Progress 09/15/00 to 09/30/05
Outputs
Eight sub-projects that formed the core of the USDA-CSREES-IFAFS-approved proposal leading to the establishment of CSTAF (Center for Subtropical Agroforestry) were undertaken: 1. At UF, Gainesville, economic studies on silvopasture focused on estimating landowners' willingness to pay for non-tangible benefits and assessing farmers' willingness to adopt the system. 2. The Southeastern Agroforestry Decision Support System, a web-based tool to assist in planning and tree/shrub selection, was developed at UF, Gainesville, with data for 12 Florida counties in the system. 3. At UF, Milton, FL, tree-crop interactions were quantified in alley cropping systems of loblolly pine, longleaf pine, and pecan, with cotton as the understory species. 4. In silvopastoral research at Ona, Florida, tree survival, wood yields, commercial value of 13 year-old south-Florida slash pine, cattle and goat production, and forage yield were determined, and factors affecting establishment of Leucaena
leucocephala, a tropical tree legume, were investigated. 5. At FAMU, Quincy, FL, silvopasture forage trials were established and run for four years. 6. Possible use of agroforestry techniques (such as organic and conventional till alley-cropping) for improving the economic viability of organic farming was investigated at the U. of Georgia, Athens. 7. Two studies were undertaken to investigate the environmental benefits of agroforestry: (i) soil runoff research at Auburn Univ., AL; and (ii) nutrient monitoring studies (based at UF, Gainesville) in the pecan/cotton intercropping plots in Milton, FL, and silvopastoral systems in different parts of FL. 8. At the U. of the Virgin Islands, St. Croix, on-farm and on-station trials investigated intercropping of Morinda citrifolia and Moringa oleifera with hot pepper and medicinal and culinary herbs. The extension component of the project developed and published a multi-media agroforestry curriculum guide for extension agents, held in-service
training workshops for extension professionals, and published on CSTAF website (http://cstaf.ifas.ufl.edu) the first case studies of a network of agroforestry demonstration sites. Publications from the project were organized as a CD and a hard-copy binder consisting of peer-reviewed journal articles (28), books (2), book chapters (6), abstracts of M. S. theses and technical reports (7) and Ph D dissertations (5), Fact Sheets (6), Newsletters (7), and other literature (19). Other CSTAF activities supported by funds from other sources included a USDA-TSTAR agroforestry research project in the U.S. Virgin Islands to develop a decision support extension tool and promote native tree planting; and developing a Web-based agroforestry distance education course at the University of Florida and an agroforestry field course at the University of Georgia as part of a USDA Higher Education Challenge grant. A third year of funding was awarded to the TSTAR project. CSTAF took an active part in
organizing and presenting the highly-successful 1st World Congress of Agroforestry held in Orlando, Florida in June-July 2004 (http://conference.ifas.ufl.edu/wca).
Impacts
Scientifically rigorous information on the economic, productive, and environmental benefits of agroforestry systems in southeastern United States are now becoming available and being disseminated to land users. Land-use decisions based on such information will help stabilize farm incomes and improve environmental conditions. A large number of undergraduate and graduate students, extension professionals, and landowners in the southeast have been trained in agroforestry.
Publications
- Publications pertaining to the subproject of S. Jose and published in 2005 are reported below:
- Allen S., Jose S., Nair P.K.R., Nair V.D., Graetz D. Brecke B.J., Ramsey C.L. 2005. Nitrogen mineralization in a pecan (Carya illinoensis K. Koch)-cotton (Gossypium hirsutum L.) alley cropping system in the southern United States. Biology and Fertility of Soils 41:28-37.
- Allen, S.C., Nair V.D., Graetz D.A., Jose S. 2005. Soil phosphorus accumulation in an alley cropping system on an Ultisol. Soil and Water Science Research Brief 01-05. Soil and Water Science Department, University of Florida, Gainesville, FL. http://soils.ifas.ufl.edu/department/briefs/sws01-05.pdf.
- Nair P.K.R., Bannister M.E., Nair V.D., Alavalapati J.R.R., Ellis E.A., Jose S., Long A.J. 2005. Silvopasture in southeastern United States: More than just a new name for an old practice. In: M.R. Mosquera-Losada, A. Riguero-Rodriquez, J. McAdam (eds.), Silvopastoralism and Sustainable Management International Congress, Lugo, Spain, April 18-24, 2004. CAB International.
- Napolitano K.E. 2005. Belowground interactions in pecan (Carya illinoensis) and loblolly pine (Pinus taeda) based alley cropping systems in the southeastern United States. MFRC Technical Report, University of Florida.
- Zamora D.S. 2005. Competitive interactions in a pecan (Carya illinoensis K. Koch) - cotton (Gossypium hirsutum L.) alley cropping system in the Southern United States. Ph.D. dissertation, University of Florida.
