ASSESSING CARBON SEQUESTRATION POTENTIAL AND SOIL QUALITY INDEX (SQI) UNDER HORTICULTURE BASED LAND USE SYSTEMS IN AGRO-CLIMATIC ZONE-I OF BIHAR
Loading...
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Dr.RPCAU, Pusa
Abstract
Soil carbon sequestration research has gained world focus as a cost effective and eco-friendly approach in mitigating elevated CO2 level of atmosphere. The various anthropogenic activities have impacted our fragile ecosystem, leading to an increased level of carbon dioxide in the earth’s atmosphere which has not only affecting our ecosystem but also poses threat to our human race. The research was formulated with the hypothesis that SOC quality, and quantity varies due to variability in input and loss of soil C under different LUS’s of agro-climatic zone –I of Bihar. The main objective of the research undertaken was to assess carbon sequestration and soil quality under dominant LUS’s by evaluating the variation in measurable soils properties with carbon and nitrogen storage patterns.
The selected experimental area lies in the middle Gangetic alluvial plain having hot dry to moist sub-humid. Based on preliminary survey, five LUS’s namely litchi solo , mango solo, litchi intercrop, rice wheat, and uncultivated were selected and accordingly composite soil sample collected i.e. total 100 samples from different soil depth 0-15, 15- 30, 30-45 and 45-60 cm. The various soil measurable physico-chemical and biological parameters were analysed and the data revealed that soil carbon is the main driver influencing various soil characteristics. Among the different LUS selected, the superior LUS followed sequence mango solo >litchi solo > litchi intercrop > uncultivated > rice wheat. The analysed soil data revealed that soil pH in different LU was moderately alkaline and ranged from 7.91 to 8.26 while electrical conductivity ranged from 0.34 to 0.48 dS m-1 which is within the safer limit. The observed soil bulk density varied significantly and was found highest in uncultivated LU 1.46 Mg m-3 while lowest in 1.41 Mg m-3 in mango solo LU. The soil surface hardness was observed highest 1368.2 KPa in uncultivated LU having highest BD value compared to other LUS’s. Soil texture in selected LU was mainly sandy loam, silty loam and clay loam but the effect of LU was non-significant. Among different LU system, the available macro-nutrient N, P, K and micro-nutrient Fe, Zn, Cu, Mn were found to be more in horticulture based LUS’s compared to rice-wheat and uncultivated LU. Significant decreases in available nutrients were observed with increase in depth of soil. The biological soil properties assessed by DHA activity, SMBC, SMBN and soil protein and found significantly better microbial properties in all three horticulture-based LUS’s when compared to rice-wheat LUS. A marked difference in SOC fraction constituents were found among different LUS’s and observed sequence NLc>VLc> Lc>LLc carbon. Among the different LUS’s soil carbon stock 0-60 cm soil depth was found to be highest in mango LU at 71.34 Mg C ha-1 followed by litchi solo 61.34 Mg C ha-1, uncultivated LU 52.33 Mg C ha-1and least it was observed in rice-wheat LU 44.69 Mg C ha-1, while similar trend also was observed in soil nitrogen stock highest in mango LU 5408.01 kg N ha-1 and least 3771.51 kg N ha-1 observed in rice-wheat LU system. In the horticultural LUS’s the total tree biomass carbon (both above and below ground) was observed highest in mango solo 51.59 q tree-1 followed by litchi solo 16.32 q tree-1 and least 15.82 q tree-1 in litchi intercrop. Soil quality index was assessed among different LU and observed best in mango solo LU 1.15 then litchi solo 1.09, litchi intercrop 1.04, uncultivated 1.02 and least observed in rice-wheat LU 0.94. The soil quality data depicts sensitive indicators selected were soil carbon stock, metabolic quotient; soil respiration, clay% and sand% in assessing SQI which may be used in future research in related studies for assessing SQI. Finally, it may be concluded that over all soil quality and carbon sequestration followed sequence mango solo > litchi solo > litchi intercrop > uncultivated > rice wheat LUS. The problem of increased current fallow area under in ACZ-I may be addressed with incorporation of horticulture tree component and adoption of suitable agronomic management practices for maintaining sustainability in the region.