In some conditions, there is better to do separate ripping and planting. These conditions can be available machinery- many bulldozers and experienced operators, soil conditions meaning hard soil difficult to go through or possibility to put together herbiciding or fertilizing.
We have got experience to do simultaneously planting and watering. Planting speed can be near 400 pcs/ hour included refills. Ripper can do in good conditions four hectare in a day. If planting head can do near two hectare a day one ripper can feed two heads.
Cost efficiency is more problematic. If you have troubles with to get employees then it will reflect also costs. Basically, this can be main reason to do it mechanically way. Ripper costs are always the same with manual or mechanical system, so only cost effect comes planting. If it is only head with doing planting and watering, planting head is much more low-priced. But you need a carrier, an operator and the head.
Still, the cost can be more lower with mechanical planting combined ripping than manual planting. The quality of planted seedling have to come first, then the easy supply chain from nursery to planting site and the most important is the percentage of living seedlings after one month.
After all, if you can combine ripping,fertilizing, herbiciding, watering and planting you need only one operator, not 5-6 employees.