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Progress 10/01/03 to 09/30/04
Outputs
A four-year research project was conducted at the University of Florida to examine the competitive interactions in a pecan-cotton alley cropping system. Pecan and cotton were chosen for the study because of their social and economic importance to producers in the Southeast. The study was undertaken with the following three objectives: 1.To quantify competition for nitrogen between pecan and cotton using 15N labeled fertilizer, 2.To determine the effect of tree-crop competion on ammonfication, nitrification, and mineralization; and 3.To determine the degree to which nutrient uptake in trees affects groundwater ammoinum and nitrate levels in this system. As part of objective 1, we examined the effect of tree-crop competition for nitrogen on crop biomass, fertilizer use efficiency, and N recovery in soil. Results of this portion of the study showed that, although nitrogen was partitioned according to the competitive abilities of pecan and cotton, existing soil nutrient
levels, water availability, and temporal plant nutrient demands were also critical factors in this process. Overall, while direct competition for nitrogen fertilizer appears to have been minimal, the alley cropping system exhibits potential for nutrient capture and increased fertilizer use efficiency, given the ability of pecan trees to intercept nitrogen fertilizer and to provide litterfall to the cropping zone. Under objective 2 we studied the effect of tree roots on N transformations in soil. We observed that temporal variations in net ammonification, nitrification and mineralization were driven primarily by environmental factors (e.g., soil moisture content and soil temperature), and by initial NH4-N and NO3-N levels. Lint yield reductions were observed in no barrier during both years compared to barrier treatment, likely due to interspecific competition for water. However, for 2002, differences in yield were more pronounced than the previous year, and are indicative of a
short-lived fallow effect. Under objective 3 we examined the safety net hypothesis to determine whether tree roots were able to capture nitrate and ammonium that had leached below the root zone of cotton. In general, the presence of trees in no barrier treatment resulted in decreased soil nitrate concentrations and leaching rates compared to barrier treatment. Overall, this study reveals that the competitive presence of trees can be utilized to decrease soil nitrate concentrations and reduce nitrate leaching, provided that the system is arranged to minimize deleterious impacts on crop growth. These related studies indicate that alley cropping systems provide a unique opportunity to manage fertilizer inputs for enhanced nutrient use efficiency and groundwater mitigation, albeit site specific. The findings provide a unique contribution to our understanding of nutrient competition and groundwater nitrogen dynamics in pecan-cotton alley cropping systems. While findings are not
specifically relevant to other systems, they at least offer the scientific basis to make pecan-cotton alley cropping and similar agroforestry systems an environmentally appealing and ecologically viable option for landowners.
Impacts
The Center for Subtropical Agroforestry brings together researchers and extension educators from diverse backgrounds and institutions to work for the common goal of promoting and advancing the science and practice of agroforestry in the southeastern U.S. and elsewhere in the subtropics. As a result of the Center activities we expect to see a large number of people adopting different forms of agroforestry that are low input, sustainable systems with great potential for increased economic returns compared to traditional agriculture or forestry practices.
Publications
- Nair, P.K.R., Bannister, M.E., Nair, V.D., Alavalapati, J.R.R., Ellis, E., Jose, S., and Long A.J. 2004. Silvopasture in southeastern United States: More than just a new name for an old practice. Mosquera-Losada, M.R., McAdam, J., and Riguero-Rodriguez, A. (eds.), CABI Publishing, Wallingford, U.K.
- Zamora, D.*, and Jose, S. 2004. Aboveground competitive interactions and production physiology of a pecan (Carya illinoensis)-cotton (Gossypium hirsutum) alley cropping system in Northwest Florida. Book of Abstracts of the 1st World Congress of Agroforestry, p. 17.
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Progress 10/01/02 to 10/01/03
Outputs
This project is a subproject of FLA-FOR-03900. This progress report pertains to only the subproject that was carried out in Jay, Florida. Spatial variation in crop yield in relation to tree rows was quantified in all the trials by harvesting plots by row in October 2001. To understand the role of shading on crop productivity, diurnal pattern of photosynthetically active radiation (PAR) was measured using a Decagon AccuPAR Ceptometer along the same spatial scale mentioned earlier. Further, net photosynthesis was also measured on selected plants in each row using a LiCOR-6400 infrared gas analyzer. Spatial variation in soil water (using Water Content Reflectometry) at fixed distances away from the tree rows was quantified to assess the competitive effects of tree roots on soil water availability. Diurnal variation in whole tree and crop water uptake was measured using Dynamax stem flow gauges to quantify competition for water between trees and crops. Nutrient
competition was assessed using 15 N enriched Ammonium Sulfate fertilizer application in selected trials. Percent nitrogen derived from fertilizer, and percent utilization of fertilizer nitrogen were calculated for trees and crops to determine the degree of competition for nitrogen. Nutrient leaching down the soil profile was quantified biweekly by using ceramic cup lysimeters installed at different distances from tree rows and in monocultural systems. Changes in soil organic matter content, soil microbial biomass, and soil respiration were quantified along a chronosequence of alley cropping systems, from 3-year-old to 47-year-old.
