Alley Cropping Research Articles

Organic matter fraction and pools of phosphorus as indicators of the impact of land use in the Amazonian periphery

The unsustainable use of the soil of the deforested area at the Amazonian border is one of the greatest threats to the rainforest. Among the causes of land degradation in the humid tropics are phosphorus depletion (P), the decrease of soil organic matter (SOM) and the loss of basic cations. The aim of this study was determine the effects of different land uses on the dynamics of soil organic matter and phosphorus, to determine whether and how changes in the P and SOM can be used to assess the degree of land degradation in the humid tropics and whether the use of ecological systems can lessen or mitigate this degradation. Five systems were chosen according to potential use in the region: pasture of 30 years; no-tillage with 5 years of rice–maize rotations; no-tillage in alley cropping systems of 10 years; a newly cleared area; and 20 years of undisturbed secondary forest. Each field was sampled in a “W” pattern, to collect the soil samples from the chosen systems, prior to the chemical analyses. The SOM was separated by physical soil fractionation. The soil P fractionation was performed. All of the soil samples showed a very low pH range. The potential acidity was high under the alley cropping system, with more intensive and continuous use. All of the more labile fractions of organic matter decreased with the continuous use of soil in the alley cropping system. Therefore under alley cropping, most of the P (approximately 95%) was found in an inorganic form, and approximately 60% was found in the less labile fractions. The pasture and secondary forest showed higher contents of the labile fractions of organic matter and organic P. Higher correlations of organic P were found with the silt and clay fractions of organic matter. The results indicate that the fractions of P and organic matter are important indicators to assess changes in the degree of land degradation in the humid tropics. These results indicate also that the intensive and continuous use of annual crops in the soils of the humid tropics must be considered as posing a high risk to the sustainability of the agrosystems, mainly because of the increase of the active and potential acidity, the decrease of the labile organic matter and the depletion of the pools of organic P, leading to land degradation.

Crescimento, acúmulo de nutrientes e fixação biológica de nitrogênio de Flemingia macrophylla

Flemingia macrophylla é uma leguminosa arbustiva asiática, pouco conhecida no Brasil. Este trabalho objetivou avaliar a produção de massa seca, o acúmulo de nutrientes e a fixação biológica de nitrogênio (N2) de flemingia. Conduziram-se dois experimentos de campo, entre dezembro de 2006 e dezembro de 2007, em Seropédica, RJ, e em Avelar, RJ. O delineamento experimental utilizado em ambos os experimentos foi de blocos casualizados, com quatro repetições, e os tratamentos foram as diferentes épocas de amostragens. A área foliar, a produção de matéria seca e o acúmulo de nutrientes da parte aérea foram determinados em 12 coletas mensais. A contribuição da fixação biológica de N2 foi estimada pelo método da abundância natural de 15N. A massa seca da parte aérea atingiu 4,0 Mg ha-1 em Seropédica e 2,3 Mg ha-1 em Avelar, aos 360 dias após transplante (DAT). O menor crescimento em Avelar foi associado ao inverno mais frio e seco, em relação a Seropédica. A taxa de crescimento da cultura atingiu valor máximo aos 165 DAT, na primeira floração. O acúmulo de N, P, K, Ca e Mg na parte aérea foi de, respectivamente, 74, 5, 33, 25 e 8 kg ha-1 aos 360 DAT. A percentagem de N, proveniente da fixação biológica de N2 em flemingia, foi de aproximadamente 76%, o que propiciou 57 kg ha-1 de N oriundo da fixação biológica, na parte aérea, aos 360 DAT. Os resultados indicam que flemingia é uma espécie que pode contribuir com quantidades significativas de biomassa e nutrientes, especialmente N, sendo promissora para uso como adubo verde e em cultivos em aleias, em sistemas de produção.

The Importance of an Alternative for Sustainability of Agriculture around the Periphery of the Amazon Rainforest

