Short-Term Effects of Solid and Liquid Manure Amendments on Microbial Activity of an Alkaline Soil with High Lime Content during Horticultural Plant Growing

ABSTRACT

This study aimed to determine the effects of solid and liquid manures on soil microbial status and activity in organic farming model under greenhouse conditions. Two different test plants, rocket (Eruca vesicaria) and lettuce (Lactuca sativa), were grown also to determine the effects of plant species on related traits of the soil. A greenhouse experiment was conducted in randomized complete blocks with three replicates. The experiment was consisted of treatments with and without plants and manure.

The combined doses of solid and liquid manure in rocket and lettuce soils resulted in an increase by 142.09 and 105.49% in urease, 130.75 and 135.24% in alkaline phosphatase, 162.40 and 195.06% in β-glucosidase, 135.29 and 329.88% in dehydrogenase activities and 306.34 and 182.42% in number of bacteria, respectively, compared to the control without manure. Significant changes for each parameter were also observed according to plant species (increase ranging from 54 to 128.06%). Even though influence of plants was positive, it was not as effective as manure on the measured parameters. It was determined that, in general, stimulating effect of the combined application of solid and liquid manures on the enzyme activities and number of bacteria in soil is significantly higher than the plant-derived effects (plant type, root secretions, etc.).

KEYWORDS:

• Lettuce
• rocket
• calcareous soil
• enzyme activity
• number of bacteria