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.     

稻虾综合种养水稻品种筛选研究进展

稻虾（克氏原螯虾）综合种养是推进水稻绿色生产的重要方式,促进了水稻产业的提质增效,有利于水稻产业转型升级。近年来,稻虾综合种养在全国多地迅速推广,但当前稻虾还存在种养产量和效益不稳、稻虾种养技术亟待优化、尤其是优质高产抗倒水稻品种较为缺乏的问题。已有研究者针对稻虾连作或共生种养条件下的水稻品种选用开展了各有侧重的研究。本文阐述了目前稻虾种养下水稻品种筛选的研究进展,探讨了不同稻虾种养模式对水稻品种特性的要求,提出了今后稻虾种养品种选育和筛选应用的发展方向,可为提高稻虾综合种养质量和效益提供参考。     

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 ...     

深水灌溉对稻渔共生水稻抗倒伏性的影响研究进展

持续一定时间的深水灌溉是稻渔共生的必要条件。稻渔共生条件下水稻品种优质、高产、抗倒伏性状的优劣直接影响到稻谷量质安全。本文阐述了稻渔共生下水稻品种的筛选、倒伏的危害与抗倒伏评价体系的构建,以及深水灌溉对水稻茎秆力学、形态学和解剖学特征的影响等研究进展,旨在为稻渔共生高质量发展提供参考。     

Labor requirements of system of rice intensification (SRI) in Cambodia

Local governments, NGOs, system of rice intensification (SRI) adopters, and researchers in Cambodia have extensively discussed the SRI. Agreement on the benefits, however, remains elusive. Some claim SRI increases rice yields at lower costs; others state that the evidence is still inconclusive. The adoption and impact of innovations influenced by the most practical SRI principles, which adopters can and do implement, as well as other SRI labor requirement have yet to be comprehensively investigated. This study aimed at elucidating and comparing distinct aspects of SRI labor requirements and conventional practices that can lead to more intensive SRI adoption. A household survey and field observations were conducted in three rain-fed villages in the southern part of Cambodia: two in Kampot Province and one in Kampong Speu Province. Findings showed little or no difference between SRI labor requirements and conventional practices. Laborers are in high demand when preparing land and nurseries, transplanting seedlings, and harvesting. Rice farmers alone or hired laborers have generally proved sufficient to date. Hired labor costs depend on the supply of farmer-family labor and the efficacy of the “Sharing-hand” system, not on farming techniques per se. This system helps alleviate hired labor costs, one of the highest cost factors. The findings also indicated that the degree of SRI adoption shows no correlation between the home-to-plot distance and availability of farmer-family labor or hired labor. The key factors for improving the degree of SRI adoption are farmer zeal and careful attention rather than the home-to-plot distance and availability of labor.     

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.     

Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond

Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture. However, the effect of rice-fish co-culture on oxygen depletion has rarely been investigated. We constructed a rice-fish co-culture system in yellow catfish (Pelteobagrus fulvidraco) and freshwater shrimp (Macrobrachium nipponense) ponds using a new high-stalk rice variety, and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption. The results showed that rice-fish co-culture reduced the nutrients (total nitrogen, ammonia-N, total phosphorous and potassium) and the dissolved oxygen content in fish and shrimp ponds. However, they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds. Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond. The respiration rates in water and sediment were significantly reduced by 66.1% and 31.7% in the catfish pond, and 64.4% and 38.7% in the shrimp pond, respectively, by additional rice cultivation. Rice-fish co-culture decreased the proportions of respiration in sediment and water, and increased the proportion of fish respiration. These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond.     

Adoption and Impact of Modern Rice Varieties on Poverty in Eastern India

The factors affecting the adoption of modern varieties(MVs) of rice and impact on poverty in Odisha, India were discussed. A total of 363 households from Cuttack and Sambalpur districts of Odisha via multistage sampling technique participated in the survey. The Cragg's Double hurdle model was used to model the determinants of adoption and intensity of adoption of MVs of rice, and the propensity score matching was used to analyze the impact of adoption on poverty. The results showed that age, education, risk aversion, land size, yield, perception of MVs as high yielding, resistant to diseases and availability of MVs positively influenced the decision to adopt. However, variables such as household size, experience of a farmer, off-farm job participation, amount of credit received, cost of seeds, insecticides and fertilizers negatively influenced the adoption of MVs. Intensity of adoption of MVs was negatively influenced by experience of a farmer, cost of fertilizer and marketability of MVs, and positively affected by household size, risk aversion, land size, cost of insecticides, perception of MVs as high yielding and availability of MV seeds. Poverty incidence, gap and severity were high among non-adopters to adopters of MVs. After matching adopters and non-adopters of MV groups using four different algorithms of nearest neighbour matching, stratification matching, radius matching and kernel matching, the impact of MV adoption resulted in higher per capita monthly household expenditure by about US$ 52.82 to US$ 63.17.     