The unsustainable use of the soil of the deforested area at the Amazonian border is one of the greatest threats to the rainforest, because it is the predominant cause of shifting cultivation in the region. The sustainable management of soils with low natural fertility is a major challenge for smallholder agriculture in the humid tropics. In the periphery of Brazilian Amazonia, agricultural practices that are recommended for the Brazilian savannah, such as saturating soils with soluble nutrients do not ensure the sustainability of agroecosystems. Improvements in the tilled topsoil cannot be maintained if deterioration of the porous soil structure is not prevented and nutrient losses in the root zone are not curtailed. The information gleaned from experiments affirms that in the management of humid tropical agrosystems, the processes resulting from the interaction between climatic factors and indicators of soil quality must be taken into consideration. It must be remembered that these interactions manifest themselves in ways that cannot be predicted from the paradigm established in the other region like the southeast of Brazil, which is based only on improving the chemical indicators of soil quality. The physical indicators play important role in the sustainable management of the agrosystems of the region and for these reasons must be considered. Therefore, alley cropping is a potential substitute for slash and burn agriculture in the humid tropics with both environmental and agronomic advantages, due to its ability to produce a large amount of residues on the soil surface and its effect on the increase of economic crop productivity in the long term. The article presents some promising patents on the importance of an alternative for sustainability of agriculture.

Redistributions of 137Cs and soil components on cultivated hill slopes with hedgerows as conservation measures

137Cs tracing technique combined with soil composition characterization was used to investigate the mechanism and effectiveness of conservation measures for cultivated hill slopes of strongly weathered acidic Acrisol. The results of analysis of 66 soil samples taken across six plots showed much lower losses of 137Cs, soil organic carbon (SOC), and nutrients in the four treatments of alley cropping with hedgerows compared to the two control treatments of bare land and without conservation measures. No-tillage cultivation combined with vetiver grass hedgerows was most effective in securing high levels of 137Cs, SOC, N, P, K, and CEC while reducing considerably the contents of dissolved cations and anions. Within the plots of alley cropping, 137Cs, SOC, nutrients, dissolved ions, and sand were accumulated in the areas immediately upslope of the hedgerows, whereas the clay content and bulk density were highest downslope of the hedgerows. SOC inversely correlates with clay in concurrence with observations for the soils derived from basaltic parent materials, in which clay minerals are predominated by kaolinite. The correlations of 137Cs with dissolved Ca, Mg, and P indicate that in the highly leaching Acrisol 137Cs may partly occur in the soil solution that is susceptible to leaching and loss. The interrelationships among soil components were interpreted as being driven by the redistribution of soil aggregates which were fractionated in situ according to their sizes and specific densities by erosion forces combined with tillage and conservation measures (hedgerows).

Assessing Light Competition for Cereal Production in Temperate Agroforestry Systems using Experimentation and Crop Modelling

AbstractIn every agroforestry system, the tree canopy reduces the incident radiation for the crop. However, cereal varieties were selected, and most crop growth models were designed for unshaded conditions, so both may be unsuited to agroforestry conditions and performance. In southern France, durum wheat productivity was monitored over 2 years in an agroforestry system including walnut trees and under artificial shade conditions. Yield components were measured in both full and reduced light conditions. The cereal yield was always decreased by shade; by almost 50% for the heaviest shade conditions (31% of light reduction). The main effect of the shade was the reduction in the number of grains per spike (35% at the most) and in the weight of grains (16% at the most). The mean grain weight was moderately affected, while the protein content was increased in shaded conditions (by up to 38% for artificial shade). Consequently, the protein yield per hectare was less reduced by the shade than the dry matter grain yield. A crop model (STICS) was also used to simulate the crop productivity in full light and shaded conditions, but the crop LAI and the yield components were not correctly simulated in the shade. The simulations emphasized the sensitivity of the wheat grain filling to shade during the critical period, 30 days before flowering, for yield elaboration. Further experimental and modelling studies should take into account the heterogeneity of shade intensity due to the shape of the tree crown, the width of the crop alley and the orientation of the tree rows and the modification of carbon allocation inside the plant.

Agroforestry: a profitable land use. An overview of the 12th North American Agroforestry Conference

This special issue features papers contributed by presenters at the 12th North American Agroforestry Conference held June 4–9, 2011 in Athens, Georgia, USA. The conference brought together agroforestry researchers, educators, practitioners, and students to highlight agroforestry research, implementation, policy, education, and entrepreneurial opportunities across North America. Eight papers cover topics ranging from adoption of silvopastoral systems across eco-regions and countries; economics of pine straw production; and timber and alley crop production in the Southeastern U.S.; reduction of sublimation of snow with shelterbelts in Canada, carbon offset incentives for agroforestry practices; consumer and market dynamics for chestnut and elderberry specialty crops; and web-based graduate degree and certificate programs in agroforestry.

