Activity of Soil Enzyme and Microorganisms in Rhizosphere Soil of Maize (Zea mays L.) as Influenced by Different Weed Management Practices

A field experiment was conducted during kharif, 2017 at the Main Agricultural Research Station, agriculture college farm, Raichur to study the “Activity of soil enzyme and microorganisms in rhizosphere soil of maize (Zea mays L.) as influenced by different weed management practices”. The experiment was laid out in Randomized Complete Block Design with three replications and twelve treatments. It was evident that before sowing, the soil enzyme activity was on par in all the treatments. At flowering and at harvest, dehydogenase and phosphatase activity in soil differed significantly by different weed management practices. Hand weeding twice and weedy check recorded higher dehydrogenase and phosphatase activity of (28.32, 19.85 μg TPF g-1 soil day-1 and 32.94, 19.05 μg PNP g-1 soil hour-1, respectively) and (28.00, 19.45 μg TPF g-1 soil day-1 and 32.60, 18.34 μg PNP g-1 soil hour-1, respectively) and were significantly superior over rest of the treatments. Whereas, within herbicidal treatments sequential application of atrazine 50 % WP @ 500 g a.i. ha-1 (PRE) at 0-3 DAS fb tembotrione 34.4 % SC @ 125 g a.i. ha-1 (POE) at 30 DAS recorded significantly higher dehydrogenase and phosphatase activity (27.64, 19.15 μg TPF g-1 soil day-1 and 32.25, 18.14 μg PNP g-1 soil hour-1, respectively) in soil and it was found to be on par with application of atrazine 50 % WP @ 500 g a.i. ha-1 (PRE) at 0-3 DAS fb topramezone 33.6 % SC @ 75 g a.i. ha-1 (POE) at 30 DAS and atrazine 50 % WP @ 500 g a.i. ha-1 (PRE) at 0-3 DAS fb halosulfuron 75 % WDG @ 90 g a.i. ha-1 (POE) at 30 DAS. Similar, was the trend with respect to N2 fixers, Phosphate solubilising microorganisms (PSM) and total bacterial population recorded.