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1.
Energy efficiency of agroforestry systems of large cardamom grown under N2-fixing Himalayan alder (alder-cardamom) and natural forest (forest-cardamom) was studied in the Sikkim Himalaya. Large cardamom (Amomum subulatum), the most important perennial cash crop of the region, is widely cultivated with Himalayan alder (Alnus nepalensis) as shade tree. Energy fixation, storage, net allocation in agronomic yield, and heat release and exit from the system were respectively 1.57, 1.44, 2.24 and 2.22 times higher in the alder-cardamom compared to the forest-cardamom system. Energy conversion efficiency and net ecosystem energy increment were also higher in the alder-cardamom than the forest-cardamom system. Energy fixation efficiency and energy conversion efficiency of large cardamom increased under the influence of Himalayan alder. Energy efficiency in N2-fixation of Himalayan alder was also high (67.5 g N2 fixed 104 kJ-1 energy). Quantum and flux of energy increased in the alder-cardamom compared to the forest-cardamom system that optimized the production potential of the cash crop under the influence of the Himalayan alder. Climatic sympatry of the large cardamom and Himalayan alder, and their synergetic energy efficiency makes this association ecologically and economically viable for the mountain regions.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
2.
Farmers are often blamed for destroying the tropical forest, especially in Laos. Converting shifting cultivation into cash
crop based agriculture is frequently presented as the solution for merging forest protection and poverty alleviation, but
many attempts have ended in failure. A rural development project has attempted to introduce medicinal cardamom (Amomum villosum) cultivation in the notably remote region of Phongsaly (northern Laos), for export to China. With nearly 300 ha planted,
the crop now involves about 75% of the farmers in the region. Farmers fitted cardamom into their farming system, to suit their
needs for sustainability with a crop compatible with existing practices. Results indicate that introducing a cash crop into
a shifting cultivation region is possible if a greater attention is paid to: (i) appraise how the new crop fits into the farming
systems; (ii) prioritise economic issues over agronomic matters, in particular identify markets, traders or commercial risks. 相似文献
3.
M. Moench 《Agroforestry Systems》1991,15(1):31-50
The Western Ghats of Kerala have been settled over the past 40 years by landless immigrants. Natural forests and cardamom
(planted under forest canopy) have been widely replaced by small-holder cultivation. Settlers plant cassava and other annuals
in the initial 3–5 years following clearing of the forest canopy. These crops are gradually replaced by black pepper, the
dominant crop 5–15 years after clearing. Finally, other perennial crops, planted during the period when pepper was dominant,
mature. A highly mixed “home garden” cropping phase is most common on sites 15–20 years after the forest canopy was removed.
Soil erosion on sites cleared 1–3 years previously averaged 120 t/ha in the 1988 monsoon season. Over the same period, soil
erosion under mature cardamom, pepper and mixed cultivation averaged 0.65, 3.5, and 1.45 t/ha respectively. Erosion levels
appear to be related to cover at ground and intermediate (1–4 m) heights above the surface. Soil organic matter is high in
the cardamom areas, declines rapidly when the forest canopy is cleared, remains low in pepper, and appears to rebuild to levels
as more mixed agroforestry systems become established. Overall, there appears to be a succession in which high erosion and
declining organic matter levels are temporary features associated with the conversion of sites from forests and cardamom to
other phases. 相似文献
4.
In Ghana, shade for cacao (Theobroma cacao L.) is becoming a critical issue because of extensive deforestation. Unlike in some other cacao-growing countries, cacao is not grown under the shade of coconut (Cocos nucifera) in Ghana. An experiment to compare the merits of four cacao-coconut intercropping systems with the traditional cultivation of cacao under Gliricidia sepium shade was undertaken at the Cocoa Research Institute of Ghana. Cacao seedling girth was not affected when intercropped with coconut but was significantly (P = 0.01) reduced when intercropped with G. sepium. High density cacao facilitated better early canopy formation. Yield of cacao spaced at 2.5 m triangular (1739 plants ha–1) with coconut at 9.8 m triangular (105 plants ha–1) was significantly higher (P = 0.05) than from the other treatments during 1993/94 to 1995/96. There were no major disease problems associated with intercropping cacao with coconuts. Widely spaced coconuts intercropped with cacao spaced at 3 m × 3 m showed better flowering and gave higher coconut yields, but cacao spaced at 2.5 m triangular under coconuts spaced at 9.8 m triangular was more profitable than the other treatments. Moisture stress was the greatest in cacao system with G. sepium shade and this could be responsible for the low yield of cacao in that treatment. It is suggested that properly arranged high density cacao under widely spaced coconuts can be a profitable intercrop system for adoption by cacao farmers in Ghana.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
5.
