Institution: Belarusian Research Institute of Land Reclamation and Water Management (BelNIIMiVH).
UDC: 626.86 : 631.6
Targeted regulation of environmental conditions to optimize plant vital factors has always been at the core of land reclamation science and practice. However, traditional hydraulic reclamation systems historically remained restricted to one-dimensional water table management. This foundational paper substantiates a systemic transition toward multi-factor, computer-controlled regulation of water, air, thermal, and nutritional regimes on peat soils.
Contents
- 1. Limitations of Single-Factor Regulation and Nutrient Decoupling
- 2. Stationary Lysimetric Experiments with Groundwater Dynamics
- 3. Mathematical Modeling of Heat and Mass Transfer in the Soil-Plant-Atmosphere Continuum
- 4. Automated Experimental Proving Grounds of BelNIIMiVH
- 5. Multi-Factor Crop Yield Performance
- 6. Original Article in Belarusian
- 7. References
1. Limitations of Single-Factor Regulation and Nutrient Decoupling
The traditional metric used to evaluate water adequacy was the mean soil moisture content within the root-inhabited layer. However, at shallow groundwater depths (up to 1.0–1.4 m), this index proved deeply flawed: it cannot guarantee optimal plant nutrient uptake even when sufficient mineral fertilizers are applied.
During rainless periods, drying of the upper peat horizon forces root water absorption to shift into deeper horizons devoid of available nutrients. Crop biomass accumulation drops markedly. This decoupling is especially severe during periodic sluicing (sub-irrigation): raising water levels to combat drought frequently triggers a 30–40% loss in grain yield (Table 1) due to oxygen deficiency in over-saturated lower horizons and root chilling.
Optimal conditions are achieved only when the maximum of the root water absorption curve coincides precisely with the soil horizon harboring maximum available nutrients, while local moisture values remain strictly within aerobic limits.
2. Stationary Lysimetric Experiments with Groundwater Dynamics
Long-term lysimeter experiments conducted by BelNIIMiVH evaluated how controlled fluctuations in groundwater levels (GWL) govern barley productivity (Table 1).
Table 1. Dependence of barley yields on groundwater level regimes
| Year | Trial Variant | Barley Yield, g/m2 | Notes | |
|---|---|---|---|---|
| straw | grain | |||
| 1969 | Constant GWL H = 0.5 m | 353 | 309 | Lysimeters 2 × 2 m |
| Constant GWL H = 0.7 m | 309 | 293 | ||
| Constant GWL H = 1.0 m | 430 | 362 | ||
| Monotonic seasonal decline from H = 0.5 to H = 1.2 m | 666 | 556 | Dry year | |
| Abrupt 3-day water table rise from H = 1.2 m to H = 0.5 m | 525 | 305 | 45% yield reduction due to abrupt flooding | |
| 1976 | Monotonic seasonal decline from 0.6 to 0.95 m | — | 688 | Lysimeters 1 × 1 m, dry season |
| Temporary rise to H = 60 cm during peak vegetative growth | — | 516 | ||
| 1977 | Monotonic seasonal decline from 0.6 to 0.95 m | — | 712 | Lysimeters 1 × 1 m, wet season |
| Temporary rise to H = 60 cm during peak vegetative growth | — | 672 | ||
| Same temporary rise during grain filling | — | 673 | ||
The trials unambiguously proved that sudden water table elevations during crop development impair cereal yields. Highest yields are secured through smooth, natural receding of water tables matching downward root penetration.
3. Mathematical Modeling of Heat and Mass Transfer in the Soil-Plant-Atmosphere Continuum
To eliminate conflicting environmental factors, BelNIIMiVH developed mathematical models for the transfer of moisture, heat, gases, and dissolved salts, resolved numerically via mainframe computers. This allowed predictive charting of moisture and temperature profiles alongside active root absorption zones.
Subsequent models conceptualized the entire biophysical system: “groundwater — soil — plant — surface air boundary layer”. By solving two-dimensional moisture transfer equations across saturated and unsaturated zones, they accurately forecast transpiration rates and plant water chemical potentials.
