Sustainable Agriculture and Natural Resource Management (SANREM) Knowledgebase

Permanent URI for this collection

The Sustainable Agriculture and Natural Resource Management (SANREM) Knowledgebase is a collection of information resources (books, reports, journal articles, videos, movies, presentations) produced or identified, classified, and summarized by SANREM researchers. This collection provides direct access or links to resources relevant to sustainable agriculture and natural resource management. -

Contact Information:

Feed the Future SANREM Innovation Lab
Office of International Research, Education, and Development (OIRED)
526 Prices Fork Road
Blacksburg, VA 24061-0378
Telephone: +1 (540) 231-1230
Fax: +1 (540) 231-140


Recent Submissions

Now showing 1 - 20 of 3994
  • Midyear report, SANREM CRSP Phase III: October 2008 - March 2009
    (Virginia Tech, 2009-04)
    The Sustainable Agriculture and Natural Resource Management Collaborative Research Support Program (SANREM CRSP) promotes stakeholder empowerment and improved livelihoods through the discovery, organization, and dissemination of sustainable agriculture (SA) and natural resource management (NRM) knowledge. The approach is participatory, engaging stakeholders at all levels in research problem formulation within priority areas of inquiry, focusing on multiple countries and/or regions to facilitate scaling research findings up and out. Program efforts are competitively driven and organized through a nested landscape systems approach. Gender sensitivity is integral to the SANREM approach and reinforced by gender-sensitive participant training programs that include degree and non-degree plans. All activities link sustainable NRM with the economic concerns of local populations and the promotion of good governance.
  • Conservation Agriculture Improves Soil Quality, Crop Yield, and Incomes of Smallholder Farmers in North Western Ghana
    Naab, Jesse B.; Mahama, George Y.; Yahaya, Iddrisu; Prasad, P. V. Vara (Frontiers Media, 2017-06-21)
    Conservation agriculture (CA) practices are being widely promoted in many areas in sub-Saharan Africa to recuperate degraded soils and improve ecosystem services. This study examined the effects of three tillage practices [conventional moldboard plowing (CT), hand hoeing (MT) and no-tillage (NT)], and three cropping systems (continuous maize, soybean–maize annual rotation, and soybean/maize intercropping) on soil quality, crop productivity, and profitability in researcher and farmer managed on-farm trials from 2010 to 2013 in northwestern Ghana. In the researcher managed mother trial, the CA practices of NT, residue retention and crop rotation/intercropping maintained higher soil organic carbon, and total soil N compared to conventional tillage practices after 4 years. Soil bulk density was higher under NT than under CT soils in the researcher managed mother trails or farmers managed baby trials after 4 years. In the researcher managed mother trial, there was no significant difference between tillage systems or cropping systems in maize or soybean yields in the first three seasons. In the fourth season, crop rotation had the greatest impact on maize yields with CT maize following soybean increasing yields by 41 and 49% compared to MT and NT maize, respectively. In the farmers’ managed trials, maize yield ranged from 520 to 2700 kg ha-1 and 300 to 2000 kg ha-1 for CT and NT, respectively, reflecting differences in experience of farmers with NT. Averaged across farmers, CT cropping systems increased maize and soybean yield ranging from 23 to 39% compared with NT cropping systems. Partial budget analysis showed that the cost of producing maize or soybean is 20–29% cheaper with NT systems and gives higher returns to labor compared to CT practice. Benefit-to-cost ratios also show that NT cropping systems are more profitable than CT systems. We conclude that with time, implementation of CA practices involving NT, crop rotation, intercropping of maize and soybean along with crop residue retention presents a win–win scenario due to improved crop yield, increased economic return, and trends of increasing soil fertility. The biggest challenge, however, remains with producing enough biomass and retaining same on the field.
