Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


Watch out for soils in winter

Watch out for soils in winter

by Bala Tikkisetty
June 10, 2014

The winter months are when farm soils can come under particular pressure from things like pugging and compaction.

So farmers are advised pay particular attention at this time of year to ensuring, as much as possible, their soils remain healthy, as this is essential to any profitable farming operation and its long-term sustainability.

If the soil is physically healthy and fertile, crop and pasture production will be high.

The physical structure of soil controls the movement of air and water through the soil, and the ability of roots to penetrate into the soil. It also provides habitat for a number of beneficial organisms, including earthworms. Soil with good structure has a significant number of pores that provide aerobic conditions, good drainage and high water-holding capacity.

Plants require about 10 elements in large quantities (macronutrients), and about eight in small quantities (micronutrients). Of the major elements, carbon, hydrogen and oxygen are obtained from oxygen and carbon dioxide in the air. Others include nitrogen, phosphorus, potassium, sulphur, calcium and magnesium. Minor elements include iron, manganese, copper, zinc, molybdenum, boron, chlorine, silicon and cobalt. In natural ecosystems when plants and animals die many of these nutrients are cycled back into the soil. However, in farming ecosystems, plant or animal biomass is removed with harvesting. To supply essential elements for plant growth farmers add nutrients to the soil in a number of ways such as using fertiliser and animal effluent application to land.

So, during the winter months, it’s important to safeguard this investment in soil health and fertility and the time and money involved.

Compaction and pugging of wet soils in winter can particularly damage the soil structure.

Pugging is caused by animals’ hooves sinking into the soil surface (sometimes as deep as 15 centimetres) when they tread in very wet soils. This leaves a ‘puddle’ effect and can lead to compacted layer of soil.

Such compaction occurs when the soil is compressed or squeezed. In addition to being caused by animal treading, vehicles or farm machinery also contribute to this problem.

Compaction on dairy and drystock sites is a particular concern as it reduces the number and size of pores available for water and gas movement in soil. It reduces aeration, nutrient uptake, root growth and distribution, and potentially decreases infiltration and increases runoff. The most sensitive indicator of compaction is macroporosity. Previous research reveals that macroporosity below 10 per cent will inhibit pasture growth.

Soil scientists have found that compacted soil can reduce the amount of dry matter in pasture by 200 kilogrammes per hectare per month. (Aerating the compacted soil at the correct depth and time can increase the amount of dry matter by about 30 per cent within six months .)

Other problems caused by pugging and compaction include more frequent and persistent surface ponding, as well as increased sediment, nutrient and effluent losses to waterways through surface run-off. It also takes longer for pugged or compacted pasture to recover after grazing and weed invasion often occurs in the bare sites pugging and compaction create.

Problems like these can be minimised by:
• reducing stock density, especially on sensitive paddocks like those that are wet
• not feeding out on sensitive paddocks
• constantly monitoring pugging and compaction during at-risk periods and moving stock off before damage occurs
• grazing the back of the paddock first.

Another important issue for soil health management and water quality is how animals are wintered.

Losses appear to be exacerbated by high density urine patches deposited at times of the year when plant growth rates are low and drainage is high (the types of conditions typical in winter). Consequently, on a per hectare basis, nitrogen leaching losses from grazed winter forage crops are high relative to losses measured under pasture.

*************

Bala Tikkisetty is a sustainable agriculture coordinator at Waikato Regional Council.

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On The Tokenism Of New Zealand's Role Against Islamic State

To date, the Opposition has continued to occupy itself with the marginalia of the issue. E.g. whether Key did or didn’t know whether Barack Obama would be present at the US briefing last week on IS, or whether New Zealand’s military involvement is or isn’t already a fait accompli.

It might be better to tackle the issue, head on. Our contribution against IS will be to send SAS forces to train the Iraqis? That’s like offering trainers to General Custer just as the 7th cavalry reached the Little Big Horn.
More>>

 

Parliament Today:

Labour: Tea Breaks 'Gone By Lunch Time'

“How cynical that on the eve of Labour weekend, the National government is pushing through legislation that takes away the statutory right to tea and meal breaks along with collective bargaining protections, and makes vulnerable workers jobs even less secure." More>>

ALSO:

Gordon Campbell: On Pharmac, Gough Whitlam And Sleater-Kinney

We’re not at the outset of these negotiations. The outset was six years ago, and negotiators were hoping to have some sort of ‘framework’ deal finished in time for the APEC meeting in a few weeks’ time. These ‘extreme’ positions are what we’ve reached near the intended end of the negotiations… More>>

ALSO:

PM Of Many Hats: October 22 — Parliament Today

Dr RUSSEL NORMAN (Co-Leader – Green) to the Prime Minister: How many times since November 2008 has he spoken with blogger Cameron Slater on the phone and how many times, if any, has he texted him?
Rt Hon JOHN KEY (Prime Minister): None in my capacity as Prime Minister. More>>

ALSO:

Aussie Investigation Dropped: Call On Minister McCully To Pursue The Case Of Balibo Five

West Papua Action is deeply concerned at the lack of any clear outcome from the Australian Federal Police inquiry into the 1975 deaths of the ‘Balibo Five’ including NZ journalist Gary Cunningham. More>>

ALSO:

'Feed The Kids' Bill: Metiria Turei To Lead Fight On Feeding Hungry Children

Green Party Co-leader Metiria Turei is urging all political parties to support the Feed the Kids Bill which she inherited today from Mana leader Hone Harawira. More>>

ALSO:

Parliament Today: State Opening Of Parliament

The House sat at 10.30am on Tuesday before MPs were summoned to hear the Speech from the Throne in the Legislative Council Chamber. More>>

ALSO:

Tertiary Education: Students Doing It Tough As Fees Rise Again

The Government is making it increasingly difficult for Kiwis to gain tertiary education as fees continue to rise and access to student support becomes even more restricted, Labour’s Tertiary Education spokesperson Chris Hipkins says. More>>

ALSO:

Housing, Iraq: PM Press Conference – 20 October 2014

Prime Minister John Key met with press today to discuss:
• Housing prices and redevelopment in Auckland
• Discussions with Tony Abbott on the governmental response to ISIS, and New Zealand’s election to the UN Security Council More>>

ALSO:

Labour: Review Team Named, Leadership Campaign Starts

Labour’s New Zealand Council has appointed Bryan Gould as Convenor of its post-General Election Review. He will be joined on the Review Team by Hon Margaret Wilson, Stacey Morrison and Brian Corban.

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news