Although climate change is likely to affect a wide variety of sectors in Zimbabwe, the risk to agriculture stands out most since agriculture is the mainstay of the country’s economy. In addition, there is little information available on how to help smallholder farming systems and livelihoods respond to these risks. To determine the effects on crop production of expected changes in precipitation patterns and projected increases in carbon dioxide (CO2) and temperature , we used two process-based crop models—the Decision Support System for Agrotechnology Transfer (DSSAT) model and the Agricultural Production Systems Simulator (APSIM) model. The models were calibrated and validated to assess the effects of single and combined climatic factors on grain and stover yield performance of maize and groundnut, across three soil types. The two models generally agree on the effects that different climatic factors have on both maize and groundnuts, however, the magnitude of the effects varied. For example, reductions on maize grain yields are more pronounced in the APSIM model while the DSSAT model shows more pronounced reduction of maize stover yields. Both models show yield benefits under elevated CO2 concentration for groundnuts negating the effects of increased temperatures when evaluating the combined effects of the climatic factors. However, yield increases for both groundnut grain and stover are more pronounced in the DSSAT model. The key finding is that soils play an important role in determining outputs of crop-climate interactions: they can buffer or aggravate climatic impacts.
Tag: Production systems
The critical role of agroforestry in forest and landscape restoration
Morphology and phylogeny of Atrocalyx acervatus sp. nov. (Lophiotremataceae) from Acer species
From diagnosis to scaling of Agroforestry Systems: lessons learned from case studies in Brazil using the PLANTSAFS tool
Differences in women’s and men’s conservation of cacao agroforests in coastal Ecuador
Chapter 9 – The Lentil Economy in India
Carbon stocks in agroforestry systems correlate with tree diversity
Adoption of Agroforestry Practices- Policy Initiatives and Innovations in India
Chapter 13 – Integrated Assessment of Crop–Livestock Production Systems Beyond Biophysical Methods: Role of Systems Simulation Models
Crop–livestock farming systems that are predominant in Africa, are complex with various interrelated ecological and economic factors. They involve multiple products or benefits (intended and nonintended), with trade-offs and synergies occurring both on- and off-site and varying over time. Understanding both simplistic relationships and complex interactions between climate and agricultural production systems to determine overall system efficiency and impacts on human well-being is a major challenge. Computer-based tools coupled with participatory approaches for systems integrated assessments have the potential to resolve multiple dimensions of these complex systems. The products of these environmental, economic, and social analyses are important in the development of climate smart adaptation strategies. To reduce burdening the environment and contributing to resilience and sustained production capacity, highly efficient technologies are required. Although some advances have been made in technology generation, their assessment for delivery of crop–livestock systems has lagged behind. This chapter describes approaches that couple participatory methods with computer-based decision supporting tools to achieve an integrated assessment of crop–livestock systems in relation to climate change. Simulation results show that climate change will have an impact on crop–livestock production systems hence smallholder farmers’ well-being will also affected. However, impacts will be varied, the three farm categories studied for Nkayi district will not be affected to the same degree due to agricultural management practices and wealth status. Tailoring adaptation packages to different farm categories can assist in developing context-specific technologies to buffer the impacts of climate change. Improved on-farm high-quality fodder production (inclusion of fodder and grain legume) and growing medium duration maize varieties would offset impacts of climate change by about 20%–30% for farmers with livestock. For those farmers without livestock (>40% of rural population) by diversifying on-farm crop production, improved management and growing medium duration crop varieties can reduce economic losses due to climate change from 25% to 19%. The integrated approach can evaluate impacts of climate change on both agricultural production and also human well-being, which is imperative in developing context-specific national adaptation strategies.
Soil chemical properties dynamics as affected by land use change in the humid forest zone of Cameroon
The conversion of forests to other forms of land use has profound effects on the distribution and supply of soil nutrients. Understanding the effects of land use on soil is essential for addressing agroecosystem transformation and sustainable land productivity. Although soil carbon stock has been previously examined in the humid forest zone of Cameroon, the dynamic and interactions between other soil chemical properties has been poorly addressed to date. The present study used the quadrat approach to assess the effect of four land use types (secondary forest, fallow, cocoa plantation and mixed cropping) on soil chemical properties. Soil samples were collected at two different depths (0-10, 10-30 cm) in all land use types and analyzed for pH, total carbon, soil organic carbon, total nitrogen, cation exchange capacity (CEC), calcium (Ca), potassium (K), magnesium (Mg) and boron (B). Land use type significantly affected B, Ca, K and pH: in general, these properties were higher in cocoa plantation and mixed cropping than in secondary forest and fallow. All soil properties were significantly greater in the upper than in the lower soil depth. In addition, all soil properties differed significantly among sites and villages within sites. Pearson correlations between soil chemical properties were positive and generally significant in the four land use types, except for some correlations with B, pH and CEC. Despite the fact that some of the fundamental soil chemical properties (carbon, nitrogen, CEC and Mg) did not differ among the four land use types, high density tree-based production systems are recommended for the storage of these elements in the soils.