Left Menu
Development News Edition

Nitrogen fertilisers least effective for grass growth during winter

To get the most effective benefit of using nitrogen in farming systems, it is important to understand the nitrogen cycle.

Devdiscourse News Desk | Wellington | Updated: 14-06-2019 07:47 IST | Created: 14-06-2019 07:47 IST
Nitrogen fertilisers least effective for grass growth during winter
With the coldest months of the year upon us, farmers should be particularly cautious when applying nitrogen fertilisers to pasture or crops during winter. Image Credit: Freestockphotos

Nitrogen plays an important role in increasing the pasture and crop yields helping to fill the feed gaps. When used strategically, nitrogen is effective in the synthesis of proteins in both plants and animals. Nitrogen is also an essential component of green pigment (chlorophyll) in plant leaves, which are vital for photosynthesis.

To get the most effective benefit of using nitrogen in farming systems, it is important to understand the nitrogen cycle.

With the coldest months of the year upon us, farmers should be particularly cautious when applying nitrogen fertilisers to pasture or crops during winter.

Winter applications of nitrogen fertilisers are generally least effective for promoting grass growth. That's because slow growth of pasture in winter and greater drainage can result in nitrate leaching before plants can take it up. The nitrogen can make its way to waterways where it can stimulate nuisance algal growth.

Lactating cows will excrete, in urine, about 70 per cent of the nitrogen they consume. Again, the risk of this nitrogen leaching from urine patches is much higher in winter.

This nitrogen leaching, along with phosphorus runoff, not only contaminates waterbodies but is a loss of economically valuable nutrients.

Nutrient budgeting using computer models such as Overseer, combined with feed budgeting, enables farmers to understand if they are using too much or too little fertiliser. By doing this, farmers can optimise the use of nutrients and reduce the impact on the environment by developing a pragmatic nutrient management plan.

Understanding the term "response rate" helps farmers when it comes to implementing these plans.

The response rate is the amount of pasture grown in terms of kilograms of dry matter per hectare per kilogram of nitrogen (N) applied. For example, when 20kg N/ha is applied and an additional 200kg DM/ha of pasture is grown the response rate is 10kg DM/kg N applied. The response is dependent on several factors such as soil temperature, plant growth, soil moisture, the deficiency of available nitrogen in the soil and the rate of nitrogen applied per application.

The best response to N fertiliser occurs on fast-growing pasture when other factors such as moisture and soil temperature are not limiting growth. Response rate variation also depends on the season and on nitrogen application rate. In winter, at the same application rate, responses are lower and slower than other times of the year.

It is better to apply nitrogenous fertiliser when the pasture cover is around 1500kg DM/ha. This ensures there is sufficient leaf area for photosynthesis leading to good pasture growth.

Also, nitrogen fertiliser reduces nitrogen fixation by clover by about one kg N/ha/year for every 3kg of nitrogen fertiliser applied. In addition, clover content will be further reduced if nitrogen-boosted pastures shade the clover. This effect is seen during spring.

Remember that the profitability of applying nitrogen is dependent on the utilisation of the extra feed. Therefore, nitrogen needs to be strategically applied to fill genuine feed deficits.

The nitrogen conversion efficiency for any farm is another key point to be remembered. This is measured by calculating total nitrogen in the product divided by the total nitrogen inputs into a farm and is expressed as a percentage. A dairy farm, for example, is probably doing fine with about 40 per cent.

A number of farmers, as well as industry organisations, are already doing a great job of trying to increase productivity and reduce environmental impacts through more careful use of nutrients. The more we can share information on the best way to do these things the better.

I suggest getting clear advice about the risks involved with winter nitrogen applications on individual properties.



Why COVID-19 is unstoppable in USA despite it being ranked at the top of GHS Index?

Several worst-hit countries such as Italy, France, Spain, the UK, Canada, and Russia have peaked COVID-19 cases in April. Almost all of them have gradually flattened the curve. However, the USA is setting new daily records of infections tha...

COVID-19 seems cooking biggest ever global scam

The increasing number of corruption cases on COVID-19 funds from throughout the world and involvement of high profile persons indicate that the countries cant ignore corruption in their pandemic response programs. This has generated the nee...

Health Management Information Systems lack holistic, integrated, and pandemic resilient character

Being a part of the United Nations system, the World Health Organization WHO deserves its share of rebuke for its alleged failure issue COVID-19 health emergency alerts on appropriate time. However, the pandemic has also exposed loopholes i...

Pride in the time of coronavirus: a welcome move online?

This year is different in many ways not least as celebrations are also taking place against the dramatic backdrop of a global health crisis and a resurgence in grassroots activism following the death of George Floyd in Minneapolis. ...


Latest News

Australia weighs further coronavirus curbs as outbreak grows

Australias most populous states will impose harsher restrictions on movement if a COVID-19 outbreak is not quickly bought under control, state premiers said on Wednesday.Australia has been heralded as a global leader in containing COVID-19,...

Rugby-Sale hoping to get more out of new signing Tuilagi

Sale Sharks will focus on the details of Manu Tuilagis daily training regime in a bid to get the injury-plagued England centre playing more regularly than he did at former club Leicester Tigers, director of rugby Steve Diamond has said. Tui...

ED’s principal special director Simanchala Dash gets one-year extension

Senior revenue service officer Simanchala Dash has been given one-year extension as Principal Special Director, Enforcement Directorate, according to a Personnel Ministry order. Dash is an Indian Revenue Service Income Tax officer of 1988 ...

First COVID-19 vaccine tested in US poised for final testing

The first COVID-19 vaccine tested in the U.S. revved up peoples immune systems just the way scientists had hoped, researchers reported Tuesday -- as the shots are poised to begin key final testing. No matter how you slice this, this is good...

Give Feedback