Econometric estimation of a global spillover matrix for wheat varietal technology

An econometric approach using international and national yield trial data is employed to estimate a spillover matrix for wheat varietal technology. The global spillover matrix is estimated based on international yield trial data from 1979–80 to 1987–88, that include 195 international trial locations and 209 wheat varieties. The locations were classified across countries using the CIMMYT's wheat megaenvironment system and varieties were classified by both their environmental and institutional origin. The model gave good explanatory power and confirmed the location specificity hypothesis, at least, for the varieties developed by national programs (NARS). The spillover matrix shows that NARS varieties developed in the home' environment generally perform better on average than varieties developed in other megaenvironments. Also, the matrix is not symmetric. CIMMYT varieties perform better on average in irrigated and high rainfall environments than NARS varieties developed for these environments. The yield advantage of CIMMYT varieties in many test megaenvironments indicates the potential of CIMMYT varieties to spill-over to these test megaenvironments. Results also indicate that national programs are efficient in selecting from among imported technologies. Analysis of international data is complemented by the analysis of country-level data for Pakistan and Kenya that confirms the above results. The country-level analysis, however, indicates that CIMMYT germplasm does not do so well in some sub-environments, such as the irrigated short-duration environment. The results of the spillover matrix have implications for the design of crop breeding programs both at the national and international levels. Information provided by the spillover matrix can be utilized by national programs to deploy their resources more efficiently by following a mixed strategy of direct importation of technology in some environments and local development of technologies in other environments which are unique to the country.     

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.     

Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential

Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750 km² case study area in southwestern Bangladesh. We combined these data with georeferenced and temporally explicitly soil and water salinity information, in addition to relative elevation classifications, in order to examine the extent of winter fallows and low productivity rainfed cropland that could be irrigated by small-scale surface water pumps. Applying observations of irrigated crop sowing dates and yields from 510 wheat, 550 maize, and 553 rice farmers, we also modeled crop intensification production scenarios within the case study area. We conservatively estimate that at least 20,800 and 103,000 ha of fallow and rainfed cropland, respectively, could be brought into intensified double cropping using SWI. Scenario analysis indicates that if 25%–75% of the fallow or low-intensity land were converted to irrigated maize, national aggregate production could increase by 10–14% or 29–42%, respectively. Conversion to wheat would conversely boost national production by 9–10% or 26–31%. Irrigated rice is however unlikely to contribute >3%. In aggregate, these actions could generate between USD 36–108 million of revenue annually among farmers. Intensification therefore has important land use policy and food and income security implications, helping to rationalizei SWI investments. Crop choice, water resource allocation, and water governance will however remain crucial considerations for irrigation planners.     

A comparative analysis of rice–wheat systems in Indian Haryana and Pakistan Punjab

Intensive irrigated rice–wheat production systems have converted the north-west Indo-Gangetic Plains into South Asia's cereal basket. Their strategic importance is undermined by a slowdown in productivity growth linked to the degradation of soil and water resources. Findings from farm surveys are used to examine contrasts and similarities between rice and wheat farms, cultivation practices, productivity, and profitability in the rice–wheat belt of India's Haryana State and Pakistan's Punjab province. In Haryana average wheat and paddy yields are markedly higher, but the yield advantage is offset by higher total production costs, resulting in lower private returns. The diverging institutional environment including varying levels of intervention in produce and input markets contributed to the evolution of the Pakistani production model as relatively ‘medium input–medium output’ and the Indian production model as ‘high input–high output’. The study reiterates the need to reinvigorate productivity growth and to reduce production costs in these intensive cereal production systems while conserving natural resources such as water and limiting negative environmental impacts. The study however also raises questions about the future of current rice–wheat systems.     

Adoption of Food Safety Practices in Milk Production: Implications for Dairy Farmers in India

This study investigates the status, estimates the cost, and identifies the determinants of compliance with food safety measures in milk production in India. The study is based on the cross section primary data collected at the farm level in 3 states of India, namely, Bihar, Punjab, and Uttar Pradesh, in the year 2007. These states capture the geographical and institutional diversity of milk production and marketing in the country. The study shows that the status of compliance with food safety measures at the dairy farm level is not encouraging and a lot of efforts are needed to bridge this gap. The adoption intensity of food safety practices shows wide inter- and intraregional variations. This intensity depicts a positive relationship with herd size. The additional cost of compliance with food milk safety measures reveals an inverse relationship with herd size. The adoption intensity of food safety practices has been found to be influenced by the dairy farmers' characteristics. Herd size, education level, expertise in dairying, and integration of dairy farmers with modern milk supply chain have positive influence on the adoption intensity of food safety practices at the farm level. The positive relationship between adoption intensity of food safety measures and farmers' realization of milk price would influence farmers for greater adoption of these measures.     

