Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Phosphorus accumulation by field-grown canola crops and the potential for deep phosphorus placement in a Mediterranean-type climate

Rose, T.J., Rengel, Z., Ma, Q. and Bowden, J.W. (2009) Phosphorus accumulation by field-grown canola crops and the potential for deep phosphorus placement in a Mediterranean-type climate. Crop and Pasture Science, 60 (10). pp. 987-994.

Link to Published Version: http://dx.doi.org/10.1071/CP08367
*Subscription may be required

Abstract

When the bulk of phosphorus (P) is located near the soil surface, spring drying of topsoil in Mediterranean-type climates can reduce P availability to crops and cause potential yield loss. In crop species that require a P supply during spring, deep-placement of P fertiliser has proved an effective method of improving P availability and grain yields; however, the spring P demand of field-grown canola (Brassica napus L.) and therefore potential response to deep P placement is not known. This study investigated the effect of deep- (0.170.18m), conventional- (shallow, 0.070.08m), split- (50% deep, 50% shallow), and nil-P fertiliser treatments on P accumulation and seed yields of canola in two field trials. In addition, a glasshouse experiment with different depths of P fertiliser placement and topsoil drying at different growth stages was conducted. In the glasshouse study, deep P placement resulted in greater P uptake by plants, but did not increase seed yields regardless of the time of topsoil drying. At the relatively high-soil-P field site (canola grown on residual P application from the previous year) in a dry season, there was no biomass response to any residual P fertiliser treatments, and P accumulation had ceased by mid flowering. At the low-P field site, P accumulation continued throughout flowering and silique-filling, and seed yields increased significantly (P≤0.05) in the order of split- > deep- > shallow- > nil-P treatments. Improved seed yields in the split- and deep-P treatments appeared to be the direct result of enhanced P availability; in particular, P uptake during vegetative growth (winter) was higher in the treatments with deep P placement. A greater understanding of P accumulation by field-grown canola in relation to soil P properties is needed for better defining optimum P fertiliser placement recommendations.

Item Type: Journal Article
Publisher: CSIRO Publishing
Copyright: © 2009 CSIRO.
URI: http://researchrepository.murdoch.edu.au/id/eprint/32541
Item Control Page Item Control Page