Experimental Agriculture

Published by Cambridge University Press (CUP)
Online ISSN: 1469-4441
Print ISSN: 0014-4797
Publications
Over a period of seven years farmers participated in trials in which common vetch (Vicia sativa (V)) or chickling (Lathyrus sativus (C)) replaced the fallow in a barley (Hordeum vulgare)–fallow rotation (F) or were introduced into continuous barley cropping (B) – giving a total of four rotations, B–F, B–B, B–V and B–C. Trials on 4 ha, 2 ha per phase of each rotation, were replicated on 6–8 farms. Some vetch and chickling crops were grazed in spring. Mean seven-year dry matter yields were 2.91 t ha−1 for B–F, 4.82 t for B–B, 5.02 t for B–C and 5.32 t for B–V; total crude protein outputs were twice as high from rotations including legumes; and the B–V rotation yielded most metabolizable energy. Realizing the benefit, farmers started to adopt vetch. In 1991 three farmers were growing vetch on 7 ha but by 1997 174 farmers in 15 villages were growing vetch on 420 ha. Forage legumes will not, however, become more widely grown until inexpensive and efficient mechanized methods of harvesting the mature crop are available in order to avoid the high cost of hand labour. Drought and cold tolerance, early maturation and high harvest index may also enhance farmers' interest in forage legumes.
 
Dry matter production and partitioning in old clonal tea bushes pruned and maintained at different heights were investigated. New tissues (leaves, new branches and small roots) consti- tuted a small fraction of the total dry matter in all bushes pruned and initially maintained at 70, 40, 25 and 10 cm high, 36 months after pruning. Leaf/frame dry matter ratio was larger and the shoot/root and frame/root ratios were smaller in the bushes initially maintained at 10 cm than in the bushes maintained at other heights. Yields per unit area of the plucking surface were greatest in the smallest bushes initially maintained at 10 cm in 42 months of recording but on the basis of the available space they were greatest in the large bushes initially maintained at 70 cm.
 
Glasshouse and field trials have been used to assess the effect of applying calcitic lime and gypsum on haulm weight, pod-filling and kernel yield of groundnuts grown in soils of Northern Malawi. Incorporation of lime prior to planting and topdressing gypsum at flowering both rectified poor pod-filling and improved kernel yield. Gypsum decreased haulm weight and usually produced lower overall kernel yield than lime. The relative merits of lime and gypsum application are discussed, together with the need for supplementation by phosphorus and sulphur.
 
To assess genotype adaptability to variable environments, we evaluated five irrigated rice genotypes, three new varieties, WAS161, a NERICA, IR32307 and ITA344, and two controls: Sahel 108, the most popular short-duration variety in the region, and IR64. In a field experiment conducted at two locations, Ndiaye and Fanaye, along the Senegal River, rice was sown on 15 consecutive dates at one month intervals starting in February 2006. Yield (0–12.2 t ha−1) and crop cycle duration (117–190 days) varied with sowing date, genotype and site. Rice yield was very sensitive to sowing date and the associated temperature regimes. Spikelet sterility due to cold stress (T < 20 °C) was observed when the crops were sown in August (Ndiaye), September (Ndiaye and Fanaye) and October (Ndiaye and Fanaye), and heat stress (T > 35 °C) resulted in spikelet sterility when sowing took place in April (Ndiaye and Fanaye) and May (Fanaye). For all experiments the source and sink balance was quantified and showed that yield was most limited by sink size when sowing between July and October. Variety WAS 161 was least affected by genotype × environment interactions, resulting in lower interactive principal component values. An increase in minimum temperature of 3 °C could decrease spikelet sterility from 100 to 45%. These changes in temperature are likely to force rice farmers in the Senegal River to adjust the cropping calendar, e.g. to delay planting or to use heat-tolerant genotypes.
 
Characteristics of 45 farmers participating in the hedgerow intercropping trial 
Average annual dry biomass yield (t ha 71 )and nutrient yield (kg ha 71 ) of hedgerow prunings and stem for the ®rst two years of production on 24 farms Prunings Stem 
The biophysical performance of hedgerow intercropping for soil fertility inprovement was assessed in a farmer-participatory trial in western Kenya over three years. Farmers successfully established dense hedgerows (median 6680 trees ha4 t ha8 t ha−1). The hedgerows reduced slopes from 7.2 to 4.5% within alleys (p < 0.01) but had no effect on grain yield over five seasons. Little of the variation in grain yield between hedgerow plots and control plots without hedgerows (adjusted r2 = 11%) and among control plots (adjusted r2 = 29%) could be accounted for by linear regression with measured agronomic and socio-economic variables. Fully researcher-managed trials are recommended for agronomic evaluation of complex agroforestry technologies.
 
