JUNE 2014 ISSUE (VOL 43, NO 2)
71 Guest Editorial: Helping small-scale farmers reduce the ‘yield gap’ through innovation in science
Abstract: There is a lack of empirical knowledge about the complex factors that shape a farmer’s decisions to participate in rural development (RD) measures. The objective of this study was to develop and test the suitability of an original typology that identifies distinct groups affected by the thematic objectives of the European Union’s RD policies. The results are based on empirical data (n = 277) drawn from two case study areas in Germany, where information related to farm structures was collected along with the self-assessment statements of farmers. The paper emphasizes the description and reasoning of the methodological steps performed to achieve this typology. First, factor analysis was used to reduce datasets and to exclude multicollinearity problems. A two-step cluster analysis was then applied to classify farms into representative types within the derived typology. Finally, farmers’ self-perception statements were analysed in relation to the farm typology by using qualitative description methods.
Abstract: Increases in the production of food crops are no longer keeping pace with population growth in Africa, so the continent is increasingly relying on food imports. This would not be the case if crop yields were closer to their potential under good crop management. As climate change makes rainfall more variable, it becomes more risky for smallholders to adopt high-input technologies for crop intensification. This paper uses case studies on the yield gap in cassava, maize and cotton and examines the factors that contribute to low yields, the disincentives for technology adoption and some of the strategies required to close the yield gap. The paper argues that institutional factors are as important as technical ones in addressing the current yield gap in Africa. The main conclusions are that the yield gap is much more difficult to close in rainfed agriculture than in irrigated production where low soil fertility constrains the response to inorganic fertilizer. The combination of institutional and agronomic factors that influence the ability of farmers to improve crop yields profitably often operates at the farm or local level.
Abstract: Organic agriculture is increasingly recognized as an adaptation measure to support sustainable livelihoods under a changing climate. This study assesses how it constitutes a suitable adaptation strategy in north-west Benin to make rural households more resilient to the increased likelihood of flooding, high-intensity rainfall or droughts. Based on household interviews, focus group discussions and expert interviews in villages around the Pendjari National Park, it was found that agricultural practices of organic cotton production directly reduced the most frequent climatic risks that households faced, and indirectly contributed to reducing economic risks and to empowering women. But there are also obstacles, such as the availability of sufficient organic material and the need for transport to dispersed fields, which currently limit adaptation potential.
Abstract: Producer organizations (POs) are often recognized as a pathway to boost rural development by enhancing farmers’ access to market opportunities. Smallholder production and marketing of new crops (such as those for biodiesel feedstock) are constrained as farmers and buyers face high transaction costs. By investigating cases of POs outside the biofuel industry, the authors explore the extent to which POs could reduce transaction costs. The findings indicate that POs are capable of linking farmers effectively to markets in cases in which high value is added to farm products and/or farmers are highly specialized. However, the scope for POs in linking farmers to biodiesel markets is limited due to organization-specific characteristics, the low value added of the feedstock, plus multiple trade-offs with current farm activities.
Abstract: Deriving accurate spatial assessments of the distribution of irrigated crops has become more important in recent years for water resource planning, particularly where irrigation water resources are constrained. However, this is easier in arid climates than in humid areas such as eastern England. The challenges in using alternative vegetation indices derived from remote sensing to discriminate between irrigated and rainfed crops in a humid climate are described, focusing on potato (Solanum tuberosum L.), the most important irrigated crop in England. Three techniques were evaluated: (a) temporal profile comparisons using the Normalized Difference Vegetation Index (NDVI); (b) cluster analysis combining the NDVI and the Normalized Difference Water Index (NDWI); and (c) identifying differences in chlorophyll content using green and near infrared bands. However, the study confirmed that the spectral signatures of irrigated and rainfed potato in England during a typical summer are very similar, presumably due to frequent rainfall events which reduce differences in water stress and chlorophyll content. The implications for using remote sensing to estimate irrigated areas in humid climates are discussed.
Abstract: The economic importance of organic production systems is growing year on year. Producers who wish to convert their farms to organic farming face significant transition costs due to changes in management, work organization and lifestyle. The aim of this study was to compare the yield and economic outputs of a conventional and an organic farming system in south-west Spain, a region characterized by a subhumid climate. The organic rotation of wheat–sunflower–peas–faba bean (green manure) was compared with a conventional rotation of wheat–sunflower over four cropping seasons. Economic analysis showed that organic farming was 62% more profitable, assuming current organic premium prices, and 36% more profitable when selling products in conventional markets. However, without the Common Agricultural Policy and regional payments and with conventional prices, the profitability of organics falls below that of conventional production.
Abstract: This study assesses the managerial efficiency of olive farming in Greece by employing a robust technical efficiency estimator and method proposed by Badin et al (2012) which allows the ranking of production units on the basis of management ability and effort in a theoretically consistent way. The empirical results, based on 478 Farm Accountancy Data Network observations, suggest that managerial efficiency and effort make an important contribution to overall productive efficiency. Managerial efficiency and effort are positively associated with the ratio of family labour to total labour and the degree of intensification of production, and negatively associated with the ratio of owned land to total land. Public policies should therefore focus on improving managerial efficiency by investing in human capital and facilitating the further integration of olive-growing farms into input markets.
Abstract: India has recently enacted Distinctiveness, Uniformity and Stability (DUS) characterization for rice. This paper focuses on DUS characterization using morphological descriptors for 21 rice varieties planted in a randomized block design during two kharif seasons (2007 and 2008). Data were recorded for 60 DUS descriptors (46 qualitative and 14 quantitative) following guidelines from the International Union for the Protection of New Varieties of Plants (UPOV) and the Protection of Plant Varieties and Farmer’s Rights Authority (PPV & FRA). Data on quantitative traits were subjected to Combined Over Years Distinctness (COYD) and Combined Over Years Uniformity (COYU) analyses. The descriptors offering the most discrimination were time to 50% heading, decorticated grain shape, and the colour of lemma and palea. The cultivar Sathi, an improved landrace entry, was observed to be the most distinct, with the rarest morphological features. Eight of the 21 qualitative and 8 of the 14 quantitative traits exhibited uniformity as determined by UPOV-recommended levels. Twelve of the quantitative traits were relatively stable as judged by seasonal variation in Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) values. Finally, the varieties were clustered following the eight grouping characteristics recommended by PPV & FRA. All the approaches clustered the improved landrace entities separately from the conventionally bred varieties.
Abstract: Long-distance signals moving from roots to shoots in response to drought lead to reduced vegetative growth. The hypothesis that the artificial manipulation of one of these signals, alkalization of the xylem sap, can reduce problems of excessive growth in arable crops, has been tested in oilseed rape (canola; Brassica napus L.) and barley (Hordeum vulgare L.). Experiments with detached shoots have shown that both crop species can respond to artificial alkaline xylem sap with reduced leaf expansion. Applications of alkalizing agents to intact plants, either as pH buffer sprays or as solid calcium carbonate, have successfully retarded leaf expansion. The retardation has, however, either been inconsistent (possibly through difficulty in penetrating the variable epicuticular wax layer) or of very short duration (possibly through efficient buffering of internal pH). It can be inferred from these results that the greatest commercial potential for alkalizing growth retardants may be with high-value, short- duration crops that do not have a thick layer of epicuticular wax, and using either multiple applications or persistent formulations.