Rhizosphere effect of kharif crops on phosphatases and dehydrogenase activities in a typic Haplustert

Abstract

In recent years phosphorus crisis is emerging at global level, every country in the world searching for alternative sources and management options for increasing its supply and use efficiency. Increasing cost of cultivation due to phosphatic fertilizers, attracting our mind towards it. In this experiment it was focused on effect of major kharif crops (maize, soybean, sorghum, pearl millet, finger millet and rice) on phosphatases and dehydrogenase activities in soil at different crop growth periods (30, 50, 75, 90 days after sowing and at crop harvest). Acid phosphatase activity varied crop wise and also at different crop growth periods. The maximum acid phosphatase activities were observed at 75 DAT in rice (0.206 mg PNP/g h), 90 DAS in sorghum (0.194 mg PNP/g h) and pearl millet (0.201 mg PNP/g h), 50 DAS in soybean (0.127 mg PNP/g h), and 30 DAS in maize (0.154 mg PNP/g h) and, 50 DAS as well as 75 DAS in finger millet (0.180 mg PNP/g h), respectively. But alkaline phosphatase activities were maximum at 75 days after sowing in all the crops i.e. sorghum (0.533 mg PNP/g h), soybean (0.465 mg PNP/g h), rice (0.440 mg PNP/g h), maize (0.538 mg PNP/g h), pearl millet (0.546 mg PNP/g h) and finger millet (0.530 mg PNP/g h), respectively. The dehydrogenase activities were also higher in 75 days after sowing in all the crops. These enzyme activities associated with higher availability and uptake of phosphorus. © 2014 The Author(s).