Marcela C. Pagano Marta N. Cabello Antonio F. Bellote Nadja M. Sá Maria Rita Scotti 《Agroforestry Systems》2008,74(3):231-242
For the purpose of reforestation and wood supply the leguminous tree Anadenanthera peregrina, a native species, was intercropped with Eucalyptus camaldulensis in a degraded semiarid area of Brazil. Single and mixed stands of these species were inoculated with Rhizobium and/or arbuscular mycorrhizal fungi (AMF). The growth of all species in mixed stands did not differ from those cultivated
in monoculture and land equivalent ratio (LER) exceeded unity in intercropped plots. Inoculated plants showed greater height
and diameter growth and dry matter and nutrient concentration in plants of A. peregrina was higher in inoculated single plots. The distribution, composition and density of AMF species was related to the rhizosphere
effect of plant species. The intercropped model where all the plants were inoculated achieved soil AMF diversity patterns
similar to those of the preserved area and showed also higher soil organic matter, nutrient content as well as a reduction
in soil macroporosity. This model of intercropping may be considered as an efficient system for reforestation under semiarid
conditions. 相似文献
6.
A field study was conducted for six years (1981–1986) on sandy loam soil on intercropping hedgerows of Leucaena leucocephala (Lam) de Wit. with three field crops viz. maize (Zea mays L), black gram (Vigna mungo L) and cluster bean (Cyamopsis tetragonoloba L Taub.). In treatments 1 and 2 Leucaena hedges were planted as pure crops at close (25 cm × 75 cm) and wide (25 cm × 375 cm) spacings. In treatments 3, 4 and 5 the
three field crops were intercropped between the hedgerows of Leucaena at the wide spacing, and in treatments 6, 7 and 8 the field crops were raised as pure crops. Leucaena was topped to 75 cm each time it attained a height of 175 cm.
The pure crop of Leucaena at close spacing produced an average, over the six years, of 34 t ha−1a−1 of green fodder and 9.4 t ha−1a−1 of air dry fuelwood. The Leucaena at wide spacing produced 18.9 t ha−1a−1 of green fodder and 6.3 t ha−1a−1 of fuelwood. Intercropping with field crops decreased the yield of green fodder and fuelwood. The yield of all the field
crops was less when raised as intercrops than as pure crops.
Mean maximum net returns were obtained from intercrops of Leucaena and cluster bean (Rs 3540 ha−1a−1) which were significantly higher than the returns from pure crop of Leucaena at wide spacing but similar to the returns from pure crops of cluster bean. Leucaena with maize (Rs 3273 ha−1a−1) and black gram (Rs 3125 ha−1a−1) gave significantly higher net returns over pure crops of Leucaena at wide spacing, maize and black gram.
ICRISAT = International Crops Research Institute for the Semi-Arid Tropics- Hyderabad, India.
CIAT = Centro International de Agricultura Tropical - Cali - Columbia 相似文献
7.
Sesbania (Sesbania sesban), which is promoted as a short-duration-fallow species in eastern and southern Africa, is an alternative host to root-knot nematode (Meloidogyne spp.). Therefore, it is important to know the extent of sesbania infection by the nematode on farms and its effects to crops grown in rotation with sesbania. A survey of 14 farms in western Kenya indicated that sesbania was infected by root-knot nematode in all the farms. The potential to build up the nematode population was much greater on farms where maize (Zea mays) was previously intercropped with a susceptible bean (Phaseolus vulgaris). Screening of 30 single plant accessions of four sesbania provenances (Kakamega, Siaya, Kisumu, and Kisii) from western Kenya in pots indicated limited scope for selecting material resistant to the nematode. All four provenances were infested by the nematode, and they increased its population in soil and root. A rangewide collection of sesbania germplasm needs to be screened to determine the scope of finding nematode-resistant material. Transplanted seedlings produced in heat-sterilized, nematode-free soil showed less nematode infection than direct-seeded plants. However, both direct seeding and transplanting seemed to increase nematode population similarly. A number of Crotalaria spp. that were found resistant to nematodes can be considered as alternatives to sesbania-planted fallows, but further field-scale testing is necessary to select appropriate species based on biomass production. Among other species suitable for short-duration fallows, only pigeonpea (Cajanus cajan) and senna (Senna siamea) showed promise. Species such as neem (Azadirachta indica), casuarina (Casuarina junghuhniana), and grevillea (Grevillea robusta) that are suitable for boundary plantings were free from the root-knot nematode.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
8.
