R. K. Rai

Root characteristics of maize as influenced by various phosphatic chemical fertilizers and biofertilizers

Field and pot experiments were conducted during kharif season of 2002 and 2003 at the Indian Agricultural Research Institute, New Delhi, to study the root characteristics of maize as influenced by various phosphatic chemical fertilizers and biofertilizers. The experimental design of the field experiment was randomized block design and in the case of the pot experiment it was completely randomized design. There were 12 treatments where various phosphatic sources were applied either singly or in combination with nitrogen and in one treatment only urea and no phosphatic source was applied. All these treatments were replicated three times. In both pot and field experiment the highest values of root growth parameters like root length, root volume, root dry weight, root length density, and root:shoot ratio were observed in the treatment where urea was applied at 120 kg N ha−1 along with rock phosphate at 30 kg P2O5 ha−1 and vesicular arbuscular mycorrhiza in maize. In the case of the pot experiment, more distinct variation among treatments was observed in those above-mentioned parameters. The specific root length value was highest when urea was applied at 120 kg N ha−1 in both field and pot experiment. In 2002, the highest root cation exchange capacity value of 19.28 meq (100 g)−1 root dry weight was observed when urea was applied at 120 kg N ha ha−1 along with single super phosphate at 30 kg P2O5 ha−1 and vesicular arbuscular mycorrhiza; while in 2003 the highest value of 20.25 meq (100 g)−1 root dry weight was obtained when urea was applied at 120 kg N ha−1 along with rock phosphate at 30 kg P2O5 ha−1 and phosphorus solubilizing bacteria.