Soil fertility and Reseeding Case Study

Waterford farmer increases grass production by 50%

A Waterford dairy farmer has made massive strides in his grass production by improving soil fertility and reseeding

Grass production on Adrian Casey’s farm in Faha Bridge, Kilmacthomas, Co Waterford stepped up a gear since he joined the Teagasc/Glanbia joint development programme in 2011. Adrian is milking 250 crossbred cows in a spring calving system. As a monitor farmer in the programme Adrian had targeted areas to improve upon his farm including: • Grass – increase grass utilised by one tonne dry matter per hectare. • Breeding – achieve a calving interval of 365 days with <10% empty. • Financial – reduce milk production costs through increased use of Teagasc eProfit Monitor and the Teagasc Cost Control Planner programmes. A big emphasis was put on improving the quantity and quality of the grass produced on the farm since he joined that programme. He started grass measuring which really helped identify paddocks that were underperforming. Grass measuring also served as a great tool to benchmark his grass production to other dairy farmers in the programme and in the locality. “In 2012 we grew 10t DM/ha and last year we grew 15t DM/ha,” according to Adrian. “We have seen year on year increases in our grass production with the exception of 2018 due to the drought that year,” he continued. This extra production did not happen by itself. Adrian said the secret was doing the basics right. “We soil test every two to three years, originally our soils were mainly index one and two for soil fertility, now they are mainly threes and fours,” he explained.

He uses compound fertilisers in the main and only uses straight nitrogen in the form of urea in the first round of fertiliser applications. Compounds such as 18:6:12 and Pasture Sward are used predominantly based on a paddocks soil fertility status.

Adrian also aims to spread lime on 25% of the farm every year so that 100% receives a lime application every four years. According to Teagasc maintaining the soil pH in the optimum range will increase the biological activity of the soil encouraging earthworms to thrive, increase nutrient availability such as nitrogen, phosphorus and potassium, it improves soil structure which is beneficial for aeration and drainage and it increases crop production. When the pH of grassland soils are maintained close to the optimum range increased grass production by at least 1.0t DM/ha/ year can be achieved. If this extra grass production is utilised by the grazing livestock it has the potential to reduce farm feed bills by at least €105 and €181/ ha/year on a drystock and dairy farm respectively.

The final element to his improved grass production strategy was and is reseeding. He usually reseeds at least 10% of the grazing platform, choosing lower yielding paddocks to target. Over the years Adrian has used Gambia’s Mastercrop grazing and silage mixes with very good results. In recent years he has gone a step further and worked with Glanbia grass specialists to create a seed mixture specific to his farm requirements. Last year for example he reseeded an outblock that is used for silage and zero grazed grass normally. In this block it was recommended that he use a mix of the grass varieties Abergain, Aberchoice and Abermagic because they have the best characteristics for that system. When choosing grass seed varieties for reseeding Adrian always looks to Teagasc’s Pasture Profit Index (PPI). “It is the EBI for grass,” said Adrian. He feels by choosing top performing grass varieties from this list he is giving his farm the best opportunity to grow lots of good quality palatable grass for cows to utilise.

His reseeding technique is very straightforward. A paddock earmarked for reseeding is grazed tight with the herd of cows. It is sprayed with Glyphosate five days later to kill off the old sward. Three to four days later the grass is stitched in and pressed with a ring roller. Reseeded paddocks receive 2t of lime per hectare and three bags of 10:10:20. “We usually graze the paddock from four weeks after seeding depending on the cover of grass and ground conditions to help the grass tiller,” Adrian explained. Because all the heifers are sent from the farm as calves to a contract rearer he has no young stock to graze these paddocks first so cows have to be used for these first grazings. He always makes sure the grass seed is firmly anchored in the soil before letting cows graze to avoid issues with seedlings being pulled from the ground.

Adrian is now able to sustain a stocking rate of 3.1cows/ ha on his grazing platform while feeding just 700 to 800kg of concentrates per annum. His advice to farmers who want to up their grass production game is to make sure your lime, phosphorus and potassium levels are near optimum and you are using the top performing grass varieties. “You need fertile land and fertile cows to be profitable,” he maintains.