CFIG Precision Agriculture Research

Investigating the benefits of applying lime and very deep ripping a sand over tight gravel soil.

Neville and Glennys Turner

Introduction
Soil investigations revealed that the soil type at the site of this trial had very tight gravel at about 40cm below the soil surface. This gravel looked to be impeding root growth at depth in the soil. The sub soil was also found to be very acidic (pH in low 4\'s). On this site it was decided to investigate what effect very deep ripping (1.5M) would have on crop growth.
Two tonne of lime per Ha has been spread along half the length of all of the plots.
We anticipate that the deep ripped plots will out yield the non-ripped sites for a number of years. However the benefits of this practice have not yet been defined.

Rotation : Canola 99 / Wheat 00 / Lupins 01 / Wheat 02
2002 crop : Noodle Wheat
Paddock Standard fertilizer: 130kg Croprass = 23kg N 10.3kg P and 21.2kg S

Treatments:
The trial consists of 5 plots, 3 being control plots and 2 being deep ripped plots.
Control = paddock standard + and - 2T/Ha lime.
Very deep rip (1.5 M) + and - 2T/Ha lime.

The plots are 100m long and the last 50m of each plot was treated with 2T/ha of lime.

Nutrient strips across production zones.
The soil tests indicated that there was adequate potassium on all soil types tested in the paddock.

Nitrogen will be applied in strips across the high, medium and low production zones.

The nitrogen rates have been determined assuming the following estimated yields in each zone.

Measurement of response.
The trial paddock will be flown over by Air Agronomics (2M resolution) to give
indication of biomass response to nitrogen rates.

Plots will be harvested according to production zone with a weight trailor at harvest.