Understanding Foliar Fertilisation In Turf Management

Foliar fertilization is the application of products to foliar or above ground plant parts as a pathway for the uptake of nutrition.  It has certainly been more widely adopted (or maybe we should say fine tuned) in the last decade or so but is by no means new.  It is a delivery method that has been used across turf management disciplines, for a range of purposes, for as long as many of us have been in the industry, but is possibly better targeted, for more specific reasons, using improved technologies, today compared to maybe 30 or so years ago.

Reasons for foliar fertilizing turf

Broadly speaking foliar fertilization is used either as the primary delivery pathway for turf on free draining profiles that struggle to hold granular products and / or as an efficient delivery pathway for rapid response from small dose applied often approaches in conjunction with a traditional soil applied granular program. Or under challenging circumstances as a means to circumvent limitations coming from poor root health or function. The smaller dose applied often principle suits other recurrent practices such as growth regulation programs and contact fungicide applications that themselves are better managed nowadays so tasks can potentially be combined for greater efficiency. The concept of efficiency is a strong theme where turf is managed at scale hence product development and technology evolution frequently also play into that sphere – nutrition has been no different.

The foliar philosophy in greens

The upswing in foliar fertilisation adoption has had a strong greens focus and there is a significant logic for this being the case. Greens by their very nature seek consistency. That is consistency in colour, speed and cut, consistency in roll and surface travel, and by logic consistency in growth. Taking out major peaks and troughs in growth rate is a strong enabler of surface consistency hence the wide adoption of growth regulation programs. The foliar application story is very much the Trinexapac turf quality story i.e. smaller doses via efficient pathways applied often ensures availability stays in a tight band that as a direct consequence allows a similar tight band of growth response. Tick.

The soil applied alternative whilst potentially still effective, has a less direct pathway to take and is sometimes less able to deliver short term consistency. The root system pathway has more obstacles for interference, dilution or loss and more variables in actual function. It is however the pathway better suited to delivery of larger quantities for longer duration of availability. This would be more suited to fairways and fields hence each has merit and applicability it’s just a matter of overlaying site characteristics and needs.

The philosophy extension on sportsfields that is relevant back to over-sown fairways and surrounds

Elite sportsfields have been another area of growth (pardon the pun) in the foliar philosophy but this has partly been on the back of other critical evolutions in that arena acting as drivers. High end fields are more commonly being constructed similar to golf greens meaning granular nutrition is either avoided or will form a smaller part of the broader nutrition equation as it is poorly held in the profile. Fields are also more often over-sown with cool season finer leaf grasses which often respond better than warm season grasses to foliar applied nutrition. Oversowing is as much about presentation as it is performance and function meaning nutrition is needing to be highly optimized to match the visual demands being made of the turf. They are slightly different drivers but funneling into very similar management approaches that arrive at the same high quality outcomes. An oversown fairway or surround would conceivably be rather similar to an oversown sportsfield.

Pressure for the efficient use of fertilisers

Across all forms of turf management the efficient use of fertilisers is becoming more focal. In particular the benefits that come from newer Nitrogen technologies are getting increased attention as the spotlight gets shone on matching nitrogen applied to nitrogen actually used. Losses from volatilization and / or leaching are being more closely monitored and the turf management fraternity continues to respond with improvements and better management practices.

Our understanding of nutrition efficiency has improved greatly and we now understand up to 50% of foliar applied N can be taken up in an hour, and 100% in about 4h in field situations. These are generalizations but are pretty robust ones even allowing for the fact differences will be seen season to season and site to site. Soil applied N is harder to keep in such defined windows courtesy of the greater variables involved in the soil – rootzone pathway.

Throughout all of this note a common theme is the efficiency with which nutrition enters plants when foliar applied, but an important caveat or warning needs to sit alongside this and that is this efficiency comes with an increased burn potential. Nature always has limits and boundaries. When we work with them we succeed. When we try to exceed them we run into trouble. Some of the limits with plants are purely physical such as the size of a molecule that can fit in transcuticular pores, others are biochemical as a process can only occur as fast as the prior step can be completed and the following step can proceed (or a substrate can be produced and a reaction can be catalyzed). We can try all we like nature usually wins in the end.

How Nuturf can help you

Nuturf stock a suite of chemistries and brands to cater for all your pre emergent needs and preferences. We stock all the major Group D options and can talk you through the characteristics of each to identify best fit for your site. We offer multiple formulations of Metolachlor and stock the newer option Specticle (Indaziflam). We have group D and G options in granular forms and can also offer combinations that include an NPK fertilizer.

We can sit down with you and match a sequence of product use that suits your site, your needs and your budget.