Inhibitory effect of high soil pH on growth and mineral metabolism of rice and its reversal by zinc.
Increasing soil pH retarded growth, tillers and bio-mass production of rice cultivar Sarjoo-52. Application of 10 to 15 kgZn ha(-1) increased the bio-mass by 33 to 41% at pH 8.5 and 27 to 32% at pH 10.3. Panicle length, rachis branches, total spikelets, filled grains, grain size were all adversely affected to the tune of 19, 23, 40, 74 and 21%, respectively by higher soil alkalinity at pH 10.3. Alkalinity resulted in 19, 31 and 65% spikelet sterility which reduced to 3, 21 and 55% at pH 8.5, 9.5 and 10.3, respectively by Zn applied @ 15 kg ha(-1). Grain yield reduced to 50% at pH 10.3 but Zn in general, raised the yield levels by 1.6 to 2.3, times. The chlorophyll decreased by 36 to 50% whereas carbonic anhydrase activities decreased only by 13% due to increase in soil sodicity and alkalinity. Further, increase in pH caused significant decrease in Zn, Ca, Mg, P and K concentrations but phenomenal rise in Na content Zinc application, apart from increasing tissue Zn content, elevated Ca :Na and K :Na ratio resulting in improved growth and yield of rice under soil sodicity and alkalinity.
Singh
H P
HP
Directorate of Research, N.D. University of Agriculture and Technology, Kumarganj, Faizabad-224 229, India.
Singh
T N
TN
D000383:Agriculture / Q000379:methods*; D018533:Biomass; D002256:Carbonic Anhydrases / Q000378:metabolism; D002734:Chlorophyll / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000254:growth & development*; D012987:Soil / Q000032:analysis*; D015032:Zinc / Q000737:chemistry*
D012987:Soil; D002734:Chlorophyll; D002256:Carbonic Anhydrases; D015032:Zinc