INTER-REGIONAL FARM EFFICIENCY IN PAKISTAN'S PUNJAB: A FRONTIER PRODUCTION FUNCTION STUDY

Agricultural production efficiency in four irrigated cropping regions of the Punjab province of Pakistan was compared on the basis of a probabilistic frontier production function estimated from whole-farm survey data for the year 1984-85. It is found that the gross income of farmers can be increased by 13% at the current levels of resource use if the production gap between ‘best practice’ and ‘average’ farmers is suitably narrowed in all cropping regions. This will increase profits by up to 40%. No significant difference in technical efficiency was found across the regions. Economic efficiency was similar across all cropping regions except in the cotton region, which had significantly lower economic efficiency due to higher allocative inefficiency, which in turn was attributable to the more dynamic production technologies being adopted in that region.     

The extent of resource use inefficiencies in cotton production in Pakistan's Punjab: an application of Data Envelopment Analysis

This paper attempts to identify sources of resource use inefficiency for cotton production in Pakistan's Punjab. The use of a non‐parametric method, Data Envelopment Analysis (DEA), is developed to study the relative technical and allocative efficiencies of individual farms which use similar inputs, produce the same product and operate under comparable circumstances. In the ‘cotton‐wheat’ system of Pakistan, there are a considerable number of farms that are both technically and allocatively inefficient. The use of DEA shows that the technique provides a clear identification of both the extent and the sources of technical and allocative inefficiencies in cotton production. However, both the interpretation of the farm level results generated and the projection of these results to a higher level require care, given the technical nature of the agricultural production processes.     

A Participatory Simulation to Facilitate Farmers' Adoption of Livestock Feeding Systems Based on Conservation Agriculture in the Uplands of Northern Vietnam

In the mountain areas of northern Vietnam, extensive husbandry of large-ruminants is limited by the lack of natural forage. Since 2000, the Mountain Agrarian System Program has been concerned with this issue and has evaluated technical alternatives aimed at sustainable integration of crop-livestock systems. One alternative consists of feeding systems for largeruminants based on cropping systems with plant cover. Diffusion of information about the new system is supported by a set of interactive communication tools for use between farmers and researchers. A participatory simulation method was developed that combines a compartmental model of the village territory with five technical innovations. Farmers simulate the adoption of the innovations they choose among food-forage cropping systems in rotation or in association, and urea-treated straw. They evaluate the quantity of forage that can be grown for their herd using the chosen set of techniques.

Simulations revealed farmers' constraints and objectives in adopting sustainable cropping systems on the hillsides while maintaining a small animal husbandry system. The results obtained by each farmer provide a useful basis for discussion about the implementation of innovation. This participatory simulation method could be more widely used to facilitate the diffusion of innovations such as integrating livestock feeding systems with conservation cropping practices.     

Forty years of irrigation development and reform in China

This study reviews 40 years of irrigation development in China including the transformation of the institutional and incentive structures in irrigation management. After rural reforms in the 1970s, irrigation investments slowed until the late 1990s. In North China, farmers became major investors in groundwater irrigation, leading to property rights’ transfer of tube wells from collective to private ownership. Despite positive effects in cropping patterns, farmer income and development of groundwater markets, privatisation has accelerated groundwater table deterioration. Since the middle of 1990s, Water User Associations have replaced village collective management of surface irrigation. This approach was adopted by most provinces by early 2001 with mixed results; only institutions with water‐saving incentives realised efficient irrigation. The Government is reforming water price policies to provide water‐saving incentives to farmers while not hurting their income. While China has focused on water rights and markets, and despite regulations and pilot projects, full implementation of water rights has been slow. Research reveals greater policy scope for expanding irrigation technologies that generate real water saving to rural areas. Given pressure associated with water scarcity and concern for food security, further effective reforms in irrigation and policy incentives are expected. The Government has also initiated some pilot projects to resolve increasing water scarcity problems through adjusting agricultural production activities.     

