Identifying paddocks for renewal
Most farm operations renew pastures every year, but how do you identify those pastures? Typically paddocks are chosen on what the pasture looks like, or a gut-feel on how that paddocks performs. There are much better ways to do it, which have many advantages.
The biggest thing to help get high returns from pasture renewal is estimating what individual paddocks are growing, as it allows three things.
Firstly, identify the poorest paddocks, so you can assess what’s wrong with them, whether it be things like weeds, drainage or just needs to be resown.
Secondly, identify your best pastures. These give you an idea of what the potential of the property is, and where you may be able to take under-performing paddocks.
Lastly, undertake a comparison across the farm of how big the differences between paddocks are, and how much of the farm is under-performing.
Research by DairyNZ has shown a 100% difference in growth between best and worst paddocks on properties. And it is believed this situation is the norm not the exception. Most farms have a number of very poor paddocks.
If this is the situation, estimating paddock performance helps quantify the benefit successful renewal would bring, to allow some strategic thinking about the level of investment in renewal the farm should undertake.
The larger the number of under-performing paddocks, the greater the potential.And if you want to renew large areas this is where you can bring in an integrated programme using a combination of crop and grass-to-grass sowings.
Then continued monitoring of paddock growth over the next few years allows you to assess the results from renewal, to make sure benefits are being captured. This is an important part of a long-term renewal programme, to tell you it’s working and is giving good returns on the investment.
This also needs to translate into increased farm production levels otherwise the return on investment from pasture renewal will be nil. (ie. As a result of pasture renewal the farm is growing more pasture but extra must utilised and this may require an increase in stocking rate)
So how do you estimate the performance of individual paddocks?
The simplest way is to estimate ‘grazing days’, how many animals that paddocks supported over the year. For dairy farms this is reasonable simple, for sheep, beef or deer farms it’s more complex.
For dairy farms you can simply count the number of ‘grazings per year’ a paddock has, which typical ranges from 7-14. Add in the silage made in the paddock, as its growth too, any other grazings (such as colostrum or sick cows) and correct for paddock size. This gives an estimate of how paddocks compare as in the example below.
On dairy farms this paddock comparison can also been done automatically if weekly farm walk data is put into software such as Pasture Coach.
On sheep, beef and deer farms the principle of ‘grazing days’ is the same, but the details more complex. There are more groups of animals, and you need to have an estimate of their kgDM/head/day intake in the paddock. These are again totaled over the year, to estimate performance.
Over a season you build up a profile of the paddocks across the property, as might be seen in the graph below. Here two properties are contrasted, with Property A having much more even pasture production across the farm.
Lastly, closely assess the grazing records - sometimes the paddocks planned to be renovated have changed! Typically you have a gut-feel of what the worst paddocks are, but this isn’t always right. Estimating their performance from data is much more accurate.
So to get the best from investing in pasture renewal, assess the performance of individual paddocks, use this information to identify and fix the paddocks that are under-performing, and keep monitoring these paddocks to assess the results.