Plant species diversity of homegardens of Cuba and its significance for household food supply

The cultivation of different plants in homegardens for self-sufficiency has a long tradition in Cuba, but knowledge about homegardens in Cuba is small. To analyse this more deeply, cultivated plants of 31 homegardens were surveyed in three villages in eastern Cuba in 2001. Two of the study villages were located in a humid area with an annual precipitation of about 2200 mm. The third village was situated in a semiarid area with about 450 mm precipitation. The plants studied in the homegardens included those for human consumption such as fruits, vegetables, tubers and cereals as well as spices and medicinal plants. In total, 101 different plant species were found with an average number of 18 to 24 species per homegarden for the three villages. A broad range of species was found in all villages, because irrigation is used under semiarid conditions, which lead to a relative high similarity in species composition between the villages. But, also differences due to the climatic situation became evident, particularly with the medicinal plants. In general, homegarden production provided a broad and diverse basis for self-sufficiency of the households. Although homegarden production showed to be only a small source of income, it is particularly important because of low-paid outside work and minimal food provision of the state.This revised version was published online in November 2005 with corrections to the Cover Date.     

Temporal changes of resource use,soil fertility and economic situation in upland Northwest Vietnam

Agricultural land in lowland Vietnam is scarce due to population growth. Hence, cultivation is increasingly practised on the steep upland slopes. Factors affecting resource use, soil fertility and household economics were studied in six villages of the Black Thai ethnic group in northwest Vietnam. Farmers were interviewed about their individual household situation. Yield development of major crops and cropping patterns in upland cultivation over the last 50 years were recorded in group discussions. In addition, soil fertility was analysed on different land‐use units. Formerly predominant upland rice changed to maize and cassava production at present. Decreasing soil fertility and a shift from subsistence to market‐oriented production, facilitated by new maize varieties and better access to markets are major causes. The Black Thai farmers economy has improved in recent years. The decline in soil fertility is concealed by higher maize yields from new varieties, and soil fertility conservation ranks low among farmers' priorities. The improved economy of the individual households might be of short duration if farmers cannot be sensitized to new resource management options. These have to be developed in line with farmers' priorities and the fragile environment of Vietnam's uplands. Copyright © 2002 John Wiley & Sons, Ltd.     

Mulching with branches of an indigenous shrub (Guiera senegalensis) and yield of millet in semi-arid Niger

Crop residues from millet production in southwest Niger are limited for their utilization as mulch because of many other uses. Thus, branches of an indigenous shrub (Guiera senegalensis J.F. Gmel.) were tested with a randomised block design for their effect on millet (Pennisetum glaucum L.) yield. Pearl millet was planted in 1995 and 1996 on a luvic Arenosol in southwest Niger. Three treatments were applied: control, 1000 kg ha⁻¹ dry matter Guiera-mulch and 2000 kg ha⁻¹ dry matter Guiera-mulch. Mulched plots had 68–94% higher millet yields compared to the control. Differences in soil properties before the treatments were applied, explained a high variability within the treatments. Significant differences of soil properties between blocks led to a distinction of infertile and fertile blocks. In infertile plots with 1000 kg ha⁻¹ Guiera-mulch, millet yield was higher than in plots with 2000 kg ha⁻¹ Guiera-mulch. Due to the many uses of Guiera senegalensis by the local farmers, an application of 1000 kg ha⁻¹ Guiera-mulch, at least on infertile soils, seems a good possibility to increase millet production.     

Scattered shrubs in pearl millet fields in semiarid Niger: Effect on millet production

Various kinds of shrubs species are found in many fields and fallows in semiarid Niger. In order to understand the nature of their interactions with millet (Pennisetum glaucum L.) and their role in soil conservation, experiments were conducted in 1995 and 1996. Three treatments were applied with different shrub densities: cutting all shrubs, cutting half of the shrubs and leaving all shrubs. Millet was harvested per plot and in different circular zones around selected shrubs. In addition, transects across shrubs were investigated for soil parameters and microtopography changes. Millet yield and soil-nutrient status were higher around shrubs compared to the open field. Microtopography was elevated up to 20 cm near shrubs. The positive influence of shrubs on increased millet production extended to 2 m distance from the shrub. Competition between uncut shrubs and millet plants was found within a distance of 1.2 m. An increasing yield of millet was found in plots with shrubs up to a density of about 450 shrubs per hectare. Shrubs showed to be effective for preservation of soil fertility of fields in south-west Niger and thus important for millet production. Optimal for shrub management in farmers' fields would be cutting half of the shrubs and leaving the other half uncut for simultaneous wood production. This revised version was published online in June 2006 with corrections to the Cover Date.     

Landscape diversity and field border density enhance carabid diversity in adjacent grasslands and cereal fields

Landscape Ecology - Permanent grasslands have declined across Europe since the agricultural intensification. Grassland vicinity, landscape heterogeneity and vicinity of hedgerows are enhancing...     

