Anne Friederike Borchert

Research Scientist

(+47) 412 10 568


Visiting address
Reddalsveien 215, 4886 Grimstad

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The objective of SCANGREEN 2019-22 was to find species, varieties and seed blends/mixtures of Agrostis, Festuca, Poa and Lolium that are suited for pesticide-free management of putting greens in the two major climatic zones of the Nordic countries and in the northern USA. The four test sites in the Nordic countries were Reykjavik GC, Iceland and NIBIO Apelsvoll in the the northern zone, and NIBIO Landvik, Norway and Smørum GC, Denmark in the southern zone. The two US test sites were located at Troll Turfgrass Research Facility in Massachusetts and at University of Minnesota. The trials included 30 candidate varieties representing eight different species and subspecies from 13 different seed companies/representatives, and three seed mixtures of red fescue and colonial and creeping bentgrass, a seed mixture of creeping bentgrass and perennial ryegrass and a seed blend of red fescue. Monthly evaluations of overall impression, tiller density, winter hardiness, disease and weed coverage etc., were done from three weeks after sowing in June-September 2019 until October 2022. The trial at Smørum GC was established in May 2021. The trials were established according to a split-plot design with three blocks (replicates), species on main plots and varieties on subplots. The experimental greens were mown three times per week – Monday, Wednesday, and Friday and deficit-irrigated to 80% of field capacity three to four times per week in periods without sufficient natural rainfall. Fertilizer (mean N–P–K ratio, 100–22–74) was given as completely balanced compound fertilizers every second week. Each experimental green was divided in different management levels: High and low fertilizer rate and high and low mowing. The two fertilizer rates were 10 and 17 g N m−2 yr−1 and the two mowing heights were 3 and 5 mm. Mixtures were managed at both regimes. There was no use of pesticides or plant growth regulators in any of the trials.


Sustainable phosphorus use is essential in golf course management to prevent eutrophication and overconsumption. The study aimed to investigate if phosphorus fertilization can be reduced without negative effects on turf quality. We compared two P fertilization recommendations based on soil analyses, one based on the annual nitrogen rate, and a zero-P control. The recommendations were the “minimum level of sustainable nutrition” (MLSN), which aims to keep treatment soil levels above 18 mg P kg–1 dry soil (Mehlich-3); the “sufficiency level of available nutrition” (SLAN), in which the threshold for excluding P fertilization is >54 mg P kg–1 dry soil (Mehlich-3); and “Scandinavian precision fertilization” (SPF), which recommends applying P at 12% of the annual N rate. The treatments were compared via monthly assessments of turf quality and the coverage of sown species and annual bluegrass (Poa annua L.) from 2017 to 2020 on five golf courses from Germany, Sweden, China, Norway, and the Netherlands. MLSN and SPF significantly reduced soil P at all sites compared with SLAN recommendations. Turf quality showed no significant differences. The results from the mixed creeping bentgrass (Agrostis stolonifera L.)–annual bluegrass green showed a 2 to 4% increase in annual bluegrass coverage with P fertilization over the zero-P treatments. The MLSN guideline is recommended for sustainable P fertilization on established greens with low P sorption capacity under diverse climatic and management conditions. The SPF may result in application of excess P to soils with high Mehlich-3 values, as soil analyses are not considered.


Denne rapporten gir resultater fra andre år (2021) i prosjektet"ROBO-GOLF: Bedre gresskvalitet, redusert gjødselkostnad og mindre bruk av fossil energi ved bruk av robotklippere på fairway og semi-rough". Arbeidspakke (WP1) omfatter forsøk med sammenlikning av robotklipper og manuell klipper (sylinder-klipper på fairway, 15 mm klippehøyde; rotorklipper på semirough, 35 mm klippehøyde) til ulike grasarter. Resultatene viste forskjeller mellom robotklipping og manuell klipping, som for det meste ble sett på semi-rough når det gjelder sykdommer, ugress (hvitkløver) og jordpakking. En tendens til lavere sykdomsforekomst med robotklipping ble sett spesielt på semi-rough i alle arter på sensommeren/høsten, men også i Agrostis capillaris på fairway. Mer hvitkløver på de robotklippede ruter med Lolium perenne i semi-rough resulterte i et lavere helhetsinntrykk. I arbeidspakke 2 (WP2) ble nitrogen (N) gjødseleffekten av retur av klipp med robot- vs. manuell klipping studert på fairway etablert i en blanding bestående av Poa pratensis, Agrostis capillaris og Festuca rubra. Årlige N-rater på 0, 30, 60, 90 og 120 kg/ha/år, hver delt inn i 6 like tilførsler, ble brukt over sesongen. Innsamling av klipp én gang per måned viste at tilbakeføring av klipp både for manuell og robotklipping økte gressveksten sammenlignet med når klippet ble fjernet. Samtidig var N-konsentrasjonen i klippet høyere om våren og forsommeren, men ikke på sensommeren og høsten. Helhetsinntrykket av gresset viste samme høye vurdering for robot- og manuell klipp. I WP3 ble demonstrasjonsforsøk med robotklippere sammenlignet med sylinderklippere på fairway og rotorklippere på semi-rough videreført fra 2020 på fem golfbaner i Norden. Helhetsinntrykk, dekning av ugress og sykdommer og energibruk ble registrert månedlig fra mai til september. Helhetsinntrykk i robotklippede ruter var stort sett lik manuelt klippede ruter på fairway og semi-rough. På noen datoer resulterte robotklipping i signifikant høyere helhetsinntrykk enn manuell klipping.


Since 2020, the Norwegian Institute of Bioeconomy (NIBIO) Turfgrass Research Group has been studying agronomic, environmental, and economic consequences of switching to light-weight robotic mowers on golf course fairways and semiroughs. Preliminary results from field trials in 2020 and 2021 at the NIBIO Turfgrass Research Center Landvik, Norway, and demonstration trials on one golf course in each of the five Nordic countries, showed that turfgrass quality with robotic mowing was similar to manual mowing. At Landvik, robotic mowing resulted in less disease in both fairway and semirough but more infestation of white clover than manual mowing in the semirough. A survey of players’ attitudes to robotic mowers conducted on the five golf courses showed that about 90% of the players were positive or neutral to the new technology. However, respondents asked for better adaptation of the local rules on the golf course and even the international rules of golf to robotic mowing.