The Response of Crops to Potassium Placement Depth and Band Spacing

The right place for K in summer dominant rainfall areas of northern Australia.


Northern Australian cropping systems are dominated by Vertosols and crop productivity is largely dependent on stored soil moisture. Cropping systems are a mix of summer crops of sorghum, cotton, maize and mungbeans and winter opportunity cropping with wheat, barley and chickpeas. Crop performance and the efficient use of water relies on access to adequate subsoil nutrient levels, but there are large variations in native soil P and K reserves. Read more

Year of initiation:2010
Year of completion:2015


07 Mar 2016

Chelmsford P and K response 2014-2015
Deep banded P and K over two crops

30 Jun 2015

Response to deep placed P, K and S in central Queensland
Summary of six crop years

04 Mar 2015

K response in wheat
Results from Chelmsford experiment.

29 Oct 2014

Results from Capella (wheat) and Gindee (chickpea) - 2013.
Response to residual K from bands applied in 2011

12 Dec 2013

Potassium nutrition in CQ Cropping Systems
Responses to applied K on wheat and chickpea

04 Sep 2013

Warra Site - 2012/13 Cotton Results
Managing K in Northern Cropping Systems

06 Jun 2013

Brookstead Site - 2012/13 Sorghum Results
Managing K in northern cropping systems

28 Feb 2013

Capella site - 2012 chickpea results
Managing K in northern cropping systems

14 Jan 2013

Managing K in northern cropping systems
Overview of current research on K placement for wheat, cotton, chickpea and sorghum.

24 Sep 2012

Multiple nutrient deficiencies in northern grains cropping
Importance of considering K, as well as N, P and S in a nutrition program.

30 Jun 2012

Gindee site - 2011/12 sorghum results
Managing K in northern cropping systems

30 Jun 2012

Warra site - 2011/12 cotton results
Managing K in northern cropping systems

29 Feb 2012

Brookstead site - 2011 wheat results
Managing K in northern cropping systems

Interpretive Summary

Two field experiments were established in central Queensland at Capella and Gindie to investigate the immediate and the residual benefit of deep-placed (20 cm) nutrients in this opportunity cropping system. The field sites had factorial combinations of P (40 kg P/ha), K (200 kg K/ha), and S (40 kg S/ha) and all plots received 100 kg N/ha. No further K or S fertilizers were added during the experiment but some crops had starter P.

The aim of the project is to explore responses to different K application strategies (i. e. , place, rate and with other nutrients) for a range of crops grown in central Queensland in modern no-till opportunity cropping systems. In this region, subsoil P, K and S are often co-limiting, although critical soil test values for P and K are poorly defined.

Two sites were established in central Queensland in 2012, one at Capella and the second at Gindee. Both sites had low soil concentrations of P, K, and S, especially in the subsoil layers. We established trials by adding single nutrients (P or K or S) into the 10 to 30 cm layer, or combinations (P+K, P+S, K+S, P+K+S). These sites were grown under commercial practice through successive crops; sorghum (2012) and the chickpea (2013) at Gindee and chickpea (2012) and wheat (2013) at Capella.

Central and southeastern Queensland cropping systems are driven by water availability, and in these summer rainfall areas either winter crops (wheat or chickpea) or summer crops (cotton or sorghum) will be selected depending on the amount of stored soil moisture. It has been shown that in these systems, the subsoil nutrient levels are moderately to severely depleted due to the rainfall and root development patterns.

We continue to see evidence of responses to additional P, K, or S fertilizer applications in winter and summer crops, with a number of sites responding more strongly to combinations of these nutrients (i. e. P and S, or PK and S) than due to individual nutrients alone. This is especially the case where sufficient N is available to allow higher yield targets to be reached. Factors which affect root system efficiency or the ability of root systems to explore large soil volumes (e. g.

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Updates & Reports


2015 Annual Report


2014 Annual Report


2013 Annual Report


2012 Response to K placement - Chickpea, Capella.


The response of crops to K placement depth and band spacing


2011 K depth and band spacing experiments


Project Description

Capella Chickpea Experiment

Project Leader

Mike Bell, University of Queensland

Project Cooperators

Cameron Ireland, Agrow P/L and Canpotex P/L

IPNI Staff

R. M. Norton


Oceania \ Australia and New Zealand \ AUS \ Queensland \ Darling Downs

Oceania \ Australia and New Zealand \ AUS \ Queensland \ Gindee

Oceania \ Australia and New Zealand \ AUS \ Queensland \ Bendee



chickpea, cotton, wheat

Potassium (K)