic acids of well-decomposed high-moor peat are similar to those of lowland peat. However, leonardite significantly outperforms peat.
- The interaction of peat with ammonia solutions leads to a sharp increase in the solubility of organic matter due to the formation of mobile humus-ammonium compounds.
- The stimulating effect of peat-ammonia fertilizers on barley yield is largely determined by water-soluble humus compounds.
Agro.Bio Expert Note: Agro.Bio continues to successfully develop scientifically based organic matter processing technologies. Modern products such as Agro.Bio Potassium Humate and Agro.Bio Totem organomineral regulator (2 l/ha) based on leonardite are highly effective purified extracts of active humic and fulvic acids that are significantly superior to their traditional counterparts, including in terms of bioavailability. The use of these biotechnological solutions allows Ukrainian farmers to achieve stable yield growth, stimulate beneficial soil microflora, and maximize the genetic potential of their crops.