02123nam a2200241 a 450000100080000000500110000800800410001902400660006010000190012624501300014526000700027552013460034565000200169165000090171165000100172065000140173065000170174465300240176165300240178565300250180965300220183465300250185611975502024-05-10       1976    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.2134/agronj1976.00021962006800050010x2DOI1 aFAGERIA, N. K.  aEffect of P, Ca, and Mg concentrations in solution culture on growth and uptake of these ions by rice.h[electronic resource]  aAgronomy Journal, v. 68, n. 5, p. 726-732, Sept./Oct. 1976.c1976  aNutrient requirements during various phases of plant growth are affected by many factors. Greater knowledge of this subject is warranted by the intensification of agriculture. The present study was undertaken to determine the effect of varying concentrations of P, Ca, and Mg on the growth and uptake patterns of these ions by rice (Oryza sativa L.). Rice plants were grown in culture solution of these ions. Minimum concentrations required for maximum growth were 25 μM P, 250μM Ca, and 33 μM Mg respectively. At higher P concentrations a linear absorption isotherm was obtained with respect to P content in the plant tissue. The critical concentration of P in the tops of 100-day old plants was 0.4%. To support maximum growth, Ca content varied from 242 to 2,373 μg-atoms/five plants for 25 to 125 days of growth. Maximum growth was characterized by a relative absorption (IM) rate ranging from 14 to 320 μg-atoms of Ca/g dry weight of roots/day during the period of cultivation. To support maximum growth, plants must absorb 13.7, 7.7, 4.3, 4.0, and 2.4 μg of magnesium per g fresh weight of roots/hour at 25, 50, 75, 100, and 125 days of growth respectively. With the advancement of age, P and Ca content in plants and their utilization quotients were increased but relative growth rate and rate of Ca and Mg absorption decreased.  aNutrient uptake  aRice  aArroz  aNutriente  aOryza Sativa  aContinuous low rate  aCritical percentage  aRelative growth rate  aUptake efficiency  aUtilization quotient