Wednesday 20 June 2018

Winter Grazing

It always amazes me how quickly time flies – as I write this, we are in June of 2018 already and winter is upon us.

With the onset of winter comes the slowing (or stopping) of pasture growth and the need to supplement feed with crops or imported supplements, so it is timely to discuss winter feed management and the environmental perils associated with feeding winter crops and supplements.

It’s a hard road finding the perfect paddock to plant your crops in, if the soil is too heavy the chances of pugging and the loss of soil and faecal matter is higher and if the soil is too light, the drainage is great but with more drainage comes higher nitrogen leaching, particularly in areas of high rainfall.  Planning ahead and selecting the right paddock or even the right areas within a paddock to grow crops can reduce the environmental risk.
There is a lot of information about good practice for feeding winter crops available, but as for any farming practice there is no one size fits all and it is a matter of taking those good practices that apply to your situation and putting them in place.  The key issues with the intensive grazing of stock over winter are the loss of soil and faecal matter through run off into water ways and the leaching of nitrogen into groundwater from intensive stocking. 

Any management practices that can be implemented to reduce run off into waterways are beneficial, this can help to reduce the soil/ sediment and faecal contamination of waterways.  These include grass strips or margins not planted in crops alongside waterways and planning the direction of cultivation so that it doesn’t lead to a flow path into a waterway carrying contamination with it.
Planning ahead and having a back up option such as taking the animals off the crop, allowing animals access to another paddock or grazing for only a few hours can make all the difference when the weather is too wet for intensive grazing.  Troughs and supplementary feed can be placed strategically so that pugging is minimised in these areas and so that if there is pugging it won’t run off into a waterway.

Some regional plans include rules with regards to the wintering of stock including requirements for intensively grazed stock and stock on winter crops to be excluded from waterbodies.   There may also be rules around standoff areas and feedpads to minimise the environmental impact of these.  In my view these rules constitute the absolute minimum with regards to the good management of stock in winter. 

For information on industry good practice, see the Beef and Lamb website, Deer Industry NZ or the DairyNZ website, in particular the following link provides some useful information which can be applied to beef cattle and deer also -

Post grazing, following the crop with a whole-crop cereal silage crop, before putting the block back into winter crop, can greatly reduce the nitrogen in the soil and therefore, leaching. 

So, with winter already here it is not too late to do some research and plan how you will manage your winter grazing this year.

Lilian Sherman, Irricon Resource Solutions Limited (NI).
Phone: (021) 378 308

Friday 15 June 2018

EM Surveying - other uses for the data

Today it's our final blog for the 4-part series on EM Surveying that we've run you through over the last month. To date we've covered off:

Today Chris is going to take you on a run-through of what some of the other uses are for your EM Survey data are & how they can be applied on farm...

...I touched on probe placement at the end of the last post, so will continue where I left off. The EM layers are very useful for making sure you have your moisture probe in the most indicative soil type if you only put one probe in under a pivot for example, or if you have several soil types it ensures you can put probes under the lightest, heaviest and average soils, to make more informed management decisions on irrigation application. The topography information collected at the time of survey can also be used for determining soil moisture probe locations. 
Figure 1: Shallow EM Map with 3 probe locations in the different soil types. 

Where the land is undulating we can bring the elevation data into the equation for probe placement to find a flat area in each of the different soil types. We can also use a moisture probe in a dry land situation for adjusting inputs to the season (such as fertiliser, re-grassing & de-stocking).

When conduiting the EM survey we are using RTK GPS to log the EM data, this topography data and its derivatives are very powerful information layers. We can create water flow maps so you can see potential areas there may be issues for your Farm Environment plans, contour maps, and water flow animated videos as shown below. The Water Shed model mimics a large rainfall event, then over time shows where the water moves from quickly and where it hangs around longer. 

These Water Shed models highlight potential avoidance areas for planting, especially for nurseries and high value crops, in areas prone to heavy rainfall.

As you can see there are many ways people are using their EM survey data, and there are many other uses tailored to the individual client’s requirements. It is generally best to discuss with you your issues then we can work together on using the data to achieve the best solutions for you.

For any more information or to discuss your requirements give me a call.

Chris Smith
Operations Manager @ Agri Optics NZ Ltd