Manure is a key input to smallholder farming systems, especially in the semi-arid environment of West Africa where cost and availability limit the use of inorganic fertilizers. This paper considers manure management by farmers in an intensive integrated farming system in the Nigerian savanna. The paper reports farmers' indigenous knowledge concerning manure production, quality and application, chemical analysis of manure nutrient content and application rates of manure. The potential manure supply of the livestock population of the Kano close-settled zone is calculated and compared with application rates. Recommendations are made concerning methods for improving manure quality through changes in management practices.
 
Relationship between concentrations of Sr and Ca in leaves of control plants exposed only to native soil Sr ( n = 52). Data are from young mature leaf samples ( ᭹ ) and older leaf samples ( ᭜ ) from all sampling dates. 
Strontium was used as a tracer to detect root activity of yam (Dioscorea alata) at distances from 0.5 to 5.5 m from the plant's crown, and at depths of 7, 15, 25 and 40 cm, in field plantings separated by plastic root barriers. Tracer bands were installed at planting, and leaves were sampled at intervals throughout the growing season. Background Sr concentrations in leaves were found to be closely related to leaf Ca concentrations, allowing the expected background Sr to be calculated from the Ca concentration in each sample. The ratio of observed to expected Sr did not alter significantly with time of sampling or leaf age for control plants providing a robust parameter for comparison across harvests. Plants at all horizontal distances from the Sr placement up to 5.5 m showed significant elevation of leaf Sr by 13 weeks after planting (WAP). The depth placement at 15 cm showed earliest Sr elevation, followed by the 7 cm placement. However, both 25 cm and 40 cm placements resulted in significant leaf Sr elevation by 13 WAP, and their final Sr concentrations at 27 WAP did not differ significantly from those of shallower placements. Three fertilizer placement options were compared with respect to Sr uptake by the treated plants and by those in adjacent rows. Placement in a ring around the crown of the seed sett resulted in high leaf Sr concentration at 5 WAP, declining considerably at subsequent samplings. Placement underneath the seed sett produced a similar pattern but at lower concentrations. Banding midway between the plant rows, 0.5 m from plants, yielded a small increase at 5 WAP increasing to 13 WAP, and ultimately attaining similar concentrations to the other two placements. Plants in adjacent rows significantly accessed all three placements by 13 WAP. The results indicate greater reach of yam roots, both horizontally and vertically, than has been previously reported, and raise concerns about the adequacy of treatment separation in previously published fertilizer experiments with yams.
 
At doses of 75 mg./kg. given per os, Neguvon was ineffective against Sarcoples scabiei var. Auchenidae. Benzene hexachloride (BHC) per os was ineffective at doses of 20 mg./kg. and killed alpacas when the dose was increased. Spraying the lesions with BHC killed the acari and lesions quickly disappeared. Psoroptes communis, the cause of otitis in alpacas, was equally susceptible to spraying. Lesions and their location are described and attention is drawn to the possible role of acari in nostrils and perinea in the epidemiology of the disease. Dipping is, at present, the only method of cure worth using, but the search for systemic acaricides should be continued.
 
Production possibility frontiers contribute much to an economic evaluation of yield advantages from intercropping. The difficulty with estimating a production frontier empirically from experimental data is one of ascertaining that the fitted curve corresponds with the frontier. This problem has been overcome by deriving the frontier from a priori knowledge of the biological processes that determine the outcome in intercropping. The hyperbolic relationship between biomass yield and plant density, and the parameters that characterize the degree of intra-and inter-specific competition in intercropping are used in this paper to derive production possibility frontiers. The method is illustrated with data from three intercropping studies. A brief review of the two main methods used by researchers to evaluate the results of intercropping, and their limitations, is also presented.
 
