Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
T2a-23P-1249
Models of Integrated Farming Systems Resilient to Soil Erosion in a
Changing Climate in Mountain Agriculture
B.U. Choudhury, V. K. Mishra, T. Ramesh, and A. Balusamy
ICAR Research Complex for NEH Region, Umiam, Meghalaya-793 103
Land degradation due to soil erosion (SE) in the tropical mountain ecosystem is a serious
environmental issue affecting agronomic development and ecosystem functions (Lobo &
Bonilla, 2019; Pijl et al., 2020). In the eastern Himalayan India (EHI), more than two-fifths of
the 26.2 million ha are subject to soil erosion and increased rainfall intensity in a changing
climate exacerbates the threat to agricultural production. The main reason is large-scale
deforestation, burning of vegetation, the expansion of shifting and sedentary agriculture along
the steep slopes of the highlands, and abandonment of cropland. Such a shift from forest to
traditional agriculture in sloping uplands has led to an estimated annual soil loss of 229.5 t ha -
1
(Choudhury et al., 2022). Cultivated uplands (sedentary and shifting agriculture) in the
region cover only 1.0 M ha (only 4.04% GA) (Choudhury et al., 2021) and additional
horizontal expansion without degradation of virgin forests is next to impossible. It is an
ecological and economic compulsion for the region to diversify the agricultural production
system, involving multiple complementary farming enterprises in the form of an integrated
farming system (IFS) mode. Given this need, micro-watershed scale IFS models were
introduced into the region's mountain ecosystem in the 1980s. To identify more resilient IFSs
and design adaptation strategies in the context of soil erosion sensitivity to climate
change, we evaluated the response of such hilly micro-watershed (HMW) based six IFS
models, using field and simulation approaches (as per the Water Erosion Prediction Project,
WEPP).
Methodology
Six micro-watershed based (HMW) IFS models were developed on a forested hill slope
(32.0-53.18%) of the ICAR research complex for the NEH area, Umiam, Meghalaya.
These were forestry (HMW 1), abandoned shifting cultivation (HMW 2), livestock with fodder
crops (HMW3), agroforestry (HMW4), agri-horti-silvi-pastoral (HMW5), and horticulture
(HMW 6). Different soil water conservation measures (SWCMs) such as contouring,
terracing, grassed waterways, and vegetative barriers were adopted in all except HMW 1. All
these HMWs were gauged at the outlet to measure runoff and soil loss for 24 years. The
WEPP model was calibrated and validated with measured runoff and soil loss data for each of
the six IFSs. Simulations on soil erosion were carried out for the baseline period (1976–2005)
and three future time slices, i.e., early (2020s), mid (2050s), and end-century (2080s) under
four RCPs, i.e., RCP2.6, RCP4.5, RCP6.0, and RCP8.5. The relative percent change in runoff
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Climate resilient agriculture for risk mitigation