Changes in the physical properties of a Vertisol following an irrigation of cotton as influenced by the previous crop
1991
Hulme, P.J. | MacLeod, D.A. (New England Univ., Armidale (Australia). Dept. of Agronomy and Soil Science) | McKenzie, D.C. (New South Wales Agriculture and Fisheries, Rydalmere (Australia). Biological and Chemical Research Inst.) | Abbott, T.S. (New South Wales Agriculture and Fisheries, Haymarket (Australia))
Tests were carried out in a field experiment into the effects of cultivated fallow, wheat and safflower on soil structure, and the growth of a subsequent cotton crop, over a 12 day period following irrigation for: soil water content and potential; core and clod bulk density; air-filled porosity; an index of macropore continuity using Rhodamine dye; and penetration resistance. The results indicated that soil physical conditions at 0.25 m should have impeded root growth regardless of water content. However, cotton roots continued to extract water in this hostile soil environment; this favourable performance was attributed to the better conditions for root growth in the interaggregate fissures than those within aggregates. Apart from water content, all indicators of soil structure were able to differentiate consistently between the 3 crop treatments to a depth of 0.25 m. Below 0.8 m, the cropped plots, particularly safflower, had lower water contents than the fallow plots.
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