  • A metamodeling framework for extending the application domain of process‐based ecological models
    Sparks, Adam H.; Forbes, Gregory Allan; Hijmans, R. J.; Garrett, Karen A. (2011-08)
    Process‐based ecological models used to assess organisms' responses to environmental conditions often need input data at a high temporal resolution, e.g., hourly or daily weather data. Such input data may not be available at a high spatial resolution for large areas, limiting opportunities to use such models. Here we present a metamodeling framework to develop reduced form ecological models that use lower resolution input data than the original process models. We used generalized additive models to create metamodels for an existing model that uses hourly data to predict risk of potato late blight, caused by the plant pathogen Phytophthora infestans. The metamodels used daily or monthly weather data, and their predictions maintained the key features of the original model. This approach can be applied to other complex models, allowing them to be used more widely.
  • Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach
    Soler, C. M. Tojo; Bado, V. B.; Bostick, W. Mcnair; Jones, J. W.; Hoogenboom, G. (2011-10)
    In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum–fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with observed soil organic matter (SOM) data similar to the study presented here, there are many opportunities for the application of the CSM for carbon sequestration and resource management in Sub-Saharan Africa.
  • Impacts of Cultivation and Fallow Length on Soil Carbon and Nitrogen Availability in the Bolivian Andean Highland Region
    Aguilera, Javier; Motavalli, Peter P.; Valdivia, Corinne; Gonzales, Miguel Angel (2013-11)
    Inclusion of periods of unmanaged or natural fallowing is an important soil management practice in the potato-based cropping systems of the resource-poor Andean highland region (Altiplano) of Bolivia. However, in recent years the area in fallow and the fallow length are being reduced due to greater land use intensity and competing land uses. The objectives of this study were to determine the effects of the length of cropping and fallowing periods on soil degradation or soil restoration, and to compare the potential soil carbon and nitrogen mineralization from a range of cropped and fallow lands at different elevations. Four representative indigenous communities of the semiarid central Altiplano were selected, 2 at a relatively high elevation and 2 at a relatively low elevation. Soil samples were collected in 2006 and 2007 from fields at the first, second, and third year of crop rotation and from fields with 1, 10, 20, 30, and 40 years of fallow and analyzed for several soil properties. In general, the upper elevations had significantly higher soil organic carbon, total nitrogen, inorganic nitrogen, soil test phosphorus and potassium, exchangeable calcium and magnesium, and cation exchange capacity than the lower elevations. Cropping significantly decreased total and active soil organic carbon and total, inorganic, and active soil nitrogen. Fallowing was observed to restore total and active soil organic carbon and total and active soil nitrogen more rapidly in the higher communities than in the lower communities; this difference was mainly attributed to differences in initial soil properties, climate, and land management in cropped fields with elevation. Further research may be needed to determine which factor has the most influence on soil degradation and soil fertility restoration in this environment in order to assist farmers to improve soil fertility.
  • Weed Dynamics during Transition to Conservation Agriculture in Western Kenya Maize Production
    Odhiambo, Judith A.; Norton, Urszula; Ashilenje, Dennis S.; Omondi, Emmanuel C.; Norton, Jay B. (2015-08-03)
    Weed competition is a significant problem in maize (Zea mays, L.) production in Sub-Saharan Africa. Better understanding of weed management and costs in maize inter-cropped with beans (Phaseolus vulgaris, L.) during transition to conservation agricultural systems is needed. Changes in weed population and maize growth were assessed for a period of three years at Bungoma where crops are grown twice per year and at Trans-Nzoia where crops are grown once per year. Treatments included three tillage practices: minimum (MT), no-till (NT) and conventional (CT) applied to three cropping systems: continuous maize/bean intercropping (TYPICAL), maize/bean intercropping with relayed mucuna after bean harvest (RELAY) and maize, bean and mucuna planted in a strip intercropping arrangement (STRIP). Herbicides were used in NT, shallow hand hoeing and herbicides were used in MT and deep hoeing with no herbicides were used in CT. Weed and maize performance in the maize phase of each cropping system were assessed at both locations and costs of weed control were estimated at Manor House only. Weed density of grass and forb species declined significantly under MT and NT at Manor House and of grass species only at Mabanga. The greatest declines of more than 50% were observed as early as within one year of the transition to MT and NT in STRIP and TYPICAL cropping systems at Manor House. Transitioning to conservation based systems resulted in a decline of four out of five most dominant weed species. At the same time, no negative impact of MT or NT on maize growth was observed. Corresponding costs of weed management were reduced by $148.40 ha(-1) in MT and $149.60 ha(-1) in NT compared with CT. In conclusion, farmers can benefit from effective and less expensive weed management alternatives early in the process of transitioning to reduced tillage operations.