Impacts
The Center for Subtropical Agroforestry brings together researchers and extension educators from diverse backgrounds and institutions to work for the common goal of promoting and advancing the science and practice of agroforestry in the southeastern U.S. and elsewhere in the subtropics. As a result of the Center activities we expect to see a large number of people adopting different forms of agroforestry that are low input, sustainable systems with great potential for increased economic returns compared to traditional agriculture or forestry practices.
Publications
- Lee, K.H. and Jose, S. 2003. Soil respiration and microbial biomass responses to soil water and nitrogen source in a pecan-cotton temperate alley cropping system. Eight North American Agroforestry Conference, June 22-25, Corvallis, Oregon.
- Allen, S.C., Jose, S., and Nair P.K.R. 2002. Groundwater nitrogen dynamics in a temperate alley cropping system with pecan and cotton. ASA-CSSA-SSSA Annual Meeting, November 10-14, Indianapolis, IN
- Jose, S., Gillespie, A.R., and Pallardy S.G. 2003. Interspecific interactions in temperate agroforestry. In New Vistas in Agroforestry. Nair, P.K.R., Rao. M.R., and Buck, L.E. (ed.), Kulwer Academic Publishers, Dordrecht, The Netherlands. In press (invited).
- Jose S., Allen S., and Nair P.K.R. 2003. Ecological interactions: Lessons from temperate alley cropping systems. In Agroforestry. Batish S. and Singh H.P. (eds). Haworth Press, New York. In press (invited)
- Allen, S., Jose, S., Nair, P.K.R., and Brecke, B.J. 2003. Competition for nitrogen in a pecan-cotton alley cropping system in the southern United States. Plant and Soil (in press)
- Lee, K.H. and Jose, S. 2003. Soil respiration, fine root production and microbial biomass in cottonwood and loblolly pine plantations along a soil nitrogen gradient. Forest Ecology and Management 185:263-273
- Allen, S. 2003. Nitrogen dynamics in a pecan-cotton alley cropping system in southern USA. Ph.D. dissertation, University of Florida.
- Allen, S., Jose, S., Nair, P.K.R., Nair, V.D., Graetz, D., and Ramsey, C.L. 2003. Nitrogen mineralization in a temperate alley cropping system in the southern United States. ASA-CSSA-SSSA Annual Meeting, November 2-6, Denver, CO.
- Allen, S., Jose, S., Nair, P.K.R., Brecke, B.J, and Ramsey, C.L. 2003. Experimental evidence for the safety-net hypothesis from a temperate alley cropping system. ASA-CSSA-SSSA Annual Meeting, November 2-6, Denver, CO.
- Zamora, D. and Jose, S. 2003. Competition for light between pecan and cotton in a pecan-cotton temperate alley cropping system. Eight North American Agroforestry Conference, June 22-25, Corvallis, Oregon.
- Allen, S.C., Jose, S., Nair, P.K.R., Nair, V.D., Graetz, D. 2003. Competition for nitrogen in a temperate alley cropping system with pecan and cotton. Eight North American Agroforestry Conference, June 22-25, Corvallis, Oregon.
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Progress 10/01/01 to 10/01/02
Outputs
This progress report is based on the research accomplishments of one of the subprojects under the main project. The overall progress report of the project is reported by the porject director, Nair P.K. Alley cropping trials with pecan, loblolly pine and longleaf pine with cotton planted in the alleys were used to investigate the biophysical interactions between trees and crops. Spatial variation in crop yield in relation to tree rows was quantified in all the trials by harvesting plots by row in October 2001. To understand the role of shading on crop productivity, diurnal pattern of photosynthetically active radiation (PAR) was measured using a Decagon AccuPAR Ceptometer along the same spatial scale mentioned earlier. Further, net photosynthesis was also measured on selected plants in each row using a LiCOR-6400 infrared gas analyzer. Spatial variation in soil water (using Water Content Reflectometry) at fixed distances away from the tree rows was quantified to assess
the competitive effects of tree roots on soil water availability. Diurnal variation in whole tree and crop water uptake was measured using Dynamax stem flow gauges to quantify competition for water between trees and crops. Nutrient competition was assessed using 15 N enriched Ammonium Sulfate fertilizer application in selected trials. Percent nitrogen derived from fertilizer, and percent utilization of fertilizer nitrogen were calculated for trees and crops to determine the degree of competition for nitrogen. Nutrient leaching down the soil profile was quantified biweekly by using ceramic cup lysimeters installed at different distances from tree rows and in monocultural systems. Changes in soil organic matter content, soil microbial biomass, and soil respiration were quantified along a chronosequence of alley cropping systems, from 3-year-old to 47-year-old. Another major accomplishment was the Forestry and Natural Resources Field Day conducted at the University of Florida research
farm in Jay, FL, where over 150 participants observed different alley cropping systems and learned about their ecological and economic significance.
