The rainfall that fell on Monday varied in intensity across the country but in general was welcomed. It is suggested that this should lead to slight increase or at least maintenance of the growths of the previous week. However is it also noticeable that that clear skies at night are yielding lower air temperature but most importantly will bring about a drop in soil temperatures – measurements in the past two days show that they are ranging from 12.5 to 13.3 degrees. With that don’t expect growth rates to be any higher for the coming week.
Now is the time to be clear about your paddock closing and grazing strategy for the remainder of the grazing season – here are the steps.
1. Carry out a Spring Grazing Budget for 2010 –using your expected Spring calving pattern identified from scanning results or accurate service records. A Spring grazing budget allows you to identify the target opening farm cover. Back budget from this opening cover allows you to predict what you closing cover in 2009 should be. Back budgeting is of course related to the expected Winter growth rate through December and January, which can be differ significantly across farms but generally ranges from 0 to 5 kgDM/ha/day, with the former on cold wet farms and the latter on dry farms with a lot of reseeded swards in the South of the country.
2. Fine tune your Autumn Grazing budget – you generally have only 6-7 weeks of grass left and the plan is to have a controlled reduction of farm cover from this weeks farm cover to the target closing cover in late November. Most farms are now past Autumn balance date where demand will exceed growth and on most farms a reduction in demand is necessary to extend the grazing season to late November. Be clear as to what is required to reduce demand sufficiently on the farm – the options have been mentioned in previous updates – be clear on the strategy that suits your situation best.
3. When should you begin closing paddocks? This should be considered in the context of the expected Winter growth rates as mentioned in Step 1 above. Those farms who expect very low Winter growth should be closing paddocks from first days of October onwards. Those with high expected Winter growth should close paddocks from 8-10 October onwards.
4. Target residual for final grazing – On farm walks in the past week I have asked the question – have you started closing paddocks? To which a common answer is “ not sure - we can decide today if they are closed or not”. So, in answering the question what is the deciding factor? To me the deciding factor is the residual height which has been achieved as the final grazing which should be circa 4cm – if this residual has been achieved then it is closed, otherwise it may need to be grazed again. If a paddock has been undergrazed – do not graze it again until it is at the 3 leaf stage – grazing it too soon will seriously effect its growth potential afterwards and it will limp through the Winter.
5. Target to get 60% of the grazing area grazed in the first 30 days of closing. This target is essential for all farms and farms types. It relates to the availability of grass for the first rotation in the Spring and helps to ensure an adequate supply. If this area is not grazed off in October then re-growth will be slower and delayed from grazing it later – effecting the Spring grass supply pattern on the farm. With most farms behind target in Autumn budgets, it is likely that this 60 % target will be achieved – if you are not achieving it, graze some lighter covers and move trough the area quicker to rewach the target
6. What paddocks to close first? In answering this question it is best to consider what paddocks you would like to graze first in Spring? Once these are identified – they should be closed circa 15-25th October – it is desirable to have a moderate cover (circa 1000 kgDM/ha) on these paddocks for the start of grazing in Spring. Now, what to do with the wet paddocks on the farm – these should be closed mid-way through closing also but rotated with dry paddocks on the farm. Subject to soil analysis, it is prudent to get slurry applied to the closed paddocks – hopefully the deadline will be extended to facilitate this into November.
It is also noted in the past few days that some paddocks “have stopped growing”. Many of these paddocks are on a long rotation (45 days +) and are beginning to senesce or die back. Identify these paddocks and graze them off ASAP – the longer they are left the harder they will be to graze out and the slower the re-growth.
