ABSTRACT
Aim: The aim of this study was to evaluate the variation in certain biochemical parameters of the earthworms, Drawida willsi (Sp1), Glyphidrilus tuberosus (Sp2), Lampito mauritii (Sp3) and Perionyx excavates (Sp4) in response to seasonal soil moisture and temperature alterations.Methodology: Soil moisture and temperatures were measured by digital moisture meter and thermometers, respectively. The sampling of earthworms was done following quadrat method during dry and wet seasons from three agro-climatic zones (Balasore (Z1), Sambalpur (Z2) and Nayagarh (Z3) of Odisha, India. Tissue protein, LPX level, catalase, acetylcholinesterase and lactate dehydrogenase activities were estimated spectrophotometrically. Results: Significant variation (P< 0.05) in soil moisture and temperature were noticed between dry and wet seasons in all the agro-climatic zones. All the earthworm species indicated lower protein level, acetylcholinesterase activity, higher lipid peroxidation, LDH and catalase activity in dry season relative to wet seasons. Soil moisture indicated significant positive correlation (P< 0.05) with tissue protein of Sp1 (r=0.59), Sp2 (r=0.64), and Sp4 (r=0.55) of Z1, Sp2 (r=0.63) and Sp4 (r=0.67) of Z2 and Sp2 (r=0.58) and Sp3 (r=0.65) of Z3. Soil temperature showed significant negative correlation (P< 0.05) with tissue protein of Sp3 (r= -0.51) of Z1, Sp2 (r= -0.56) and Sp4 (r= -0.69) of Z2 and Sp1(r= -0.54) of Z 3. Interpretation: Enhanced physiological stress level caused due to moisture deprivation could influence synthesis and storage of protein with enzyme activities.
ABSTRACT
Aim: The study aimed to evaluate the effects of various concentrations of organophosphate agrochemicals, namely monocrotophos and glyphosate on soil chemical parameters, microbial population and activities of certain vital exoenzymes e.g. invertase, amylase, cellulase, dehydrogenase and protease at 7 days interval over an incubation period of 84 days. Methodology: Three concentrations of monocrotophos (1.0 g kg-1 soil-low T1, 2.0 g kg-1 soil-medium T2, 3.0 g kg-1 soil-high T3) and glyphosate (0.1 g kg-1 soil-low T1, 0.15 g kg-1 soil-medium T2, 0.2 g kg-1 soil-high T3) were applied to soil. Soil pH, electrical conductivity, organic carbon (OC), available nitrogen, phosphorous and potassium (NPK) were assessed. Bacterial and fungal population along with activities of exoenzymes were also studied. Data were analysed using two way ANOVA and Duncan's multiple range test (DMRT). Results: Significant variations (p<0.05) of chemical parameters, except P and K, in treated soil between concentrations and time over the incubation period were observed. Microbial population and exoenzymes showed significant variations (p<0.05) in response to agrochemical treatments. Invariably, lower microbial load and enzyme activities were noticed in treated soil relative to control. Interpretation: The study indicated that monocrotophos and glyphosate at recommended and elevated concentrations in soil could adversely impact microbial growth. Inhibited microbial population culminated in lower exoenzyme activity
ABSTRACT
Phosphogypsum (PG) is produced as a solid waste from phosphatic fertilizer plants. The waste slurry is disposed off in settling ponds or in heaps .This solid waste is now increasingly being used as a calcium supplement in agriculture. This study reports the effect of PG amendment on soil physico chemical properties, bacterial and fungal count and activities of soil enzymes such as invertase, cellulase and amylase over an incubation period of 28 days. The highest mean percent carbon loss (55.98%) was recorded in 15% PG amended soil followed by (55.28%) in 10% PG amended soil and the minimum (1.68%) in control soil. The highest number of bacterial colonies (47.4 CFU g-1 soil), fungal count (17.8 CFU g-1 soil), highest amylase activity (38.4 ?g g-1 soil hr-1) and cellulase activity (38.37 ?g g-1 soil hr-1) were recorded in 10% amended soil . Statistically significant difference (p<0.05) has been recorded in the activities of amylase and cellulase over the period of incubation irrespective of amendments. Considering the bacterial and fungal growth and the activities of the three soil enzymes in the control and amended sets, it appears that 10% PG amendment is optimal for microbial growth and soil enzyme activities.