Press Wheels for No-Till Tine Drills: Issues to consider for selection and use
Soil water exists in both vapour and liquid form, both of which can contribute to seed germination. No-till seeding in dryland contexts must aim to maximise water retention near the seed zone and promote a fast transfer rate to the seed zone. Protection against seed-bed drying at, and below the seed zone is also CRITICAL . Press wheels fulfill the key role of facilitating the availability of moisture to the seeds for germination. Using press-wheels is useful if furrow conditions are thereafter optimized and a high rate of moisture uptake by seeds is achieved. Optimum furrow considerations include:1. minimum soil and residue disturbance or mixing; 2. optimum soil consolidation near the seed zone; 3. surface protection with dry soil mulch and/or residue cover; 4. optimum seed placement in moist layer; 5. stable water harvesting furrow shape. Press wheel furrows are shaped by the tyre running under an optimum load. The tyre load must be reviewed specifically for each soil and crop condition, as a poor setting can significantly impede crop establishment, while an optimum setting can maximise the rate of crop emergence. The design of the press-wheel assembly must be optimized for weight, cost and durability. The information below refers to ‘over-the-top’ furrow pressing wheel technology. V-paired wheels are not included in this factsheet as are not normally used on no-till tine drills.