Browsing by Author "Jones, J. W."
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- Analysis of productivity and soil carbon in response to time-controlled rotational grazing in the West African Sahel regionBadini, Oumar; Stöckle, C. O.; Jones, J. W.; Nelson, R.; Keita, Moussa (2005)Preliminary data from Mali indicate that soil carbon levels are higher under pastures than croplands. Rotational grazing allowing biomass growth during periods (days or weeks) with no livestock grazing could result in more root and aboveground mass residues added to the soil. It is therefore hypothesized that rotational grazing will increase both soil carbon and pasture biomass production. A rotational grazing area (150 ga) was established in Torokoro, Mali (West Africa) to test this hypothesis. Because it could take many years to experimentally evaluate whether soil carbon levels are indeed increasing, a simulation-based sensitivity analysis was performed to evaluate potential changes in production and soil carbon and to assess critical factors that might affect the performance of this management practice. A cropping systems model, CropSyst, was used to conduct this analysis. For this purpose, an improve soil carbon and a new rotational grazing submodel were incorporated in the model.
- Carbon enhancing management systems (CEMS): Estimation of soil carbon sequestration potential in small-holder farming systems in Northern GhanaNaab, Jesse B.; Koo, J.; Traore, P. C. S.; Adiku, S. G. K.; Jones, J. W.; Boote, K. J. (Gainesville, FL: University of Florida, 2008)This bulletin explores the results of a study which measured the carbon sequestration potential for soils under different management options in Northern Ghana. Using simulation modeling, these researchers determined that soil organic carbon accumulation can be enhanced if farmers incorporate residue retention and fertilizer application practices and incorporate no-till practices into their crop management strategy. This study implies that exploring different soil management techniques in farming systems could help mitigate global climate change by promoting carbon retention in soil.
- A simulation-based analysis of productivity and soil carbon in response to time-controlled rotational grazing in the West African Sahel regionBadini, Oumar; Stöckle, C. O.; Jones, J. W.; Nelson, R.; Kodio, Amadou; Keita, Moussa (Elsevier Ltd., 2007)In the Sahel region of West Africa, the traditional organization of the population and the grazing land avoided overexploitation of pastures. Since independence in the 1960s, grazing lands have been opened to all without specific guidance, and the vulnerability of the pastures to degradation has increased. Rotational grazing is postulated as a possible solution to provide higher pasture productivity, higher animal loads per unit land, and perhaps improved soil carbon storage. The objective of this study was to conduct a simulation-based assessment of the impact of rotational grazing management on pasture biomass production, grazing efficiency, animal grazing requirement satisfaction, and soil carbon storage in the Madiama Commune, Mali. The results showed that grazing intensity is the primary factor influencing the productivity of annual pastures and their capacity to provide for animal grazing requirements. Rotating the animals in paddocks is a positive practice for pasture protection that showed advantage as the grazing pressure increased. Increasing the size of the reserve biomass not available for grazing, which triggers the decision of taking the animals off the field, provided better pasture protection but reduced animal grazing requirements satisfaction. In terms of soil carbon storage, all management scenarios led to reduction of soil carbon at the end of the 50-year simulation periods, ranging between 4% and 5% of the initial storage. The differences in reduction as a function of grazing intensity were of no practical significance in these soils with very low organic matter content, mostly resistant to decomposition.
- Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approachSoler, C. M. Tojo; Bado, V. B.; Bostick, W. Mcnair; Jones, J. W.; Hoogenboom, G. (2011-10)In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum–fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with observed soil organic matter (SOM) data similar to the study presented here, there are many opportunities for the application of the CSM for carbon sequestration and resource management in Sub-Saharan Africa.