Header Image

Helping grow
the country

< Back to Blog
Blog
1 September 2018 Jessica Dunbar

Spring crop paddock selection

Soil testing is an important tool in your cropping calendar. It can be utilised to assist in selecting the correct paddocks to use for high value crops, like fodder beet, and for selecting which paddocks can be planted with a lower value crop in order to start the process of increasing soil fertility in areas lined up for pasture renewal.

Soil testing provides the ability to develop a tailored fertiliser programme and focus on the key nutrients required for your farms maintenance programme, or for a specific crop. Fertiliser spend makes up a significant portion of the farm budget, therefore it is always worth taking a measured approach and only applying the nutrients that are needed.

So what are nutrients? They are the 16 mineral elements that plants and animals require to grow and function, with plants getting their nutrients from the soil. Soil testing prior to planning for the season ahead gives a base foundation and understanding for the nutrient levels you are working with. In your farming system, growth or yield will be limited by the nutrient in shortest supply.

Soil testing is an essential component when it comes to nutrient interactions. Having an abundance of one nutrient can effectively antagonise another, or vice versa, where you have a synergy of increased availability of one nutrient due to the increase in level of another nutrient. For example, excess potassium leads to an imbalance of magnesium and calcium, which can have an effect of poor yield or quality, as well as the potential for metabolic disorders in stock to arise.

Another reason behind soil testing is for developing trends across your farm system against previously collected data. It is recommended that you get your PGG Wrightson Technical Field Representative, or Ballance Agri-Nutrients representative to soil test at the same time every year, to maintain consistency. Taking samples six to eight weeks out allows for tests to be sent away, analysed and sent back to develop effective fertiliser programmes.

Sampling depth for soil testing is directly related to the potential rooting depth of the crop. Pasture, or herb paddock samples should be taken at 75 mm, and arable or cropping paddocks sampled at 150 mm in depth.

Fertiliser inputs will be based on your soil test results and will determine if your fertiliser programme is maintenance, or capital. Maintenance nutrient requirements are the quantity of fertiliser nutrients required to maintain a particular soil test level over a one year period. Capital nutrient requirements are the quantity of fertiliser nutrients required to increase the soil test value to the optimum target value, for example increasing soil fertility levels to get an optimal Olsen P for the soil type and farm production level.

Taking a soil test to determine soil nutrient levels, prior to planting crops and applying maintenance fertiliser over the whole farm ensures rates of nutrients applied are in line with dry matter yield goals for your crops and overall farm production goals. Knowing what nutrients are already present in your soil also helps to avoid applying excess fertiliser, thus helping to farm in an environmentally sustainable manner.

For more information on soil testing, contact your local PGG Wrightson Technical Field Representative.

Jessica Dunbar

Related Articles

Get the paddock right

28 August 2018

Time spent now selecting and preparing your brassica crop paddock may pay off later.

Paddock history, location and soil fertility are just three of the considerations that should be kept in mind when deciding where to grow your next brassica crop.

“Be mindful of paddock history with brassicas,” says Murray Lane, Forage Specialist for Ballance Agri-Nutrients. “If previous crops have been infested with wild turnip, it is not recommended to plant swede, turnips or kale into the same paddock. If you have had dry rot or club root don’t plant brassicas, even varieties tolerant to these problems, in that spot for five years following.”

Consider access and suitability for machinery and stock. “Choose a paddock that is less prone to pugging or compaction, and one where you can easily provide grazing stock with drinking water while keeping them away from natural waterways and drainage channels,” advises Murray.

In relation to paddock rotation, think about whether you have pasture that could benefit from a break to address weed and pest issues, contouring, or other performance problems.

“Above all, select your paddocks early,” says Murray. “This gives you time to prepare them properly, which pays off with a better crop. Spray-out weeds this autumn, put in a winter ryegrass, graze that, then spray again before sowing in spring. This will minimise the amount of weeds in the crop.”

Early paddock selection also gives you time to adjust pH and fertility. “Brassicas like a pH between 5.8 and 6.2. Lime applications need up to a year to take full effect so the sooner you select your paddock, test pH and if necessary apply lime, the better.”

Test soil nitrogen, phosphorus, potassium, sulphur, magnesium and boron six months before sowing to inform your fertiliser strategy. “Brassicas can be expensive to grow. Hitting that sweet spot where you get the best yield gains from your inputs, in other words an economically optimal yield, is the aim. Also consider the value of the feed as this influences the size of the gap between the economic and maximum yields,” explains Murray.

Looking further ahead, regardless of base fertiliser needs, the value of placing a starter fertiliser at sowing cannot be underestimated. Cropzeal Boron Boost is a good option for brassicas providing phosphate close to the germinating seed to support early root development, and boron to guard against common problems such as brown heart.

To assist you in planning your next brassica crop, talk to your Ballance Nutrient Specialist or your local PGG Wrightson Technical Field Representative.

Article supplied by Ballance Agri-Nutrients

Spring pasture checklist

01 September 2018

New pastures are an opportunity to lift farm production and match pasture growth to the stock class you are producing. Taking time to do it well pays off in the long-term.

