Effect of Organic Sources on Microbial Population and Enzymatic Activities Under Salt Degraded Soil Condition.

Abstract

Excessive salt in soil limits the availability of plant nutrients during crop growth period. Addition of organic sources may reduce the intensity of salt by acting as the absorption mechanism during mineralization. In this, hypothesis, a field experiment was conducted with nine organic (farm yard manure-FYM, pressmud-PM, vermicompost-VC) treatments combinations (T₁-control, T₂-RDF, T₃-RDF + FYM 10 t/ha, T₄-RDF + FYM 2.5 t/ha + PM 2.5 t/ha, T₅-RDF + FYM 5 t/ha + PM 5 t/ha, T₆-RDF + PM 2.5 t/ha + VC 2.5 t/ha, T₇-RDF + PM 5 t/ha + VC 5 t/ha, T₈-RDF + FYM 1.25 t/ha + PM 2.5 t/ha + VC 1.25 t/ha, T₉-RDF + FYM 2.5 t/ha + PM 5 t/ha + VC 2.5 t/ha). Mustard crop was raised with recommended packages and practices in saline soil. Rhizospheric samples were collected and analyzed for soil microbial population (bacteria, fungi and actinomycetes) and enzymatic activities (alkaline phosphatase, dehydrogenase activity-DHA, aryl sulphates). Analytical result showed that addition of 10 t/ha by the combination of FYM (2.5 t/ha), PM (5 t/ha) and VC (2.5 t/ha) measured highest population 148.4 × 10³ CFU/g, 15.3 × 10³, 28.01 × 10³ of bacterial, fungi and actinomycetes, respectively. Similarly, soil enzymatic activities alkaline phosphatase (210.7 µg PNP /g soil/h), DHA (92.7 µg TPF/g soil/h) and aryl sulphatase (54.4 µg PNP /g soil/h) were also found highest in T9 treatment (RDF + FYM 2.5 t/ha + PM 5 t/ha + VC 2.5 t/ha). In this experiment the type of organic source and application levels were directly influenced by the microbial population and enzymatic activities in soil. This study is very useful for improving the microbial population and plant nutrient availability under saline soils for improving mustard crop yield.