互联网使用对农户采纳绿色农业技术的影响研究——基于河北省436个设施蔬菜种植户的调研数据

目的 推广绿色农业技术、强化农业绿色发展的科技支撑是实现农业经济高质量发展的根本要求。方法 文章选择了4项设施蔬菜种植户常用的绿色农业技术（抗病虫抗逆性强的新品种、生物防治、生物农药、水肥一体化）,通过计算互联网使用综合得分,运用有序Probit模型实证分析了互联网使用对农户绿色农业技术采纳强度的影响。进一步,结合工具变量法和条件混合过程估计法（CMP）来克服互联网使用的内生性问题,同时检验了社会网络在互联网影响绿色农业技术采纳过程中的调节效应。结果 互联网使用能够显著提高农户的绿色农业技术采纳强度,互联网使用程度高的农户更倾向于采纳多项绿色农业技术;社会网络在互联网使用影响绿色农业技术采纳行为的过程中具有负向调节作用,在影响农户采纳绿色农业技术的过程中互联网使用能够对社会网络产生替代作用。结论 政府应加快推进农村地区互联网基础设施建设,增加农户使用互联网的可行性和便易性;积极开发公益性的绿色技术知识普及、培训、推广和教学软件,帮助农户认识、接受并采纳绿色农业技术;引导农户使用互联网促进产品销售,实现绿色农产品的优质优价。     

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.     

Optimal Flex Cropping and Storage of Spring Wheat under a Progressive Income Tax

This article presents two versions of a stochastic dynamic programming model: one version is used to obtain the optimal decision rule for flex cropping of spring wheat assuming sale of grain at harvest, while the second version is used to obtain the jointly optimal decision rule for flex cropping and storage of spring wheat. The objective function for the model is the expected present value of after-tax income. The first version of the model illustrates that the flex cropping strategy that maximizes the present value of after-tax income differs from the strategy that maximizes the present value of before-tax income. The second model illustrates that production and grain-storage marketing decision rules are inseparable under a progressive income tax. That is, the optimal flex cropping strategy assuming sale of grain at harvest differs substantially from the flex cropping strategy when grain storage is permitted. L'article propose deux versions d'un modèle de programmation dynamique stochastique: I'une est utilisée pour obtenir la décision optimale d'emblaver ou non en blé de printemps en prévision de la vente du grain à la moisson, I'autre recherchant une décision optimale d'assolement du blé avec intention de stocker à la récolte. La fonction objective du modèle est la valeur actuelle attendue du revenu après taxe. La première version révéle que la stratégic d'assolement axée sur une valeur actuelle maximale après imposition, diffère de celle qui est axée sur la valeur actuelle du revenu avant impostion. Le second modèle montre que les décisions de production et de vente ou de stockage du grain sont inséparables dans un régime d'imposition progressive. C'est-à-dire que la stratégie optimale axée sur la vente à la moisson est sensiblement différente de celle qui suppose le stockage du grain à la récolte.     

Land use changes to cash crop plantations: crop types,multilevel determinants and policy implications

Cash crop plantation has recently become an expanding global phenomenon. Characterizing the dynamics of cash crop plantations and the corresponding determinants should provide critical references for land use policy. Using aerial photos and geographic information system, this paper investigated the trends of four types of cash crops (tea, fruit, mulberry and nursery) and their relations to other land use changes within Hangzhou region in subtropical China. Results showed that the total cash crop cultivated surface increased by 541.3 ha from 2004 to 2014. Most of the new tea and fruit plantations were established in places previously used as forest and woodland. Mulberry and nursery mainly expanded by replacing paddy, woodland and forest. By combining household survey, geospatial techniques and multilevel regression, multilevel determinants of cash cropping probability and cash crop expansion were quantified. At the parcel level, tea and fruit plantations inclined to occur on hilly land with gentle slope. Mulberry and nursery plantations were likely to be observed in flat areas with low elevation. Parcels covered by high quality soils and with convenient communications experienced greater cash cropping probability. At the household level, households constituted of female and old-aged labor or with low agricultural labor intensity demonstrated high probability of tea and mulberry plantations. Conversely, households constituted of middle-aged labor or with high agricultural labor intensity tended to grow more fruit and nursery. Besides, wealthier households were prone to establish fruit and nursery plantations but were reluctant to involve in tea and mulberry cropping. At the village level, population density was a significant determinant of cash cropping probability, but was an insignificant determinant of cash crop expansion. Greater occurrence of cash cropping was observed in villages with higher proportion of migrant labor and leasing land. Distance to county road and distance to provincial road were identified as negative determinants. Policy was evidenced to be of significant influence on cash cropping probability and cash crop expansion. We argue that a balance should be achieved between cash cropping promotion and natural resources protection in formulating the local land use policy.     

