ABSTRACTThe root mats of barley seedlings grown in sand without N and P were allowed to have contact with different soil-fertilizer systems for 10 d, after which plant yield and offtake of N, P, K, Ca, Mg, S, and Na were assessed. There was a linear relationship between N offtake (mg/pot) and N applied (mg/pot) over a concentration range of 0–20 mg N per 100 g soil in two of the soils (Gambari and Sapoba) tested; a negative curvilinear relationship was obtained in Insch soil with a higher native N. Similarly, barley seedlings showed a rapid growth response to P applications in Gambari and Sapoba soils with low initial P status, while the response in Insch soil of very high native P was low. Whereas the influence of high rates of applied N on plant N, P, K, and Ca was positively significant in all soils, high levels of applied P (100 mg 100 g-1 soil) depressed the off-take of N, K, and Ca; and this trend varies with soil type. The high crop response to applied P in Gambari and Sapoba soils sampled from the rain forest zone of Nigeria stresses the imperativeness of P fertilization for successful crop production in the region.
The root mats of barley seedlings grown in sand without N and P were allowed to have contact with different soil-fertilizer systems for 10 d, after which plant yield and offtake of N, P, K, Ca, Mg, S, and Na were assessed. There was a linear relationship between N offtake (mg/pot) and N applied (mg/pot) over a concentration range of 0–20 mg N per 100 g soil in two of the soils (Gambari and Sapoba) tested; a negative curvilinear relationship was obtained in Insch soil with a higher native N. Similarly, barley seedlings showed a rapid growth response to P applications in Gambari and Sapoba soils with low initial P status, while the response in Insch soil of very high native P was low. Whereas the influence of high rates of applied N on plant N, P, K, and Ca was positively significant in all soils, high levels of applied P (100 mg 100 g-1 soil) depressed the off-take of N, K, and Ca; and this trend varies with soil type. The high crop response to applied P in Gambari and Sapoba soils sampled from the rain forest zone of Nigeria stresses the imperativeness of P fertilization for successful crop production in the region.
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