Internal browning disorders, including brown fleck (BF), in potato (Solanum tuberosum) tubers greatly reduce tuber quality, but the causes are not well understood. This is due, in part, to the highly variable data provided by visual value-based rating systems. A digital imaging technique was developed to quantify accurately the incidence of internal browning in potato tubers. Images of tuber sections were scanned using a flatbed scanner and digitally enhanced to highlight tuber BF lesions, and the area of affected tissue calculated using pixel quantification software. Digital imaging allowed for the determination of previously unused indices of the incidence and severity of internal browning in potato tubers. Statistical analysis of the comparison between digitally derived and visual-rating BF data from a glasshouse experiment showed that digital data greatly improved the delineation of treatment effects. The F-test probability was further improved through square root or logarithmic data transformations of the digital data, but not of the visual-rating data. Data from a field experiment showed that the area of tuber affected by BF and the number of small BF lesions increased with time and with increase in tuber size. The results from this study indicate that digital imaging of internal browning disorders of potato tubers holds much promise in determining their causes that heretofore have proved elusive.
 
Cotton seedling stand (%) as a function of mulch and seed dressing under two cover crops.
Cotton seedling vigour according to mulch presence and seed dressing under two cover crops. 
Dynamics of aphid infestation according to mulch presence and seed dressing.
The present study evaluated the pest constraints of an innovative crop management system in Cameroon involving conservation tillage and direct seeding mulch-based strategies. We hypothesized that the presence of mulch (i) would support a higher density of phytophagous arthropods particularly millipedes as well as pathogenic fungi that cause severe damage to cotton seedlings and (ii) would reduce early aphid infestations. The impact of two cover-crop mulches Calopogonium mucunoides and Brachiaria ruziziensis on the vigour of seedling cotton stands and arthropod damage was assessed in two independent field experiments conducted in 2001 and 2002 respectively. In both experiments the presence of mulch negatively affected cotton seedling stand by 13–14% compared to non-mulched plots and the proportion of damaged seedlings was higher in mulched than in non-mulched plots supporting the hypothesis that mulch favoured soil pest damage. In both experiments insecticidal seed dressing increased the seedling stand and the number of dead millipedes collected and fungicide had little or no effect on seedling stand and vigour. It was however observed in 2002 that the fungicide seed dressing had a positive effect on seedling stand in non-mulched plots but not in mulched plots suggesting that fungi may have been naturally inhibited by B. ruziziensis mulch. The dynamics of aphid colonization was not influenced by the presence of mulch. In 2001 taller seedlings were found in mulched than non-mulched plots probably due to greater water and nutrient availability in C. mucunoides-mulched plots than in non-mulched plots
 
Plectranthus edulis (syn. Coleus edulis) is a tuber-bearing labiate species cultivated in parts of southern Ethiopia. To learn about traditional cultural practices and their rationale, a survey was conducted among farmers from Chencha and Wolaita experienced in growing this crop. A pre-tested questionnaire was used to interview 48 family heads categorized into three wealth groups per site. Information was checked through group discussions and field observations. In Wolaita, poorer farmers cropped a larger portion of their land to P. edulis than richer farmers. Land was usually prepared for planting between January and April. In Wolaita, the crop was mostly grown in a furrow. In Chencha growing in patches and on flat land also occurred. Farmers mostly used a digging hoe for land preparation. Tuber pieces were planted about 5 cm deep. According to farmers, using tuber pieces resulted in more stems, more progeny tubers and higher yields than using whole tubers. Tubers were broken into pieces 0¿1 day before planting. Tuber pieces were planted with sprouts or after desprouting. Crops were usually fertilized with manure, but in Wolaita sometimes also with compost. Applying fertilizer was thought to give more and bigger tubers. Earthing up took place 1¿3 times (usually twice), to increase yield. Tipping was also done 1¿3 times (usually once), to increase the number of stems. Based on the survey, an overview of the practices and their rationale is compiled for use in further research into this orphan crop.
 
Farmer field schools (FFSs) were conducted in southern India to reduce pesticide input and enhance sustainability of cotton production systems. This study was carried out to determine the additional benefits of FFSs in the social and economic arena, using the sustainable livelihoods (SL) concept to frame the evaluation. Farmers who had participated in the integrated pest management (IPM) FFSs perceived a range of impacts much beyond the adoption of IPM practices. The reduced cost of cultivation allowed for financial recovery fromdebt and the building of physical assets. IPMFFShouseholds and production systems were perceived by the participants to have become more economically resilient than Non-IPMFFS control groups when faced with adversity. In the participants¿ view, IPMFFSs also led to enhanced individual and community social well-being, a benefit valued in particular by the women participants. The study tested a new application of the SL conceptual framework as a tool for evaluation.
 
