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Wadt L. H. De O. - One of the best experts on this subject based on the ideXlab platform.
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Swidden Fallow management to increase landscape-level Brazil nut productivity.
Forest Ecology and Management v. 464 n. 118019 2020., 2020Co-Authors: Bongiolo E. S., Kainer K. A., Cropper W., Staudhammer C. L., Wadt L. H. De O.Abstract:Brazil nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden Fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase nut productivity by allowing their Fallows to grow into Brazil nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden Fallows of different ages. We also conducted interviews to determine landowner perspectives on the Fallow potential for increasing nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 Fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four Fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all Fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha?1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of Fallow. Our simulation model is the first to explore fruit productivity of Brazil nut in secondary forest. It likely underpredicts B. excelsa growth and nut production, considering that swidden Fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden Fallows could indeed translate into greater adult densities and thus potentially, higher nut production – a conclusion mirrored by most participant landowners.bitstream/item/216397/1/cpafro-18445.pd
Lucia Helena De Oliveira Wadt - One of the best experts on this subject based on the ideXlab platform.
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swidden Fallow management to increase landscape level brazil nut productivity
Forest Ecology and Management, 2020Co-Authors: Eduardo Bongiolo, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Abstract Brazil nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden Fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase nut productivity by allowing their Fallows to grow into Brazil nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden Fallows of different ages. We also conducted interviews to determine landowner perspectives on the Fallow potential for increasing nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 Fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four Fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all Fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha−1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of Fallow. Our simulation model is the first to explore fruit productivity of Brazil nut in secondary forest. It likely underpredicts B. excelsa growth and nut production, considering that swidden Fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden Fallows could indeed translate into greater adult densities and thus potentially, higher nut production – a conclusion mirrored by most participant landowners.
P L Mafongoya - One of the best experts on this subject based on the ideXlab platform.
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soil nitrogen and physical properties and maize yields after mixed planted Fallows of tree and herbaceous legumes
Nutrient Cycling in Agroecosystems, 2016Co-Authors: P L Mafongoya, Obert JiriAbstract:An experiment was conducted at Msekera Research Station from 1998 to 2002 to determine effect of planted Fallows of tree species mixed with herbaceous legumes and those of single species Fallows on biomass production, soil properties and subsequent maize grain yields. After 2 years of Fallow the highest total above ground biomass of 9.2 t ha−1 was recorded in sole Gliricidia. Pre-season soil total inorganic N in 0–20 cm soil depth under tree Fallows was highest in Sesbania + Macrotyloma axillare mixture. Sesbania + M. axillare mixture had the highest cumulative water intake at Fallow clearing. Among the 7 mixtures and 3 sole species treatments, Sesbania + M. axillare mixture produced the highest maize yield of 2.7 and 1.9 t ha−1 in 2001 and 2002 season, respectively, after 2 years of Fallow. The results of the study indicate the complementarity of herbaceous legumes and tree mixtures in improving soil quality. We conclude that mixed species have the potential to increase the amount and quantity of total N added to the soil and increase nutrient cycling. However, maize grain yields were not significantly improved as compared with single species due to low biomass production of the trees. The coiling nature and the added labour requirements for weed control would limit the use of these mixtures by smallholder farmers who are labour constrained. Agroforestry trees and non-twining legumes could be promoted instead.
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long term effects of improved legume Fallows on soil invertebrate macrofauna and maize yield in eastern zambia
Agriculture Ecosystems & Environment, 2006Co-Authors: Gudeta W Sileshi, P L MafongoyaAbstract:Abstract Though improved Fallows have been widely promoted as low-input technologies suitable for soil fertility replenishment in smallholder agriculture in southern Africa, their interaction with soil invertebrates has not been studied. In the present study we compared the population of soil macrofauna in maize grown in gliricidia (Gliricidia sepium), leucaena (Leucaena leucocephala), Leucaena diversifolia, sesbania (Sesbania sesban) and acacia (Acacia anguistissima) and continuously cropped monoculture maize. The objectives of the study were to determine (1) the effect of the type and length of Fallows on soil macrofauna communities and functional groups, and (2) the long-term effect of legume Fallows on maize yield. The number of invertebrate orders per sampling unit was significantly influenced by the type of Fallow but not by the length of Fallow period. Maize grown in legume Fallows had more numbers of invertebrate orders than monoculture maize. Among the soil invertebrate macrofauna, centipede and millipede populations were significantly influenced by Fallow type. The density of earthworms varied with both the type and length of Fallow practice. Earthworm populations under maize grown in gliricidia Fallows were significantly higher than those under fully fertilized monoculture maize. The population densities of other invertebrate orders and functional groups did not significantly differ between maize grown continuously in monoculture and in legume Fallows. The highest maize grain yield (3.0–6.0 t ha−1) was recorded in fully fertilized monoculture. Maize grown in gliricidia and leucaena Fallows consistently gave 2.0–4.0 t ha−1 throughout the study period, while maize grown without fertilizer yielded less than 2 t ha−1. These legumes produced 0.4–2.9 t ha−1 of re-sprout biomass annually, which released nutrients contributing to higher maize yields over a long period of time. It is concluded that these legume Fallows can improve maize yields in addition to their positive impact on the diversity and functions of soil invertebrates.
