Conservation agriculture and smallholder farming in Africa: The heretics’ view

Conservation agriculture is claimed to be a panacea for the problems of poor agricultural productivity and soil degradation in sub-Saharan Africa (SSA). It is actively promoted by international research and development organisations, with such strong advocacy that critical debate is stifled. Claims for the potential of CA in Africa are based on widespread adoption in the Americas, where the effects of tillage were replaced by heavy dependence on herbicides and fertilizers. CA is said to increase yields, to reduce labour requirements, improve soil fertility and reduce erosion. Yet empirical evidence is not clear and consistent on many of these points nor is it always clear which of the principles of CA contribute to the desired effects. Although cases can be found where such claims are supported there are equally convincing scientific reports that contradict these claims. Concerns include decreased yields often observed with CA, increased labour requirements when herbicides are not used, an important gender shift of the labour burden to women and a lack of mulch due to poor productivity and due to the priority given to feeding of livestock with crop residues. Despite the publicity claiming widespread adoption of CA, the available evidence suggests virtually no uptake of CA in most SSA countries, with only small groups of adopters in South Africa, Ghana and Zambia. We conclude that there is an urgent need for critical assessment under which ecological and socio-economic conditions CA is best suited for smallholder farming in SSA. Critical constraints to adoption appear to be competing uses for crop residues, increased labour demand for weeding, and lack of access to, and use of external inputs.     

Factors Affecting Adoption of Improved Rice Varieties among Rural Farm Households in Central Nepal

The use of improved high yielding crop varieties is an important avenue for reducing hunger and food insecurity in developing countries. Using cross-sectional data obtained from a survey conducted during 2013 crop season, we performed a probit model(plot-level analysis) to determine the probability of adopting new improved rice varieties(NIRVs) by smallholder farmers particularly from two main agro-ecological regions(hills and tropical plain terai regions) of Central Nepal. The results revealed that education, extension services and seed access play significant roles in adoption decisions.Additionally, farm and field characteristic variables such as farm size, endowment of favorable land type(e.g. lowlands), and animal power(e.g. oxen) are the key factors influencing the probability of adopting NIRVs. The results showed that technology specific variables(e.g. yield potential and acceptability) are significant for explaining adoption behavior, implying that it is important to take farmers' preferences to varietal characteristics into consideration in the design of a research and development program. Given the significant role played by extension and access related variables, increased emphasis on information dissemination, field demonstration, and farmers' participatory research and training programs to popularize new rice varieties and enhance their adoption rate are required. This also suggests that policy intervention should be made on improving the educational status of farming households, and developing programs on varietal package of rice seed which offer farmers a variety of choices among the appropriate pools of germplasm. Such programs ultimately help farmers develop more profit-oriented behavior which are necessary to enhance adoption rate, production and food security in the long run.     

Large-scale sugarcane farmers' knowledge and perceptions of Eldana saccharina Walker (Lepidoptera: Pyralidae), push–pull and integrated pest management

A push–pull strategy for controlling Eldana saccharina Walker is being promoted as part of an area-wide integrated pest management (AW-IPM) programme in the South African sugar industry. Understanding farmers' perceptions of pests and pest management can improve rates of adoption of pest management strategies, in particular for knowledge-intensive practices such as AW-IPM. Fifty-three large-scale sugarcane farmers were interviewed using a semi-structured questionnaire. Respondents recognised the threat which E. saccharina posed, and 83% had heard of push–pull and IPM. Ecozone delineations played a more important role in adoption decisions than demographic and general enterprise factors such as farmer age, experience and land tenure, supporting the suggestion that experiential learning activities with small, local groups of farmers are suitable for introducing new pest management strategies. Notwithstanding good basic knowledge of E. saccharina, push–pull and IPM which farmers demonstrated, there is still a need for more detailed and practical knowledge on the implementation of push–pull at farm level. This knowledge should be made available to farmers in a hands-on manner with an emphasis on locally-oriented field days and model farms. Eldana saccharina may not be a priority for all farmers in the region where surveys were conducted. However, farmers should not be allowed to become complacent about this pest, as its range is increasing. These results will be used to formulate future push–pull and AW-IPM dissemination activities amongst large-scale sugarcane farmers in South Africa.     

