Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: A review

Ma, Q., Bell, R.ORCID: 0000-0002-7756-3755, Scanlan, C. and Neuhaus, A. (2022) Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain production: A review. Crop and Pasture Science . Online Early.

Abstract

Abstract

Negative potassium (K) balances on farmlands globally are widespread because fertiliser K input is often less than losses (leaching) and removal of K in hay, straw and grain, which leads to a rundown of plant-available K. When soil K reserves are not large and the plant-available K pools are not well buffered, the risk of K rundown in soils is high. In the south-west of Western Australia, soil K rundown, particularly by continuous cropping or in systems where a large portion of crop biomass is removed, is increasing the prevalence of crop K deficiency even on soils where K was not previously a limiting factor for crop yields. While fertiliser K is required for adequate supply of plant-available K, maximising K use efficiency is also important for cropping profitability and sustainability in dryland agriculture. Plant K uptake and use efficiency can be affected by soil types, crop species and sequences, seasonal conditions, and K management. In water-limited environments, crop K nutrition, especially root access to subsoil K, plays a crucial role in promoting root growth, regulating plant water relations and alleviating biotic and abiotic stresses. Optimised use of both soil and fertiliser K is increasingly necessary to sustain crop yields under stressed conditions in the context of K rundown in soils.

Item Type:	Journal Article
Murdoch Affiliation(s):	Centre for Sustainable Farming Systems SoilsWest
Publisher:	CSIRO Publishing
Copyright:	© 2022 The Authors.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/64807

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