  • Conservation Agriculture Practices in Rainfed Uplands of India Improve Maize-Based System Productivity and Profitability
    Pradhan, Aliza; Idol, Travis; Roul, Pravat K. (2016-07-15)
    Traditional agriculture in rainfed uplands of India has been experiencing low agricultural productivity as the lands suffer from poor soil fertility, susceptibility to water erosion and other external pressures of development and climate change. A shift towards more sustainable cropping systems such as conservation agriculture production systems (CAPS) may help in maintaining soil quality as well as improving crop production and farmers net economic benefit. This research assessed the effects over three years (2011-2014) of reduced tillage, intercropping, and cover cropping practices customized for maize-based production systems in upland areas of Odisha, India. The study focused on crop yield, system productivity and profitability through maize equivalent yield and dominance analysis. Results showed that maize grain yield did not differ significantly over time or among CAPS treatments while cowpea yield was considered as an additional yield in intercropping systems. Mustard and horsegram grown in plots after maize cowpea intercropping recorded higher grain yields of 25 and 37%, respectively, as compared to those without intercropping. Overall, the full CAPS implementation i.e. minimum tillage, maize-cowpea intercropping and mustard residue retention had significantly higher system productivity and net benefits than traditional farmer practices, i.e. conventional tillage, sole maize cropping, and no mustard residue retention. The dominance analysis demonstrated increasing benefits of combining conservation practices that exceeded thresholds for farmer adoption. Given the use of familiar crops and technologies and the magnitude of yield and income improvements, these types of CAPS should be acceptable and attractive for smallholder farmers in the area. This in turn should support a move toward sustainable intensification of crop production to meet future household income and nutritional needs.
  • Sustainable smallholder poultry interventions to promote food security and social, agricultural, and ecological resilience in the Luangwa Valley, Zambia
    Dumas, Sarah E.; Lungu, Luke; Mulambya, Nathan; Daka, Whiteson; McDonald, Erin M.; Steubing, Emily; Lewis, Tamika; Backel, Katherine; Jange, Jarra; Lucio-Martinez, Benjamin; Lewis, Dale; Travis, Alexander J. (2016-06)
    In Zambia's Luangwa Valley, highly variable rainfall and lack of education, agricultural inputs, and market access constrain agricultural productivity, trapping smallholder farmers in chronic poverty and food insecurity. Human and animal disease (e.g. HIV and Newcastle Disease, respectively), further threaten the resilience of poor families. To cope with various shocks and stressors, many farmers employ short-term coping strategies that threaten ecosystem resilience. Community Markets for Conservation (COMACO) utilizes an agribusiness model to alleviate poverty and food insecurity through conservation farming, market development and value-added food production. COMACO promotes household, agricultural and ecological resilience along two strategic lines: improving recovery from shocks (mitigation) and reducing the risk of shock occurrence. Here we focus on two of COMACO's poultry interventions and present data showing that addressing health and management constraints within the existing village poultry system resulted in significantly improved productivity and profitability. However, once reliable productivity was achieved, farmers preferred to sell chickens rather than eat either the birds or their eggs. Sales of live birds were largely outside the community to avoid price suppression; in contrast, the sale of eggs from community-operated, semi-intensive egg production facilities was invariably within the communities. These facilities resulted in significant increases in both producer income and community consumption of eggs. This intervention therefore has the potential to improve not only producers' economic resilience, but also resilience tied to the food security and physical health of the entire community.
