
Internal MPI COMMENTS CHEERS GERALD How might these be addressed.

I think we need to be careful with the suggestion of imported feed increasing soil C.
Obviously, without 100% digestibility and 100% partitioning to export product, there is a net C remaining inside the farm gate. However, it usually occurs with a greater stocking rate, which could undermine any advantage of imported C I presume, and the CO2eq/ha can be 50% or more greater than a system that does not import feed.

Furthermore, one of the primary supplements in the N Island is maize silage, which can cause the loss of tonnes of C during tillage and during the following fallow period. I would imagine it’s the same for domestically produced barley and wheat.

Of course, there’s also nitrate leaching effects associated with either longer lactations ( N Island) and additional wintering cows (S. island)

And these say nothing about the cost of marginal milk (and the value of all milk because of increased supply).
It concerns me when I see simplistic messages like this don’t account for the multitude of variables that change with these farm system changes.