English

Alley cropping; Maize intercropped with fruit trees (MIFT), is a system of technified agro forestry cultivation of central Mexico. MIFT is one of the most feasible cultivation systems to show the biodiversity richness of the country; however, the effect this system exercises on the soil organisms has not been measured, whereby the macrofauna, mites and collembolans from the furrows of perennial production (Prunus persica) and from the middle part dedicated to annual species (Zea mayz, Capsicum annum, Medicago sativa) have been sampled,  considering 4 MIFTs of the dry and plane environment of Puebla, plus another 4 of the humid and hillside environment of Oaxaca; and the forest of both regions as a control. Results showed that abundance and biomass were greater in ants and worms, respectively; while in Oaxaca, the greatest values were in diplopods. In both regions, the density and the biomass of macrofauna and with the m/m+s index, showed the gradient “Forest-MIFT”, with lower values in Puebla; only Oaxaca showed more favorable conditions for edaphic biota, possibly due to handling of organic materials (OM). According to our results, in Puebla there are opportunities to stimulate the diversity and the population of edaphic biota through OM handling and to achieve a MIFT which takes advantage of the capacity for nutrient recycling of soil organisms and impacts on fertility restoration.   Key words: Edaphic biota, macrofauna, alley cropping, maize intercropped with fruit trees (MIFT).

Morphological response of Vitex negundo var. heterophylla and Ziziphus jujuba var. spinosa to the combined impact of drought and shade

Light and soil moisture availability are two important abiotic factors influencing plant growth in an agroforestry system. Different soil moisture and light treatments were applied to examine the combined impact of drought and shade on the morphological plasticity of Vitex negundo var. heterophylla (Chinese chastetree) and Ziziphus jujuba var. spinosa (Spine jujube). We found that the interaction of light and soil moisture was orthogonal in the two species. V. negundo captured irradiance efficiently with relatively long petiole and petiolule, while Z. jujuba maintained higher branches to absorb light than V. negundo. Compared to the seedlings under full sunlight, the palmately compound leaves of V. negundo under low light showed larger specific leaf area (SLA), lower ratio of leaflet length to width and higher leaf mass ratio (leaf biomass to total biomass); in contrast, the simple leaves of Z. jujuba under low light showed larger SLA and ratio of leaf length to petiole length. In both species, drought reduced the branch number, mean internode length of stem, and increased root mass ratio (root biomass to total biomass), but leaf morphology showed little variation to the decreased soil moisture. Between the two species, V. negundo is more shade-tolerant, while Z. jujuba is more drought-tolerant. In an alley cropping system, the spacing can be smaller in the V. negundo-crop system than the Z. jujuba-crop system when soil moisture is adequate. However, the V. negundo-crop system should be managed with more caution under the soil moisture limited conditions.

Agroforestry strategies to sequester carbon in temperate North America

Information on carbon (C) sequestration potential of agroforestry practices (AP) is needed to develop economically beneficial and ecologically and environmentally sustainable agriculture management plans. The synthesis will provide a review of C sequestration opportunities for AP in temperate North America and the estimated C sequestration potential in the US. We estimated carbon sequestration potential for silvopasture, alley cropping, and windbreaks in the US as 464, 52.4, and 8.6 Tg C yr−1, respectively. Riparian buffers could sequester an additional 4.7 Tg C yr−1 while protecting water quality. Thus, we estimate the potential for C sequestration under various AP in the US to be 530 Tg yr−1. The C sequestered by AP could help offset current US emission rate of 1,600 Tg C yr−1 from burning fossil fuel (coal, oil, and gas) by 33 %. Several assumptions about the area under different AP in the US were used to estimate C sequestration potential: 76 million ha under silvopasture (25 million ha or 10 % of pasture land and 51 million ha of grazed forests), 15.4 million ha (10 % of total cropland) under alley cropping, and 1.69 million ha under riparian buffers. Despite data limitation and uncertainty of land area, these estimates indicate the important role agroforestry could play as a promising CO2 mitigation strategy in the US and temperate North America. The analysis also emphasizes the need for long-term regional C sequestration research for all AP, standardized protocols for C quantification and monitoring, inventory of AP, models to understand long-term C sequestration, and site-specific agroforestry design criteria to optimize C sequestration.

