“The most important thing to do after the spring we’ve had is assess the damage and redo your feed budgets accordingly,” he said.
“If you don’t do anything these areas will still grow grass again but it won’t be the species you want. It will be twitch and couch and other weeds. As well, there is more chance they will be pugged again next winter.
“And if you haven’t already done anything about it, it’s possibly too late with the dry conditions we’re now experiencing. Moisture levels are falling off quite rapidly.”
He said farmers should use a farm map and walk each paddock marking the damaged area and calculating the area.
“In the most affected areas dig several holes to look for signs of compaction and lack of soil structure to see if water is not draining away because of a compacted layer below the surface.
“The deeper it goes the more aerating the area will need.”
Damage should be ranked between one and three, with one being mud, possibly dried, with little or no pasture growing, two as severe pasture damage with the surface pugged but not churned up and three as light to moderate damage to pasture and soils.
“All three need to be treated differently. Where the soil is highly compacted you need to rip it to aerate it again and it has to be dried out enough to be able to do this.
“If you try to drill without aerating, if they are too wet the seed won’t take and when they dry out the slots will crack open and you’ll lose the seed.”
Ripping pugged paddocks also caused other problems, with many Southland farmers this spring locating their water pipes.
Lighter pugging could be rolled to produce a seed bed and small areas could be hand-sown.
“If the paddocks are too bad consider making them your crop paddocks but on some Southland farms at the moment that would mean you would have too many crop paddocks.”
Sticking to the plan
Following the DairyNZ Spring Rotation Planner meant milkers and colostrum cows at the demonstration farm were kept on 60m2 of pasture/day/cow and springers 40m2/day/cow in August.
With no ability to stand cows off, pasture damage from pugging now has to be addressed. Cows were opened up to 100m2 of pasture/day/cow in mid-September when soil temperatures rose and covers began increasing.
“We thought last spring was pretty tough until this spring happened,” the farm’s business manager Stacy McNaught said at the focus day on October 15.
The planner calculates the area that can be allocated per cow between planned start of calving and balance date, when feed supply from pasture equals feed demand.
Milkers were allocated less than 10kg drymatter (DM)/day of pasture with the rest of their diet made up of supplements. Some supplements were fed in the paddock, causing further damage.
“We dried off in May with 2050kg DM/ha and our opening cover was 2220kg DM/ha on August 4. We wanted average pasture covers to be at 2150kg DM/ha on balance date which for us is October 5,” DairyNZ consulting officer Nathan Nelson said.
By the first week of October average pasture cover was 2350kg DM/ha with cows fed 18kg DM/cow/day of pasture.
Production for the season dropped to 44,956kg milksolids (MS) for the end of September from 660 cows compared with 48,815kg MS in the 2014-15 season from 680 cows and 54,481kg MS from 644 cows in the 2013-14 season.
McNaught said the high early-October average cover included paddocks locked up for balage.
“We go from a stocking rate of 2.9 cows/ha to about 3.5 cows/ha in October because we have calves on the ground, we’ve got paddocks locked up for balage and we’re taking paddocks out to spray before planting in winter crops,” he said.
“We need average covers up about 2500 to give us a 20-day round at this time of the year.”
