Anyone who has been farming for any period of time has undoubtedly walked away from their computer for too long, only to discover they have missed that window of opportunity between planting seeds and harvesting the plant, and everything has returned back to nothing. As with other professions, you have to remain mindful of tool repairs also for fear of them becoming irreparably damaged.
What I am wondering, however, is if there is any benefit of planting 20 fields of something as opposed to 50, or even 100, for example. It seems the less fields you plant at a time the greater your yield is, but I would like to get others' input on the matter. Thank you.
The yield of each field has nothing to do with how many fields you plant before harvesting them. How many fields you plant before starting to harvest only affects whether or not you can harvest the first field before it decomposes.
If your goal is just to level up the low crafting levels, you might decide to just plant fields and not harvest them. In that case you don't care about the field vanishing, and can just set the 50, 100, or whatever number of fields and walk away for a bit. This was done by some back when LOTRO first launched and it's much cheaper to do so now. Except instead of walking away they would just chat.
There are several blogs and other resources that covers this = )
To be somewhat efficient, check what speed your farming tool is. Basic tools you can sow 5-6 fields in a row and then harvest all without the first one disappearing. With the faster tools (univ. toolkit and critted eastemnet tools for certain - and I assume a couple of the other tools crit versions lvl 55-70) you can plant 10 fields and then harvest.
Note that for whatever reason, with cherry trees you can only do 5 with slow tools and 9 with fastest.
You plant the fields all in the same spot. No turning, no moving around. Set the number of fields to what suits the speed of your tools.
To harvest, use the function DEL and U. DEL selects the nearest target you can interact with, U uses this target. These are the preset keys, if you changed them around, see what you should use in keymapping options.
DEL + U
DEL + U
etc until you harvested all, then sow again and repeat.
If you press DEL+U one time too many, your character will try to move to the next target it can interact with, typically some field another gamer is sowing, a workbench or one of the farm NPCs. To avoid this, uncheck the option Move to Use. You find this option in ctrl+O / UI options (right next to the Always Loot All).
That was a quick guide.
If I am planting with the intention of harvesting, what works best for me is to plant 8 fields then harvest. I harvest with the "DEL" key to select the field then "U" to "use" (harvest). I think I could maybe push it out to 9 or 10 fields before they start melting, but 8 works for me. But maybe I missed the point of the question, I have not seen any difference in average yield per field based on how many fields I plant for that particular session. I just make sure I don't plant more fields than can be harvested before the first fields planted start to fade away.