Wheat breeding,productivity and slow variety change: evidence from the Punjab of India after the Green Revolution*

Variety change and genetic diversity are important means of combating crop losses from pests and diseases in modern agricultural systems. Since the Green Revolution, genetic diversity among wheat varieties released in India has increased but variety change on farms continues to be slow. In this article, we define and summarise indices of variety change and genetic diversity for the wheat varieties released and grown in Indian Punjab during the post‐Green Revolution period. We evaluate the effect of each index on technical efficiency with a Cobb‐Douglas yield model after testing for exogeneity. Findings support the hypothesis that slow variety change has offset the positive productivity effects of diversifying the genetic base in wheat breeding during the post‐Green Revolution period. Policies that speed the rate of variety change and contribute to a more equitable spatial distribution of modern varieties could support wheat productivity in the Punjab of India, reinforcing plant breeding successes.     

The economic determinants of cereal crop diversity on farms in the Ethiopian highlands

In less favoured areas such as the highlands of Ethiopia, farmers manage risk through land allocation to crops and varieties since they cannot depend on market mechanisms to cope. They also grow traditional varieties that are genetically diverse and have potential social value. Supporting the maintenance of crop and variety diversity in such locations can address both the current needs of farmers and future needs of society, though it entails numerous policy challenges. We estimate a model of crop and variety choice in a theoretical framework of the farm household model to compare the determinants of crop and variety diversity, revealing some of these policy considerations. Farm physical features and household characteristics such as wealth and labour stocks have large and significant effects on both the diversity among and within cereal crops, varying among crops. Policies designed to encourage variety diversity in one cereal crop may have opposing effects in another crop. Trade-offs between development-related factors and diversity in this resource-poor system are not evident, however. Market-related variables and population density have ambiguous effects. Education positively influences cereal crop diversity. Growing modern varieties of maize or wheat does not detract from the richness or evenness of these cereals on household farms.     

Unpacking a crop diversity hotspot: farmer practice and preferences in Northern Malawi

Crop diversity is a key principle of sustainable food production systems. Yet, inter and intra specific diversification is declining in many regions of the world. In Northern Malawi, a participatory action research project (Soils Food and Healthy Communities) has conducted agroecological co-learning with farmers for over a decade, providing an opportunity to explore farmer management, crop choice and variety selection practices. Farmers who participate receive seed for 0.10 ha of on-farm testing for one growing season and then decide whether to continue to grow the crop. Cropping system diversity, management practices and traits associated with crops grown and lost were assessed through interviews with 198 farm households (757 fields). We found an average of 1.3 species per field and 4.0 crops per farm. This is almost twice the level of diversity in other reports from Malawi smallholder farms. Farmers cited a wide range of preferred groundnut variety traits, as well as concerns (namely, high labour requirements). Both modern and local maize varieties are being grown and those retained were often associated with early maturity or preferred grain quality traits such as storability. Overall, farmers at this Northern Malawi agroecology education site are growing diverse crop mixtures that include traditional as well as modern varieties of maize and groundnut.     

Utilizing conjoint analysis to design modern crop varieties: empirical example for groundnut in Niger

Preferences for monetary and non-monetary plant traits influence modern crop variety adoption decisions of farmers. To enhance adoption probability of modem crop varieties, it is necessary to identify and locus research on traits that significantly contribute to utility while de-emphasizing insignificant plant attributes. This paper illustrates the potential for applying conjoint analysis to aid the design and targeting of client-responsive modern crop varieties, farmers ranked eight orthogonally-derived plant trail combinations used in an illustrative example. Utilities were estimated using the choice-probability-based method of ordered probit. Results showed that conjoint analysis can differentiate significant and non-significant trails of modern crop varieties. The usefulness of applying conjoint analysis over identifiable disaggregated groups of a sample was also evident. Future application of conjoint analysis to the design and targeting of modern crop varieties should carefully consider sample composition and size to permit the estimation of relevant sub-models for desired farmer segments.     