Impacts
The Center for Subtropical Agroforestry brings together researchers and extension educators from diverse backgrounds and institutions to work for the common goal of promoting and advancing the science and practice of agroforestry in the southeastern U.S. and elsewhere in the subtropics. As a result of the Center activities we expect to see a large number of people adopting different forms of agroforestry that are low input, sustainable suystems with great potential for increased economic returns compared to traditional agriculture or forestry practices.
Publications
- Wanvestraut, R. H. 2002. Competition for water in a pecan (Carya illinoessis) and cotton (Gossypium hirsutum) alley cropping system in the southeastern United States. M.S. Thesis, University of Florida.
- Lee, K.H. and Jose, S. 2002. Soil respiration and microbial biomass in soils under alley cropping and monoculture cropping systems. Agroforestry Systems (submitted)
- Lee, K.H. and Jose, S. 2002. Nitrogen mineralization along a fertilization gradient in hardwood plantations. ASA-CSSA-SSSA Annual Meeting, November 10-14, Indianapolis, IN
- Lee, K.H. and Jose, S. 2002. Soil respiration and microbial biomass in a pecan-cotton temperate alley cropping system. ASA-CSSA-SSSA Annual Meeting, November 10-14, Indianapolis, IN
- Allen, S.C., Jose, S., and Nair P.K.R. 2002. Soil nitrogen dynamics in a temperate alley cropping system with pecan and cotton. ASA-CSSA-SSSA Annual Meeting, November 10-14, Indianapolis, IN
- Wanvestrout, R. Jose, S. and Nair, P.K.R. 2002. Competition for water in a pecan-cotton alley cropping system in southern U.S.A. ASA-CSSA-SSSA Annual Meeting, November 10-14, Indianapolis, IN
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Progress 10/01/00 to 10/01/01
Outputs
The official inaugural meeting of the Center for Subtropical Agroforestry (CSTAF) took place in Gainesville on November 14, 2000. All the investigators and collaborators attended this important meeting where administrative, research, extension and educational plans for the CSA were discussed in detail. Hiring of office personnel, research staff and graduate students have been completed during the reporting year. A website has been created to educate the public and the scientific community about the activities of CSTAF. Several new field trials are being set up as part of the CSTAF research activities. An advisory committee was also formed to guide and monitor the progress of the CSTAF activities.
Impacts
The Center for Subtropical Agroforestry will bring together researchers and extension educators from diverse backgrounds and institutions to work for the common goal of promoting and advancing the science and practice of agroforestry in the southeastern U.S. and elsewhere in the subtropics. As a result of the center activities we expect to see a large number of people adopting different forms of agroforestry that are low input, sustainable systems with great potential for increased economic returns compared to traditional agriculture or forestry practices.
Publications
- Jose, S., Gillespie, A.R., Seifert J.E., and Pope, P.E. 2001. Comparison of minirhizotron and soil core methods for quantifying root biomass in a temperate alley cropping system. Agroforestry Systems 52: 161-168.
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Progress 10/01/99 to 09/30/00
Outputs
The official inaugural meeting of the Center for Subtropical Agroforestry (CSA) took place in Gainesville on November 14, 2000. All the investigators and collaborators attended this important meeting where administrative, research, extension and educational plans for the CSA were discussed in detail. Hiring of office personnel, research staff and graduate students will be completed during the first year of the project. Several new field trials are being set up as apart of the CSA research activities. An advisory committee will be formed immediately to guide and monitor the progress of the CSA activities.
Impacts
The Center for Subtropical Agroforestry will bring together researchers and extension educators from diverse backgrounds and institutions to work for the common goal of promoting and advancing the science and practice of agroforestry in the southeastern U.S. and elsewhere in the subtropics. As a result of the center activities we expect to see a large number of people adopting different forms of agroforestry that are low input, sustainable systems with great potential for increased economic returns compared to traditional agriculture or forestry practices.
Publications
- Jose, S., Gillespie, A.R., Seifert J.E., and Pope, P.E. 2000. Comparison of minirhizotron and soil core methods for quantifying root biomass in a temperate alley cropping system. Agroforestry Systems (submitted)
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