Effect of humic acid on growth, protein and mineral composition of pearl millet (pennisetum glaucum (l.) fodder

Based on shortage of organic fertilizers in arid regions, the present study aimed to evaluate alternative sources of organic fertilizers that required in small quantity and that to be easy in shipment, and universally available. After an extensive literature search, we were prompted to evaluate the effect of humic acid (HA) on millet (Pennisetum glaucum (L.) R.Br) by using 7 different concentrations (0, 5, 10, 15, 20, 25, and 30 kg ha/sup -1/) because HA, which is recognized as an exogenous growth regulator/soil activator, and its effects have been evaluated in its limited quantities only on fruits and vegetables. This study evaluated the effects of soil application of high levels of HA on the field crop. The experiment was conducted following a randomized complete block design. The results of the study indicated that the increasing level of HA to certain level (20-25 kg ha/sup -1/) constantly and significantly (p<0.05) increased plant growth (i.e., plant height, number of leaves plant-1, leaf area index (LAI), green and dry matter yield). The increase in growth was further confirmed by the chemical analysis of crude protein and mineral content. Based on the results, this study recommends application of 20 to 25 kg ha/sup -1/ of HA to soil for improving millet crop yield and quality in arid and saline conditions. (author)