The value of plant genetic diversity to resource-poor farmers in Nepal and Vietnam

Genetic resources for food and agriculture are the biological basis of world food and nutrition security; and they directly or indirectly support the livelihoods of over 2.5 billion people. Genetic diversity gives a species or a population the ability to adapt to changing environments. For resource-poor farmers, adaptive animal breeds, crop varieties and cultivars adapted to particular micro-niches, stresses or uses are the main resources available to maintain or increase production and provide a secure livelihood. The economic value of genetic diversity for productivity and yield traits is discussed in the literature. However, it is difficult to value many other aspects of agricultural biodiversity as these have both direct and indirect values in terms of qualitative traits such as food, nutrition and environmental uses that include adaptation to low input conditions, co-adaptive complexes, yield stability and the consequent reduction of risk, specific niche adaptation, and in meeting socio-cultural needs. Together, the direct and indirect values of genetic resources for resource-poor farmers are expressed in a range of options in the form of the crop varieties and species they use for managing changing environments.

The value of genetic diversity to resource-poor farmers is seldom captured by markets or addressed by the international research agenda. This paper presents lessons learned from our work over 5–10 years in the Asia and Pacific Ocean (APO) region on participatory crop improvement, home gardens and on-farm management of agricultural biodiversity. The lessons illustrate how farmers adapt genetic resources to suit local environmental conditions. The paper focuses on the value of genetic diversity of selected crop species to meet people's food and other needs. Genetic diversity valued by resource-poor farmers is often maintained, selected and exchanged by local social seed networks. Identification of such genetic resources and their custodians is important if international agricultural research is to contribute to the reduction of poverty. The paper highlights some good practices from case studies that illustrate how such genetic resources could be exploited by informal research and development strategies or participatory plant breeding or for marketing value-added products.     

Does mixed crop‐livestock farming lead to less diversified diets among smallholders? Evidence from Laos

Malnourishment continues to remain a challenge in developing countries. As the undernourished are largely smallholder farmers, it is widely assumed that farm diversification and mixed crop‐livestock agricultural systems can help alleviate this problem. However, empirical evidence in this context is limited. Hence, we use a two‐year panel's data from Laos to examine whether farm production diversity as well as a mixed crop‐livestock farming system improves household dietary diversity among smallholder farmer. The results from the fixed effects regression indicate that although farm production diversity does lead to a higher dietary diversity, the effect diminishes with continued farm diversification. The counterfactual analysis from the endogenous switching regression reveals that mixed crop‐livestock farming systems do not necessarily enhance dietary diversity. However, we further find that purchasing food from the markets plays an important role in enhancing the dietary diversity of rural smallholder farmers.     

Market Analysis,Technical Change and Income Distribution in Semi-Subsistence Agriculture: the Case of Bangladesh

For the first time, the model developed by Hayami and Herdt is applied to determine gains from modern varieties of rice in Bangladesh and the distribution of these gains between consumers and producers. The results suggest that consumers' surplus is much greater than it would have been had the high yielding crop varieties (HYVs) not been introduced. By keeping the real price lower than it would have been otherwise, the modern varieties have tended to be income equalizing for urban consumers. The Hayami-Herdt partial model even suggests that, given the relatively inelastic demand for rice in Bangladesh, the real cash income of producers has risen slightly as a result of these new technologies. In reality, however, the impact of these changes on incomes of farmers and the distribution of income between those involved in production is more complex. It is suggested that if a less partial view is taken and if account is taken of lower cost of obtaining home-consumed produce, the increase in income may be greater. In any event, there are dangers in using such a partial model to predict the developmental consequences of technological changes affecting a staple crop, and attention needs also to be given to the possibility that the supply curve may not have the simple form and pivot in the way supposed by Hayami and Herdt. While the Hayami-Herdt model is simple to apply, it is best used as a first approximation or starting point rather than a final solution. It ignores a number of criteria that could be important in assessing new agricultural technologies, such as their impact on the variability of benefits to producers and consumers and their consequences for sustainability of production. Furthermore, the Hayami-Herdt model does not deal specifically with changes in factor shares in farm production. Nor does it consider the impact on income distribution of the ownership and control of critical input like irrigation and imperfection in the rural credit market. It is pointed out in our paper that the adoption of HYVs has been associated with important variations in factor shares in Bangladeshi rice production. Analysis of available farm level data indicates that the relative share of labour has fallen, suggesting an uneven distribution of gains from technological changes between the owners of non-labour resources and those of labour resources. However, the absolute share of labour has increased, and it seems that rural employment has risen as result of the new technologies.     