Litterfall and decomposition were studied in agroforestry systems involving large cardamom (Amomum subulatum) and mandarin (Citrus reticulata) in the Sikkim Himalaya, India. There were stands with N2-fixing trees (Alnus nepalensis over large cardamom, and Albizia stipulata over mandarin agroforestry) or without them (native non-symbiotic mixed tree species) in both systems. The total annual litter (litter + crop residue) production was higher in the Alnus-cardamom than in the forest-cardamom stand and in the mandarin than in the Albizia-mandarin stand. The ratio of litter production to floor litter was higher in the N2-fixing stands than in the non-N2-fixing stands, indicating a faster litter turnover in the former. Tree litterfall occurred throughout the year, but with marked peaks during November to April. Total soluble polyphenolics of fresh litter were higher in N2-fixing species than in mixed tree species and crops. Half-life values for ash-free mass were shortest in the leaves of N2-fixing species. N loss was higher from N2-fixing Alnus and Albizia leaves, whereas P loss was faster and nearly equal in Alnus leaf litter and cardamom residue in cardamom, and Albizia leaf litter and crop residue in mandarin agroforestry systems. The P turnover in N2-fixing Alnus and Albizia twigs was faster than in the twigs of mixed tree species. The N2-fixing tree species increased the N and P cycling through production of more above-ground litter and influenced greater release of these nutrients. 相似文献
9.
The choice of an appropriate hedgerow species is one of the most critical decisions in exploiting the value of a contour hedgerow system. The implications of hedgerow species with nitrogen (N)-fixation capacity on hedgerow-crop competition and crop productivity have been widely debated. We examined the agronomic significance of N-fixation by comparing the performance of species representing three classes of hedgerow vegetation: A nitrogen-fixing tree legumeGliricidia sepium), a non-nitrogen fixing tree (Senna spectabilis syn.Cassia spectabilis), and a forage grass (Pennisetum purpureum). The 4-year study investigated the hedgerow biomass and nutrient yields, and their relative effects on the performance of two annual crops commonly grown in alley farming systems, with emphasis on hedgerow-crop interference. The work was done on an Ultic Haplorthox (pH 4.8, organic C 1.9%, total N 0.18%).Senna produced 46% more pruning biomass on an annual basis than didGliricidia; N supplied to the alley crops was similar toGliricidia in the first year of observation, but 20–30% higher in the succeeding years. Upland rice and maize grain yields and total dry matter were unaffected by tree species, but the nitrogen-fixing tree exerted less competitive effects on the annual crops growing in adjacent rows. Grass hedgerows reduced maize yields 86% by the second year, indicating an unsustainable drawdown of nutrients and water. We conclude that hedgerow systems composed of a nitrogen-fixing tree did not exert significant advantages compared to a non-fixing tree species, and that factors other than N-fixation were more important determinants for the choice of hedgerow species. 相似文献
10.