The potential for carbon offset trading to provide added incentive to adopt silvopasture and alley cropping in Missouri

Global carbon trading may present a unique opportunity to change the rural landscape by allowing landowners to make an environmental impact with financial incentives. By enticing point source polluters to trade to an optimal level of pollution by offsetting their emissions with compatible carbon reduction projects, markets are able to facilitate a cleaner environment. Agroforestry provides a set of practices that can sequester carbon with managed tree and crop plantings. However, the initial lack of financial resources has been an obstacle to its adoption in the United States. This paper explores the potential for carbon offset trading to provide an added incentive to adopt agroforestry practices. Chicago Climate Exchange carbon sequestration projects are used as a baseline assessment, and the requirements that Missouri landowners would need to do in terms of contracting and ownership are identified. Data from landowners in central Missouri and the Ozarks (353 individuals) are used to determine characteristics of potentially interested landowners in agroforestry. A model to evaluate agroforestry profitability scenarios is used to compare the added carbon credit trading revenue to traditional alternate uses for the property. The findings from this analysis indicate that in the current context carbon trading does not provide an added incentive value for Missouri landowners to adopt either silvopasture or alley cropping practices because of the low magnitude of annual return.

Effect of root competition and shade on survival and growth of nine woody plant taxa within a pecan [Carya illinoinensis (Wangenh.) C. Koch] alley cropping system

Suitability for production of woody floral stems in a pecan [Carya illinoinensis (Wangenh.) C. Koch] alley cropping was determined for nine shrub species in northwest Florida. Treatments included partial shade without root competition, partial shade with root competition, and full sun. Only three species had high rates of survival for all treatments throughout both years of the study: Callicarpa americana L. (American beautyberry), C. americana var. Lactea (white American beautyberry), and Crataegus marshallii Eggl. (parsley haw). For C. americana, plant growth index increased through time and was similar among the three treatments, indicating that this species grew equally well in sun or shade irrespective of root competition from the tree crop. C. americana var. Lactea had similarly high rates of survival and grew largest in partial shade without root competition (81.7 cm) compared to partial shade with root competition (67.2 cm) and full sun (57.0 cm). C. marshallii had 100 % survival in partial shade without root competition, with one mortality in partial shade with root competition (91.7 % survival) and one in full sun (91.7 % survival). Growth index did not increase over time and was similar among all three treatments. Other species tested had low rates of survival in all treatments throughout both years of the study and included: Ilex glabra L. (inkberry), Ilex myrtifolia Walt. (myrtle-leaf holly), Hydrangea paniculata Seibold var. ‘Tardiva’ (panicle hydrangea), Hydrangea quercifolia Bart. (oakleaf hydrangea), Lyonia lucida (Lam.) K. Koch, and Salix matsudana Koidz. F. tortuosa Rehd. (corkscrew willow). No species produced sufficient flowers, fruits or ornamental stems during this establishment period to allow a florist evaluation of the stems for use as woody floral stems.

Biomass production for biofuels using agroforestry: potential for the North Central Region of the United States

As demand for energy increases in the United States, alternative energy sources are being sought both domestically and abroad. Biofuels have been promoted as a major source of alternative energy, but sustainable supply of biomass still remains a major challenge. Agroforestry offers a potential way to integrate perennial woody bioenergy crops with traditional agricultural crops to satisfy energy demands without sacrificing food production in the North Central Region of the United States. We suggest shelterbelts, alley cropping and working riparian buffer strips as ideal candidates for biomass production in agroforestry settings in this region. In addition to satisfying domestic energy demands, these systems could also potentially increase water quality, sequester carbon, improve aesthetics, and provide critical wildlife habitat. However, obstacles to implementing agroforestry systems for biomass production, such as a competitive price structure and stable markets, must be overcome before large-scale adoption by landowners.

Nutrient input on rocket growth and soil microbial activity in alley cropping of pigeon pea

The effects of organic fertilization combining cattle manure and pigeon pea shoots on the culture of rocket, planted with one or two plants per hole, including soil microbial biomass carbon, soil respiration, the metabolic quotient, soil fumigation labile carbon, and the dry matter content and total N, K, P, Ca and Mg contents in the leaves and roots of rocket were investigated. The experimental design was randomized blocks in a 2 × 2 × 2 factorial experiment: 0 and 160 kg ha-1 N from cattle manure, 0 and 160 kg ha-1 N from pigeon pea shoots, and one or two plants per hole, with three replicates. The most significant and positive correlations were obtained between leaf K × soil respiration, microbial biomass × leaf N and root Ca × metabolic quotient. The use of 160 kg ha-1 N from cattle manure along with 160 kg ha-1 N from pigeon pea shoots with two plants per hole resulted in a lower relative loss of C-CO2; the same result was found for the treatment of two plants per hole fertilized with 160 kg ha-1 N from cattle manure. Increased leaf and root N contents were observed in the treatment that combined two plants in each plot, fertilized with 160 kg ha-1 N from pigeon pea shoots, whereas the highest dry matter content was obtained by using one plant per hole, specifically: combining one plant per hole without fertilization; one plant per hole fertilized with 160 kg ha-1 N from pigeon pea shoots; and one plant per hole fertilized with 160 kg ha-1 N from cattle manure and pigeon pea shoots.

Economics of intercropping loblolly pine and switchgrass for bioenergy markets in the southeastern United States

The main objective of this study was to assess the economics of alley cropping of loblolly pine (Pinus taeda L.) and switchgrass (Panicum virgatum) in the southern United States. Assuming a price range of switchgrass between $15 and $50 Mg−1 and yield of 12 Mg ha−1 year−1, we investigated the effect of switchgrass production on the optimal forest management for loblolly pine stands under different stumpage prices. We considered the following potential scenarios: no competition between species for resources; reduced loblolly pine productivity due to competition with switchgrass; and reduced productivity of both species due to competition for nutrients, water and light. Findings also suggested that the optimal system would depend on the competitive interactions between switchgrass and loblolly pine crops, and the expected prices for each crop. Loblolly pine monoculture would be the most profitable option for landowners compared to intercropping systems with switchgrass below $30 Mg−1. However, when switchgrass prices are ≥$30 Mg−1, landowners would be financially better off adopting intercropping if competitive interaction between crops were minimal. In order to realize higher economic returns for intercropping system, forest landowners must make some efforts in order to diminish the decline of productivity.

The barrier to women involvement in agro forestry and role of oil palm in Nigeria

The problem of high rate of deforestation of the country�s natural resource caused by population growth and economic pressure necessitates interest in agroforestry to encourage sedentary agriculture and rejuvenate degraded soils. The study therefore aims at assessing the constraint to the utilization of women knowledge of agroforestry in Oluyole local government area of Oyo State and the role of oil palm in these practices. The study was done randomly by sampling and interviewing an average of 25 women farmers in each of the 4 wards selected from 10 wards in the local government, giving a total sample size of 100 respondents. The results show that the main constraint in the practice of both border planting and shifting cultivation is land. This makes the practice of �taungya system� very difficult for most of the women. Meanwhile, the only constraint to the practicing of alley cropping is the shade the tree casts on the crop when it is matured, while the practice of grazing is hindered by the diseases that attack the livestock. About 16% of the respondents perceived agroforestry benefit is low, 69% belongs to the medium perception while 15% perceived agroforestry has high benefits. The results indicate that some are engaged in both farming and non-farming activities for livelihood.

Temporal and compositional differences of arbuscular mycorrhizal fungal communities in conventional monocropping and tree-based intercropping systems

Previous research has found that conventional agricultural systems adversely affect arbuscular mycorrhizal (AM) fungi. However, there is little information on how more ecologically sustainable agricultural practices such as tree-based intercropping (TBI) influence AM fungal communities. In this study, we investigated whether TBI promotes a more abundant and diverse AM fungal community compared to conventional monocropping (CM). Abundance was estimated by measuring spore abundance and hyphal length in soil, and AM fungal colonization of corn (Zea mays) roots. Overall, AM fungal abundance was similar in both systems as corn roots from the CM and TBI systems were heavily colonized (>50%) by AM fungi throughout the growing season. Additionally, soil samples from the CM and TBI systems contained similar spore densities and hyphal length. Molecular analysis of the AM fungal community was assessed using terminal restriction fragment length polymorphism (T-RFLP) analysis of large subunit rRNA genes amplified from roots in the two cropping systems. A total of fourteen AM fungal phylotypes that belonged to the Glomeraceae were found in the two cropping systems. The TBI system had a higher AM fungal richness and contained several taxa not found in the CM system. Molecular analysis of AM fungal communities also revealed significant temporal and compositional differences between the TBI and CM systems. Within the TBI system, tree species differentially influenced the AM fungal community composition in the alley cropping regions. Future research should focus on determining whether compositional differences among AM fungal communities in CM and TBI systems have a functional effect on crop growth and productivity.

