SUSPHOS: Sustainable phosphorus (P) fertilization on golf courses

Summary

Phosphorus has large environmental impacts and is the plant nutrient of which global reserves are most limited.

• WP1 focuses on turfgrass grow-in; i.e. the developmental phase that is usually considered to require most P, especially at low soil temperature. In spring 2017 and 2018,turfgrass coverage, clipping yield, root development and P uptake at constant nitrogen (N), but increasing P rate, were studied over a 7-8 wk period after sowing creeping bentgrass in cylinders filled with silica sand (pH:5.3; Mehlich 3: 12 mg P/kg) in the Ås phytotrone at 7, 12 and 17 °C. While control cylinders without P fell significantly behind, development of turfgrass coverage after seeding did not respond to a fertiliser P/N ratio > 0.12 (STERF recommendation for established turf ) at any temperature. There was no indication that more P is required for root than for shoot growth; in fact, root/top ratio decreased with increasing P rate.

• WP2 investigates the effect of increasing temperature on green-up and early spring growth of established turf. Two time-replicates were conducted in the Ås phytotron in spring 2017 and spring 2019 (Photo 1). For this, 12 cm deep cylinders were taken shortly after snowmelt/soil thaw from a 4-6 year old creeping bentgrass green (pH: 5.6; Mehlich 3: 34 mg P/kg) and transferred to the phytotron at 7, 12 and 17 °C. The pots were fertilised with increasing P as either granular or foliar fertiliser (same amount of P) during the first 5 weeks. Colour/green-up and clipping yield showed a strong effect of temperature, but a small effect of increasing P rate. These results indicate that low soil temperature cannot be compensated for by increasing P inputs. The lack of visual effect of P in this experiment was in agreement with MLSN, as the initial Mehlich(3) P-level was 34 mg P/kg soil (the MLSN-guideline is 18). Foliar P input showed no advantage over granular P input at any temperature.

• WP3 field trials were started in China, Netherlands, Sweden and Norway in 2017 and supplemented with a new trial in Germany in 2018. The trials compare three different P fertilisation concepts: MLSN, SLAN (old American standard) and Scandinavian Precision Fertilisation (SPF). The results for turfgrass quality 2017-2019 showed few significant effects, but tendencies for more moss without P fertiliser at Princenbosch in
the Netherlands, more Poa annua with increasing P rate in Falkenberg, Sweden, and slightly deeper roots without P in Dütetal, Germany.

 

Project background:

Phosphorus (P)
results in eutrophication of freshwater and is the plant nutrient for which global reserves are most limited. Many countries have lowered fertilizer guidelines for P in agriculture, but not for turf. STERF’s Precision Fertilization recommends P inputs at a constant ratio of 12 % relative to nitrogen, but this seems redundant for many soil types. The objective of this project is to generate knowledge on how fertilizer costs and environmental impact can be reduced by adjusting P fertilization to soil P according to ‘Minimum Levels of Sustainable Nutrition (MLSN)’ (Woods et al. 2016). In the  study, the need for more P at low temperature and during turfgrass (re)establishment is tested in greenhouse trials, while the MLSN guideline for P is tested on golf greens in Europe and China. Results are spread through STERF, GEO and FEGGA.

Fosfor (P) er en kilde til forurensning av ferskvann og samtidig det plantenæringsstoff der verdens reserver er mest begrenset. Mange land har redusert gjødslingsnormene for P i landbruk, men ikke for gress til grøntanlegg. STERFs gjødslingshåndbok tilrår gjødsling med 12 % P i forhold til N, men dette er trolig overflødig på mange golfbaner. Målet med dette prosjektet er å skaffe kunnskap om hvordan gjødslingskostnader og skadelige miljøvirkninger kan reduseres ved å tilpasse fosforgjødslinga til ‘Minimum Levels of Sustainable Nutrition (MLSN)’ (Woods et al. 2016). I prosjektet skal behovet for ekstra fosfor ved lav temperatur om våren og i forbindelse med (re)etablering av greener undersøkes i fytotron, og MLSNs grenseverdi for P skal etterprøves på golfgreener i Europa og Kina. Resultater vil bli kommunisert gjennom STERF, GEO and FEGGA.

Hållbar fosforgödsling på golfbanor

Fosfor är en källa till förorening av sjöar och hav och det är en begränsad naturresurs med risk att ta slut inom en nära framtid. I många länder finns stränga restriktioner när det gäller fosforgödsling. Det är därför viktigt att skapa optimala gödslingsstrategier för nordiska golfbanor dvs strategier för hur gödslingskostnader och negativ miljöpåverkan kan minimeras. I projektet medverkar forskare och praktiker från flera länder i Norden, övriga Europa och Asien. Projektet kommer att pågå under fyra år och genomförs vid NIBIO försöksstation i Norge med fältförsök på olika platser i världen.

 

Contact
Trygve S. Aamlid

Trygve S. Aamlid, NIBIO Division for Environment and Natural Resources, Turfgrass Research Group, Landvik, N-4886 Grimstad, Tel: + 47 90 52 83 78. E-mail: trygve.aamlid@nibio.no

FACTS
Category: Water, nutrients, construction
Status: Ongoing
Project period: 2017 - 2020

Fundings (kSEK)

  2017 2018 2019 2020 Total
STERF 525 551 452 458 1 986
 Other  149  149  149  145  593
 Total  674 700  601 603 2579

 

Objectives

Principal objective:

Economic savings and lower environmental impact by reduced and more targeted fertilization with phosphorus (P) according to soil analyses.

Subgoals (corresponding to workpackages (WPs)):

  1. Determine the need for extra P fertilizer for turfgrass establishment or reestablishment on sand-based golf greens with low soil P values and at various temperatures (WP 1)
  2. Determine the effect on time of green-up and turfgrass quality of foliar or granular applications of increasing amounts of P at various soil temperatures in spring (WP 2)
  3. Document effects on turfgrass quality and fertilizer costs by switching form conventional SLAN-based fertilization to SPF or MLSN-based fertilization on golf course representing a range of climatic zones, soil types and turfgrass species.

Project participants

Trygve S. Aamlid

Head of Research

Norwegian Institute for Bioeconomy (NIBIO), Department for Urban Greening and Environmental Technology, Turfgrass Research Group, Landvik, Reddalsveien 215, 4886 Grimstad, Norway.

+47 90 52 83 78

+47 90528378

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