The water dynamics of cropping systems containing mixtures of Gliricidia sepium (Jacq.) Walp trees with maize (Zea mays L.) and/or pigeonpea (Cajanus cajan L.) were examined during three consecutive cropping seasons. The trees were pruned before and during each cropping season, but were left unpruned after harvesting the maize; prunings were returned to the cropping area in all agroforestry systems to provide green leaf manure. The hypothesis was that regular severe pruning of the trees would minimise competition with crops for soil moisture and enhance their growth by providing additional nutrients. Neutron probe measurements were used to determine spatial and temporal changes in soil moisture content during the 1997/98, 1998/99 and 1999/00 cropping seasons for various cropping systems. These included gliricidia intercropped with maize, with and without pigeonpea, a maize + pigeonpea intercrop, sole maize, sole pigeonpea and sole gliricidia. Soil water content was measured to a depth of 150 cm in all treatments at 4–6 week intervals during the main cropping season and less frequently at other times. Competition for water was apparently not a critical factor in determining crop performance as rainfall exceeded potential evaporation during the cropping season in all years. The distribution of water in the soil profile was generally comparable in all cropping systems, implying there was no spatial complementarity in water abstraction by tree and crop roots. However, available soil water content at the beginning of the cropping season was generally lower in the tree-based systems, suggesting that the trees continued to deplete available soil water during the dry season. The results show that, under rainfall conditions typical of southern Malawi, the soil profile contains sufficient stored water during the dry season (ca. 75–125 mm) to support the growth of gliricidia and pigeonpea, and that gliricidia trees pruned before and during the cropping season did not deleteriously compete for water with associated crops. Water use efficiency also appeared to be higher in the tree-based systems than in the sole maize and maize + pigeonpea treatments, subject to the proviso that the calculations were based on changes in soil water content rather than absolute measurements of water uptake by the trees and crops. 相似文献
11.
N. Salafsky 《Agroforestry Systems》1995,32(1):63-79
Whereas a natural ecosystem is stochastically created by mechanism of natural selection, an agroecosystem is systematically fashioned by farmers in response to specificperceived ecological and economic constraints. In this paper, I employ a geographical information systems (GIS) based analysis to examine the beliefs of forest garden owners in West Kalimantan, Indonesia, regarding ecological factors involved in maximizing durian fruit (Durio zibethinus) production. Factors that I tested included individual tree characteristics (age, size, color), microsite factors (on or off ridge, near stream, slope, proximity to rock outcrops, in dry or swampy site), species associations (with other types of trees, spacing to nearest large tree), and the overall position of the garden (on flat land or hill, distance to natural forest). I first conclude that respondents generally had accurate perceptions as to how ecological factors influence durian production. I then briefly discuss how the findings of this study could be used to improve existing and future durian gardens. Finally, I discuss the potential for studying slow-growing agroforestry systems using cross-sectional data collected from plots owned and managed by individual house-holds through the use of a GIS and statistical control.In spite of the high specific richness of the gardens' vegetation ... the place of each plant is carefully chosen, and often corresponds to its ecological niche in the natural forest. Enauiries have shown that people have a certain ecological knowledge in individual care towardseach plant that is in contradicion to the mass treatment of cultivated crops in monoculture.-G.Michon (1983, p.19) 相似文献
12.
[目的]为了解红花尔基地区沙地樟子松天然纯林的结构特征,指导沙地樟子松的保护与经营。[方法]在红花尔基地区设置2块100 m×100 m的樟子松天然纯林固定样地,利用样地内每木定位调查数据和分析统计软件进行一元分布及二元分布特征分析。[结果](1)樟子松天然林纯林直径分布为单峰或多峰山状分布,垂直结构简单,只有乔木层和草本层。(2)樟子松天然纯林的林木分布格局为均匀分布,接近随机分布,林木分布格局类型与林分密度无关;林分中樟子松个体竞争激烈,多数单元中林木呈较密集状态。(3)2块样地中随机分布状态下的林木多数为中等密集或比较密集,不同分布状态下的林木优劣性差异较小;低密度樟子松天然纯林中多数密集状态的林木为绝对优势木或优势木,而高密度林分中林木密集度分布与林木大小无关。[结论]红花尔基沙地樟子松天然林结构不合理,应选择病腐木及聚集分布的个体作为潜在调整对象,进行密度调整和结构优化。 相似文献
13.
The traditional Acacia senegal bush-fallow in North Kordofan, Sudan, was disrupted and the traditional rotational fallow cultivation cycle has been shortened
or completely abandoned, causing decline in soil fertility and crop and gum yields. An agroforestry system may give reasonable
crop and gum yields, and be more appealing to farmers. We studied the effect of tree density (266 or 433 trees ha−1) on two traditional crops; sorghum (Sorghum bicolor) early maturing variety and karkadeh (Hibiscus sabdariffa), with regard to physiological interactions, yields and soil water depletion. There was little evidence of complementarity
of resource sharing between trees and crops, since both trees and field crops competed for soil water from the same depth.
