Externally funded project

Social-Ecological Systems in the Indian Rural-Urban Interface: Functions, Scales and Dynamics of Transition. Cluster A: Matter flows in rural-urban cropping systems


Abstract

Scarcity of land, water, and labour are the main constraints to
agricultural production along the rural-urban interface of Bangalore.
This has led to the widespread replacement of diverse dryland farming
systems by intensive irrigated vegetable production on open lands at the
city fringe and in scattered city areas. The consequences of such
changes in traditional Indian farming systems on the nutrient dynamics
and soil fertility are largely unknown. This project therefore addresses
transformation-related changes in the intensity of agricultural
production systems at the micro(plot)- and meso-scale (field and
household) by analysing horizontal and vertical flows of nutrients and
carbon in field and laboratory experiments, turnover of soil organic
carbon and soil nitrogen in different pools, and their effects on
nutrient and water use efficiency under rainfed and irrigated conditions
on-station and on 72 selected farmer fields. It combines expertise in
agronomy, plant nutrition and non-destructive measurements of soil
physical properties and plant growth (Bürkert) with modelling of water
dynamics, crop growth, and carbon (C) and nutrient fluxes (Ludwig). The
project will contribute to the overall goals of FOR2432 by providing
spatially explicit data on the effects of intensification-related land
use changes on nutrient and water use efficiencies for major food crops
in the study region. It also aims at assessing the impact of these
changes on key chemical soil parameters (pools of C and nitrogen N,
phosphorus P, potassium K, and sulphur S) that govern crop output and
ecosystem services. It thereby provides data for the calibration and
validation of models to predict medium- and long-term changes of key
soil parameters determining crop productivity and ESS. To this end we
will investigate the plant uptake and turnover of C and N, P, K, and S
including gaseous (N2O, NH3, CO2) and leaching losses (NO3-, dissolved
organic carbon, organic P, and SO4[2-]), by photo-acoustic spectroscopy,
gas chromatography, and resin cartridges /micro-lysimeters,
respectively, and relate them to the soil hydrological data of A02 and
the multi-spectral cropping / land use signatures of C01 and C02. Using
15N in the central experiment will allow to determine the fate of added
fertilizer N. The data will also be used to parameterize the DNDC
model. High resolution aerial photography and multispectral canopy
scanning from hexacopters will be used to non-destructively monitor, in
cooperation with C01, plant growth in the on-station experiments and
the spatial variability of final biomass on-farm and to collect high
resolution, low altitude multispectral crop signature data. Thereby this
project will contribute to the estimation of the current productive
value of agricultural lands which partly explain a decisions of farmers
to intensify crop production or give up land for urban development.


Last updated on 2018-22-11 at 13:43