Ecology, Environment and Conservation Paper

LONG TERM EFFECT OF ORGANIC MANURES AND FERTILIZERS ON SOIL DEHYDROGENASE ACTIVITY IN SORGHUM-WHEAT SEQUENCE UNDER VERTISOLS

Prajakta M. Metkari, Papita H. Gourkhede and Archana S. Nagargoje

Abstract

A permanent field experiment is continued since 1988 at Research Farm, LTFE, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra with a view to find out the Long Term Effect of Organic Manures and Fertilizers On Soil Dehydrogenase Activity in Sorghum-Wheat Sequence Under Vertisols. The long term impact of manure and fertilizer application on soil enzyme was studied after 24th and 25th cycle (2011- 12 and 2012-13). The treatment comprised different levels of recommended dose of fertilizers (RDF), viz. 50, 75, 100, 150% RDF in combination with farm yard manure. The results indicated that, the application of 100% NPK with FYM and only FYM proved better than only chemical fertilizers in increasing the dehydrogenase activity. The highest dehydrogenase activity in sorghum (56.10, 54.55 μg TPF g-1 24 h-1) and in wheat (51.79, 51.11 μg TPF g-1 24 h-1), at two grand stages was observed in 100% NPK + FYM @ 10 t h-1. FYM increased availability of substrates for dehydrogenase and comparatively more activity of dehydrogenase in 150% NPK may be attributed to the fact that inorganic sources of nutrients stimulated the activity of microorganisms to utilize the native pool of organic carbon as a source of carbon, which act as substrate for dehydrogenase. The lowest dehydrogenase activity was observed in absolute control.