4. Automated Experimental Proving Grounds of BelNIIMiVH
These theoretical concepts were materialized across dedicated testing grounds in Belarus:
- Polesian Experimental Peatland Station (POBS, Luninets):
- Commissioned in 1978: an automated sprinkling sector (11 ha) driven by programmatic timers and in-situ soil moisture thresholds;
- Operating since 1975: a vertical tube-well drainage sector (400 ha) capable of lowering regional water tables while reusing pumped groundwater for topsoil sprinkler irrigation;
- “Lesnoye” Sovkhoz (Kapyl District): Joint testbed with the Moscow Hydro-Reclamation Institute for automated sprinkler and drainage control;
- “Kalinovka” Site (Lyuban District): A 40-hectare tract featuring underground water reservoirs and forced mechanical aeration of the peat root zone;
- Telemetry Instrumentation: Jointly designed with the Agrophysical Research Institute (Leningrad), featuring automated data-logging stations capturing micrometeorological and soil-plant parameters.
5. Multi-Factor Crop Yield Performance
Yield responses achieved by transitioning from conventional agronomy to comprehensive multi-factor regulation are detailed in Table 2.
Table 2. Crop yields under varying degrees of environmental factor regulation, c/ha
| Experimental Treatment | Yield, c/ha (centners per hectare) | ||
|---|---|---|---|
| Perennial grass hay | Barley grain | Potato tubers | |
| Natural background with recommended PK doses | 75.9 / 102.1 | 56.8 / 37.2 | 480 / 247 |
| Same + supplemental mineral nitrogen fertilization | 108.8 / 139.5 | 54.3 / 39.6 | 526 / 260 |
| Same + nitrogen and automated sprinkler irrigation | 128.2 / 150.8 | 52.7 / 35.9 | 652 / 298 |
| Same + peat sand mulching (thermal optimization) | 134.8 / 152.2 | 55.2 / 37.2 | 648 / 340 |
Note. Numerator: dry 1976 season; denominator: wet 1977 season. Plot area 36 m2, fourfold replication.
Comprehensive regulation boosted perennial hay yields to 150–152 c/ha of dry matter (15 t/ha) and potatoes to 648–652 c/ha. The study confirmed that targeted factor compensation (such as offsetting drought-induced nitrogen starvation via automated micro-sprinkling) provides an indispensable tool for programmed high-yield crop cultivation on peat soils in Belarus.
6. Original Article in Belarusian
Р. І. АФАНАСІК, У. М. ПЯТНІЦКІ, М. С. ШАБАН, В. П. ТРЫБІС, Л. Б. АЎДЗЕЕЎ
КОМПЛЕКСНАЯ МЕЛІЯРАЦЫЯ — АСНОВА ПАВЫШЭННЯ ЎРАДЖАЮ СЕЛЬСКАГАСПАДАРЧЫХ КУЛЬТУР
Накіраванае рэгуляванне ўмоў знешняга асяроддзя месцазнаходжання раслін з мэтай аптымізацыі іх фактараў жыцця было заўсёды ў цэнтры ўвагі меліярацыйнай навукі і практыкі…
[The complete Belarusian original is preserved in the corresponding Russian edition].
7. References
- Shaban N. S. et al. Soil Science (Pochvovedenie). — 1975. — No. 7.
- Gilis M. B. Rational Methods of Fertilizer Application. — Moscow, 1975.
- Demidenko D. M. Land Reclamation and Water Management. — Minsk, 1978. — Issue 1.
- Afanasik G. I. Reclamation of Peatlands and Their Agricultural Utilization. — Minsk, 1977.
- Nerpin S. V., Chudnovsky A. F. Energy and Mass Transfer in the Plant-Soil-Air System. — Leningrad, 1975.
- Afanasik G. I. Reclamation of Waterlogged Soils. — Minsk, 1974.
Manuscript received February 15, 1978.