Effect of Biomethanated Spent Wash on Enzymatic Activities under Irrigated Condition

Abstract

The biomethanated distillery spentwash is a nutrient rich liquid organic waste obtained from molasses based distillery industries after biomethanation process. The effect of different levels and methods of spentwash application on soil enzymatic activity was examined through a field experiment using sesame c.var.VRI (Sv) 2 as the test crop at Research and Development Farm, The Sakthi Sugars Pvt. Ltd., Appakkudal, Erode District. The experiment was formulated with six treatments with four replications and laid out in a randomized block design. As per the treatment schedule, the calculated quantity of biomethanated distillery spentwash (DSW) was uniformly applied to the plots @ 25, 50, 75 and 100 % along with recommended dose of NP (19.4, 25.2, 58.3 and 77.77 L, respectively) before sowing as pre-sown application. In addition, one absolute control and a treatment with recommended dose of NPK (35:23:23 kg NPK/ha) have been imposed for comparison. The soil samples were collected at 30 d intervals and analyzed for the changes in soil enzyme activities. The results of the study showed that the enzymatic activities of the soil were substantially increased throughout the crop growth period due to biomethanated DSW application, compared to check. However, application of 100 % N through DSW (77.77 L/1200 m2) and 75 % N through DSW + 25 % N through inorganic source (58.3 L/1200 m2) was found to be significantly superior by increasing the activities of phosphatase (15.07 μg p-nitrophenol g-1 soil h-1), dehydrogenase (29.92 μg TPF g -1 soil h-1 ) and urease (10.97 μg NH4-N g-1 soil h-1), respectively.