Turf grass Cultivation Tools:WHERE, WHEN AND HOW TO USE THEM IN YOUR CULTURAL PROGRAM

摘要

Unlike most other crops, turfgrass soils are rarely exposed to tillage and therefore many turfgrass soils become compacted due to traffic. Our cultivation program is our best defense against soil compaction and the myriad of problems it can cause. Inturfgrass, nearly everything we do — mowing, fertilizing, topdressing, rolling, playing games, etc. — happens on the horizontal plane. Turfgrass cultivation is one of the few things that happens on the vertical plane (I borrowed this from Dr. Trey Rogers at Michigan State). As we maintain and use turf soils, downward forces are applied and soil particles are pushed closer together. Soil pores, particularly macropores, are eliminated and the bulk density of the soil increases. If we think of an "idealsoil" we think of one that has 50% pore space and 50% solid space. When we consider that quartz is the dominant mineral in soils, then our ideal soil would have a bulk density of 1.33 g/cm~3 given that the density of quartz is 2.65 g/cm~3 (83 lbs/ft~3).A bulk density range of 1.2 to 1.5 g/cm~3 is a good working range for healthy turfgrass. Once bulk densities creep above 1.6 g/cm~3 root growth begins to be affected and at bulk densities above 1.9 g/cm~3 root growth nearly stops. Roots are not drills, they grow in the pore space, and compacted soils have less and less pore space, particularly macropore space and therefore limited root growth.