Determinants of integrated pest management adoption for olive fruit fly (Bactrocera oleae) in Roudbar,Iran

Extensive use of highly toxic pesticides for pest management has generated concerns over the negative impact of these chemicals on both human health and the environment. The use of integrated pest management (IPM) can address some of these concerns, but studies on the adoption behavior of growers are generally limited. A survey of 171 olive growers was conducted to analyze factors determining adoption of IPM practices for the control of olive fruit fly (Bactrocera oleae) in Roudbar county of Guilan province, Iran. Data were collected through face-to-face interviews with randomly selected olive growers of the study area using a structured questionnaire. Some growers (9.9%) did not adopt any IPM practice for olive fruit fly control, while the majority of the growers (almost 54%) showed some low level of adoption. Twelve variables were found to be strongly correlated with adoption of IPM practices for olive fruit fly control. The strongest link was demonstrated with growers' annual income, land area under cultivation, farming experience, extension activities, technical knowledge, and average olive fruit production. Discriminant analysis was used to identify the variables with the greatest power of classifying growers in three groups of IPM adopters (low, medium, and high level of adoption). The variable: farming experience and especially the olive farming experience along with the variables: family size and extension activities gave an overall classification accuracy of 72.1%, implying a strong capability of correctly differentiating growers in the IPM groups. Understanding growers' characteristics and behavior concerning the adoption of IPM can be a first major step for boosting adoption rates among olive growers of the study area or among growers of other areas with a similar profile. To this end, government policies should strengthen growers' technical knowledge of IPM concerning olive fruit fly through extension services and community involvement, particularly among inexperienced small-scale growers.     

The intrinsic plasticity of farm businesses and their resilience to change. An Australian example

This paper examines the idea that plasticity in farm management introduces resilience to change and allows farm businesses to perform when operating in highly variable environments. We also argue for the need to develop and apply more integrative assessments of farm performance that combine the use of modelling tools with deliberative processes involving farmers and researchers in a co-learning process, to more effectively identify and implement more productive and resilient farm businesses.In a plastic farming system, farm management is highly contingent on environmental conditions. In plastic farming systems farm managers constantly vary crops and inputs based on the availability of limited and variable resources (e.g. land, water, finances, labour, machinery, etc.), and signals from its operating environment (e.g. climate, markets), with the objective of maximising a number of, often competing, objectives (e.g. maximise profits, minimise risks, etc.). In contrast in more rigid farming systems farm management is more calendar driven and relatively fixed sequences of crops are regularly followed over time and across the farm. Here we describe the application of a whole farm simulation model to (i) compare, in silico, the sensitivity of two farming systems designs of contrasting levels of plasticity, operating in two contrasting environments, when exposed to a stressor in the form of climate change scenarios;(ii) investigate the presence of interactions and feedbacks at the field and farm levels capable of modifying the intensity and direction of the responses to climate signals; and (iii) discuss the need for the development and application of more integrative assessments in the analysis of impacts and adaptation options to climate change.In both environments, the more plastic farm management strategy had higher median profits and was less risky for the baseline and less intensive climate change scenarios (2030). However, for the more severe climate change scenarios (2070), the benefit of plastic strategies tended to disappear. These results suggest that, to a point, farming systems having higher levels of plasticity would enable farmers to more effectively respond to climate shifts, thus ensuring the economic viability of the farm business. Though, as the intensity of the stress increases (e.g. 2070 climate change scenario) more significant changes in the farming system might be required to adapt. We also found that in the case studies analysed here, most of the impacts from the climate change scenarios on farm profit and economic risk originated from important reductions in cropping intensity and changes in crop mix rather than from changes in the yields of individual crops. Changes in cropping intensity and crop mix were explained by the combination of reductions in the number of sowing opportunities around critical times in the cropping calendar, and to operational constraints at the whole farm level i.e. limited work capacity in an environment having fewer and more concentrated sowing opportunities. This indicates that indirect impacts from shifts in climate on farm operations can be more important than direct impacts from climate on the yield of individual crops. The results suggest that due to the complexity of farm businesses, impact assessments and opportunities for adaptation to climate change might also need to be pursued at higher integration levels than the crop or the field. We conclude that plasticity can be a desirable characteristic in farming systems operating in highly variable environments, and that integrated whole farm systems analyses of impacts and adaptation to climate change are required to identify important interactions between farm management decision rules, availability of resources, and farmer's preference.     