Frequency distribution of root lengths grouped in 25 cm length ranges, (A) for all 800 primary roots measured from 21 WAP to 37 WAP, and (B) for the maximum root length of each of the 40 plants harvested over the same period. 
Dry weight of plant parts at sequential harvests of D. esculenta grown at Valateruru. Data are means of 10 plants. Error bars show standard errors of means. 
Growth analysis parameters for D. esculenta grown at Valeteruru. Plant spacing was 4 m 2 plant − 1 . Data are 
A growth analysis study involving monthly excavation of Dioscorea esculenta plants revealed that the root system developed fully in the period before tuber initiation, and extended radially for a distance between 2.3 and 4.3 m. Primary roots initially remained in the top 10 cm of the soil profile, but descended to approximately 30 cm near their full extension. Tuber number increased from initiation around 21 weeks after planting (WAP) until maximum vine growth was reached around 33 WAP, but tuber dry weight continued to increase throughout the senescence period of the vine, to 45 WAP. Tubers lost dry matter but not fresh weight during dormancy in the soil, to 55 WAP. The results indicate that a distance of at least 4.5 m is required to separate experimental fertilizer treatments, and that post-establishment burial of fertilizers around the mound or ridge risks damage to roots near their base, while inter-row application is accessible to roots and may be preferable.
 
The first ever on-farm soil fertility research in the rainfed lowland rice (Oryza sativa) fields of Sukumaland, in northwest Tanzania, was carried out between 1990 and 1996 in response to farmers' complaints about declining rice yields. From diagnosis to extension, the research approach followed that of the International Maize and Wheat Improvement Center (CIMMYT). In 1990/91, rice yields in the Maswa district increased sharply when nitrogen at a rate of 30 kg ha−1 in the form of urea was broadcast in flooded rice fields at tillering. Similar research was subsequently conducted in other parts of Sukumaland to evaluate this type of low-dose nitrogen application under varying circumstances. In 1995/96, higher doses of nitrogen (60 and 120 kg ha−1) and a high dose of phosphorus (17.5 kg ha−1) were applied for comparison in Sengerema district. Between 1990 and 1996, the average increase in rice yield from the application of 30 kg N ha−1 varied between 463 and 986 kg ha−1. In 1995/96, the same application of N was more economical than both 60 and 120 kg N ha−1, and no phosphorus deficiency was found. The deteriorating ratio between the price of rice at the farm gate and that of urea, however, threatens the adoption of this technology by farmers. Adaptability analysis showed that the relatively small differences in response per field (environment) in all years did not justify a need for multiple different extension messages. Until more detailed recommendations can be made, therefore, a single dose of 30 kg N ha−1, in the form of urea, applied to rice at tillering is recommended for the whole of Sukumaland to reverse the decline in yields. Further on-farm research should concentrate on improving the efficiency of nitrogen fertilization and on determining the optimum rates of other major nutrients to refine this initial recommendation.
 
Dates of biomass and CAN application, of planting of maize, and daily rainfall distribution between October and March 2001/02 (total rainfall [Oct–Mar] = 800 mm).  
Effect of gliricidia prunings applied at various times on mineral N present in the soil surface layer (0-0.2 m) during the maize growing period. The bars represent s.e.d. at 5% for the means of the treatments at each sampling time. See text for definition of treatments.
Relationship between delta N uptake by maize and inorganic N fertilizer applied.  
Nitrogen uptake by maize (grain and stover) fertilized with gliricidia prunings applied at various times during the season and/or with inorganic fertilizer.
Asynchrony between nitrogen (N) released by organic materials and N demand by the crop leads to low N use efficiency. Optimizing the time of application could increase the N recovery. A field experiment was designed to determine the effects of time of application of Gliricidia sepium prunings and of the addition of small doses of inorganic N fertilizer on N recovery and yield of maize. Six split applications of gliricidia prunings (in October, December and February) were compared. The prunings were incorporated into the soil while fresh. The application in October was done four weeks before planting the maize. Higher N uptake and maize yields were obtained when gliricidia prunings were applied in October than when applied in December and February. The corresponding substitution values were 0.66, 0.32 and 0.20. Split applications of prunings prolonged mineral N availability in the soil until March but did not increase N uptake and maize grain yield compared to a sole application in October. Combinations of gliricidia prunings and inorganic fertilizer increased N uptake and maize yield over prunings alone but the effect was only additive. We concluded that application of gliricidia prunings in October was more efficient than application in December and February
 
