Bowling Green Performance Standards (D)

13) Infiltration rate: the removal of water from the surface increases the likelihood of a game being played. High sand specification greens will typically have a minimum rate of 100-150mm per hour, although in practice this might be higher for a newly constructed green. However, for a summer sport this is arguably an over specification for greens in the UK. Sandy soil-based greens might aim for a minimum of 25mm per hour, whilst general quality greens a figure of no less than 12mm per hour might be acceptable. The rate of percolation is also important because whilst the initial infiltration into the surface might be satisfactory, if the rootzone has a compaction layer in the soil profile then the water won’t be transmitted very far and gradually the soil pores will fill up with water resulting in a waterlogged green, and this will be particularly problematic where an undesirable thickness of thatch is also present.
14) Fine particles (i.e. <0.125mm): There is little that can be done with an existing soil texture in practice, unless excessive cost is to be incurred. So, whilst parameters might be given any weighting used for an overall quality assessment might be low as this is outside the control of a ground’s manager. However, most greens have been constructed with a relatively free-draining sandy material, but this can still contain a relatively high percentage of fines. For an existing and established green a figure of no more than 30% fines might be desired, especially considering that a sandy loam in the UK Soil Textural Triangle will contain from 50% to 70% sand, and 30% to 50% silt and clay. For a high specification sand based or sand dominated green this might be a maximum of 10%.
15) Soil pH: Changing the pH of a rootzone in any significant way is usually impractical. However, the vast majority of soils will typically be within the range of pH 5.0 -7.0 which provides conditions that could range from ideal (pH 5.0-6.0), to satisfactory (pH 6.0-7.0) for a browntop bent and red fescue dominated sward. Very acidic soils of pH 4.5 – 5.0 can still produce excellent bowling surfaces, although these conditions need to be managed carefully. Where perennial ryegrass is being used within a bowling green then the soil pH would typically be given as pH 6.0 – 7.0 for optimum performance, although the less acidic the soil the more competitive annual meadow grass becomes, so there is a direct and introduced problem which can arise by including perennial ryegrass within a bowling green where the soil pH is suitable for that species. Knowing the soil pH and especially that of any applied top-dressings can help inform on the fertiliser programme, likelihood of earthworm surface activity, as well as the quality expectations from a green.
For soil pH a preferred range and acceptable range might be more desirable. Even if a soil pH is measured outside of the acceptable range, yet good playing surfaces are still produced, then care needs to be taken in deciding whether or not to adjust a soil pH to a supposedly suitable level for a specific green.
16) Nutrient levels: This is usually identified as Phosphate (P2O5) and Potash (K2O) and measured using the Defra Index scale. The ADHB Nutrient Management Guide (RB209, updated March 2022, p25) states that “Typically, maximum yield of arable crops or grass is reached at Index 2 for phosphorus and Index 2- for potassium.” (https://ahdb.org.uk/knowledge-library/rb209-section-1-principles-of-nutrient-management-and-fertiliser-use)
Fertilisers are then applied to ensure the Index is maintained at that level. Similar Index figures might be typically used for bowling greens to ensure that these nutrients are essentially always available. However, the likelihood is that an Index 1 could be quite adequate for general maintenance purposes. The aim of maximum yield (i.e. leaf growth) is certainly not a requirement for turfgrass surfaces, in fact this is the opposite of what is required, ideally availability which encourages healthy development in contrast to maximum growth which, when combined with nitrogen inputs, will require unnecessary and time consuming mowing. Relatively high levels of phosphate will also encourage clover and annual meadow in particular, with high levels of any nutrient acting as a resource for weeds and undesirable grasses. Preferred and acceptable index figures might be given, along with Magnesium which is also given in the Defra indices.