Open Access Repository

Ameliorating dense clay subsoils to increase the yield of rain-fed crops

Sale, P, Tavakkoli, E, Armstrong, R, Wilhelm, N, Tang, C, Desbiolles, J, Malcolm, B, O'Leary, G, Dean, G ORCID: 0000-0002-3502-2248, Davenport, D, Henty, S and Hart, M 2021 , 'Ameliorating dense clay subsoils to increase the yield of rain-fed crops' , Advances in Agronomy, vol. 165 , pp. 249-300 , doi:

Full text not available from this repository.


The yield of rain-fed crops needs to increase to meet the requirements of a growing human population. One way to achieve this is to store more rain in the root zone of soils and increase its use by crops. This will be difficult where poorly structured, dense clay subsoils occur. These subsoils limit crop yields by reducing root growth, and the uptake of soil water and nutrients. Reduced root growth results from physical factors, such as low porosity restricting the movement of air and water, high soil strength and temporal water logging which impedes the roots. Chemical factors such as alkalinity, salinity, and sodicity may further restrict root growth in neutral pH and alkaline clay subsoils.This review will focus on the challenging task of improving structure in these dense clay subsoils and to overcome physicochemical constraints in the subsoil, in order to increase crop yields. Early attempts to ameliorate these subsoils using tillage practices, and amendments in some cases, were rarely successful. A more recent and successful approach has been to deep-band nutrient-rich organic amendments in the subsoil, and to follow with a field crop. This increased root growth in the subsoil, and was often associated with improved subsoil structure. It was able to produce substantial and prolonged increases in crop production. A key benefit was an increase in plant available water in the subsoil and the utilization of this water by the crop. The impact of the practice depends on the amount and distribution of rainfall, and this results in increased financial risk for the farm business. Specialized machinery will need to be developed to handle the amendments, while the form, rate of incorporation, and placement depth of amendments will need to be optimized to reduce high upfront costs of the practice.

Item Type: Article
Authors/Creators:Sale, P and Tavakkoli, E and Armstrong, R and Wilhelm, N and Tang, C and Desbiolles, J and Malcolm, B and O'Leary, G and Dean, G and Davenport, D and Henty, S and Hart, M
Keywords: crop yields, rain-fed crops, clay subsoils, soil structure
Journal or Publication Title: Advances in Agronomy
Publisher: Academic Press
ISSN: 0065-2113
DOI / ID Number:
Copyright Information:

Copyright 2021 Elsevier Inc

Related URLs:
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page