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.     

高海拔稻田养鱼与常规粳稻新品种选择试验探索

在以往试验的基础上,结合稻田养鱼的成功经验,通过不断完善试验方案,在高海拔养鱼稻田开展了粳稻新品种选择试验。结果为,养鱼稻田新品种比较试验田稻谷产量575.1 kg/667 m^2,鱼产量40.6 kg/667 m^2,周边非养鱼稻田稻谷产量645.2 kg/667 m^2,试验田稻谷价高,养鱼增收1497.3元/667 m^2。     

A research agenda to explore the role of conservation agriculture in African smallholder farming systems

Controversy surrounds the promotion of conservation agriculture (CA) in smallholder farming systems in sub-Saharan Africa. The introduction of CA is a profound change in farm management. Benefits in reduced erosion and stabilized crop production may be obtained, but technical performance at field level is but one of the determinants of adoption. For various reasons, all of the CA principles are not always fully implemented by farmers and results not as favourable as expected. As with other approaches to increasing agricultural productivity, the production constraints, farmers’ objectives, and the expected benefits and costs of implementing CA are important aspects that influence adoption. At farm and village levels, trade-offs in the allocation of resources become important in determining how CA may fit into a given farming system. At a regional level, factors such as the market conditions, interactions among stakeholders and other institutional and political dimensions become important. At each level, opportunities or difficulties emerge that enhance or impede development, adaptation and adoption of CA. The ex-ante identification of situations for where CA (and which form of CA) is appropriate demands research from a multi-stakeholder, multi-level, and interdisciplinary perspective. Recommendations are made where research is required to address key knowledge gaps.     

Acceptance of diffused light storage technology by potato farmers in the Benguet and Mountain Provinces of the Philippines

Improper seed potato storage was considered to be a major constraint in the Philippine highlands. For this reason a program of introducing diffused light storage technology was launched in early 1978 to resolve the problem. Scattered reports indicated a rapid adoption of the technology by the farmers; however no follow-up had been done to determine the extent of adoption. Hence, a survey was conducted from July to December 1983 to assess the impact of the diffuse light storage (DLS) technology among potato farmers. Of the 1412 farmers interviewed 42% have adopted the DLS technology. Nearly all adopters have simply modified existing structures to permit diffuse light to enter and store tubers in thin layers. Only 1.5% have constructed simple storages. Generally the farmers who accepted the technology are close to the main access road and are the more progressive farmers. Most reported better quality seed and subsequent higher yields as a result of the technology. Conversely, 35% of the respondents, primarily in remote areas, were not even aware of the DLS technology. Another 27% of the respondents planned to accept the technology by improving their traditional storages. To increase the utilization of the technology, more extension effort needs to be put forth demonstrating the benefits of the DLS by improving existing storage structures found in remote areas where potato production is not well developed.     

Evaluating smallholder farmers’ demand for rice variety attributes in Nepal

Despite the release of many modern varieties of rice (Oryza sativa), farmers in Nepal have been cultivating relatively few rice varieties. The objective of this study is to estimate farmers’ demand for rice variety attributes and to identify the factors that influence their decision regarding varietal choice. Yield increase is considered jointly with other attributes, such as cooking and eating quality, drought tolerance, and maturity period. Choice experiments were conducted and results showed that there was significant demand from farming households for yield increase, improvement in cooking and eating quality, tolerant to drought, and short maturing varieties. The choice data were analyzed using a multinomial and random parameter logit model. From a policy perspective, results showed that for broader adoption of crop varieties, variety development programs should give priority to aforementioned attributes rather than solely on increased crop productivity.     

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.     