Adoption of Improved Rice Varieties in the Global South: A Review

Improved rice varieties(IRVs) play a significant role in establishing food security and improving livelihood in the Global South since its introduction in the 1960s. However, the adoption of new IRVs has remained relatively low. This low adoption poses a challenge to rice-producing and consuming countries as they are increasingly threatened by production shortages, malnutrition, and poor rice quality. Many empirical studies have attempted to identify the determinants influencing the adoption of ...     

Die Rolle der Ertragssteigerung im Anpassungsprozess der Landwirtschaft

Measures undertaken in the Federal Republic of Germany to rationalize agricultural production, viz. a reduction of intensive farming, simplification of farm production methods, and the introduction of specialization and mechanization, have been carried to their near completion in modern agricultural holdings. It is now necessary to introduce a new overriding economic principle if we are to successfully meet further wage increases and price reductions and improve the income level of the agricultural population. A new farm management concept based on the idea of a radical increase in specific intensive production methods is now being developed. In view of the high fixed costs in West German agriculture, the degression of fixed costs per production unit outweights the progression of variable costs when output is increased. In other words, higher yields per hectare and animal effect a decrease in unit costs. Nitrogen fertilizer being the most important factor in output increase, its profitable level is examined by means of six marginal value analyses. The fertilizer optimum is reached when marginal costs and marginal yields balance each other out. In all six examples this optimum coincides almost exactly with the point of maximum yield per hectare. This simplifies the problem considerably, at least under the conditions established for six examples. The optimal input level of nitrogen fertilizer does not have to be determined by means of a complicated marginal value analysis. It lies just under the maximum yield per hectare. We cannot expect that price-cost alterations will push this fertilizer optimum up within the near future. However, we may assume that new possibilities will open up for nitrogen fertilizer. In the first place, the majority of the agricultural holdings are still a long way from having reached the fertilizer optimum now economically feasible. Secondly, the present level of fertilizer optimum is constantly being raised as the result of technological advances. It is the task of economic counselling to achieve the fullexploitation of available earning power resources and the task of scientific research todevelop new earning power resources. The exploitation and the development of earning power resources can have very positive results in the case of inorganic fertilizer, since through its application it is possible to even out income disparities in agriculture

—help small holdings in particular, mineral fertilizer being a divisible input factor

—come closer to a solution of the central probrem of the agriculture of the Federal

—Republic of germany, that of combining high labour productivity with high soil productivity.

     

Logistic Regression Analysis on Factors Affecting Adoption of Rice-Fish Farming in North Iran

We evaluated the factors influencing the adoption of rice-fish farming in the Tavalesh region near the Caspian Sea in northern Iran.We conducted a survey with open-ended questions.Data were collected from 184 respondents(61 adopters and 123 non-adopters) randomly sampled from selected villages and analyzed using logistic regression and multi-response analysis.Family size,number of contacts with an extension agent,participation in extension-education activities,membership in social institutions and the presence of farm workers were the most important socio-economic factors for the adoption of rice-fish farming system.In addition,economic problems were the most common issue reported by adopters.Other issues such as lack of access to appropriate fish food,losses of fish,lack of access to high quality fish fingerlings and dehydration and poor water quality were also important to a number of farmers.     