Here are some key things to focus on:

  • The spray-out
    Good soil moisture is key to strike seed and get any pasture off to a great start. Consider spraying out early if you don’t need the feed to conserve soil moisture for when you drill. Check for existing insect pest populations and take this opportunity to deal with them.
  • Seedbed preparation 
    Seedbed preparation is about creating an environment for the seed to germinate but also fixing any underlying problems such as compaction and perennial weeds. In drier climates, use cultivation techniques such as not leaving the furrow up to conserve soil moisture. In wetter areas you can do the opposite.
  • Drilling
    When drilling the seed, use a sowing rate which gives the result you’re after. Seed requires moisture to germinate so ensure a consolidated seedbed. Keep a wary eye on the weather and use it to your advantage. To ensure good establishment, deal to pests like slugs and springtails around drilling time. Direct drilling is more prone to slugs due to lack of soil working, so drilling with slug bait is a good idea.
  • Establishment of pasture plants
    Continue to keep a close eye out for any damage from pests such as slugs. Often damage to small plants is difficult to detect and a spray may be needed to prevent plant loss during this early phase of establishment.
  • Maximise yield 
    After the crop is in the ground, remember weeds will emerge and compete with the pasture plants. Small weeds are easier to control than larger weeds so the early weed spray often gives a better result and easily pays for itself in extra production.

New pasture establishment requires planning and careful execution for a good result, so if you want to discuss your plan further or get advice on any aspect of pasture establishment, contact your local PGG Wrightson representative.

Watch out for weeds
Weeds can change the way your farm operates. A new weed can spread over time and compete with valuable grazing plants and in some cases get caught in wool and even meat. 
Here are some ways to keep your farm clean:
  • Control weeds around stock yards, this is a source of seeds which are then spread around the farm.
  • If buying in feed, check it for unwanted contaminants. If possible, only feed out in specific areas which you can monitor, then keep an eye out for anything out of the usual.
  • If you see an unusual plant in your paddock, identify it and remove it before it seeds. Weeds can produce large numbers of seed, so removing or controlling when there are a small number of plants can prevent a lot of trouble in later years.

The key to successful spring cropping

01 October 2018

Since 2016, Neil and Stacie Fagan have utilised spring sown Cleancrop™ brassicas as part of a programme to control pasture weeds before establishing new pastures in autumn.

Cleancrop rape was initially used as a summer feed on their sheep and dairy support block in Te Kuiti, but more recently they have been planting Cleancrop leafy turnip. “Cleancrop leafy turnip has a slightly better system fit enabling us to finish more lambs on the property versus selling to store” explains Neil.

Prior to spring planting Cleancrop brassica crops, existing pastures are sprayed out with glyphosate to kill the existing pasture and problem weeds including Californian thistles. As the crops are established via direct drilling, a second glyphosate application is applied prior to drilling to ensure a complete kill of existing pasture and problem weeds.

Immediately following drilling, the broad spectrum herbicide Telar®, supplied as part of the Cleancrop Brassica System, is applied to provide residual weed control. Due to the high root reserves associated with Californian thistles, there have been instances where the thistles have ‘punched’ through the pre-emergent herbicide. When this happened, Neil was able to request the chemical for a second application of Telar® free of charge and achieve post-emergent control.

Following summer brassica crops, Neil and Stacie have been keen to replace older pastures with modern perennial ryegrass genetics. In autumn 2017, following a Cleancrop rape crop, they planted
Platform AR37 perennial ryegrass.

Platform is a dense, medium-leaved diploid ryegrass with a late heading date (+12 days) that is well suited to both dairy and progressive sheep and beef systems. “Parentage for Platform AR37 includes a combination of elite New Zealand and north-west Spanish genetics to provide both spring and cool season growth when it’s needed most” says PGG Wrightson Seeds Plant Breeder, Tom Lyons.

Within the first few months, Platform’s cool season growth was noticed. “I am also impressed with the speedy response we saw from this ryegrass after the dry spell we had in December 2017. Nothing else on our farm responded like Platform did, this area can now support our dairy heifers as well as our ewes” explains Neil.

Independent National Forage Variety Trials (NFVT) have also confirmed Platform’s agronomic value with the ryegrass jumping straight to the top of this year’s National NFVT summary1 and gaining Dairy NZ ‘Five Star’ status in the 2018 Forage Value Index (FVI).

Platform paddocks have also been incredibly valuable during the summer with impressive quality and the ability to hold lambs while they were transitioned onto a crop of Cleancrop leafy turnip. Neil added “our lambs had quality feed all round this season.” Neil and Stacie said that so far, this is definitely their standout block and they would definitely use both Platform and Cleancrop leafy turnip again.

For more information on Platform perennial ryegrass or the Cleancrop range of forage brassicas, contact your local PGG Wrightson Technical Field Representative.

Supplied by PGG Wrightson Seeds

12017/18 NFVT Perennial Ryegrass Summary: https://www.nzpbra.org/wp-content/ uploads/Perennial-Ryegrass-Summary-2017.pdf.

Share this page