Heavy Metals and Soil Enzyme Activities in different Agro-Ecological Units of Intensively Managed Pineapple (Ananas comosus) Cultivated Fields in Kerala

Abstract

Pineapple cultivation is very popular in central Kerala which include high density planting, foliar application of fertilisers, hormonal applications and imprudent use of biocides such as pesticides, herbicides and fungicides. Indiscriminate use of agrochemicals will change the soil chemistry furthermore affect the soil biota and pollutes the nearby water bodies. Pineapple cultivated areas from three agro-ecological units such as South Central laterites (AEU1), Southern and Central Foot Hills (AEU2) and Southern High Hills (AEU3) from Ernakulam district were selected for the study. Soil pH, total heavy metal such as lead, nickel and cadmium Soil enzymes such as Dehydrogenase, Urease and Acid and Alkaline phosphomonoesterases activity were determined. The pH at AEU3 was significantly lower than those observed at AEU2 (p<0.05). Soils of pineapple cultivated fields showed high content of total heavy metals as compared with control sites. Significant higher Cadmium content was observed for both AEU1 and AEU2 compared with that of control sites (p<0.05). Significant positive correlation were observed between the pH and dehydrogenase enzyme (r=0.52, p< 0.0462). Moreover there is positive correlation between Urease activity and AcPME activity (r=0.52, p<0.0446). Significantly lower pH and higher Cd content, especially at Southern and Central Foot Hills (AEU2), compared to control stations reflects the presence of agrochemicals like fertilizers in this region. The increased activity of soil enzymes also strengthens this fact. It should be noted that these agrochemicals are likely to be leached to the nearby fields during heavy rain or flood. The positive relationship observed for dehydrogenase and pH, urease and AcPME also calls for further investigation in this regard.

Keywords: Heavy metals, dehydrogenase, Urease, Phosphomonoesterases, agrochemicals

Cite this Article

Samitha K.A., Rajathy Sivalingam, Sandeep S. Heavy Metals and Soil Enzyme Activities in different Agro-Ecological Units of Intensively Managed Pineapple (Ananas comosus) Cultivated Fields in Kerala. Research & Reviews: Journal of Ecology. 2019; 8(1): 7–11p.