Peasant farmer behavior and cereal technologies: Stochastic programming analysis in Niger

Peasant farmers in Sahelian West Africa adjust to rainfall uncertainties in the agricultural season by making decisions sequentially as a function of the evolving rainfall patterns. Understanding such flexibilities in farmer decision-making is central to technology introduction. This paper determines how sequential decision-making under weather uncertainty affects the adoption and farm-level effects of cereal technologies in Niger. The study also draws policy implications for a price floor to arrest the substantial fall in cereal prices in good rainfall years when farmers have more grains to sell. The methodology used is Discrete Stochastic Programming. This paper shows that the ability of peasant farmers to adapt cropping and resource-management strategies to the rainfall patterns is the basis for their survival in this high-risk environment. Model results show that by (a) carrying a portfolio mix of varieties of varying maturities, and (b) making sequential decisions based upon rainfall expectations, farmers can adapt to the production uncertainties. Breeding programs should therefore be diversified to develop not only early-maturing cultivars, but also improved intermediate and long-season varieties.     

Integrated assessment of cropping patterns under different policy scenarios in Quzhou County,North China Plain

Agricultural land use is affected by government policies and leads to different consequences of regional sustainability. In this work, changes in cropping patterns including acreage, cropping locations and management-related environmental impacts were simulated under various policy scenarios for Quzhou County, China. This county is in China's major agricultural region, the North China Plain. Four dominant crop systems were categorized (winter wheat/summer maize, winter wheat/summer maize/spring maize, cotton, and vegetables) and analyzed, following two alternative policy scenarios that either prioritized government funding to subsidize crop production (“subsidy” scenario) or promoted advanced irrigation techniques (“technique” scenario). Input–output coefficients for all four crop systems were determined, mainly irrigation demand, yield, and price of produce, but other factors like a limited area of arable land and scarce regional water resources were also considered. For the simulation, a LINDO Inc. system was linked with the CLUE (Conversion of Land Use and its Effects) model. Temporal changes of crop systems were simulated with the LINDO system, whereas spatial dynamics of cropping patterns were simulated with the CLUE model, based on land suitability maps. The results show that crop patterns changed variably with time under the two scenarios, and water availability was the primary constraint on sustainability of land use. Under the subsidy scenario, winter wheat/summer maize/spring maize became dominant across the entire county, replacing other crop systems. In contrast, the vegetable system gradually occupied farmland surrounding the township under the technique scenario. The different policies produced opposite consequences for regional sustainability. Although a “subsidy” policy contributed to farmers’ income, it did not encourage water conservation for sustainable crop production, leading to land abandonment because of water shortage. In contrast, the “technique” policy partially cut direct financial benefits to farmers, but promoted water conservation and made a substantial contribution to agricultural sustainability.     

Adoption of new tobacco varieties in Greece: Impacts of empirical findings on policy design

Greece is a major international tobacco producer. Flue-cured tobacco varieties constituted the major alternative crop to Greek farmers growing certain oriental tobacco varieties. Diffusion of flue-cured tobacco was rapid due to its high yields and the depressed market for certain oriental tobacco varieties. Currently, the common organisation of the tobacco market is undergoing substantial changes, and the farmers' response will be a vital factor of success. A portfolio selection model reveals that the major factors influencing the adoption decision of tobacco growers are the size of the farm measured in annual work units, the farm's proximity to urban centres, the farm's diversification and the farmer's age. The number of contacts with institutions is, surprisingly, inversely related to adoption. Future tobacco policies impinging on factors influencing decisions to adopt new varieties or production practices may be more cost-effective.     

