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Agricultural systems have a long history of responding to various economic and socio-political forces, including supply and demand, political preferences and power inequalities. Our current food system continues to respond to contemporary forces with a call for sustainable transformations in the face of increased pressure and competition over resources, severe consequences of climatic change, widespread degradation of land and water resources, and the accelerating loss of biodiversity. Both agroforestry and agroecology have evolved as approaches to agricultural management that focus on the application of ecological principles to achieve sustainable agriculture. Agroecological principles are designed to engage with the entire agrifood system, for instance identifying broad participation and involving a diversity of actors and knowledge systems. Agroecological approaches to production have significant historical and contemporary links to agroforestry approaches, but not all agroecology involves trees and not all agroforestry is in line with agroecological principles. Drawing on (1) a literature review, (2) case studies on the agroforestry and agroecology nexus presented at the 5th World Congress on Agroforestry (WCA), and (3) audience responses to statements presented at the Congress, we explore the two main ways that agroforestry and agroecology come together: agroforestry that encompasses agroecological principles and agroecological transitions that involve trees. We review the status of agroecology, the functions specific to agroforestry that can enhance the achievement of agroecological outcomes, the tensions between simple agroforestry systems and agroecology, and the larger potential of multidimensional sustainability of agroforestry with the inclusion of agroecological principles. We also present the level of agreement on four key statements about the agroforestry-agroecology nexus enumerated at the WCA. It is clear that some features of agroforestry operationalize agroecological principles that aim to transition away from monocultures and the use of environmentally disruptive agrochemicals, and toward strengthening biodiversity and resilience. Yet, much remains to be done to enhance agroecological principles more fully in framing agroforestry practices and to incorporate trees within agroecological practices. Pathways to strengthen the nexus of agroforestry and agroecology are proposed, which focus on the role of trees in multifunctionality and resilience and using agroecological principles related to knowledge sharing and equity to enrich agroforestry practices. [ABSTRACT FROM AUTHOR]

In the current debate on the role of increase soil carbon in addressing both climate change and food security, there is consensus that farmed lands have the higher potential provided the best management practices are implemented. In the Sahel where farms usually have few sparse old trees with declining soil fertility, there is an ongoing re-greening process with increases in tree cover for which there is still a dearth of quantified information on its impacts on soil properties. This research aimed at filling that gap. We sampled soil using a concentric zone design around individual trees of dominant species and at different soil depths (0–10, 10–30, 30–50 and 50–70 cm) in four Sahelian countries: Burkina Faso, Mali, Niger and Senegal. The results showed increase total carbon content of the top 0–10 cm soil, generally with high sand content (> 70%), ranged from 0.16 to 0.44% (mean 0.23%). Under trees it was a factor 1.04–1.47 higher than away from trees. Different tree species thrived in different ecological niches and had different impacts on soil properties, highlighting the need for site and species matching in restoration activities. These results suggest that increase vegetation cover in the Sahel is associated with an increase in soil total carbon and this trend is more pronounced on sandy soils. [ABSTRACT FROM AUTHOR]

Understanding crop performance and productivity in relation to intercropped tree species, tree management and prevailing environmental conditions may assist farmers in managing agroforestry systems appropriately. Our study evaluated the management and spatial effect of six dominant tree species (Eucalyptus spp., Sesbania sesban, Grevillea robusta, Calliandra calothyrsus, Markhamia lutea and Croton macrostachyus) on water availability and crop performance in smallholders' maize fields in Rift valley, Kenya. Maize performance under C. macrostachyus and M. lutea was also evaluated at on-station experiment in the same area. The smallholder farmers in the study area remain important maize producers in Kenya with an average maize yield of 6.5 tons ha−1 recorded. Maize yield under the dominant tree species in studied smallholder farms showed significant differences (P < 0.001) with leguminous species (C. calothyrsus and S. sesban) recording the highest amount of grain weight. Farmers selectively prune tree they perceive as competitive but still want to maintain them in the farms such as Eucalyptus spp. and G. robusta but miss to equally prune M. lutea and C. macrostachyus which would greatly improve performance of associated crops. In addition to presence of great tree management diversity, the study clearly showed that tree in smallholder farms either have competitive, complementary or balanced-off interaction with crops. Lastly, despite the adequate rainfall throughout the cropping season, dominant tree species in smallholder farms were shown to significantly (P < 0.0001) influence the spatial distribution of soil water. [ABSTRACT FROM AUTHOR]

