Humic acid improved efficiency of fertigation and productivity of tomato

Studies were conducted during 2010–2012 at University of Horticulture & Forestry, Solan, Himachal Pradesh, India. Four fertigation levels were tested with humic acid (combined fertigation) and without humic acid (sole fertigation or fertigation alone). The experiment comprising eight treatment combinations in Randomized Block design, replicated four times. Investigations revealed that combined fertigation significantly increased plant height (5.7%), total dry matter (7.7%), leaf area index (3.2%), chlorophyll content (4.7%) and fruit yield (9.6%) over sole fertigation. Higher available N and K in was recorded in surface soils whereas, better translocation of available P was noted at 10–20 cm soil layers under combined fertigation. Higher nutrient recovery and fertilizer use efficiency was also noted in combined fertigation. Fertigation along with humic acid resulted in 20 per cent fertilizer savings over fertigation alone. It is concluded that efficiency of fertigation can further be increased by using humic substances in any agricultural production system.