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A long-term field study was commenced in 1995-96 to assess the impact of continuous application of inorganic fertilizers and organic manure on sustainability, productivity and chemical indicators of soil quality in an irrigated soybean-wheat cropping system (SWCS). Six treatments comprised inorganic fertilizers (NPK) and manure (M) either alone or in combination. Soybean yield indicated declining trend −22.50, −56.0 and −25.0 kg ha⁻¹ year⁻¹ under unfertilized control, sole nitrogen and NPK treatments, respectively while addition of organic manure resulted in a positive yield trend. Plot receiving NPK had positive yield trend of 118 kg ha⁻¹ year⁻¹ in wheat crop. The highest positive yield trend was obtained with manure (M) and NPK treatment, values being 17.60 and 191 kg ha⁻¹ year⁻¹ in soybean and wheat, respectively. Significantly (p < 0.05) the highest grain yield was also observed under the …