Economic implications of herbicide resistance and high labour costs for management of annual barnyardgrass (Echinochloa crus-galli) in Philippine rice farming systems

Implications of increasing labour costs and the development of herbicide resistance for profitable weed management in Philippine rice farming systems are investigated. The study employs RIMPhil (Resistance and Integrated Management in the Philippines), a bioeconomic simulation model developed to provide a comprehensive assessment of integrated weed management programmes for the control of annual barnyardgrass (Echinochloa crus-galli) in rice crops. Results indicate that herbicide application will become increasingly economically attractive, relative to manual weeding, as labour cost increases. This is important since urban migration in the Philippines continues to increase the scarcity of rural labour. Results also show that the onset of herbicide resistance results in substantial losses in farm profit. It is worthwhile for farmers to take management actions to prevent or delay the onset of herbicide resistance, provided that these changes are effective and not too costly. The study highlights the complexity of decision making about integrated weed management on rice farms in the Philippines.     

Soybean yield physiology and development of high-yielding practices in Northeast China

Soybean (Glycine max (L.) Merrill), one of the most important crops in China, has been known to man for over 5000 years. Soybean production in China increased from 7.5 million Mg in 1978 to 26 million Mg in 2005. The largest production areas in China are in the Northeast China's three provinces, where soybean is spring seeded and grown as a full-season crop. Development of research programs and rapid adoption of technologies emerging from agricultural research by producers including a better understanding of the physiological processes of growth and development, improved cultivars and cultural practices, and a higher demand of the soybean processing industry has contributed much to the upward trend in on-farm yield and total production. Research on leaf area index (LAI), light interception and canopy photosynthesis, source–sink relationships, phytohormones, environmental stresses (drought and cold damage), development of cultivar selection, tillage systems, cultivation practices as well as weeds, insects and diseases during the last half century in Northeast China were reviewed. The intent is to document a summary of the understanding of soybean physiology and culture for high yields mainly from Chinese scientists’ perspective.     

Annual forage legumes in dryland agricultural systems of the West Asia and North Africa Regions: research achievements and future perspective

Forage legumes are vitally important to animal production in the dryland farming systems of the Mediterranean region. Of the diverse forage‐legume species adapted to the Mediterranean climate, vetches, (Vicia spp.), chicklings (Lathyrus spp.), annual medics (Medicago spp), clovers (Trifolium spp.) and species of the Lupinus, Lotus, Onobrychis, Hedysarum and Ornithopus genera are considered to be the most agronomically important and economically valuable species for the region. Adoption of perennial self‐regenerating medic (Medicago spp.) has been limited because of technical difficulties, but annual vetch (Vicia spp.) has the greatest potential as a viable animal‐feed source and a rotation crop with cereals. Some forage legumes survive harsh conditions by their unique underground growth habit, for example, V. amphicarpa and Lathyrus ciliolatus. Efforts to improve forage legumes have been based on both management/cultural factors and breeding. Research based on several long‐term barley‐ and wheat‐based rotation trials has demonstrated the viability of forage legumes, especially vetch, in the region's improved farming system. An additional benefit to such legumes is the enhancement of soil quality, that is, soil fertility, soil organic matter and soil physical properties. Thus, the development of forage legumes is essential to agricultural sustainability in the Mediterranean region and in other dryland cereal‐growing areas of the world where grazing livestock is a dominant enterprise. To build upon the considerable research conducted on forages, intensified efforts are needed to develop locally adapted forage cultivars, to provide economic assessment of forages in cropping systems and to promote technology transfer at the farm and community level.     

浅析农业机械化与农业增效、农民增收

介绍了农业机械化在节约农业生产成本、提升农产品品质、提高农业综合生产能力,增加农业产出,促进农业劳动力转移,增加农民收入中的积极作用。提出落实农机购置补贴政策,提高和优化农机装备水平;实施农机服务组织创新,提高农机利用率和机械化作业水平;加强农机新技术的推广应用,促进农业产业结构调整;大力发展非农产业,促进劳动力转移;加强农机培训工作,提高农民自身素质等发展农业机械化的建议。     

The Role of Cover Crops in North American Cropping Systems

SUMMARY

The benefits of cover crops in cropping systems have long been recognized. Legumes have historically been used lo provide biologically fixed nitrogen to cash crops, and it has been shown that soil erosion can be slowed significantly with even minimal amounts of soil cover during vulnerable times of year. The role of cover crops in North American farming systems is expanding to include management of weeds, disease and pests, and overall enhancement of soil quality through organic matter enrichment, improved nutrient cycling and reduction of soil compaction. While the predominant temporal niche for cover crops in North America remains the winter, other opportunities in diverse cropping systems exist for cover crop inclusion, such as summer fallow, living mulches or full-year fallow crops. To date, the use of cover crops is constrained by economic, biological, and farm operational factors, but farmer education, continued research, and government policy changes can aid in overcoming existing barriers to adoption.     

