Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Planning fertiliser use in spring

Planning fertiliser use in spring – what you need to think about

By Bala Tikkisetty

With a refreshed National Policy Statement for Freshwater Management around the corner, there is increasing pressure for farmers to improve nutrient management in their farming systems.

As the soil starts warming up over the next few weeks, farmers will be preparing to fertilise their paddocks. Finding that balance between getting best bang for buck while protecting economic and environmental bottom lines is critical for farmers and requires advice from their fertiliser reps and consultants.

That’s because healthy soils are a balance of biological, physical and chemical properties, and are a dynamic mixture of minerals, organic residues and living micro and macro organisms – all of which support farm production and provide various ecosystem services.

As there are a range of risks when applying fertiliser, and strategies to help you avoid them, it’s recommended all farmers have a nutrient budget and a nutrient management plan for their properties and discuss their situation with their fertiliser rep.

There are a range of tools to help practice sustainable nutrient management.

Nutrient budgeting is widely accepted as the appropriate first step in managing nutrient use and it’s also the preferred tool for evaluating the environmental impact of farm management practices.

Overseer, a computer decision support model, is being used to advise on nutrient management and greenhouse gas emissions. It predicts what happens to the nutrients that are brought onto the farm in the form of fertilisers and supplementary feed in the same way that a financial budget can track money.

When doing nutrient budgets in Waikato, bear in mind recent soil quality monitoring results that reveal high fertility and compaction remain problems on dairy and some dry-stock sites.

Another issue to consider is nitrate leaching. Plants need nitrogen (N) for healthy leaf growth. But N is an extremely mobile nutrient. If more nitrogenous fertiliser is applied than plants can take up, most of the unused nitrogen ends up leaching down through the soil into groundwater. Sometimes N will also be lost to waterways as run off and some is always released back into the air as gas.

The amount of N leaching from pastures can be reduced by:

timing fertiliser application to avoid periods when plant uptake of N will be low, such as when soils are saturated, during heavy rain, colder periods and times of low soil temperatures
applying N fertiliser in split dressings (as many split doses as possible)
irrigating farm dairy effluent to a large enough area
adjusting fertiliser policy for effluent irrigated areas to account for the nutrient value of effluent
using fenced wetlands and well-managed open drains as nutrient traps.

The nutrient phosphorus behaves very differently to N because it binds with the soil and only dissolves slowly in water over time. This means it doesn’t readily leach to groundwater. But it can damage the health of waterways through soil erosion and surface run off into water.

Farmers can reduce the amount of phosphorus run off by keeping Olsen P to optimum agronomic levels. Other tips include:

following the Codes of Practice for FertMark and SpreadMark
applying fertiliser when the grass is in an active growing phase
leaving a grassed buffer strip between paddock and waterway – the strip filters the phosphorus before the run off reaches the water
controlling run off from tracks, races, feed and stand-off pads.

A clear assessment of fertiliser requirements will both improve economic returns from pasture and help avoid contamination of ground and surface water with nutrients, particularly nitrogen and phosphorus.

In New Zealand, the common nitrogenous fertilisers are urea (46 per cent N), ammonium sulphate (21 per cent N), DAP (18 per cent N) and calcium ammonium nitrate (27 per cent N). The form of nitrogenous fertiliser best used depends not only on the cost per unit N, but also on the overall efficiency of the fertiliser N.


ends

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 

Toxicology Tests Planned: Dead Rats Washed Up On Beaches

As many as 600 rats washed up on Westport's North Beach over the weekend to the horror of locals. DOC said they may have been killed by a recent 1080 poison drop 140km away and washed down the Buller River after heavy rain battered the coast. More>>

ALSO:

Transition To Low Carbon: Mineral And Petroleum Resource Strategy

Responsibly Delivering Value – A Minerals and Petroleum Strategy for Aotearoa New Zealand: 2019-2029 has been developed to provide the direction for the sector in the transition to a low carbon and productive, sustainable and inclusive economy. More>>

ALSO:

MethaneSAT: Methane Satellite Mission Control In New Zealand

Mission Control for an international space mission to help tackle climate change will be based in New Zealand, with the Government putting $26 million towards the state-of-the-art satellite...More>>

ALSO:

Real Estate: Late Spring Surge

The continued shortage of quality real estate listings, coupled with record low mortgage interest rates have combined to add some zing to the property market over October. More>>

Wellbeing Stats: Finances Less Terrible And Less Great

According to results from the General Social Survey, the proportion of people who felt they had enough or more than enough money to meet everyday needs increased from 51 percent in 2008 to 63 percent in 2018, Stats NZ said today. More>>

ALSO: