Now that grass growth has taken off around the country, a lot of farmers can see a surplus of grass coming on their farms.

The question that most farmers are asking is when should they act and take out a paddock and how many paddock should they take out?

The first step is to walk your farm. A grass walk should be completed at least every seven days on farms. The top farmers will be walking their farms every five days for the next six weeks.

Vital information

Once a walk is complete on your farm the next step is to record it on Pasturebase. Pasturebase will do all the calculations for you and give you the vital information you need to make a decision.

There are four key pieces of information you should look at when making a decision on your farm.

The first one is the pre-grazing yield - what cover of grass is on the next few paddocks to be grazed. These will be the paddocks at the top of your wedge and the target should be 1,400kg to 1,500kg/ha.

An example of a grass wedge.

The next two figures you need to look at are growth and demand. These figures tell you what you’re growing per day and what grass your cattle are eating per day and if you’re going to build grass over the coming week (growth will be higher than demand) or eat into the current reserve (demand will be high than growth).

And the final figure you need to look at is your cover/LU - this figure will tell you if you have enough grass for the stock you are carrying.

As a general rule of thumb for summer grazing, you want 10 days of grass ahead of your stock. Taking that the average dairy cow eats 18kg of grass/day, to have 10 days grass ahead of her you need a cover of 180kg/LU on the farm.

It’s very important to remember that you need to look at all four of these figures before making your decision.

For example, a farmer with a cover/LU of 230kg, at first glance you would say he has surplus grass. However, if his demand/day over the next week is 70kg and his growth/day is only 60kg, he will find himself at a cover/LU of 160kg next week without taking out any paddocks, as his cattle are eating 10kg more than he is growing for the week.

So don't make decisions based on any one figure - you need to look at the full picture.