Weather is a major contributory factor to grass growth. Over 50 farmers in my groups have grass measurement data which allows us compare the last two years. Table 1 shows that they only grew 609 kg DM of grass in 2013 and this increased to 871 kg in 2014 from 1 December to 10 April.

Therefore, these farmers grew 262kg DM/ha more grass this spring (to 10 April). Farmers on wet land got the greatest increase, a 43% boost on 2013. Weather is so important in farming and we should cash in on the extra growth of grass it delivers to help us cope with adverse conditions.

Stocked at 2.5 cows/ha with a mean calving date of 20 February, this amount of extra grass should result in savings of 2.1kg of meal per cow per day (= 60c/day or a total saving/ha of €73).

Grass is our cheapest feedstuff, costing €80/1,000 units of energy, and it is 2.5 times cheaper than first cut silage and 3.5 times cheaper than dairy ration at €275/tonne.

But we are not growing enough of it. For every tonne of grass DM that the 90 farmers in my discussion groups grew, they increased their profit per hectare by €188 (Figure 1). This benefit would be much greater if measured on common profit/ha, because many of these farmers had labour employed and very significant amounts of land rented.

The average amount of grass utilised by these dairy farmers on the whole farm in 2013, using the Moorepark Grass Calculator, was 8.56 tons/ha and the profit /ha was €1,483. Disappointing!

But it was a difficult year, across all soil types, wet and dry, with some winter feed deficits resulting from 2012.

As outlined above, grazed grass is the cows’ cheapest feed source. Figure 2 shows the connection of savings on cost per litre. For every extra 10% grass in the cows’ diet, the costs were reduced by 2.55 c/l – a very significant saving!

Message

This surely should convince farmers of the importance of grass in the cows’ diet and the need to grow maximum quantities per hectare. If we grow more grass then, as a consequence, we will be able to provide a higher percentage of grass in the diet. So, how can we grow more grass?

Factors reducing grass yield

Low pH: Over 60% of Irish grassland soils have low pH and each hectare uses up 0.5 to 1.0 tons of lime per ha per year. The optimum pH for grassland is 6.2-6.3 (do not exceed 6.0 for soils high in molybdenum or 5.4 for peat soils).

The benefits from lime use are: (a) increased yields; (b) better grass species and clover survival; (c) makes phosphorus, potassium, sulphur, calcium, magnesium and soil nitrogen more available to the plant; (d) better soil structure; (e) more earthworm and microbial activity and (f) more balanced uptake of nutrients by the plant.

Because of its massive benefits it must be the first fertiliser money to be spent on every farm.

Soil fertility: Soil samples should be taken every three to five years and action taken on the recommendations. Over 90% of grassland soils are “not fit for purpose” in that they are deficient in either P, K or pH. And we are crying out for new “fandangles” to grow more grass!

Phosphorus is the most important to get correct as table 2 shows that yield of grass can be increased by over 1.5 tons/ha.

Sulphur: The good thing is you will grow up to 40% more grass if S is corrected and there are no environmental restrictions. Each silage cut requires 20kg/ha and the grazing area requires 20kg/ha, applied in one application in April or in small increments throughout the summer.

Nitrogen: This should and generally is used to the maximum allowed under the Nitrate regulations. The max allowed is 279kg/ha (226units/acre) for a stocking rate of 2.4 to 2.56 cows/ha. But, in my experience, far too many farmers are not applying adequate N early in the year and too much from July onwards. By 15 May, over 64% of the annual N allowed should be used, or 144 units of the 226 allowed above. You will save 0.5c/l by using Urea instead of CAN up to May.

Poor Drainage: We know that wet farms grow less grass both early and later in the year. Therefore, where possible, these and wet land areas on dry farms should be drained to facilitate growth and grazing as best possible in wet weather.

Poaching and soil compaction: Research has shown that moderate and severe poaching results in 16% and 34% reduction, respectively, in annual grass yield. Some recovery takes place after 50 days. Because the cost of overcoming poaching is very high, it is essential to practice all the wet weather grazing practices recommended for Ireland. These practices should be implemented at all times during the year whenever weather is disagreeable. Spreading slurry with a vacuum tanker causes severe soil compaction. I suggest that farmers with “wettish” land should use the umbilical system to spread slurry.

Reseeding: Paddocks which are in the bottom 20% yielders year in year out must be reseeded. Experience, derived from grass measurement, indicates that reseeding can improve grass yield by 20-30% over the old pasture. However, much reseeding is done very poorly. Moorepark have a new booklet, “Pocket Manual for Reseeding”.

Pre- and post-grazing influence on grass yield: Grazing management throughout the season has a big influence on the yield of grass per hectare.

Not alone will grazing below 3.5cm reduce animal intake per day but will reduce grass yield by 15-20% – and will delay the time to go back into a paddock by three to five days.

Michael O’Donovan, Moorepark, suggests that farmers should buy a plate meter to measure this and get their “eye in” on post-grazing heights.

This is a very important tool where a manager/young staff member is in charge of the grazing decisions. Where paddocks are not grazed out to 4-4.5cms after a grazing, it is suggested you let the cows into a paddock for one to two hours after milking to “clean-out” a paddock of 4.5cms.

Adverse effect of high autumn covers: This will result in grass yield being reduced by one to two tonnes of yield the following spring/summer and may result in the field having to be reseeded.

Extended grazing in spring and autumn: This is the single most important development in the last 20 years to growing and utilising more grass at the “shoulders” of the year. The spring and autumn grassland planner facilitates this dual objective and it has resulted in probably one to three tonnes of extra grass being grazed between mid-October and 1 April.

Follow a grassland plan: Very few farmers make a grazing/silage plan in March for their farms and this is so important for the new entrants to dairying who will have been used to operating at low stocking rates.

This results in many farmers being short of winter feed because they haven’t planned to have a grazing density of 4.0-4.5 cows/ha during April/May. It should also be noted that silage fields generally yield more tons/year than grazed fields, being aware that it is of lower quality but adequate for winter feed.

Weeds reduce grass yield: Grassland farmers in Ireland rarely spray their most valuable crop, grass, for weeds. What would the yield of cereals be if they were not sprayed? We give out about NZ farmers, but they are much more diligent on this task than we are – it is a relatively small cost.

For every 1% that a pasture is covered by docks, the yield will be reduced by 1%. A moderate infection of 5% would result in the yield being reduced by 450 kg DM/ha. This would feed 27 cows for a day.

Ground Cover Score: It is like cow body condition scoring – the pasture in each paddock is scored from zero to nine. A paddock with a score of nine will have all perennial ryegrass, no weeds or weed grasses, and no open spaces where clay is visible, something like a lawn or correctly managed sheep pasture. A paddock ranked zero will be the very opposite. There is a direct correlation between this ground score and grass yield.

Summary:

The first step to maximising grass yield for a farm is to do a paddock needs analysis (PNA). By doing this analysis, you will identify the gap between the desired and existing yield of grass on a paddock. This is facilitated by weekly grass measurement, using any of the computer packages to record the data.

With this, you will identify what the paddock is yielding and what it is capable of yielding, using the best paddocks or other discussion group members’ data as the benchmark. This creates the paddock profiles; poor grass, low fertility, wet patches, poor grassing etc. Action must then be taken based on research/advisory practice and advice.

Therefore, now set about doing your paddock needs analysis by recording grass measurements every week.