Hydroseeding & Hydraulic Seeding

The method

Application equipment and formulation are two different things.

Hydroseeding is the umbrella term for spray-applied, hydraulically pumped revegetation and erosion-control systems. The term itself does not define the mixture's composition — that is determined by the formulation. Hydromulching is a supplementary term sometimes used alongside hydroseeding; it does not describe an independently defined process of its own.

In hydraulic application a pumpable mixture is sprayed onto the target area under pressure. Tank size, pump capacity and hose configuration determine reach and area output — at SRBT up to several hundred metres of throw.

The equipment is only the tool. What decides the outcome — erosion protection, vegetation establishment, long-term stability — depends entirely on what is in the mixture: mulch material, biopolymer class, carrier medium, seed spectrum and additives are configured for each site individually.

SRBT uses in-house simulation tools to calculate germination forecasts, soil temperature curves and water savings against dry seeding from a handful of core inputs — postcode, application window and site class. The result is a sound basis for decisions before work begins.

Fields of application

Where hydraulic application is used.

The method is universal — the formulation is not. Substrate, objective and accessibility determine the composition.

Hydroseeded embankments with green mulch at a newly built roundabout

Slope revegetation & infrastructure

Road and motorway slopes, railway embankments, noise barriers — fiber-reinforced formulations with biopolymer binders for lasting erosion stability under traffic and mowing loads.

Reclaimed slope covered with hydromulch and emerging vegetation

Reclamation & restoration

Post-mining land, landfills, bogs, floodplains — pedogenesis methods and site-adapted seed mixtures build biologically active soil structures on extreme sites with no natural topsoil.

Operator spraying hydroseeding slurry onto a lakeside bank from a truck-mounted hydroseeder

Water-adjacent areas

Stormwater basins, dam slopes, riparian buffer strips — exclusively fully biodegradable formulations. No polybutadiene-based binders, and seed mixtures selected for alternating wet conditions.

Chairlift on an alpine ridge with revegetated slopes

Alpine & inaccessible terrain

High altitudes, steep faces, lift corridors, avalanche defense structures — short vegetation periods call for Thermocontrol formulations. Applied from the ground or by aerial seeding.

Slope protection on a mining and landfill site

Mining, landfill & industry

Stabilization carried out alongside operations — every formulation fully biodegradable. Dust control and staged revegetation without interrupting production.

Hydromulch as a low-cost method for establishing turf

Golf & sports turf

New construction, renovation and repair to USGA standards. Formulations that leave no residues in the rootzone, with seed mixtures selected for high-performance turf.

Our approach

From site analysis to field application.

SRBT supports hydroseeding projects from the first technical specification through to acceptance — planning and execution from a single source.

Site analysis & simulation

Substrate, aspect, gradient, climate zone and the constraints of the site are recorded. In-house simulation tools model the soil temperature curve and germination forecast — before the work, not after it.

Formulation development

Mulch material, biopolymer class, seed mixture and additives are configured for the project. C/N ratio and the constraints recorded for the site feed directly into the recipe.

Execution & monitoring

Our own hydroseeder fleet, trained crews and laboratory-backed quality control. Documentation and establishment monitoring are part of every contract.

Formulation depth

Mulch material and thermal management — the underrated parameters.

C/N ratio as the key parameter

Thermocontrol — thermal management in the germination layer

Mulch material is the most frequently underrated parameter in hydraulic application. Chopped straw is still widely used — cheap, but with an unfavourable C/N ratio that microbially immobilizes nitrogen in the soil. On demanding sites that regularly leads to inhibited germination and slow vegetation build-up.

SRBT works with wood fiber mulches and project-specific carrier media whose C/N ratio is matched to the substrate, the fertilization plan and the seed spectrum.

SRBT uses its own Thermocontrol additives based on biochar and humic acid. In winter they lower surface albedo and raise the temperature in the germination layer by 2–4 °C — measurably bringing forward the usable germination window for spring and autumn seeding.

In summer the effect reverses: higher albedo, less heat absorption, a cooler soil surface — which matters on extreme sites under heat stress. Biochar is biodegradable and free of microplastics.

Technical background:

C/N ratio, water sensitivity, albedo

C/N ratio: straw-based mulches have an unfavourable C/N ratio (>80:1) that microbially immobilizes nitrogen in the soil and inhibits germination. Wood fiber mulches with a C/N ratio between 30:1 and 50:1 perform considerably better on demanding sites. SRBT matches the C/N ratio of the whole formulation to the substrate and the fertilization plan.

Proximity to water: polybutadiene-based binders persist in the water body and are unsuitable for stormwater basins, riparian buffer strips or any area with a direct connection to a watercourse. For water-adjacent areas SRBT formulates exclusively with fully biodegradable binders.

Thermal management (albedo): biochar-based additives (Thermocontrol) lower surface albedo in winter — the surface absorbs more solar radiation and warms the germination layer by 2–4 °C. In summer the effect reverses: higher albedo, less absorption, a cooler soil surface. Reduced fungal pressure is a useful side effect; the material is biodegradable and free of microplastics.

The shift in the germination window achieved with Thermocontrol is calculated with our in-house ThermoBoost simulation tool for sites across Germany and Austria, based on postcode and application window.

Planning support

Simulation-based decision-making.

SRBT uses in-house planning tools that model system behaviour from a handful of core inputs — as the basis for formulation decisions and execution planning.

TES simulation: enter a postcode → climate data → simulation of the daily soil temperature curve, the reduction in germination time and the water saved against dry seeding. Four TES product variants (TES-14/21/21-HP/30), with worldwide postcode coverage.

ThermoBoost simulation: for spring and autumn seeding across Germany and Austria — frost risk assessment, the shift in the germination window achieved with Thermocontrol, and a site-specific temperature forecast for the germination layer based on postcode and application window.

Costing tool V1.5: recipe, quantity requirement and unit price in a single pass — from site class, area, gradient and seed specification. The C/N ratio of the whole formulation and the fertilization correction are built in.

In development: sediment loss models to ASTM, particle formation composition based on soil samples, and rainfall-to-loss correlation — towards fully simulation-based planning from the soil profile to the application recipe.