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Not AvailableDuring a 3-year experimental period (between 1992 and 1995), residual effects on yields of subsequent crops of phosphorus applied either to soyabean or wheat, and on recoveries of the added P and changes in the available P, were studied in a soyabean–wheat cropping system on a typic haplustert very low in available P at Bhopal, India. Phosphorus was applied at rates of 0–52 kg P ha-1 (five treatments) to soyabean and 0–39 kg P ha-1 (three treatments) to wheat during the first year, and in the subsequent years the residual effects were studied in relation to fresh applications of 39 kg P ha-1 to each crop. The yields of soyabean and wheat were increased significantly by the application of P to each crop. Phosphorus applied to soyabean showed residual effects in two succeeding crops, whereas P applied to wheat showed a residual effect in only one succeeding crop. Phosphorus applied to soyabean was more efficiently utilized by the succeeding crops compared to that applied to wheat in the rotation. The recoveries of added P were greater with smaller rates of added P and greater in the first two residual crops. Olsen P in soil was adequate only in the first year and it fell below the critical limit in the subsequent two cycles of cropping. Cumulative P uptake by crops determined the levels of available P in the soil and soil test values declined with increase in cumulative P uptake over time.Not Availabl