Analysis and Integrated Modelling of Biophysical and Socioeconomic Determinants of Cropping Systems Productivity in the Volta Delta
Date
2019-07
Authors
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Journal ISSN
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Publisher
University of Ghana
Abstract
Cropping systems productivity in the Volta Delta is dependent on complex interconnecting
biophysical and socioeconomic determinants. The study analysed the determinants of cropping
systems yield and developed an integrated model for managing desired sustainable crop
production scenarios. The analysis was conducted on change in yield over time, rainfall,
temperature, Land use/land cover (LULC) and soil characteristics. District level crop yield was
regressed on the biophysical variables. Multinomial logistic regression was used to determine
the socioeconomic factors that determine different household crop yield levels. Biophysical
and socioeconomic determinants were integrated into the Bayesian Network (BN) model for
yield predictions to support management and policy decisions. A statistically significant
positive trend of the major wet season and the mean annual rainfall were observed for Ada and
Akatsi while a statistically highly significant decreasing trend in rainfall was observed for
Adidome. Minimum, maximum and mean temperatures showed increasing trends over time.
The LULCC showed a 2.82% net gain for active croplands for the period 2002-2017 and a high
net loss was experienced by grass savannah, mangrove, and shrub savannah and thicket: -
2.59%, -1.68% and -1.24%, respectively. The soils were mainly sandy, moderately acidic, and
had low total nitrogen and potassium; however, the organic matter content and phosphorus
were medium and high, respectively. Almost all the biophysical determinants significantly
predicted crop yield. For the socioeconomic factors, male-headed households and households
that ever-hired labour, were more likely to produce more than 200kg/acre of maise. Femaleheaded
households that used fertiliser and farmed on a minimum of 6.01acres of land were
more likely to produce at least 200kg/acre of vegetables. The BN model results showed that
the likelihood of high cropping systems productivity is more sensitive to input use, averaged
cropped area and soil health. Under the climate change scenario, a combination of high GDP,
good government policies and improved soil organic matter estimated the likelihood of high
cropping systems productivity at 61.2%. Government, relevant institutions and agencies should
strengthen the adaptive capacity of farmers by providing an accurate forecast of rainfall
information, small-scale irrigation and encourage adoption of drought-resistant crop varieties
and crop diversification. This will minimise the effects of the observed rainfall and temperature
trends and variabilities in the Delta. The study also recommends the development of a dynamic
version of the BN model and improving empirical data generation for enhanced model
forecasting capacity, widening of its applicability and performance.
Description
PhD. Environmental Science
Keywords
Biophysical, Socioeconomic Determinants, Cropping Systems, Volta Delta