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High subsoil chloride concentrations reduce soil water extraction and crop yield on Vertosols in north-eastern Australia

Dang, Y.P. and Dalal, R.C. and Mayer, D.G. and McDonald, M. and Routley, R. and Schwenke, G.D. and Buck, S.R. and Daniells, I.G. and Singh, D.K. and Manning, W. and Ferguson, N. (2008) High subsoil chloride concentrations reduce soil water extraction and crop yield on Vertosols in north-eastern Australia. Australian Journal of Agricultural Research, 59 (4). pp. 321-330.

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Article Link(s): http://dx.doi.org/10.1071/AR07192

Publisher URL: http://www.publish.csiro.au/

Abstract

Salinity, sodicity, acidity, and phytotoxic levels of chloride (Cl) in subsoils are major constraints to crop production in many soils of north-eastern Australia because they reduce the ability of crop roots to extract water and nutrients from the soil. The complex interactions and correlations among soil properties result in multi-colinearity between soil properties and crop yield that makes it difficult to determine which constraint is the major limitation. We used ridge-regression analysis to overcome colinearity to evaluate the contribution of soil factors and water supply to the variation in the yields of 5 winter crops on soils with various levels and combinations of subsoil constraints in the region. Subsoil constraints measured were soil Cl, electrical conductivity of the saturation extract (ECse), and exchangeable sodium percentage (ESP). The ridge regression procedure selected several of the variables used in a descriptive model, which included in-crop rainfall, plant-available soil water at sowing in the 0.90-1.10 m soil layer, and soil Cl in the 0.90-1.10 m soil layer, and accounted for 77-85% of the variation in the grain yields of the 5 winter crops. Inclusion of ESP of the top soil (0.0-0.10 m soil layer) marginally increased the descriptive capability of the models for bread wheat, barley and durum wheat. Subsoil Cl concentration was found to be an effective substitute for subsoil water extraction. The estimates of the critical levels of subsoil Cl for a 10% reduction in the grain yield were 492 mg cl/kg for chickpea, 662 mg Cl/kg for durum wheat, 854 mg Cl/kg for bread wheat, 980 mg Cl/kg for canola, and 1012 mg Cl/kg for barley, thus suggesting that chickpea and durum wheat were more sensitive to subsoil Cl than bread wheat, barley, and canola.

Item Type:Article
Corporate Creators:Department of Employment, Economic Development and Innovation (DEEDI), Agri-Science, Crop and Food Science, Animal Science , Plant Science, Emerging Technologies
Business groups:Agri-Science, Crop and Food Science, Animal Science
Additional Information:© CSIRO.
Keywords:Barley; bread wheat; canola; chickpea; durum wheat; ridge regression; chloride; concentration (composition); crop production; legume; soil property; soil quality; soil water; subsoil; wheat; Brassica napus; Brassica napus var. napus; Cicer arietinum; Hordeum; Triticum aestivum; Triticum turgidum subsp. Durum.
Subjects:Agriculture > Agriculture (General) > Soils. Soil science > Soil and crops. Soil-plant relationships. Soil productivity
Plant culture > Field crops
Deposited On:29 Jan 2009 05:27
Last Modified:26 Oct 2011 06:23

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