Pacific Fertiliser has purchased the TTQ deep ripper setup as a trial deep placement machine. The equipment has been bought for in-house trials and product development but it is also available for dry or wet hire.

The ripper has two feed boxes on top to provide deep placement of both soil conditioners (gypsum/lime/manure) and fertiliser.

The deep ripper has 3 big front/gypsum tynes which can go down to 800mm deep and the 5 back tynes can go to 600mm deep (adjustable). Example you can have the front at 600mm deep the back tynes can be manually adjusted from 200-500mm deep.

The front box (ie gypsum) has a capacity of 2.3m3 with 3 outlets and the back box (ie fert) has a capacity of 0.6m3 with 5 outlets. The Seebrook seeder controller which drives electric rotary valves under the boxes controls the feed rate of each product during operation. Gypsum rates upto 5000kg/ha and the fert box up to 500kg/ha can be achieved. Control is via wi-fi and a smartphone or table. The front box was designed for bulk mined gypsum so it can handle slightly sticky product, but we are developing the machine further for trials with granular soil conditioners and liquid gypsum using trailing product carts.

If the ripper is wet hired it comes with a John Deere 8370RT tractor and operator.

Currently there has been a lot of work on deep ripping and placement of gypsum (sub soil sodicity), lime (subsoil acidity) and phosphorous into the soil profile. Pacific Fertiliser bought the trial ripper to help farmers see if deep placement and soil conditioning will work on their farms to treat sub soil constraints and whether it is cost effective. From farmer trials we aim to further develop the deep ripping machine and products to chase yields gains for our customers.

Notes from a GRDC day in Goondiwindi:

Phosphorous:

Phosphorous is fairly immobile in the soil profile so you can generally find P levels are okay in the top 200-300mm from broadcast and starter applications of P, but most crops roots go past that and it will probably be depleted >300mm range and that is why you see on most trials that deep ripping with P application gets a yield increase. Past trials have seen deep P rates at 100-180kg/ha of MAP.

Ripper spacing is key so the roots can find the rip zone and the placed nutrients (ie phosphorous). Less than 500mm wide is good, and double the width of normal planting row spacing is desired. Ripping across normal row direction is good, from 10 deg offset to 90 deg.

Sodicity:

Sodicity is the biggest soil constraint in Australia being most prominent in the Nth NSW & Sth QLD region. Sodicity creates two issues in soils:

  • Physically – Dispersive soils
  • Chemically – restricts nutrient uptake (eg plants take sodium before potassium)

Gypsum – with one deep placement application you could see the benefits over 4-5 years. Generally in the trials to date there has been no noted step change in the first year. Differences with gypsum application over control plots could stand out more in drier years.

A Yetman farmer said it cost him $100/ha to rip at his country down to 300-400mm deep with no inputs. They did the lighter and harder areas in paddocks and got an immediate yield increase  in the 1st year. The GRDC speakers thought you shouldn’t rip clays without ameliorants because the soil might slump back in even tighter over a few years.

Please visit the GRDC and DPI websites for more information on deep ripping and deep placement of both gypsum and phosphorous.