Water use assessment in alley cropping systems within subtropical China

Alley cropping systems may influence soil water movement and the water budget because of its complex interactions between crop and tree rooting systems. The objective of this paper was to evaluate water balance and water competition in an alley cropping system, consisting of deciduous tree wild jujube (Choerospondias axillaris) and economic crop peanut (Arachis hypogaea) within subtropical China. Five treatments (20- by 6-m plots) with three replications were included in this study. The treatments were monoculture peanut cropping (P), monoculture younger trees (T1), monoculture older trees (T2), peanut intercropped with younger trees (T1P), and peanut intercropped with older trees (T2P). A multi-layered water balance model, with water movement between soil layers, was implemented by the measurement of soil water potential using sets of tensiometers during the periods from March 1999 to December 2002. The spatial and temporal variations of soil water regime indicated that the trees used soil water below the 60-cm soil depth and alleviated the water stress. The direction of soil water movement indicated that soil water moved to the tree row, which indicated that trees competed with peanuts for water, especially during the seasonal drought period. Water competition was related to the tree spacing and tree age. Compared to the tree monoculture systems, the alley cropping system significantly influenced water budget components and water use patterns, as indicated by the increased evapotranspiration (6–11%), and decreased net drainage (7–45%), water storage (6–29%), and runoff (50–60%). Furthermore, alley cropping systems encouraged the rapid growth of trees, and depressed the biomass and yield of peanuts by 20–50% associated with tree shading effects. The results suggest that competition for water and light must be taken into account when optimizing the alley cropping system.

KONSERVASI LAHAN MELALUI PENERAPAN TEKNOLOGI BUDIDAYA LORONG (ALLEY CROPPING) DI DAERAH TRANSMIGRASI KURO TIDUR, BENGKULU

The research of land productivity through the application of alley cropping has been carried out in transmigration area Kuro Tidur, Bengkulu. The research was done continously within three planting seasons, from 1997 to 1998. The results of the research showed that Flemengia congesta as a fence crop or hedgerows was beneficial. The returning of organic matter from prunning of the hedgerows into the soil can conserve the soil through improvement of nutrients availability, increasing pH, decreasing availability of aluminium (Al) by chelate formation. The effect of dolomit 2,5 ton/ha and organic matter 5,0 ton/ha will increase soy beans production 28,9 % and increase corn production 33,1 %. The effect of dolomit 2,5 ton/ha and organic matter 10,0 ton/ha will increase soy beans production 38,6 % and increase corn production 54,9 %.

Desempenho da gliricídia no cultivo em aleias em pomar orgânico de mangueira e gravioleira

Foi estabelecido um sistema de cultivo em aléias de gliricídia em um pomar orgânico de mangueira e de gravioleira de um ano, no município de Campos dos Goytacazes-RJ-Brasil. Os objetivos do trabalho foram avaliar a sobrevivência e o desempenho da gliricídia no cultivo em aléias, quanto à produção de fitomassa seca e ao fornecimento de nutrientes ao sistema. A gliricídia apresentou elevada sobrevivência (93%). A média anual de produção de fitomassa seca e de adição de nutrientes ao sistema foi maior no segundo ano de avaliação (2007) do que no primeiro ano (2006), ambos com de três podas anuais que se adequaram às épocas recomendadas para a adubação das frutíferas, especialmente a gravioleira. A quantidade de N adicionada ao pomar com as podas da gliricídia foi maior que a adubação recomendada para mangueira e gravioleira. Por outro lado, a quantidade de P e K adicionada ao pomar não foi suficiente para suprir a adubação demandada para ambas as culturas.A gliricídia apresentou bom desempenho nas condições do experimento, com potencial de uso contínuo no sistema e possibilidade de aproveitamento dos nutrientes disponibilizados no sistema pelas frutíferas. Contudo, mais avaliações são necessárias ao longo do tempo para verificar a sustentabilidade do consórcio.

Effect of pruning frequency and pruning height on the biomass production of Tithonia diversifolia (Hemsl) A. Gray

Addition of tree or shrub prunings through alley cropping or biomass transfer systems have contributed to sustainable land-use systems in the tropics. Long term productivity of biomass transfer systems require shrub or tree species that coppice after cutting to provide sufficient plant nutrients. The effect of pruning frequency and cutting height on the biomass production of Tithonia diversifolia was studied to provide information for managing hedges. Results showed that height of cutting, pruning frequency, and their interactions significantly affected dry matter production of T. diversifolia. The results also showed that a significantly higher biomass production could be produced when Tithonia was pruned at long time intervals. Pruning height was also of importance in the harvesting of Tithonia biomass and it was evident that dry matter production was highest when Tithonia was pruned bimonthly at 50 cm height. With bi-monthly pruning frequency, dry matter production could be as high as 7.2 t ha−1 yr−1 which might be a sufficient biomass to improve soil productivity in biomass transfer systems.