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The Root zone layer as specified by the USGA specification its’ attributes and short comings. A Proposal to improve this with particular reference to Bent grass. What are the attributes of a good putting green?. Smooth putting surface. Well drained. Perched water table. Well aerated.
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The Root zone layer as specified by the USGA specification its’ attributes and short comings.A Proposal to improve this with particular reference to Bent grass.
What are the attributes of a good putting green? Smooth putting surface. Well drained. Perched water table. Well aerated. It is important to note that these attributes hold true only when the specs are in place.
What are the short comings? • Low cation exchange capacity. • No real water holding capacity. • Organic material always a problem. • Sand is a very sterile medium. • Low natural microbial activity although this is challenged by several researchers. • Not a great growing medium for Bent grass?
Low cation exchange capacity. • Starts off with less than 1 meq / 100g. • Treat as Hydroponic system? • Salinity problems due to low buffering capability. • Nutrient balances become difficult. • Calcium problems at high pH’s. • Rely on natural organic matter build up which defeats the spec.
Organic material always a problem. • Thatching associated problems. • Deviation from spec in porosity. Increase in micro porosity (from spec 15-25%) and decrease macro porosity (from spec 15-30%). • Water holding capacity increases in top layers. (Perched water table) • Infiltration decreases. • Oxygen levels decrease.
THE TWO EDGED SWORD IN ROOT MIXES FOR GOLF GREENS. • As can be seen from the previous slide all the problems are caused by organic material in the process of decay that accumulates over time and basically “clogs up the system”. • This is why it is removed as efficiently and quickly as possible. • Organic matter is however a vital component of growing crops including grass.
Sand is a sterile medium / Low microbial activity / Poor medium for Bent grass. • In its natural habitat Bent grass (Agrostisstolonifera) can not survive without Mycorrhizae. • Mycorrhizae require several specific assisting microbes. • Sand does not test positive for these.
What is Mycorrhizae? • It is a group of Fungi that live in a mutualistic or symbiotic relationship with a host plant by colonizing its roots. • This fungus adds kilometers of hyphae or fungal strands that work as roots for the host plant. • The host plant provides the Mycorrhizae with carbohydrates and Mycorrhizae in turn provides the host plants with nutrients, water and protection against pathogen invasion.
Other benefits to Bent grass. • Poaannua (Winter grass) happen to be Mycorrhizae negative or neutral. Some discrepancy in the literature exists here. • Strengthen the Mycorrhizae association with Bent and achieve effective control from complete Winter grass invasion.
THE IMPORTANT CARBON FACTOR. • The stable carbon in Microbial Carbon can not be degraded by microbes as is the case with carbon from peat. • The stable carbon actually acts as a safe biota for microbes including Mycorrhizae and the assisting bacterial colonies.
MICROBIAL CARBON RESOLVES MOST OF THESE PROBLEMS. • USING A STABLE FORM OF CARBON WILL :- • Improve Cation exchange capacity which will improve buffer capacity in decrease salinity risk. • Improve water holding capacity without interfering with drainage. • Establish a safe biota for the important soil microbiology.
Pencross Bent grass planted with Peat on left and Microbial Carbon on right at 10% (v/v) addition in both instances. (16 days after sowing)
What conditions stimulate rapid Mycorrhizal association? • Healthy Mycorrhizae spores in abundance. • Stable Carbon. • Mycorrhizae Helper Bacteria. • MICROBIAL CARBON CONTAINS ALL OF THESE COMPONENTS.