This paper analyses the organization of the rice seed sector in Guinea with the overall objectives to assess how organizational settings affect seed supply to small-scale farmers and to suggest institutional changes that would favour seed service and uptake of varieties. Data were collected in Guinea, West Africa, using focus group discussions with extension workers, farmers, representatives of farmers’ associations, agro-input dealers, researchers and non-governmental organization (NGO) staff, and surveys of 91 rice farming households and 41 local seed dealers. Findings suggest that the current institutional settings and perceptions of stakeholders from the formal seed sector inhibit smallholder farmers’ access to seed. Seed interventions in the past two decades have mainly relied on the national extension system, the research institute, NGOs, farmers’ associations and contract seed producers to ensure seed delivery. Although local seed dealers play a central role in providing seed to farmers, governmental organizations operating in a linear model of formal seed sector development have so far ignored their role. We discuss the need to find common ground and alternative models of seed sector development. In particular we suggest the involvement of local seed dealers in seed development activities to better link the formal and the informal seed systems and improve smallholder farmers’ access to seed from the formal sector.
 
Soils of South Africa. By FeyM.. Cape Town: Cambridge University Press (2010), pp. 287, $60.00. ISBN 978-1-107-00050-6. - Volume 47 Issue 2 - R. Webster
 
Banana Breeding: Progress and Challenges. Edited by PillayM. and TenkouanoA.. Boca Raton, FL, USA: CRC Press (2011), pp. 363, US$139.95. ISBN 978-1-4398-0017-1. - Volume 47 Issue 4 - Mike Smith
 
Sustainable Urban Environments: An Ecosystem Approach. Edited by BuerenE. B., van BohemenH., ItardL. and VisscherH.. Heidelberg, Dordrecht, London, New York: Springer (2012), pp. 429, £44.99 (p.b.) ISBN 978-94-007-1293-5. - Volume 48 Issue 4 - Emmy B. Simmons
 
Farming for Food and Water Security. Edited by E.Lichtfouse. Heidelberg, Germany: Springer (2012), pp. 274, £126.00. ISBN 978-94-007-449-8. - Volume 49 Issue 1 - Brian Sims
 
Sustainable Potato Production: Global Case Studies. Edited by Z.He, R.Larkin and W.Honeycuff. Heidelberg, Germany: Springer (2012), pp. 539, £153.00. ISBN 978-94-007-4103-4. - Volume 49 Issue 1 - David J. Midmore
 
The Impact of Climate Change and Bioenergy on Nutrition. Edited by B.Thomson and M. J.Cohen. Dordrecht, Netherlands: Springer (2012), pp. 120, £90.00. ISBN 978-94-007-0109-0. - Volume 49 Issue 2 - Thomas Kleinen
 
Plants and Heavy Metals. Edited by A.Furini, G.Dal Corso, A.Manara, E.Fasani and A.Neslar. Heidelberg, Germany: Springer (2012), pp. 86, £44.99. ISBN 978-94-007-4440-0. - Volume 49 Issue 1 - Andy Meharg
 
Bioenergy for Sustainable Development in Africa. Edited by JanssenR. and RutzD.. Heidelberg, Germany: Springer Science (2012), pp. 413, £117.00. ISBN: 978-94-007-2180-7. - Volume 48 Issue 4 - Amir Kassam
 
Farming Systems Research into the 21st Century. The New Dynamic. Edited by I.Darnhofer, D.Gibbon and B.Dedieu. Dordrecht: Springer Science + Business Media (2012), pp. 490, £153.00. ISBN 978-94-007-4502-5. - Volume 49 Issue 2 - M. Collinson
 
Sustainable Agriculture Reviews 6: Alternative Farming Systems, Biotechnology, Drought Stress and Ecological Fertilisation. Edited by Lichtfouse E.. Dordrecht, Heidelberg, London, New York: Springer (2010), pp. 354, £135.00. ISBN 978-94-007-085-4. - Volume 47 Issue 4 - Susanne Padel, Jo Smith
 
Sulfur Metabolism in Plants. Mechanisms and Applications to Food Security and Responses to Climate Change. By L. J.De Kok, M.Tausz, M. J.Hawkesford, R.Hoefgen, M. T.McManus, R. M.Norton, H.Rennebereg, K.Saito, E.Schnug and L.Tabe. Dordrecht: Springer (2012), pp. 284, £126.00. ISBN 978-94-007-4449-3. - Volume 49 Issue 2 - Geoffrey Michael Gadd
 
