The Pedospheric Variation of DTPA-Extractable Zn, Fe, Mn, Cu and Other Physicochemical Characteristics in Major Soil Orders in Existing Land Use Systems of Punjab, India

The agricultural production in Punjab has increased manifold that aggravated the deficiencies of micronutrients in soils and plants. The availability of soil micronutrients in different soil orders depends upon the soil mineralogy, topography, climatic conditions and cropping sequences. Hence, to study the pedospheric variations of DTPA-extractable micronutrients, viz., zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu), in three prominent soil orders of Punjab, a total of 144 depth-wise soil samples were collected from four major land-use systems (cultivated, horticulture, forest and pasture lands). The DTPA extractable micronutrients varied from 1.74–2.81, 1.83–2.82 and 1.81–2.80 for Zn; 5.3–6.8, 5.6–6.9, 4.3–6.3 for Fe; 5.1–7.8, 5.5–7.9, 5.4–7.5 for Mn; and 0.84–1.40, 0.93–1.68, 0.87–1.65 for Cu in soil orders Aridisol, Entisol and Inceptisol, respectively. The average content of DTPA-extractable micronutrients was highest under soil order Entisol followed by Inceptisol and Aridisol. The content of micronutrients showed a declining trend with increase in soil depth in all orders. Among different soil properties, the pH and EC showed significantly negative correlation, however, OC had non-significant correlation with DTPA-extractable micronutrients in soils. Therefore, it is concluded that parent material, land use systems and soil depth affected the distribution of DTPA extractable micronutrients in different soil orders.

Diversity and Seasonal Dynamics of Arthropods in Okomu Forest Reserve

A field survey was conducted in Okomu Forest Reserve Edo State, to assess the diversity and seasonal dynamics of arthropod species in selected land use systems (Okomu national park, Okomu rubber plantation and Okomu oil palm plantation). Samplings of arthropods were carried out between February and September 2020, arthropods were collected by hand picking and sweep net in each sampled plots at 25 m x 25 m in the study area. Insects encountered were killed and preserved by chloroform. Arthropods samples were taken to the laboratory for oven dry and identification. A total of 382 arthropods spread across 15 orders, 34 families and 81 species were recorded. The most dominant orders were Hymenoptera (Ants) followed by Odonta (dragonfly) and Lepidoptera (butterfly and Moth) during dry season while highest abundance of orders were Spirostreptida (millepde) followed by Hymenoptera (Ants) and Araneae (spider) during rainy season. Okomu National Park has the highest (220) insect species abundance follow by Okomu Rubber Plantation (136) while the least was Okomu Oil Palm Plantation (72) in the study area. Study revealed that Okomu Rubber Plantation has no record of Scolopendromorphra (centipede) andHemiptera (bug) while in Okomu Oil Palm Plantation no record of Scolopendromorphra (centipede), lepidoptera (butterfly), also there were norecord of blattodea (crockroach) order of insect species in Okomu National Park. The highest species diversity and evenness was observed in Okomu National Park (H’ = 3.03 and E’= 0.83) follow by Okomu Oil Palm Plantation (H’=1.89 and E’=0.86) while Okomu Rubber Plantation was the least (H’ = 1.53 and E’= 0.60). ANOVA showed significant (P≤0.05) different on diversity and abundance between land use systems while there is nosignificant (P≥0.05) different seasons in the study area. Observation was made on seasonal variation of arthropods species in different land use systems and dominant species as bio-indicators in the study area.

Forms and Dynamics of Soil Potassium in Acid Soil in the Wolaita Zone of Southern Ethiopia

Quantity-intensity (Q/I) characteristics are among conventional approaches for studying potassium dynamics and its availability. This was assessed to determine availability in four districts: namely, Sodo Zuria, Damot Gale, Damot Sore, and Boloso Sore, at three different land use systems (enset-coffee, crop land, and grazing land). Fractionation and dynamics of K sources were studied in soil samples, which were collected from 0–20 cm depth of each land system. The study revealed that water extractable K (H2O-K) concentrations ranged from 0.13 to 0.34 cmolc kg−1 soils at enset-coffee and grazing land use systems, respectively, and had a mean value of 0.28 cmolc kg−1 soils ammonium acetate extractable (NH4OAC-K) and nitric acid extract (HNO3-K) had a mean value of 0.25 cmolc kg−1 soils. In this study, the means of nonexchangeable- and exchangeable-K concentrations were of 0.11 and 0.14 cmolc kg−1 soils for land use types. Significant correlations were found between soil properties and Q/I parameters and among equilibrium solution parameters and Q/I parameters. There was no significant variation among the mean quantity values of the soils. The soils had higher change in exchangeable-K and potential buffering capacity than the enset-coffee land use soils, and the cop land had the highest values for these parameters. However, the enset-coffee land use soils had higher K-intensity. Therefore, application of site specific soil fertility management practices and research can improve soil K status and Q/I parameters to sustain productivity soils.