丘陵山区稻鱼综合种养技术规程

稻田综合种养模式下稻谷和水产品价值协同提升,显著增加单位面积产值,并改善农田生态环境。该规程规定了稻鱼综合种养环境条件、品种选择、田间设施建设、稻鱼共生期管理及收获等管理技术,为丘陵山区稻田综合种养提供技术支持。     

“烟草-水稻”轮作模式耦合养鸡养鱼的技术要点

烟草是我国重要的经济作物。连作种植作为烟草的主要栽培方式，具有节省劳力、劳作时间、生产成本等优势，但烟草长期采用连作会导致土传病虫害增多、杂草群落较为单一、土壤肥力和微量元素下降等诸多问题，降低了烤烟产量和烟叶品质；加上烟草连作中烟叶采收后，农田基本处于闲置状态，造成土地资源浪费，加重了烟粮争地的矛盾，导致烟农收入减少。针对烟草连作栽培所出现的问题，笔者提出了“烟草-水稻”轮作耦合养鸡养鱼的综合种植与养殖模式。该模式在烤烟采收后，将水稻直接种植在烟垄的两侧，实现烟垄免耕，节省了水稻生产成本。水稻种植后，垄肩保持湿润无水，便于鸡捕食等活动，垄沟灌水便于水稻生长和养鱼，通过鸡鱼在稻田活动可防控田间病虫草害，鸡鱼粪便可培肥土壤，利于降低农药和肥料用量，进而改善农田生态环境，产出优质的稻米、鸡和鱼等农产品，显著提高稻作经济效益，并实现烟田土壤改良和烟农收入增加的双重目标。本文结合“烟草-水稻”轮作耦合养鸡养鱼的具体实施情况，论述了该模式的技术要点、综合效益和发展展望等，以期为“烟草-水稻”轮作下开展养殖提供技术借鉴。     

Socioeconomic and Agricultural Factors Associated with Mixed Cropping Systems in Small Farms of Southwestern Guatemala

SUMMARY

Many small farming communities in Latin America have modified their traditional cropping systems to incorporate non-traditional export crops (NTEC). The shift from subsistence to commercial agriculture is perceived by development agencies as an opportunity to alleviate poverty in rural areas. However, most small-scale farmers are not familiar with the production problems of NTEC, such as Bemisia tabaci and various geminiviruses transmitted by this whitefly species. In the absence of adequate technical assistance, due to drastic budgetary reductions in national agricultural research programs, farmers have relied on agrochemicals to protect their NTEC. This situation has led to considerable pesticide abuse and rejection of contaminated produce in international markets. This study analyzes some of the factors determining the adoption of NTEC and displacement of traditional food crops in southwestern Guatemala, and suggests possible measures to allow small farming communities to benefit from broad-based cropping systems that include both traditional and non-traditional food and cash crops.     

Predicting adoption of double cropping in paddy fields of northern Iran: a comparison of statistical methods

Factors affecting the adoption of double cropping were explored in rice farms of Fouman County of Guilan Province in northern Iran using artificial neural networks (ANNs), linear discriminant analysis (LDA), and logistic regression (LGR). Eleven factors (age, education, occupation, family size, type of farm ownership, distance to the agricultural service center, attending agricultural extension courses, use of financial resources and bank loans, number of domestic animals, area under cultivation, and social participation) were examined. An additional objective was to compare the ability of the three models in predicting the adoption of double cropping. ANNs showed an overall predictive power of 89.8%. LDA showed an overall predictive power of 83.2%, with seven of the eleven independent variables being effective on the adoption of double cropping. LGR indicated an overall predictive power of 87.6%, with eight of the eleven independent variables being effective on the adoption of double-rice cropping. ANNs showed higher power than LGR and LDA in predicting the adoption of double cropping. Based on all three methods used for analysis, the most important independent variables were social participation and area under cultivation (positive factors) as well as distance to the agricultural service center and family members (negative factors). Establishment of cooperatives or other kinds of farmers’ associations to foster social participation could motivate adoption of double cropping, particularly among small-scale farmers. To increase agricultural services, more local centers should be created in rural areas. The government should promote double cropping through effective incentives and technology transfer to small-scale farmers.     

Phage Therapy and Photodynamic Therapy: Low Environmental Impact Approaches to Inactivate Microorganisms in Fish Farming Plants

Owing to the increasing importance of aquaculture to compensate for the progressive worldwide reduction of natural fish and to the fact that several fish farming plants often suffer from heavy financial losses due to the development of infections caused by microbial pathogens, including multidrug resistant bacteria, more environmentally-friendly strategies to control fish infections are urgently needed to make the aquaculture industry more sustainable. The aim of this review is to briefly present the typical fish farming diseases and their threats and discuss the present state of chemotherapy to inactivate microorganisms in fish farming plants as well as to examine the new environmentally friendly approaches to control fish infection namely phage therapy and photodynamic antimicrobial therapy.