  • Land Use Change, Fuel Use and Respiratory Health in Uganda
    Jagger, Pamela; Shively, Gerald E. (2014-04-01)
    This paper examines how biomass supply and consumption are affected by land use change in Uganda. We find that between 2007 and 2012 there was a 22% reduction in fuelwood sourced from proximate forests, and an 18% increase in fuelwood sourced from fallows and other areas with lower biomass availability and quality. We estimate a series of panel regression models and find that deforestation has a negative effect on total fuel consumed. We also find that access to forests, whether through ownership or proximity, plays a large role in determining fuel use. We then explore whether patterns of biomass fuel consumption are related to the incidence of acute respiratory infection using a cross-sectional data set of 1209 women and 598 children. We find a positive and significant relationship between ARI and the quantity of fuelwood from non-forest areas; a 100 kg increase in fuelwood sourced from a non-forest area results in a 2.4% increase in the incidence of ARI for children. We find the inverse effect of increased reliance on crop residues. As deforestation reduces the availability of high quality fuelwood, rural households may experience higher incidence of health problems associated with exposure to biomass burning.
  • Effect of conservation agriculture on maize-based farming system in the mid-hills of Nepal
    Paudel, Bikash; Radovich, Theodore J. K.; Chan-Halbrendt, Catherine; Crow, Susan; Tamang, Bishal B.; Halbrendt, Jacqueline; Thapa, Keshab (2014)
    Conservation agriculture (CA) systems composed of intercropping and strip tillage practices were evaluated on marginalized maize-based farming system in hill region of Nepal. On-farm experimental trials were conducted on the field of 25 smallholder farmers in three villages of central mid-hill region. Results indicated that although CA systems did not increase crop yields; higher return and revenue were generated due to increased number of crop harvests and higher price of the cash crops used in intercropping. Therefore, it was concluded that smallholder farmers should adopt CA system for increasing return and improving sustainability of the farming system.
  • Nocturnal intermittency in surface CO2 concentrations in sub-Saharan Africa
    Hicks, B. B.; O'Dell, D. L.; Eash, N. S.; Sauer, Thomas J. (2015-01-15)
    An exploratory study of CO2 concentrations and fluxes was conducted during 2013, at a site 12 km North of Harare, Zimbabwe. CO2 measurements were made over four adjacent fields of differing surface vegetation. The data illustrate the role of atmospheric intermittency as a mechanism for transferring CO2 between the surface and the atmosphere. At night, limited atmospheric mixing permits CO2 concentrations to increase to levels well above those conventionally reported (exceeding a spatial average of 450 ppm on some nights), but these high levels are moderated by a periodic intermittency that appears similar to that observed elsewhere and often associated with the presence of strong, synoptic-scale winds aloft (especially low-level jets). The availability of CO2 data with adequate time resolution facilitates investigation of the general behavior, which is suspected to be a common although rarely observed feature of the lower terrestrial atmosphere. If true, this means that the nocturnal vertical transfer of momentum, heat and mass is not solely through a constrained spectral continuum of turbulence as much as by intermittent bursts, propagating from above and penetrating the surface boundary layer. (C) 2014 The Authors.
  • SANREM News, June 2014
    (Virginia Tech, 2014-06)
    The SANREM Innovation Lab uses science to improve the livelihoods and food security of small farmers in the developing world. This issue of the SANREM newsletter includes technological advances helping farmers in Southeast Asia, a multi-functional tool designed for smallholders in Africa, and more news from Phase IV.