基于无人机样方事后分层的作物面积估算

无人机是开展野外调查的一种新型、有效的手段,能够及时、准确地获取地面调查样方信息,为作物面积遥感估算提供精准的样方数据。研究针对无人机抽样调查的样方特点,提出了适合于无人机样方的多层次事后分层指标(多层次-异质性指标、多层次-面积规模指标)。将这些指标分别用于事后分层抽样,估算冬小麦面积。并根据变异系数(coefficient of variance,CV)对其抽样效率进行评价。多层次指标是将多种分层指标分层结果叠加形成的,能够充分反映作物种植空间分布特征、空间异质性及种植规模,可以保证作物种植面积遥感估算的精度。以河南省冬小麦面积估算为例,在冬小麦空间分布空间范围,建立300m×300m抽样框格网,作为抽样基本单元。分别利用实验设计的多层次-面积规模指标、多层次-异质性指标、面积规模指标、异质性指标计算各抽样基本单元的对应指标值。按照累计平方根法计算不同分层指标下的分层界限值。最后进行事后分层估计,计算分层效率,对分层结果与分层效率进行对比分析。计算得到以上4种分层方法的变异系数分别为1.85%、1.41%、2.16%、1.55%。结果表明,结合无人机抽样调查,利用多层次指标法进行分层,各层内作物均质性较好,能够提高农作物面积估算的精度;此外,异质性指标较面积规模指标更能提高分层的层内作物均质性与农作物面积估算精度。     

Hybridizing local and generic information to model cropping system spatial distribution in an agricultural landscape

For quantitative water management, fine analysis of spatial and temporal interactions between cropping systems and water resources helps identify time and site-specific withdrawal situations. However, it is a methodological challenge to provide fine-resolution analyses at the scale of large watersheds used for crises management. In this study, we present a methodology based on multiple methods and mixed sources of information to finely model an agricultural landscape (AL) that represents the spatial distribution of cropping systems. Our approach is based on progressively hybridizing databases and local actors' and experts' knowledge to produce a spatially explicit and dynamic model. The Land Parcel Identification System database, which resulted from the European Common Agricultural Policy, is crucial for our method since it provides the spatial and temporal basis of our model (i.e., geographic delineation of islets and information about crop sequences). Local knowledge is used to identify factors determining spatial distribution of cropping systems and to build a generic model that simulates farmers' crop-management strategies. The model was qualitatively and quantitatively evaluated using a multi-agent simulation platform (MAELIA). We asked local experts on quantitative water management to evaluate the ability of the platform to reproduce intra- and inter-annual dynamics at different levels when using our model of the AL as input. The experts were satisfied with the results; they validated the predicted dynamics of the variables, and some discussed the objectivity of the values. We discuss the method’s contribution to current challenges in modeling large agricultural areas and the associated tradeoffs. The approach is promising for policy makers who wish to develop integrated, locally adapted land-management strategies.     

A household hedonic model of rice traits: economic values from farmers in West Africa

New crop varieties often have been promoted in developing countries based upon superior yield vis-a-vis locally available varieties. This research presents a hedonic price model for upland rice by drawing upon the input characteristics and consumer good characteristics model literature. Model specification tests determine that a combination of production and consumption characteristics best explains the willingness to pay for new upland rice varieties. The household model specification determined that five traits explain the willingness to pay for new rice varieties: plant cycle length, plant height, grain colour, elongation/ swelling and tenderness. Yield was not a significant explanatory variable of the willingness to pay for seed. The implications of this model are two-fold. First, varietal development and promotion must include post-harvest characteristics in addition to production traits when determining which varieties to promote for official release. Secondly, non-yield production characteristics such as plant height and cycle length are significant factors in producer's assessments of the value of a new variety. Overall, this paper provides an alternative explanation for limited adoption of modern upland rice varieties in West Africa: varietal evaluation programs have focused too narrowly on yield evaluation and have not promoted varieties with superior non-yield characteristics than locally available varieties.     

On‐Farm Conservation of Rice Biodiversity in Nepal: A Simultaneous Estimation Approach

This paper presents an empirical case study about farmer management of rice genetic resources in two communities of Nepal, drawing on interdisciplinary, participatory research that involved farmers, rice geneticists and social scientists. The decision‐making process of farm households is modelled and estimated in order to provide information for the design of community‐based conservation programmes. A bivariate model with sample selection examines the simultaneous process of whether farmers decide to plant landraces or modern varieties, and whether the landraces they choose to plant constitute the genetic diversity of interest for future crop improvement. Findings show that the two landrace choices are affected by different social and economic factors, but in certain cases the decision processes are interrelated. Policies to promote the conservation of local rice diversity will need to take both processes into account.     

