If soil fertiliser requirements was just about putting soil test numbers into a spread sheet that spat out a nutrient recommendation which was both effective and efficient, life would be very much simpler.
There would be little if any discussion on the merits of different products, whether liquid fertilisers replaced solids or are best used in conjunction with, or whether the cheapest form of nutrient provides better value than a higher priced product.
What is not up for debate is the fact that in areas with intensive dairying the levels of nitrate nitrogen in ground water, streams, and rivers, is steadily increasing and in many instances now well above acceptable levels.
It is also a fact that the water available for irrigation has already been over allocated and if everyone used their full allocation a major and rapid overhaul of the system would be required.
And the fault lies with no one individual or group. It’s just what happens when there is rapid growth of any industry. It’s not been possible to foresee the full environmental consequences of rapid intensification of land use, but the results are now being measured.
There are solutions that can be implemented with significant benefits for all parties. There doesn’t have to be a trade off with someone losing for someone else to win.
The solution lies with the soil. The present disregard of soil quality by the farming industry at large means that there is the ability to both grow greater volume of crops and pasture with a few sound fundamental changes.
With increased volume comes improved quality, that’s just the way natural systems work. Healthy fruit trees always produce more fruit that taste better and have greater nutritional quality, and that’s the same for all crops including pasture.
So if lower quality means less is actually growing how then is the sale of nitrogen fertiliser rationalised. The reality, in our view, is that when pasture growth over twelve months is driven by regular applications of fertiliser nitrogen total growth declines.
It declines because when nitrogen fertiliser is over used, and anything other than a little strategically in late autumn and winter, the periods when clover is largely dormant, is overuse, the humus content of the soil declines.
Humus is the ‘glue’ that holds soil together and stores both moisture and nutrient including nitrogen for plant use, and with less humus pasture growth becomes less even and total growth steadily declines.
I’m often told that if there was an easy way of breaking the dependency on fertiliser nitrogen less would be applied.
Here’s a couple of ways to start the restorative process that will result in more production over the next twelve months. Where magnesium fertiliser is a requirement apply 200 – 250kg/ha of Golden Bay Dolomite any time before calving.
This will ensure fewer calcium/magnesium related metabolic disorders around calving and higher per cow levels of production. As dolomite is also a proven soil conditioner excess moisture will drain more freely. Drier soils warm more quickly as sunlight hours increase which encourages early growth.
With improved physical structures plant roots penetrate more deeply accessing greater amounts of both nutrient and moisture. This ensures more even and stronger growth as soils start to dry.
The energy content of the plant also lifts and a better balance of carbohydrate and protein is achieved, resulting in firmer dung, cleaner cows, and less weight loss after calving.
And this next suggestion is another that over the last ten years has always worked. When applying nitrogen over autumn and winter reduce the amount of each application by 20%. I’m yet to find anyone who has done this recording less growth as a result.
With deeper rooting pastures, healthier cows, higher milksolid production, and lower costs, the coming season can be one to genuinely look forward to.