  • The Role of Risk Mitigation in Production Efficiency: A Case Study of Potato Cultivation in the Bolivian Andes
    Larochelle, Catherine; Alwang, Jeffrey R. (Wiley-Blackwell, 2013-06-01)
    Using a stochastic production frontier to model potato production in Bolivia, we quantify the costs of environmental and activity diversification in the form of efficiency losses and yield forgone. We find that efficiency decreases with the number of fields in a geographic cluster, distance between the dwelling and a particular field, discontinuity between fields, and off-farm income. However, environmental diversification is more detrimental than activity diversification. Using spatial analysis of field and household efficiency measures we assess production vulnerability to climatic shocks and the potential of environmental diversification in mitigating shocks. We find important spatial clusters of low and high efficiency at the field-level suggesting that climatic shocks influence efficiency measures. Household-level efficiency measures exhibit random spatial patterns suggesting that on average households can mitigate the adverse effects of shocks through environmental diversification.
  • An integrative approach for introducing conservation agriculture practices to tribal societies in India
    Halbrendt, Jacqueline; Lai, Cynthia; Chan-Halbrendt, Catherine; Idol, Travis; Ray, Chittaranjan; Evensen, Carl; Roul, Pravat K. (Honolulu, Hawaii: University of Hawaii at Manoa, Department of Natural Resources and Environmental Management, 2011)
    This poster presents the results from implimenting CAPS methods in tribal villages located in Odessa State, India. It gives socio-economic data for households in the study villages as well as project objectives and methods. It presents the results of the experimental plots and socio-economic survey data. Finally, it gives conclusions and implications for future research.
  • An integrative approach for introducing conservation agricultural practices to tribal societies in India
    Halbrendt, Jacqueline; Lai, Cynthia; Chan-Halbrendt, Catherine; Idol, Travis; Ray, Chittaranjan; Evensen, Carl; Roul, Pravat K. (Honolulu Hawaii: University of Hawaii, Department of Natural Resources and Environmental Management, 2011)
    Small-holder farms in rural India struggle with reduced maize yields due to traditional farming methods. The introduction of modern conservation agriculture practices can provide higher yields and household income while boosting soil productivity. This poster abstract presents the results of CAPS implementation on experimental plots in tribal villages located in the Indian state of Odessa.
  • Conservation agricultural practices to the tribal communities of Odisha, India
    Halbrendt, Jacqueline (University of Hawaii at Manoa, Department of Natural Resources and Environmental Management, 2011)
    This presentation introduces the SMARTS project and gives 1st year results of CAPS implementation in Odessa, India. The presentation uses yield data as well as socio-economic analysis to develop conclusions and implications for future research.
  • Conservation agriculture production systems (CAPS) poster for Orissa, India 2011
    Halbrendt, Jacqueline (Honolulu, HI: University of Hawaii, Natural Resources and Environmental Management, 2011)
    This poster illustrates how the short-term costs of CAPS implementation are outweighed by long-term benefits. The CAPS shown are specific to those implemented on trial plots in Orissa, India; minimum till, cover crops and intercropping with legumes. Specific factors mentioned include farm labor, yields, soil disturbance, and nutrition.
  • mAgri Programme Website
    The GSMA Development Fund (2011)
    This website provides information on GSMA Development Fund's mAgri and mFarmer programs. mAgri, initiated in 2009, currently supports mobile information programs in India and Kenya. The mFarmer program began in 2011 and seeks to assist over two million smallholders in gaining access to agricultural information through mobile communication services.
  • Farmers’ preference: AHP workshop and analysis
    Lai, Cynthia; Chan-Halbrendt, Catherine (Honolulu, HI: University of Hawaii, Manoa, CTHAR, 2011)
    A presentation presenting detailed steps in conducting AHP to determine tribal Indian farmers' preference for cropping strategies that improve profit, labor savings, yield, or soil quality. These strategies are in pursuit of the overall goal of improving income. This presentation served as both an explanation of AHP and a tool for administering AHP surveys in a classroom setting.
  • Introduction to SANREM / SMARTS Project
    Halbrendt, Jacqueline (Honolulu, HI: University of Hawaii, Manoa, 2011)
    This presentation provides an introduction to SANREM SMARTS Project, discusses project goals, traditional agriculture impacts on soil quality, conservation agriculture systems, which include minimum tillage, intercropping, and soil cover.