Intercropping significantly affected the soil water status, photosynthesis and stomatal conductance in trees and crops. Gum
production per unit area increased when sorghum was intercropped with trees in low or high density. However, karkadeh reduced
the gum yield significantly at high tree density. Yields of sorghum and karkadeh planted within trees of high density diminished
by 44 and 55% compared to sole crops, respectively. Intercropping increased the rain use efficiency significantly compared
to trees and field crops grown solely. Karkadeh appears to be more appropriate for intercropping with A. senegal than sorghum and particularly recommendable in combination with low tree density. Modification of tree density can be used
as a management tool to mitigate competitive interaction in the intercropping system. 相似文献
14.
Arthropod diversity in alley cropped black walnut (Juglans nigra L.) stands in eastern Missouri, USA
W. Terrell Stamps Terryl W. Woods Marc J. Linit Harold E. Garrett 《Agroforestry Systems》2002,56(2):167-175
Knowledge of the complex interactions among trees, crops and their associated fauna is necessary to determine the viability of a particular agroforestry practice. Information is lacking concerning these interactions, particularly in temperate agroforestry practices. We examined the effects of two forages on the growth, nut production, and arthropod communities of alley cropped eastern black walnut, Juglans nigra L. Experimental plots of eastern black walnut, intercropped with alfalfa, Medicago sativa L., smooth bromegrass, Bromis inermis Leyss., or no vegetation were sampled with sweep nets prior to each cutting date for the forages. Comparisons were made between treatments and sampling dates. Tree growth measurements, nut yield and other nut quality measurements were taken at the end of each growing season. There were no differences in tree growth among alleyway treatments. The first season's nut yield was greater from trees with vegetation-free alleyways; otherwise nut production did not differ among the treatments. Arthropods were more numerous and diverse in alley cropped alfalfa than in alley cropped bromegrass or in the vegetation-free controls. Alley cropped bromegrass supported a more diverse population of arthropods than did the vegetation-free control. Arthropod diversity in the tree canopies did not differ among treatments. Alley cropped forages supported a more diverse and even arthropod fauna than did adjacent monocropped forages. We conclude that alley cropped forages had a relatively minor impact on the growth and nut yield of walnut trees.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
15.
Field studies carried out in a forest transition site on a tropical Alfisol in southwestern Nigeria, show that shading by
gliricidia (Gliricidia sepium (Jacq.) Steud) and leucaena (Leucaena leucocephala (Lam.) de Wit) hedgerow species reduced density of speargrass (Imperata cylindrica (L.) Raeuschel) by 67% and 51%, respectively. Shoot biomass of speargrass decreased by 81% and 78% in gliricidia and leucaena
hedgerows, respectively. Reduction in speargrass rhizome biomass in gliricidia plots was 96% while rhizome reduction in the
leucaena plots was nearly 90%. Rhizome mortality was significantly higher in gliricidia plots than in leucaena and control
plots. The bulk of rhizomes was found between 10 cm and 20 cm of soil depth but rhizome did not penetrate further than 30
cm depth in the Alfisol in which this study was carried out. Gliricidia was better than leucaena hedgerow species in suppressing
speargrass. 相似文献
16.
In order to study the effect of tree crop intercropping on a young plantation of Populus tomentosa in the plains along the Yellow River, field experiments were conducted by observing the growth of the plantation, the nutrient
content in leaves, the nutrient and water content in the soil, and the output of crops. The relationship between forest growth
and nutrient content in the tree leaves and the soil were analyzed. Results show that tree crop intercropping in young plantations
can not only improve soil water content, but also enhance the contents of organic matter and the available nitrogen, phosphorus
and potassium in soil resulting in the vigorous growth of the individual trees. Diameter at breast height (DBH) was positively
related to the contents of organic matter in the soil, and the contents of N, P and K in the tree leaves had correlation coefficients
of 0.967, 0.955, 0.988 and 0.972, respectively. Whole tree leaf area, crown width, number of branches and the mean length
of branches in the intercropped plantation (intercropped with watermelon and vegetables, peanut and winter wheat, and soybean)
were, respectively, 1.70–3.0 times, 2.22–2.47 times, 1.0–1.41 times and 1.70–2.32 times of those of CK (without intercropping).
Diameter at breast height (DBH) and tree height in the intercropped plantation were 50.5%–136.7% and 27%–59.5% higher than
those of the CK, respectively. The study also showed that intercropping with watermelon and vegetables proved to have the
highest economic return among the treatments adopted. Tree crop intercropping in young plantations is an effective measure
to increase forest growth and economic benefit.