Modelling the Crop Variety Demand of Semi‐Subsistence Households: Bananas in Uganda

We propose an approach to model the derived demand for crop varieties among semi‐subsistence farmers in a developing economy, and apply it to smallholder banana producers in Uganda. We model variety planting decisions as being composed of an extensive margin decision to grow a subset of locally available varieties (variety choice); and an intensive margin decision about the scale or extent of variety cultivation per farm (variety demand). We estimate variety demand equations using a more complete representation of the choice set upon which observed planting decisions are made. Computed elasticities of variety demand with respect to variety attributes indicate that the relative importance of consumption and production attributes varies by location and proximity to markets, from which we draw implications for the social and economic impact of crop improvement. The approach that we propose has broad appeal for analysing adoption decisions for modern or traditional varieties of both major and minor crops in developing countries.     

Farmers' Subjective Valuation of Subsistence Crops: The Case of Traditional Maize in Mexico

Shadow prices guide farmers' resource allocations, but for subsistence farmers who grow traditional crops they may bear little relationship with market prices. We theoretically derive shadow prices for a subsistence crop with nonmarket value, then estimate shadow prices of maize using data from a nationally representative survey of rural households in Mexico. Shadow prices are significantly higher than market prices for traditional but not improved maize varieties. They are particularly high in the indigenous areas of southern and southeastern Mexico, indicating large  de facto  incentives to maintain traditional varieties there.     

多时相GF-1卫星PMS影像提取农作物种植结构

[目的]及时准确获取农作物种植结构信息,对农作物种植结构调整具有重要意义。[方法]文章以多期GF-1卫星PMS影像为主要数据源,通过分层分类方法成功提取了朱仙镇一个种植年内秋播蔬菜、冬小麦、春花生、早熟西瓜、夏玉米、夏花生等农作物,并通过叠加分析得到朱仙镇的农作物种植模式。[结果]朱仙镇有10种种植模式,以一年两熟的冬小麦-夏玉米为主要倒茬模式,占比49.7%,其他9种种植模式所占比例之和接近50%;从整体景观的角度对朱仙镇的主要作物种植模式进行衡量,斑块丰富度PR达到9.0,香农多样性指数SHDI达到1.483 6,说明朱仙镇种植模式多样,有利于多元农业种植结构发展;分层分类的方法能够延续最优提取结果的精度,各类作物提取精度均达到了80%以上。[结论]PMS影像的高分辨率能够清晰的表达地块边界,一定程度上呈现了非大宗作物的空间分布,GF-1卫星PMS为多尺度的农业监测提供了更多的选择。     

A trait-based model of the potential demand for a genetically engineered food crop in a developing economy

We predict the potential demand of smallholder farmers for genetically transformed varieties of a food crop, the cooking banana of the East African highlands. Farmer demand for planting material is derived in an agricultural household model that accounts for variety traits and missing markets. The demand for candidate host varieties is predicted using a Zero‐Inflated Poisson (ZIP) regression system. The fitted model is used to illustrate the sensitivity of farmer demand for improved planting material to (a) investments in research and development, represented by the effectiveness of gene insertion and expression, and (b) other public investments in education, extension, and market infrastructure that support diffusion. By comparing the characteristics of agricultural households we demonstrate that the choice of host variety can have social consequences, favoring one rural population compared with another. Clients for transgenic banana planting material are likely to be poorer, subsistence‐oriented farmers in areas greatly affected by biotic constraints. A model of this type might be useful in assessing the investments needed to support the systematic dissemination of improved planting material. The approach can be generalized to other crop biotechnologies for smallholder farming systems, particularly in developing economies.     

Regional heterogeneity and spatial interdependence as determinants of the cultivation of an emerging alternative crop: The case of the Styrian Oil Pumpkin

In the course of the liberalisation and globalisation of agricultural markets the Common Agricultural Policy (CAP) of the European Union (EU) has shifted from quantity-based to quality-based policies, encouraging a diversification of agricultural production. For policy makers it is therefore relevant to understand better the drivers which influence the adoption and spatial distribution of emerging alternative products and production systems in agriculture. Taking the Styrian Oil Pumpkin as an example, the aim of this study is to quantify the determinants of spatial variations in the cultivation of an emerging alternative crop. We estimate Tobit and SLX Tobit models for two regions, drawing on cross-sectional data from the year 2010 of 549 municipalities in the Styrian Oil Pumpkin Protected Geographical Indication (PGI) area. Our findings indicate that, apart from (i) crop-specific factors, there are also (ii) region-specific factors such as marketing possibilities and there is (iii) spatial interdependence influencing spatial variations in oil-pumpkin-cultivated area and we conclude that these factors also need to be considered for the support of other emerging alternative products and production systems in agriculture.     

