Cross country maize market linkages in Africa: integration and price transmission across local and global markets

In order to study short‐run price shock propagation, we model twenty seven Sub‐Saharan Africa (SSA) domestic maize markets within a Global Vector Autoregression framework. The main purpose is to fully embed multilateral trade flows as a way to better structure local price transmission dynamics and interdependencies, and get a more comprehensive picture of food price shocks propagation. We found significant between‐country market contagion and prompt regional price shock propagation when trade connection exists. Yet, the integration of SSA domestic maize markets within the continent and with global markets remains generally weak. Furthermore, under regular market conditions, most local price series appear to be more responsive to regional neighbors than to global shocks.     

平房仓玉米“内结露”调质增湿试验

东北地区储粮粮堆由于气候原因存在一个巨大的“冷心”,冷心的应用主要方式为膜下环流均温控制和缓式通风上调冷心控粮温,这两种方式都是利用冷资源进行的粮温控制。而目前的粮堆增湿方式主要为湿膜机增湿和各种调质机增湿,利用“冷心”增湿还没有成功的案例。利用冷心增湿,内结露现象很严重,而且容易出现局部水分偏高现象,且违反机械通风操作规程1。但通过缓式通风的精确掌握和粮堆增湿理论的精确控制,精细控制,大胆试验,事实证明冷心内结露增湿方式是可行的。试验将出仓前平均水分13．5％提高到最高14．8％,平均水分14．1％,达到试验预期目的。试验仓出仓验证实际增量21．05t,效益十分可观。更重要的是避免了资源浪费,为粮食安全和粮食水分这对矛盾体找到了一个在实践中切实可行的平衡点,它的发展前景是广阔的,也必然会成为将来的一种常态储粮管理手段。     

Integration of conservation agriculture in smallholder farming systems of southern Africa: identification of key entry points

A component-omission experiment based on the principle of conservation agriculture (CA) was established on smallholder farms for three seasons in Murehwa and Hwedza districts, Zimbabwe; Barue district in Mozambique; Balaka district and Chitedze Research Station in Malawi, and Monze district in Zambia to identify strategies for improving crop productivity and livelihoods for smallholder farmers. The objective of the experiment was to evaluate the effect of tillage, residue retention, fertiliser application and weed control on maize yield. In addition, the study analysed possible combinations of these factors that could provide a sustainable entry point for intensification through CA. Results showed that fertilisation had the strongest effect on crop yield in both tillage systems; adequate fertilisation is therefore key to success in CA. Retention of crop harvest residues increased yield in no-tillage systems; no-tillage without residues depressed yield by 50% when compared with yields of conventional tillage. A step-wise integration of CA into the smallholder farming systems is proposed as a possible strategy to avoid new constraints on smallholder farms. If resources are limiting, farmers may apply all principles on small areas to overcome the initial demand in resources (labour, fertiliser and residues), and once productivity is raised, they can expand.     

Ex Ante Evaluation of Drought‐Tolerant Varieties in Eastern and Central Africa

This study presents a model to estimate potential benefits of drought‐tolerant varieties of maize, sorghum and millet in Kenya, Uganda and the Amhara region of Ethiopia. In addition to the benefits from mean yield increases, the model takes into account risk benefits associated with yield‐stabilising varieties. Ex ante estimates provided for different drought zones and for different household types within drought zones of each country suggest that drought resistance generates substantial benefits from both mean yield improvements and yield variance reductions for both consumers and small, medium and large producers.     

高水分玉米烘干过程中降低损耗的探讨

随着社会主义市场经济体制的日趋完善,粮食企业已经成为相对独立、自主经营的生产者与销售者,企业要生存和发展,不仅要从生产中获利,而且要向微观物流要效益。本文通过对某粮库进行跟踪调查,将微观物流理论应用到塔式烘干机汽烘高水分玉米的环节中,针对企业如何降低烘干损耗的问题作一次尝试性探讨。     

垦单5号玉米制种技术措施

垦单5号具有早熟高产、品质好、适应广的特点。2000年2月通过黑龙江省品种审定委员会审定并命名为垦单5号。     

Does the Use of Mobile Phones by Smallholder Maize Farmers Affect Productivity in Ghana?

ABSTRACT

This study evaluates the effects of mobile technology on productivity and the channels of transmission of these effects. Using propensity score matching procedures, the results show that mobile phone ownership and use significantly improves agricultural productivity. Specifically, the mobile phone improves the productivity of user-farmers by at least 261.20 kg/ha per production season. Further, we find that phone ownership and use impacts productivity more than phone use only. The identified channels of effect are extension services, adoption of modern technology and market participation. These results have key policy implications for Ghana and developing economies at large.     

Structural Adjustment Programme, Deforestation and Biodiversity Loss in Ghana

An empirical investigation is undertaken into the impact of the Structural Adjustment Programme (SAP) on forest and biodiversity loss in Ghana between the period 1965–1995. In the first part of the analysis, a four-equation recursive model, consisting of forest loss, cocoa land, maize land and timber production equations, is employed to examine the impact of the SAP on forest loss. The first equation is a function of the last three, and the last three are functions of mainly prices. Piecewise linear and switching regression approaches are used to distinguish between the influence of the post from the pre-adjustment impacts. These results together with a specie-forest area relationship are used to investigate the impact of the SAP on biodiversity loss. The overall results indicate that cocoa land expansion and timber production, but not maize land expansion, are the significant causes of forest loss in Ghana. However, the impact on forest loss in the post-adjustment period was reduced. The rate of biodiversity loss also reduced in the post-adjustment period. Changes in relative output and input prices due to the SAP may have played a significant role in the reduced impact of agricultural and timber related deforestation and biodiversity loss in the post-adjustment period.