Fallow cultivation system and farmers' resource management in Niger,West Africa

A survey was carried out in 136 farm‐households from seven villages in 1995 and 1996 to analyse the traditional fallow cultivation system in Niger. Farmers were asked to give information about land use on their fields, focusing on cropping and fallow periods as well as on cultivation changes compared to the past. In addition, they were interviewed about their management strategies to maintain or improve soil fertility. Millet‐based systems clearly dominate at all sites, either in pure form or intercropped with cowpea, groundnut, sorghum or roselle. At present, almost half of all farmers cultivate their fields on average up to 5 years until it is left fallow. About one‐third use their fields permanently. Most farmers use short fallow periods of 1 to 5 years. Moreover, there was a decrease in the cropping area left fallow, and the fallow period also decreased steadily in the past years. In the mid‐1970s the average fallow period was about 8 years, decreasing to 2.5 years in 1996. The actual fallow periods are too short to allow sufficient positive effects on soil fertility and farmers are aware of this problem. Consequently, farmers employ different fertilization techniques which aim at maintaining or restoring the soil nutrient pool of the fields while providing physical protection against wind and water erosion. Most farmers use animal manure to improve soil fertility and apply mulch from different sources, millet stalks and branches, for soil regeneration. Few farmers employ other strategies such as mineral fertilizer or planting pits. The farmers try to optimize the use of internal and external resources resulting in a mixture of different fertilization and soil protection methods. Internal resources play by far the most important role. Due to the generally limited resource availability farmers concentrate their management efforts on certain areas within each field or on selected fields only. This means a decreased crop production for the individual household and a higher risk of soil degradation because of soil mining or increased erosion risk on the field area where soil fertility management cannot be practised. Copyright © 2002 John Wiley & Sons, Ltd.     

Using biodiversity to valorise local food products: the case of fish ponds in a cultural landscape, their biodiversity, and carp production

Today, we need to produce sufficient food and simultaneously conserve biodiversity. But, could biodiversity associated with certain food production practices also be used in marketing products? We analyse this possibility for creating a food quality label for carp raised in the Dombes territory, a cultural landscape of fish ponds in France. The biodiversity of 99 fish ponds was studied in the Dombes territory by analysing aquatic vegetation, dragonflies, amphibians, macroinvertebrates, habitats around ponds, and water quality. In addition, a survey with 200 questionnaires and interviews was conducted with consumers to investigate fish and carp consumption and knowledge about quality labels and biodiversity. Findings reveal that fish production practices conserve remarkable species diversity, particularly for aquatic vegetation, dragonflies and amphibians, and habitats around the ponds. This relatively high level of biodiversity is found in spite of having very nutrient-rich fish pond systems, systems for which normally a low level of biodiversity is expected. Nevertheless, currently this biodiversity cannot be valorised for setting up a quality label for locally produced carp. Firstly, few consumers have adequate knowledge about carp and are interested in eating it. Secondly, most of them have less knowledge about the quality label which wanted to be established for carp from the Dombes. Thirdly, only less than one-third of the consumer is familiar with the term “biodiversity”. Fourthly, the stakeholder network of the supply chain is presently not able to communicate the message of biodiversity as they themselves lack a sufficient knowledge about biodiversity of their systems.     

Contribution of cacao agroforestry versus mono-cropping systems for enhanced sustainability. A review with a focus on yield

The demand for cocoa has increased over the past years following the growth of cocoa-based products linked to the rise in living standard in highly populated countries. Cacao industry is therefore currently facing the dilemma of producing more cacao while ensuring its sustainability. Cacao monocrops and agroforestry systems (AFS) are two contrasting ways to produce cocoa, yet their impact on yields, contribution to farmer livelihood, cocoa quality remains understudied. Therefore, we reviewed existing literature comparing (1) monocrop cacao farming systems with (2) simple or (3) complex AFS. We found 19 comparisons of the cocoa yields in monocrops and simple AFS and 20 comparisons of monocrop and complex AFS. Three main research findings derive from this work. First, in about one third of cases, cacao trees yield more (or equally) in AFS than in monocrops. However, when considering only simple AFS, cacao trees yield more or equal to cacao monocrop in 52% of the cases. Second, cocoa AFS yields an average of 14% less than cacao monocrop. Yet, on average simple AFS yielded 2% less than cacao monocrops. Finally, there are too little elements to draw conclusions about the nexus between cocoa quality and cacao tree cultivation system.

     

Farmers' perception of vegetation changes in semi‐arid Niger

Vegetation changes due to climate and human impact in Sahelian countries are rarely documented at species composition level. The decrease or disappearance of certain plant species reduces vegetation cover and enhances the exposure of soil surfaces to wind and water erosion leading to increased land degradation. Men and women in Niger were asked to note plant species and relate their numerical development to pre‐defined observation criteria comparing the present and past. Plant species in decline or that had disappeared were reported more often than species that had increased or were newly introduced. The increasing species that were mentioned were often in use for different purposes and seem to be robust enough and well adapted to the semi‐arid environment. But the interviewed farmers also stated the loss of many valuable species that they used for construction and hand tools, consumption, medicine or fodder. Those declining species are of socio‐economic importance for individual households and the rural ecology. Men mentioned 18 species that had disappeared. Differences in the perception of men and women could be found. Women seemed to have a better perception for species which had increased or were newly introduced, whereas men perceived more a decrease or disappearance of species. Copyright © 2000 John Wiley & Sons, Ltd.