Herveld, The Netherlands
Lumbricus, Environmental Research & Consultancy
Turfgrass (Agrostis capillaris, var. Cleek (DLF))
RootFit, Flexx, Topmix 8-5-8, FertAmino 7-2-2 & PlantForce
Objective
This study aimed to evaluate whether the GrowSolutions strategy (treatment F) improves turfgrass performance compared with reference treatments and a fertilised control under nitrogen deficit conditions. The experiment used nitrogen gradients to successfully and consistently create a controlled nitrogen deficit in turfgrass.
Treatments
The nitrogen deficit experiment evaluated seven treatments (A-G) with six replicate pots per treatment, in a complete randomized design across three blocks. Over two months, repeated non-des-tructive measurements and destructive biomass harvests were conducted. Pots (19 cm depth, 1,539 cm³) contained an 80/20 sand-heather compost mixture (pH 5.5; 1.2% organic matter; C:N ratio 24; bulk density 1.336 g/cm³). Biostimulants (B–G) were applied per manufacturer specifications, with nitrogen standardized to isolate biostimulant effects. Nitrogen stress was imposed using a gradient of the following three nitrogen supplies: High N (120 kg/N/ha), Medium N (80 kg/N/ha), and Low N (40 kg/N/ha). This trial info sheet focusses on the results after Low N (40 kg/N/ha) application.
- Treatment F (GrowSolutions) consistently increased turfgrass performance under nitrogen stress.
- Turf treated with GrowSolutions showed the greatest height, highest vitality, and highest NDVI index, indicating clear nitrogen deficit-mitigating effects.
- Other treatments displayed limited or inconsistent responses, highlighting the robust and reliable benefit of the GrowSolutions under severe nitrogen deficit.
Turfgrass growth height under low N (40 kg/N/ha)
Growth height was measured biweekly using a prism above 8 mm cutting. Under nitrogen deficit (low N), treatment F (GrowSolutions) consistently produced the highest turfgrass in week 4 to 8, compared to the other reference groups. This indicates that the strategy of GrowSolutions has a growth-promoting effect on turfgrass even under low N availability.
Turfgrass vitality and NDVI index under low N (40 kg/N/ha)
The vitality was scored visually on a 1-10 scale. Under low N, treatment F (GrowSolutions) showed the clearest positive effect on the vitality compared to the control (A) and other reference groups. Additionally, the NDVI was measured non-destructively with a Fieldscout TCM 500 meter. Under low N, treatment F also performed better than the other groups. Other treatments showed overall lower NDVI score. In general, the strategy of GrowSolutions seems consistently beneficial even under the lowest amount of N application.
The GrowSolutions strategy (treatment F) consistently improved turfgrass performance under nitrogen stress. Turf treated with GrowSolutions strategy maintained noticeably better height, vitality, and NDVI, demonstrating reliable enhancements in growth, stress resilience, and overall turf quality, while other products showed limited or inconsistent effects.