__________
Translated from Journal of Beijing Forestry University, 2006, 28(3): 81–85 [译自: 北京林业大学学报] 相似文献
17.
Dry matter production and nutrient cycling in agroforestry systems of cardamom grown underAlnus and natural forest 总被引：4，自引：0，他引：4
A study on dry matter production and nutrient cycling in agroforestry systems of cardamom grown under N2-fixingAlnus and mixed tree species (non-N2-fixing) was carried out in the Sikkim Himalaya. The stand total biomass, and tiller number, basal area and biomass of cardamom crop was much higher under the influence ofAlnus. Annual net primary productivity ofAlnus trees was slightly higher than mixed tree species in spite of lower stand density ofAlnus. The agronomic yield of cardamom increased by 2.2 times under the canopy ofAlnus. Litter production and its disappearance rates were also higher in theAlnus-cardamom stand. Nitrogen and phosphorus concentrations of different components ofAlnus were higher than those of mixed tree species, whereas their back translocation from leaf before abscission was lower inAlnus. The cardamom based agroforestry system under the influence ofAlnus was more productive with faster rates of nutrient cycling. The poor nutrient conservation and low nutrient use efficiency ofAlnus, and malleability of nutrient cycling under its influence make it an excellent association which promotes higher availability and faster cycling of nutrients. 相似文献
18.
In Minas Gerais, Brazil, Eucalyptus plantation agroforestry techniques for small farms appear to be an adequate alternative to small-scale plantations, and by integrating timber and food production, they can meet local demands for aliment and wood. Intercropping of Eucalyptus camaldulensis with rice and beans was studied to compare yields of intercropping and monocultures over 2 years. In the first year, no differences were found in the productivity between the intercropped and monoculture systems of E. camaldulensis, rice and beans in both seasons. In the second year, E. camaldulensis in monoculture showed the lowest productivity. If compared with E. camaldulensis intercropped with agricultural crops, during the rainy season, beans intercropped with E. camaldulensis showed similar productivity when compared to monoculture. In the dry season, the productivity of beans in monoculture was higher than intercropping. In the second year, rice productivity was very low for both systems due to the lack of precipitation during the fructification phase. The equivalence area index (EAI) confirmed the advantages of the intercropping system over the monoculture system for E. camaldulensis and beans and rice, at least in the first 2 years. 相似文献
19.
Bukoba district is located in the north-western part of Tanzania and its economy is predominantly agricultural. Banana and coffee are, respectively, the most important food and cash crops. Population density is very high (500–1250 persons per km2 of cultivated land) and so is the pressure on land and other natural resources. Farm holdings (homegardens) are mostly smaller than a hectare and continue to fragment as population continues to grow. A homegarden is locally known as Kibanja and it is both a social and economic unit of farm families in the district. Various crops, trees, shrubs, herbs and livestock are managed on the same piece of land mainly by family labour to provide food, cash, medicine, shade, poles, timber and some socio-cultural functions. This paper describes the homegarden agroforestry farming system of Bukoba, evaluates its viability and identifies critical constraints as well as research needs. 相似文献
20.
Maize/cassava were intercropped between hedgerows of Senna spectabilis [(DC.) Irwin and Barneby], Flemingia macrophylla [(Willd.) Merrill] and Dactyladenia barteri [(Hook f ex Oliv.) Engl.] for five consecutive years on an Ultisol in southern Cameroon. Crop yields and hedgerow biomass production in the third to fifth year of cropping are reported. S. spectabilis produced more biomass than F. macrophylla and D. barteri in all years. Cumulative maize grain and cassava tuber yields were highest in F. macrophylla alley cropping, outyielding the no-tree control consistently by 42 to 67% (average 56%). Between hedgerows of D. barteri and S. spectabilis, crops yielded 17% and 16% more than the no-tree control, respectively. However, between S. spectabilis hedgerows, yields were highly variable between years (–15% to +35% compared to the no-tree control) and thus the system is at risk of failure. F. macrophylla is recommended for continuous alley cropping of maize/cassava intercrop. The use of D. barteri may require fallow phases for biomass accumulation followed by cropping phases with rigorous pruning. Although this may lead to lower cumulative yields, the products of the fallow phase, such as stakes and firewood, may provide some compensation.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献