Côte d'Ivoire produces 40 % of the world supply of cocoa but much of the plantation area is aging and declining in productivity, while opportunities for land expansion into new forest land are quickly disappearing. Rejuvenation strategies for cocoa presently coalesce either around improved varieties and greater use of agro-chemical inputs in full sun systems or eco-certification that requires trees to be integrated with cocoa. Here, we explore the possibility of uniting these approaches through building on current farmer practice of incorporating trees in their cocoa fields to improve cocoa productivity and diversify their livelihoods. We interviewed 355 farmers about trees integrated in their cocoa fields across four locations in the South-West of Côte d'Ivoire in 2012, stratified by whether or not farmers were eco-certified. Despite the massive deforestation, a rich diversity of trees was found in cocoa fields and an overwhelming majority of farmers (95 %) wanted more trees and/or more tree species, regardless of their certification status or ethnic origin. There was a consensus that most trees were compatible with cocoa, but farmers also traded off negative impacts of some species against their productive contribution to their livelihood. Farmers valued tree diversity on their cocoa plots and provided detailed information on how 32 tree species interacted with cocoa in terms of soil moisture retention, soil fertility improvement and pest and disease interactions but also had key gaps in knowledge about alternative hosts of mirids and mistletoe. The majority of farmers were not aware of the certification requirements for tree species and shade cover but a much higher proportion of certified farmers (76 %) had received information about shade trees than non-certified farmers (15 %), although advice only related to eight tree species. Scope for building on local knowledge and practice to sustainably increase cocoa productivity through promoting tree diversity while enhancing other ecosystem service provision was identified and the next steps required to realize this set out. [ABSTRACT FROM AUTHOR]

The effects of search criteria upon recall performance following a word classification task were investigated. Rival hypotheses were tested, one based on the number of cues available at retrieval and the other on the amount of processing carried out during classification. After being presented with two-component category names, subjects classified words on the basis of either category membership or the number of semantic components the words shared with a target category, and then they received an unexpected recall test. Experiment 1 favored an amount-of-processing explanation, but it was felt that redundancy in the stimulus materials might invalidate this conclusion. Experiment 2 confirmed this suspicion and clearly supported an explanation in terms of retrieval cue availability. The notion of partial semantic processing of words is discussed, and it is argued that the number of congruent encodings formed during classification can be used as an index of elaboration and subsequent memory performance. [ABSTRACT FROM AUTHOR]

After routine inguinal herniorrhaphy we gave 12 patients a wound infiltration regimen of bolus doses of 20 ml of 0.5% bupivacaine via a catheter within the wound and rectally administered indomethacin (100 mg). Peak venous plasma bupivacaine concentrations ranged from 0.07 mg·l to 1.14mg·l (mean (SD) 0.47 (0.33) mg·l), and occurred at between 0.25 and 2 h after the first dose. Plasma concentrations were well below the toxic threshold of 4 mg·l and there was no accumulation. The regimen provided satisfactory analgesia. There were no wound infections nor signs of toxicity. [ABSTRACT FROM AUTHOR]

Growth variability and effect of seed size on growth of seedlings ofAcacia nilotica ssp. tomentosa of a Senegalese provenance were studied in a greenhouse experiment. Seedlings were raised from a sample of52 seeds with a seed weight range of 0.070 g to 0.258 g; and a rangeof growth variables were measured on seedlings harvested 11 weeks after planting. Based on the sample mean and variance, the sample size required to estimate the parameter (mean) of the growth variables wasdetermined. Seedlings showed a large variability in growth. There were five-fold and three- fold differences between seedlings in leaf area and total dry weight, respectively. Seed weight has little effect on seedling growth. The number of replications required to estimate aparameter mean of the different growth variables, within 20% margin of error at P = 0.05, ranged from nine to 24. The observed growth variability was indicated to be an important biological variable which could be used to improve growth and yield in A. nilotica. [ABSTRACT FROM AUTHOR]