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mixed planted Fallows using coppicing and non coppicing tree species for degraded acrisols in eastern zambia
Agroforestry Systems, 2003Co-Authors: T S Chirwa, P L Mafongoya, R ChintuAbstract:The widespread planting of Sesbania sesban Fallows for replenishing soil fertility in eastern Zambia has the potential of causing pest outbreaks in the future. The pure S. sesban Fallows may not produce enough biomass needed for replenishing soil fertility in degraded soils. Therefore, an experiment was conducted at Kagoro in Katete district in the Eastern Province of Zambia from 1997 to 2002 to test whether multi-species Fallows, combining non-coppicing with coppicing tree species, are better than mono-species Fallows of either species for soil improvement and increasing subsequent maize yields. Mono-species Fallows of S. sesban (non-coppicing), Gliricidia sepium, Leucaena leucocephala and Acacia angustissima (all three coppicing), and mixed Fallows of G. sepium + S. sesban, L. leucocephala + S. sesban, A. angustissima + S. sesban and natural Fallow were compared over a three-year period. Two maize (Zea mays) crops were grown subsequent to the Fallows. The results established that S. sesban is poorly adapted and G. sepiumis superior to other species for degraded soils. At the end of three years, sole G. sepium Fallow produced the greatest total biomass of 22.1 Mg ha−1 and added 27 kg ha−1 more N to soil than G. sepium + S. sesban mixture. During the first post-Fallow year, the mixed Fallow at 3.8 Mg ha−1 produced 77% more coppice biomass than sole G. sepium, whereas in the second year both sole G. sepium and the mixture produced similar amounts of biomass (1.6 to 1.8 Mg ha−1). The G. sepium + S. sesban mixture increased water infiltration rate more than sole G. sepium, but both these systems had similar effects in reducing soil resistance to penetration compared with continuous maize without fertilizer. Although sole G. sepium produced high biomass, it was G. sepium + S. sesban mixed Fallow which resulted in 33% greater maize yield in the first post-Fallow maize. However, both these G. sepium-based Fallows had similar effects on the second post-Fallow maize. Thus the results are not conclusive on the beneficial effects of G. sepium + S. sesban mixture over sole G. sepium.
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effect of rotational Fallows on abundance of soil insects and weeds in maize crops in eastern zambia
Applied Soil Ecology, 2003Co-Authors: Gudeta W Sileshi, P L MafongoyaAbstract:Abstract Improved Fallows or the rotation of fast growing nitrogen-fixing legume species with cereals have been shown to accumulate nitrogen and organic matter, recycle nutrients in the soil and improve soil physical and chemical properties, and increase crop yield compared to traditional Fallows. However, the effect of soil nutrients added by Fallow species on the incidence of pests, weeds and pathogens in the subsequent crop has not been assessed in southern Africa. In this study, we assessed the relationships between nutrients in the soil after Fallows of crotalaria ( Crotalaria grahamiana ), pigeon pea ( Cajanus cajan ), sesbania ( Sesbania sesban ), tephrosia ( Tephrosia vogelii ), and their mixtures, and the incidence of soil insects, namely, snout beetles ( Diaecoderus sp.) and termites, and weeds in eastern Zambia. Rotational Fallows of sesbania+crotalaria, sesbania+tephrosia, sesbania+pigeon pea and tephrosia+pigeon pea increased infestation of maize by snout beetles as compared to the natural Fallow or unfertilised maize grown continuously in monoculture. The beetles showed aggregated spatial distribution, influenced mainly by the nitrate and total inorganic nitrogen content of the soil. Termite incidence was higher in maize after a natural Fallow and pure crotalaria, which had 11 and 7 times as much damage as maize planted after pigeon pea+tephrosia mixture. Total weed biomass in maize grown after a natural Fallow was six times higher than in maize planted after pure sesbania Fallows. The weed biomass was correlated positively with the potassium content of the top 20 cm soil and negatively with plant litter on the soil surface. It is concluded that organic inputs from pure sesbania, sesbania+pigeon pea, sesbania+tephrosia and tephrosia+pigeon pea reduce infestation by termites and weeds, and give maize grain yield comparable with the recommended rates of inorganic fertilisers. However, these Fallows have the potential to increase infestation by snout beetles. This is the first study on the snout beetle in Africa, and we recommend more systematic investigation on its ecology in agroforestry systems.
Bongiolo E. S. - One of the best experts on this subject based on the ideXlab platform.
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Swidden Fallow management to increase landscape-level Brazil nut productivity.
Forest Ecology and Management v. 464 n. 118019 2020., 2020Co-Authors: Bongiolo E. S., Kainer K. A., Cropper W., Staudhammer C. L., Wadt L. H. De O.Abstract:Brazil nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden Fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase nut productivity by allowing their Fallows to grow into Brazil nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden Fallows of different ages. We also conducted interviews to determine landowner perspectives on the Fallow potential for increasing nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 Fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four Fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all Fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha?1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of Fallow. Our simulation model is the first to explore fruit productivity of Brazil nut in secondary forest. It likely underpredicts B. excelsa growth and nut production, considering that swidden Fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden Fallows could indeed translate into greater adult densities and thus potentially, higher nut production – a conclusion mirrored by most participant landowners.bitstream/item/216397/1/cpafro-18445.pd
Eduardo Bongiolo - One of the best experts on this subject based on the ideXlab platform.
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swidden Fallow management to increase landscape level brazil nut productivity
Forest Ecology and Management, 2020Co-Authors: Eduardo Bongiolo, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Abstract Brazil nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden Fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase nut productivity by allowing their Fallows to grow into Brazil nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden Fallows of different ages. We also conducted interviews to determine landowner perspectives on the Fallow potential for increasing nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 Fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four Fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all Fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha−1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of Fallow. Our simulation model is the first to explore fruit productivity of Brazil nut in secondary forest. It likely underpredicts B. excelsa growth and nut production, considering that swidden Fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden Fallows could indeed translate into greater adult densities and thus potentially, higher nut production – a conclusion mirrored by most participant landowners.