Modern variety adoption and risk management in drought prone areas: insights from the sorghum farmers of eastern Ethiopia

Adoption rates of improved or modern varieties (MV) of sorghum in eastern Ethiopia are generally low. Although these MV may represent an effective means of coping with droughts, given their early maturing traits, landraces could prove to be more drought‐tolerant and better adapted to marginal production conditions. Whether MV adoption is a risk reducing technology is very much an empirical question which this article investigates using a unique dataset from eastern Ethiopia in a year of extreme weather conditions. Results show that risk‐factors coupled with access to markets and social capital drive farmers’ decisions to adopt MVs. On the one hand, it appears that farmers use MVs to mitigate moderate risks. On the other hand, farmers who have been most vulnerable to extreme weather events are less likely to use MVs suggesting that MV adoption does not necessarily represent an effective means of coping with drought. Finally, findings show that MV growers are more likely to be affected by sorghum failure once controlling for exogenous production factors.     

近10年嫩江市大豆种植结构空间演变研究

目的 我国是世界上最大的大豆进口国，随着近几年中美贸易战的摩擦升级、新型冠状病毒影响导致的全球贸易交流减少，乌克兰战事致其大豆出口骤降等各种因素的影响，我国大豆生产存在潜在危险。研究大豆主产区大豆种植结构动态分布及空间演变，对中国粮食安全和进出口大豆体量都有重大意义。方法 文章依托2011—2021年Landsat系列多景影像，利用“3S”技术、随机森林算法，得到黑龙江省嫩江市大豆空间面积，并通过J-M距离法对样点进行精度验证，最后通过景观格局指数方法，分析黑龙江省嫩江市大豆种植结构时空演变特征。结果 2011—2021年黑龙江省嫩江市大豆种植面积在时空上整体上先减少再增加，主要种植面积从东北部至西南部、东南部增加。大豆面积总体以增加为主，但分阶段面积变化幅度较大。结论 该文利用近10年遥感影像对黑龙江省嫩江市大豆种植结构空间演变研究，以作为东北地区作物种植结构调整、优化粮食安全保障的依据，同时为国家粮食生产政策制定提供参考。     

Potential of feed additives to improve the environmental impact of European livestock farming: a multi-issue analysis

Today, less than 3% of the 250,000 plant varieties available to agriculture are in use. Sources of (agricultural) biodiversity are under threat and disappearing in many regions. Increasing industrialisation of agriculture and top-down agricultural research have contributed to this dependence on a relatively few plant varieties. This article argues that new approaches to agricultural development research are needed to conserve agricultural diversity, improve crops, and produce food of quality for all. Such an approach should enable small farmers on marginal lands to participate as equal partners alongside agricultural scientists, fairly sharing their know-how, expertise and seeds. Three case studies illustrate how farmers and plant breeders are working together in a diversity of agro-ecological, socio-economic and political contexts to put these new approaches into practice. New forms of collaboration are producing an increase in diversity and a number of promising improved varieties in terms of yields, agronomic traits and taste. These varieties are showing better adaptation to the local environmental conditions without requiring extra external inputs. Long-term success requires that these efforts be backed up by supportive policies, by actions to ensure that policies are implemented, and where necessary by related legislation.     

收储制度改革背景下农户玉米种植调整行为研究基于优势产区与非优势产区423个农户调查数据对比

目的 为了解收储制度改革背景下农户玉米种植调整行为,从而对优化农业种植结构、保障玉米稳定供给的科学决策提供参考。方法 文章基于辽宁、吉林、黑龙江、内蒙古423个农户调查数据,通过建立有序多分类Logistic回归模型,将玉米种植优势产区与非优势产区样本农户的玉米种植调整行为进行对比分析。结果 研究发现不同产区农户玉米种植调整行为影响因素存在差异。在优势产区,农户新品种采用意愿、家庭劳动力数量、其他作物面积、玉米收入占比、生产者补贴标准满意度对玉米种植调整行为影响显著。在非优势产区,农户上一年种植面积、玉米收入占比、合作组织对玉米种植调整行为影响显著。结论 进一步完善生产者补贴机制,适当提高优势产区玉米补贴标准;加强玉米良种研发,实施“藏粮于技”战略;加强对农业经营主体的培育扶持,有效推动种植结构调整。