A decision-making model for rice paddy cropping in an urbanizing area of the Lao PDR

In Southeast Asia, economic and population growth are expected in the near future. Rapid change is anticipated especially in the Lao PDR. Concern has been expressed that population growth will lead to an increased demand for food and economic growth to changes in the use of land. For food production to keep pace with the growth of population, it is very important to understand decision-making in rice paddy cultivation in urbanizing areas; for this reason, this study with the SEM model was conducted. The original data were collected by a questionnaire survey in some Lao villages; the survey included questions on various conditions, such as the availability of water in the dry season (irrigation), the access to a city, and job opportunities other than farming. The findings of the study demonstrate that the planting of a second rice crop was related to such factors as the productivity of rain-fed rice and cash crops and, most importantly, job opportunities other than farming.     

Effect of herbicide application on weed flora under conservation agriculture in Zimbabwe

Increased challenges of weed control in the smallholder farming sector of southern Africa have often resulted in small yields. The objective of this study was to evaluate the effects of different weed control strategies on weed flora and composition under conservation agriculture (CA) systems in Zimbabwe. This study was conducted at three on-station trial sites namely Domboshawa Training Centre (DTC), University of Zimbabwe farm (UZ farm) and Henderson Research Station (HRS) in a maize–soybean rotation for four seasons from 2009–2010 to 2012–2013 seasons. Hand weeding was done whenever weeds were 10 cm tall or 10 cm in circumference for weeds with a stoloniferous growth habit. Weed identification was done up to the weed species level, and the Shannon–Weiner diversity and evenness index was used to determine the response of weed flora to herbicides. Results showed that there were more weeds in the early years which decreased gradually until the final season. Weed species diversity was not affected by herbicide application and the results indicated that weed species diversity was small in CA systems. Annual weed species constituted a greater proportion of species, and species richness decreased with the duration of the study. Richardia scabra L. and Galinsoga parviflora Cav. were the most common dominant weed species at all sites and in all seasons. Moreover, herbicide application had no effect on the evenness of weeds in the plots but site characteristics had a significant effect on the distribution of weed species (weed species evenness). The results presented in this study suggest that herbicide application facilitates a depletion of weed seed bank/number of weeds over time. Thus, herbicide application in CA has potential to reduce weed density, species richness and species diversity in the long term which may lead to more labour savings and larger yields.     

A multi-field bio-economic model of irrigated grain-cotton farming systems

We present a participatory modelling framework that integrates information from interviews and discussions with farmers and consultants, with dynamic bio-economic models to answer complex questions on the allocation of limited resources at the farm business level. Interviews and discussions with farmers were used to: describe the farm business; identify relevant research questions; identify potential solutions; and discuss and learn from the whole-farm simulations. The simulations are done using a whole-farm, multi-field configuration of APSIM (APSFarm). APSFarm results were validated against farmers’ experience. Once the model was accepted by the participating farmers as a fair representation of their farm business, the model was used to explore changes in the tactical or strategic management of the farm and results were then discussed to identify feasible options for improvement.Here we describe the modelling framework and present an example of the application of integrative whole farm system tools to answer relevant questions from an irrigated farm business case study near Dalby (151.27E - 27.17S), Queensland, Australia. Results indicated that even though cotton crops generates more farm income per hectare a more diversified rotation with less cotton would be relatively more profitable, with no increase in risk, as a more cotton dominated traditional rotation. Results are discussed in terms of the benefits and constraints from developing and applying more integrative approaches to represent farm businesses and their management in participatory research projects with the aim of designing more profitable and sustainable irrigated farming systems.     

