Consequently farmers must use increasing quantities of fertilisers to encourage grass growth, even as the too-large herds further trample out the goodness - a vicious cycle that can only end in a chemical-imbued wasteland, affecting the rivers and everyone downstream too.
Surely, you would think, the men and women of the land can see the futility of this approach.
But no. While their industry bodies argue for more intensification and fiercely fight off attempts at land use regulation, it is left to "special interest" groups such as Forest & Bird or Fish & Game to strive to redress the problems.
For this they are pilloried, roundly, and painted as interfering luddites.
No surprise then that Fish & Game this week decided to take no further part in the Government's much-hyped Land & Water Forum, an initiative whose collaborative and inclusive approach promised much but has delivered little. Or rather, has delivered over 200 recommendations, which have largely been ignored.
Fish & Game have accepted being constrained by the forum rules - which curtail speaking out or lobbying independently - while Federated Farmers have ignored those rules and gone about changing things to suit their view. Yet it is Fish & Game who are painted as spoilsports and copouts.
Their main beef is that the forum has, in the words of CEO Bryce Johnson, focused on "creating more headroom for irrigation expansion and land use intensification, and very little for the primacy of the environment", despite the RMA requiring the environment be considered first.
Environment Minister Nick Smith's reaction - claiming Fish & Game were more interested in protest than progress - is especially instructive given mooted pro-development changes to the RMA this year; changes which the Act's original lead author, Sir Geoffrey Palmer, said were "driven by anecdote, prejudice and interest rather than evidence".
He also said regional councils getting involved as developers in projects like the Ruataniwha dam scheme raised serious conflicts of interest that "ought not to be tolerated".
A pertinent comment given it has been left to another interest body, Forest & Bird, to seek a judicial review of the proposed land-swap deal brokered between DoC and Smedley Station on behalf of HBRC/HBRIC to allow the dam to proceed as planned.
It seems the Government - and its profit-driven supporters - are happy to endorse the status quo for land use and entrench new rules and technologies that will further degrade the environment. While that part of the public with a conscience are unfairly called into disrepute for opposing them.
That's the right of it.
-Bruce Bisset is a freelance writer and poet.