Bulk samples of 26 soils (India) ranging in DTPA-extractable Zn from 0.24 to 2.00 ppm were subjected to greenhouse study to find critical levels of soil and plant Zn for predicting response of clusterbean (Cyamopsis tetragonoloba) to Zn fertilization. Bray's per cent yields (BPY) at 5 ppm added Zn varied from 37 to 117 and was positively correlated with… (More)