Conceptual Model for Sustainable Cropping Systems in the Southeast: Cotton System

SUMMARY

Many small to mid-size family farms face an economic and ecological crisis due to the changing face of agricultural production. Increasing production costs and lower revenues are causing many producers to leave the farm. Rural communities face economic hardships due to declining farm numbers and continued loss of the brightest youths who often seek employment in urban areas. Small to mid-size family farms and rural communities can be sustainable if economic and environmental risks are recognized and solutions developed that reach all members of the farm and rural communities. Our project focuses on the involvement of farmers, scientists, and other stakeholders to enhance understanding of sustainable principles at the farm level and extend awareness of the central components to sustainability of rural communities. Conservation tillage with cover crops is being used to modify pest pressures, reduce chemical inputs, improve soil productivity and reduce environmental risks to producers, the community and the environment in cotton (Gossypium hirsutum L.) production systems. Preliminary results indicate that reductions in use of pesticides can be achieved due to enhanced presence of beneficial insects. Cotton offers the best opportunity to enhance the understanding and use of sustainable practices in ecologically-based farming systems because of its predominance in southern farm enterprises. Farmer participation and understanding is being facilitated through the participation of the farmer based Georgia Conservation Tillage Alliance. To achieve greater outreach and broaden community participation within the region we are involving at-risk rural youth through the Communities in Schools of Georgia program. Outreach includes the use of traditional and newer internet based technologies through the development of databases and expert systems that allow, farmers, ranchers, and community members an opportunity to evaluate economic and environmental effects of alternative production practices at local and regional scales. Through interactions with existing federal, state, and private organizations we are encouraging expansion of these sustainable approaches regionally.     

Transferring water from irrigation to higher valued uses: a case study of the Zhanghe irrigation system in China

The Zhanghe irrigation system (ZIS) is located in the Yangtze River Basin approximately 200 km west of Wuhan in Hubei Province. The reservoir was designed for multiple uses—irrigation, flood control, domestic water supply, industrial use, aquaculture, and hydropower. Over a period of more than 30 years a steadily increasing amount of water has been transferred from irrigation to other uses. Activities on the part of government, irrigation system managers, and farmers made this transfer possible with only modest decline in rice production. Most important factor was the steady increase in rice yields. The water pricing system provided an incentive for ZIS to reduce irrigation releases. With the steady decline in releases, farmers were forced to find ways to save water. Farmers improved existing ponds and built new ones to store water (improved infrastructure). Access to pond water on demand facilitated the adoption of alternate wetting and drying (technology) particularly in dry years. The establishment of volumetric pricing (price policy) and water user associations (institutions) may also have provided incentives for adoption of AWD, but more research is needed to establish their impact. These activities taken together can be seen as potentially complementary measures. Farmers received no direct compensation for the transfer of water, but recently farm taxes have been reduced or altogether abolished. Further reduction in water releases from the ZIS reservoir could adversely affect rice production in normal or dry years.     

Systems approaches to innovation in crop protection. A systematic literature review

The objective of this paper is to explore the extent to which systems approaches to innovation are reflected in the crop protection literature and how such approaches are used. A systematic literature review is conducted to study the relation between crop protection and systems approaches to innovation in 107 publications. The analysis of the crop protection literature demonstrates that only a small fraction is systems-oriented as compared to the bulk of publications with a technology-oriented approach. The analysis of agricultural innovations systems literature shows that, although crop protection is addressed, the potential of this systems approach remains largely unexplored for crop protection innovation. A large share of the publications included in this review focus on cropping or farming ‘systems’ while ‘innovation’ often equals the development, transfer, adoption and diffusion of crop protection technologies at farm level. There is relatively little attention for the institutional and political dimensions of crop protection and the interactions between farm, regional and national levels in crop protection systems. The traditional division of roles and responsibilities of researchers as innovators, extension personnel as disseminators, and farmers as end-users, is challenged only to a limited extent. The majority of publications discusses ways to optimise existing features of crop protection systems, without exploring more structural transformations that may be required to enhance the resilience of crop protection systems.