Glossary of Golf Turfgrass Terms (G-L)
grain - As applied to putting greens, the tendency for grass leaves and runners to make horizontal growth in one direction, which interferes with the true natural roll of the ball. With today's low mowing heights and improved maintenance practices, the effect of grain is rarely observed on highly maintained putting greens.
gypsum - A material containing calcium sulfate used to treat sodic and saline-sodic soils. Gypsum flocculates soil particles that have been dispersed by the presence of high soil sodium or sodium added by a poor quality irrigation source. Gypsum also can be used to supply calcium as a plant nutrient.
hydrated lime - Calcium hydroxide (Ca(OH) 2 ). The product resulting from the addition of water to burnt lime (CaO). Also called slaked lime. When used to lime soils, hydrated lime acts more quickly than ground limestone, but can cause leaf burn if not applied carefully.
infiltration rate - The speed at which water moves into a soil or HTMLContent zone mixture. Frequently confused with Saturated Hydraulic Conductivity (SHC) - a laboratory procedure used to measure the speed at which water moves through the pores of the soil.
intermediate layer - The layer of fine gravel found between the gravel drainage blanket and the HTMLContent zone mixture in a USGA green. This layer serves to prevent migration of the HTMLContent zone mixture into the gravel drainage blanket. It sometimes is inaccurately referred to as the "choker layer."
ions - Many water-soluble materials which, when dissolved in water, split apart into electrically charged atoms or groups of atoms called ions. The ions with a negative charge are called anions and those with a positive charge are cations.
lime - Materials containing calcium and magnesium used to neutralize soil acidity and to supply calcium and magnesium as plant nutrients. Aids in soil flocculation; decreases soluble iron, aluminum, and manganese, and aids decomposition of organic matter in acid soils. Lime materials include limestone, shell, marl, and slag.