Strategic applications of nitrogen help grow quality feed for livestock
Spring applied nitrogen (N) is an effective tool for growing quality feed for livestock. However, N must be applied strategically to coincide with times that plants are actively growing as N is a growth multiplier and does not initiate growth.
As all farms are unique, an N fertiliser policy for one farm may not work for another. Therefore, before applying N fertiliser consider feed demand and supply, spring climatic conditions, farm subdivision, soil fertility and pasture species.
Identifying feed deficits through feed budgeting is the first step to planning for spring N. The budget enables active management of pasture supply and animal demand on-farm and allows for a forward plan to be completed, identifying pasture shortages in advance. Applying N fertiliser four to six weeks before a feed deficit is best practice.
In early spring, low soil temperatures influence the pasture response to the N fertiliser applied. The warmer the soil, the greater and more immediate the N response will be. Nitrogen fertiliser applied in cooler soil temperatures of below five degrees Celsius, or during extended dry or wet periods, lowers pasture production potential from N fertiliser. Waiting until soil temperatures reach six degrees Celsius and rising at 9:00 am in the morning is recommended.
On extensive areas with less subdivision, managing spring growth from N fertiliser can be more difficult than intensive areas with subdivision. Well subdivided areas can manage feed and pasture more effectively by rotationally grazing and planning which paddocks are to be grazed. This means the feed grown will not exceed demand and lose quality. The extra feed grown from N can be utilised within feed budget requirements. Managing pasture grown from N fertiliser on properties with improvements to subdivision will provide better economic returns from the investment of the N applied.
Nitrogen is one of the 16 essential nutrients a plant requires for health and vigour. Soil and herbage testing will identify base fertility as all of these nutrients need to be present in adequate amounts to achieve a maximum N response. If one nutrient is deficient, potential growth may be restricted from the applied N and therefore needs addressing. In contrast, if soil N is adequate or in excess, N losses to the environment can occur.
Modern pasture species require higher soil fertility than native pasture species. As new pasture responds well to N fertiliser, create a plan to apply N strategically to maximise N response and set the pasture up for the future.
If you have further questions about spring nitrogen applications, contact your local PGG Wrightson Technical Field Representative.
