Thumbnail Image

Theses

Browse

20201
Reset filters
Subject: Soil Sciences × Author: Barala, Jatiprasad × Start date: 2017 ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    DISTRIBUTION OF MICRONUTRIENTS UNDER DIFFERENT LAND USES IN SOILS OF GOLAGHAT DISTRICT OF ASSAM
    (AAU, Jorhat, 2020-09) Barala, Jatiprasad; Basumatary, Anjali
    An investigation was carried out to study the depth-distribution of available micronutrients and their relationship with soil physico-chemical properties in soils of Golaghat district of Assam. Soil samples were collected at 0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm and 80-100 cm depth under five land uses viz. rice, vegetable, sugarcane, bamboo and tea. Results indicated that sand, silt and clay content of the soils showed a significant variation among depths. The highest content of sand (59.53%), silt (51.13%) and clay (43.17%) were found at 80-100 cm, 20-40 cm and 80-100 cm under bamboo, vegetables and sugarcane land use, respectively. The soils were very strongly to medium acidic in reaction with a pH range of 4.70 to 5.73 and significantly the highest value of pH was recorded at 80-100 cm under all land uses. Organic carbon content of the studied soils was found higher in surface layer and decreased significantly with increasing soil depths. The significantly highest (13.27 g kg-1) and lowest content of organic carbon (1.47 g kg-1) in soil were observed under tea and bamboo land use, respectively. The exchangeable Ca2+, Mg2+, Na+ and K+ content was higher in soils of rice as compared to other land uses. The significantly highest and lowest mean values of both cation exchange capacity and per cent base saturation were observed under rice and bamboo land use, respectively. The content of available micronutrients showed a significant variation among different depth sunder different land uses. The content of available micronutrients was higher in surface layers and decreased with depths. The value of DTPA-extractable Fe, Mn, Zn and Cu content of the studied soils ranged from 10.28 to 80.28, 2.02 to 29.18, 0.08 to 0.77 and 0.12 to 1.76 mg kg-1, respectively under different land uses indicating the sufficiency of Fe, Mn and Cu. Content of DTPA- Zn was sufficient at 0-20 cm depth under rice and tea whereas deficiency was observed at lower depths in all the land uses. Among the land uses, surface layer of rice land use recorded significantly the highest concentration of DTPA-Fe, Mn, Zn and Cu as compared to other land uses. Significantly the highest content of boron was exhibited at surface layer in all the land uses and significantly the highest content of HWS-B (0.58 mg kg-1) was observed at 0-20 cm depth under tea land use. Most of the soils were found below critical limit except sugarcane and tea at 0-20 cm depth. DTPA-extractable micronutrients and HWS-B correlated positively and significantly with soil organic carbon, cation exchange capacity and per cent clay but negatively and significantly with soil pH. Clay showed a significant and positive correlation with DTPA-Mn, DTPA-Zn and DTPA -Cu. Step-down multiple regression analysis revealed that organic carbon, pH and clay were the dominant factors accounting for maximum variability in available micronutrient contents.