Pasture management for newbie
Looking for some guidance on pasture management. Very new to this so please be gentle. We purchased a 5 acre property a little over 12 months ago and the portion in question is about half of that. It is not currently divided up and home to 2 lawnmowers in the form of 2 Dexter cows. To my untrained eye the pasture looks to be in reasonable shape - the grass could be longer but we kept on top of the obvious weeds last year by hand pulling (I never want to see another piece of Fireweed) and spot spraying with Roundup. My plan, such as it is, aims to rest and restore sections of this area on rotation so we can improve the rested section by poo removal, fertilizing and weed removal. It's the latter aspect that I'm struggling with. I know there are selective products like GrazeOn etc that should take care of the weeds but I understand that one of the components hangs around for a while and will find its way into the cows and onward into their poo. As we like to use collected poo elsewhere as a soil improver (especially in the veggie garden), that presents a problem. Hence the request for advice. Are there other selective products that don't leave a residue or do we have to accept it and give up on the idea of using the collected poo? I should also say that the weeds we would be dealing with are new growth weeds that are well interspersed with grass (which is kikuyu btw) so spot spraying is not an option.
One last question about the fertilisation stage - I was planning on applying Seasol (which we have already), lime and a general NPK fertiliser. Are there any liquid products which would allow me to do that in one application? I have a small tow behind boom sprayer and keen to put that to use if possible.
Hope this makes sense and thanks in advance for any guidance and comments