The intensity change of urban development land: Implications for the city master plan of Guangzhou,China

The Chinese economy has experienced substantial development over the last thirty years. This growth has resulted in an enormous expansion of China's urban areas and it has also led to a growing scarcity of land resources. Consequently, there is currently an urgent need to mitigate the conflict between the needs of growing urban areas and the shrinking supply of land resources. Understanding land-use intensity and its changes can provide important information to find mitigating measures for this conflict in the demand for land. Previous studies have found that increasing the utilization efficiency of land resources is one of the most effective ways to resolve this issue. This study focuses on the city of Guangzhou, which is an intensively developed megalopolis. A number of different data sources have been analyzed to find the characteristics and changes in urban land use in Guangzhou, including: Landsat data from 1979, 1990, 2000, and 2009; relative socioeconomic data from the Guangzhou statistic yearbooks; and the master plans of Guangzhou. The results indicate that the area of developed land has continued to increase. Urban development land intensity and its change were then explored using a Back Propagation neural network model of the city. Although the analysis revealed that urban development land did not have a higher intensity overall, it also showed that there was a sectional upward trend throughout the study period. Consequently, there is a potential to improve the land-use intensity of Guangzhou. A linear regression model was then adopted to explore the mechanism of land use change. The results reveal that rapid industrialization and urbanization have improved land-use intensity in Guangzhou. The per capita urban road area and per capita GDP show a strong relationship when compared with land-use intensity. Using the relative city master plans, the authors have argued that local government in Guangzhou has taken active steps to address land issues to promote the city's socioeconomic development; however, a scientific city master plan in the study area is still necessary to ensure the effective utilization of the city's limited land resources.     

Estimating loss of ecosystem services due to paddy straw burning in North-west India

Crop residue burning is severe in rice–wheat cropping system of North-western states (Punjab, Haryana, Uttarakhand, and western Uttar Pradesh) of India, where mechanized harvesting of rice using combine harvesters is a common practice, and management of leftover residue in the short window of 10–15 days for timely sowing of wheat is a formidable task. Moreover, there is a lack of user-friendly, cost-effective, and economically viable options and, around 23 million tonnes of rice residue is burnt annually in the region. Burning biomass not only pollutes environment but also results in loss of appreciable amount of plant’s essential nutrients. Straw burning releases soot particles, nitrogen oxides, sulphur dioxide, carbon dioxide, carbon monoxide, and polycyclic aromatic hydrocarbons, thus causing serious deterioration in atmospheric quality and human health hazards. We attempted to identify and quantify the environmental cost of paddy straw burning in North-west India. Using extant coefficients, it is estimated that cost of paddy residue burning is INR (Indian National Rupee) 8953?per?ha, and the social cost of burning is INR 3199 crores per annum in the region.     

An economic analysis of sheep flock structures for mixed enterprise Australian farm businesses

A strategic question facing many mixed enterprise broadacre farm businesses in Australia is, ‘What sheep flock size and structure is most profitable to complement the farm’s cropping enterprises?' This study answers this question for a typical large mixed enterprise farm business in a key production region of Australia. Whole‐farm bioeconomic modelling, combined with broad‐ranging sensitivity analysis, is used to examine the profitability of different sheep flock structures and sizes. We find the most profitable flock structure is to run Merino ewes and turn off finished Merino or first‐cross lambs. The profitable selection of these flocks is robust to commodity price variation but does require the farmer to give more attention to sheep management. The correct choice of flock structure greatly adds to farm profit. A farm based on cropping and a self‐replacing Merino flock using surplus ewes for first‐cross, meat lamb production earns 33 per cent more profit than a similar farm that runs a traditional self‐replacing Merino flock that emphasises wool production. Of far less importance than flock structure, as a source of additional profit, is to increase flock size or adjust cropping intensity.     

Induced innovation and land degradation: Results from a bioeconomic model of a village in West Africa

This paper introduces a modeling method which simulates a village's response to population and market pressure. The method combines a recursive and dynamic linear programming model with a biophysical model of soil condition and plant growth that predicts yields and land degradation for different type of land, land use and cropping patterns. The linear programming model simulates farmers' plans aggregated at the village level under constraints of risk aversion, food consumption, land area, soil fertility, soil depth, labor and cash availability. Detailed agroecological factors determine Ihe main processes of land degradation. A large number of technological alternatives, representing different degrees of labor and/or land-saving techniques available in the study areas, are introduced, taking into account their respective constraints, costs and advantages. The method has been calibrated for a village located in the sub-humid region of Burkina Faso. Several simulations are carried out to the Year 2030. The results show that population pressure leads to intensification and investment in land conservation practices out not necessarily to better farm incomes. Increasing market opportunities can play a more positive role in boosting productivity, but for the next decades the best way to increase production per farmer is to let farmers migrate from the high-population-density areas to the low-population-density areas because, under the current economic conditions of most Sahelian countries, intensification per hectare is stil more expensive than the fallow system.