A new forage plantain, bred in New Zealand but now available in DLF and Oliver Seeds grass ley mixtures in the UK, significantly reduces nitrate leaching from dairy cow urine patches, as well as providing high quality feed.

AgritaiN can be managed similarly to perennial ryegrass and will comfortably withstand a grazing round of between 20 and 30 days. It is a good companion to red and white clover and can produce between 10 to 19 tonnes of dry matter per hectare a year (t DM/ha/year).

“Typically, a cow will graze an area of 140m² in a day,” explained Dr Glenn Judson, a ruminant nutritionist for New Zealand seed company Agricom/DLF, on a recent webinar transmitted to a global audience.

“Half the nitrogen she consumes ends up in her urine in a tiny area measuring just 3m^2.  This means urine patches typically contain the equivalent of 600 to 800kg N/ha, a concentration that is too high for the surrounding plants to take up, leading to nitrate leaching.

“But when cattle graze pastures with AgritaiN in it, research has shown a reduction in nitrate losses, offering a natural plant solution to what is a significant problem.”

Research

Trials at News Zealand’s Massey University measured nitrate leaching from paddocks grazed by 80 dairy cows. At the end of the four-year study, researchers found that nitrogen losses were reduced by up to 60% in perennial ryegrass swards containing between 30% and 50% plantain. There were no differences in milk production compared to the control pastures.

More recent research at Teagasc in Ireland looking at individual urine patches, showed the inclusion of AgritaiN in grass/white clover swards at levels of 30%, reduced nitrate loss in free-draining soils by 32-74% (average figure of 56%) in year one, and 93-99%, (mean 96%) in year two. The researchers concluded that growing plantain in grass clover swards has a significant effect on mitigating nitrate leaching.

“AgritaiN reduces nitrate losses in four different ways through the animal and the soil,” Dr Judson explains. “Firstly the cows urinate in greater volume and more often, thereby diluting the amount of nitrogen in their urine. Secondly, more of the protein consumed by the cow is utilised for production, which leads to less dietary nitrogen being excreted (Table 1)

Table 1. Trial results showing how AgritaiN diets reduce the total nitrogen in urine compared to perennial ryegrass (PRG) diets

Source: DLF

“The urine from the cows also slows down the nitrification process making the nitrogen in the urine slow release. This delays the conversion from ammonium which is not leachable to nitrate which is leachable, giving plants a longer period to take up the free nitrogen. The AgritaiN plants and roots also reduce nitrate leaching.”

AgritaiN has been developed from decades of plant breeding from original unproductive wild plantain, to produce a large-leaved, upright, tall cultivar that grows from early spring to late autumn.

It has a high value feed when managed to be grazed/fed in its vegetative state – with zero to 25% stem. Being deep rooting, it also draws up high levels of vitamins and minerals from the soil. It is very responsive to nitrogen fertiliser, even during summer.

Trials have shown there should be between 30% and 50% of AgritaiN in the sward for optimum results, which means in perennial ryegrass mixtures it can make up to between 5% and 10% of the seed mix.

AgritaiN is available in grass seed mixtures from DLF UK: https://www.dlf.co.uk/