The Plant Family Brassicaceae: Contribution Towards Phytoremediation. Edited by N. A.Anjum, I.Ahmad, M. E.Pereira, A. C.Duarte, S.Umar and N. A.Khan. Heidelberg, Germany: Springer (2012), pp. 339, £71.71. ISBN 978-94-007-3912-3. - Volume 49 Issue 1 - Richard Mithen
 
Agroecology and Strategies for Climate Change. Edited by E.Lichtfouse. Heidelberg, Germany: Springer (2012), pp. 335, £135.00. ISBN 978-94-007-1904-0. - Volume 49 Issue 2 - Adrian Newton
 
Improving Soil Fertility Recommendations in Africa Using the Decision Support System for Agrotechnology Transfer (DSSAT). Edited by KiharaJ., FatonjiD., JonesJ. W., HoogenboomG, TaboR. and BationoA.. New York: Springer (2012), pp. 195, US$165.87. ISBN 978-94-007-2959-9. - Volume 48 Issue 4 - Ahmed Mukhtar
 
Plant Tissue Culture. Techniques and Experiments. Third edition. By R. H.Smith. Amsterdam: Academic Press (2013), pp. 188, £54.99. ISBN 978-012-415920-4. - Volume 49 Issue 2 - Stephen Millam
 
Genetics and Improvement of Barley Malt Quality. Edited by ZhangG. and LiC. Hangzhou and Heidelberg: Zhejiang University Press and Springer (2010), pp. 296, £171.00. ISBN 978-7-308-06382-1 and ISBN 978-3-642-01278-5. - Volume 47 Issue 3 - W. T. B. Thomas
 
Fifty Animals that Changed the Course of History. Edited by ChalineE.. Cinciannati, OH, USA: David and Charles Press (2011), pp. 223, £12.99. ISBN 978-1-4463-0143-2. - Volume 48 Issue 2 - Nick Birch
 
Crop Yield Response to Water. FAO Irrigation and Drainage Paper 66. By P.Steduto, T. C.Hsiao, E.Fereres and D.Raes. Rome, Italy: Food and Agriculture Organization of the United Nations (2012), pp. 500, US$100.00. ISBN 978-92-5-107274-5. The whole report can be downloaded from: http://www.fao.org/docrep/016/i2800e/i2800e00.htm. - Volume 49 Issue 2 - M. K. V. Carr
 
Crop Plant Anatomy. By R.Maiti, P.Satya, D.Rajkumar and A.Ramaswamy. Wallingford, UK: CABI (2012), pp. 317, £75.00. ISBN 978-1-78064-019-8. - Volume 49 Issue 2 - P. J. White
 
Climate, Water and Agriculture in the Tropics. Second edition. By JacksonI. J., Harlow, Essex: Longmans, (1989), pp. 377, £13.99, ISBN 0-582-02159-6. - Volume 28 Issue 2 - J. M. Hirst
 
Biofuels from Agricultural Wastes and Byproducts. Edited by BlaschekH. P., EzejiT. C. and ScheffranJ.. Ames, IA: Wiley-Blackwell (2010), pp. 262, £125.00. ISBN 978-0-8138-0252-7. - Volume 47 Issue 2 - John R. Hillman
 
Technological Innovations in Major World Oil Crops, Volume I: Breeding. Edited by GuptaS. K.. Heidelberg, Germany: Springer (2011), pp. 405, £153.00. ISBN 978-1-4614-0355-5. - Volume 48 Issue 3 - Rajeev K. Varshney
 
Food System Sustainability: Insights from duALIne. Edited by C. Esnouf , M. Russel and N. Bricas . Cambridge University Press (2013), pp. 303, £60.00. ISBN 978-1-107-03646-8. - Kenneth J. Thomson
 
State of the World 2012. Moving Toward Sustainable Prosperity. Project Directors: E.Assadourian and M.Renner. Washington, DC: Island Press (2012), pp. 241, US$ 21.95. ISBN 978-1-61091-037-8. - Volume 49 Issue 1 - J. R. Hillman
 
Top-cited authors
Mike K. V. Carr
  • Cranfield University
K.D. Joshi
  • International Rice Research Institute
David Harris
  • Bangor University
J. R. Witcombe
  • Bangor University
Bhuwon Ratna Sthapit
  • Bioversity International