It’s pretty obvious that letting cows wander into waterways, collapsing stream banks and defecating in the water is not good for our rivers.
But the most serious freshwater health issue facing NZ’s waterways still involves cows but is much less obvious and there’s no amount of fencing or streamside planting that can deal with it.
It’s cow urine.
Cow urine is full of nitrogen. Nitrogen in small quantities can be taken up by plants and used to grow. But dairy cows urinate, a lot and in the same spot.
The plants receiving this huge load of cow urine from an overstocked, intensive dairy farm can’t use it all up so the nitrogen either runs off into waterways or leaches through the soil and gets into the groundwater.
From the groundwater it either rears its ugly head back in rivers or sink... Read more >