Faidherbia albida on the Tonga Plateau of southern Zambia: an agroecological analysis

Faidherbia albida is a tree species indigenous to semi-arid regions of Africa that reportedly substantially increases maize (Zea mays) yields in its immediate vicinity. In southern Zambia, F. albida is widely used in indigenous maize farming systems and this has apparently increased over the past two decades. Using a combination of interviews, group meetings, and observations, this study sought to understand why this species seems to have recently been embraced, while other technological innovations apparently have not. We observed a bimodal age distribution of the trees in agricultural fields and posit that the missing cohorts were removed as weeds as a result of evolving notions of what constituted modern farming practices in the emerging maize economy. With subsequent research and social promotion of the beneficial effects of F. albida, farmers now allow the trees to grow in their fields. A holonic analysis points to the important relationship of F. albida to contexts that shaped past and current uses of the tree by farmers on the Tonga Plateau: information, maize, cattle, land tenure, and government policy. Advice promulgated by social promotion activities took root in farmer knowledge contexts because of positive regard for F. albida and timeless injunctions against cutting mature specimens. Furthermore, cultivation of the tree was highly compatible with other important contexts in which farmers operate. However, our research also revealed the potential for adoption of the tree to create new tensions arising from the strong gendering of work and crops in the region.     

Consumer acceptability and perceptions of maize meal in Giyani,South Africa

This study examined the acceptability and perceptions of traditionally prepared maize meal porridge, cooked from commercial roller-mill white maize meal and hammer-mill white and yellow maize meal (with and without fibre), among female Tsonga consumers in Giyani in Limpopo Province, South Africa. The study used sensory evaluation tests, followed by focus group discussions to gather supportive information about consumer attitudes, perceptions and practices regarding the consumption of maize meal porridge prepared from these maize meal types. Giyani consumers preferred commercial roller-mill white sifted fortified and white super-fortified maize meal, but, contrary to popular belief, were also willing to accept hammer-mill yellow maize meal, mainly for its nutritional value.     

实施伏季休渔制度以后的思考

伏季休渔适合我国国情，在国内外产生了重大影响。当前最关键的是要控制捕捞强度，限制渔船增长。现在海洋捕捞计划产量实行"零增长"，将来可能还要提出"负增长"。保护生态环境和渔业资源，实现渔业的可持续发展，是我们的发展目标。     

Impacts of Market Reform on Spatial Volatility of Maize Prices in Tanzania

Maize is one of the major staples and cash crops for many Tanzanians. Excessive volatility of maize prices destabilises farm income in maize‐growing regions and is likely to jeopardise nutrition and investment in many poor rural communities. This study investigates whether market reform policies in Tanzania have increased the volatility of maize prices, and identifies regional characteristics that can be attributed to the spatial price volatility. To achieve the objectives, an autoregressive conditional heteroskedasticity in mean (ARCH‐M) model is developed and estimated in this study. Results show that the reforms have increased farm‐gate prices and overall price volatility. Maize prices are lower in surplus and less developed regions than those in deficit and developed regions. Results also show that the developed and maize‐deficit regions, and regions bordering other countries have experienced less volatile prices than less developed, maize‐surplus and non‐bordering regions. Our findings indicate that investments in communication and transportation infrastructures from government and donor countries are likely to increase inter‐regional and international trade, thereby reducing the spatial price volatility in Tanzanian maize prices in the long run.     

如何看待玉米的生物能源地位

能源短缺困扰世界经济的发展,许多国家纷纷调整能源政策,寻找矿物质能源的替代产品.玉米作为集粮,经、饲为一体的经济作物,研发燃料乙醇作为能源替代品,得到了世界各国的普遍关注和重视.     

基础设施在中国农业全要素生产率中的作用

This paper uses the Malmquist index to examine the sources of Total Factor Productivity (TFP) in Chinese agriculture. The overall goal of this study is to create a framework for assessing the trend of China’s agricultural infrastructure and to measure its impact on Total Factor Productivity. The main methodological contribution is to provide more contributive measure of crop-specific technologies. Based on the province-level panel data set during 1988–2002, the primary finding is that infrastructure has positively and statistically significant association with the estimated coefficient on Total Factor Productivity for rice, wheat, maize, and bean. An erratum to this article is available at .     

Prediction of the Indian summer monsoon using a stacked autoencoder and ensemble regression model

The study of climatic variables that govern the Indian summer monsoon has been widely explored. In this work, we use a non-linear deep learning-based feature reduction scheme for the discovery of skilful predictors for monsoon rainfall with climatic variables from various regions of the globe. We use a stacked autoencoder network along with two advanced machine learning techniques to forecast the Indian summer monsoon. We show that the predictors such as the sea surface temperature and zonal wind can predict the Indian summer monsoon one month ahead, whereas the sea level pressure can predict ten months before the season. Further, we also show that the predictors derived from a combination of climatic variables can outperform the predictors derived from an individual variable. The stacked autoencoder model with combined predictors of sea surface temperature and sea level pressure can predict the monsoon (June-September) two months ahead with a 2.8% error. The accuracy of the identified predictors is found to be superior to the state-of-the-art predictions of the Indian monsoon.     

Demand for maize hybrids and hybrid change on smallholder farms in Kenya

Kenya is a globally recognized maize “success story.” As the overall percentage of maize farmers growing hybrids tops 80% and the seed industry matures, the slow pace of hybrid replacement on farms, and the continued dominance of the seed industry by Kenya Seed Company, may dampen productivity. Our econometric analysis identifies the factors that explain farmer demand for hybrid seed, and the age of hybrids they grow, considering hybrid seed ownership. Male‐headed households with more education, more assets, and more land plant more hybrid seed. Scale of seed demand per farm is differentiated by agroecology. We find a strong farmer response to the seed‐to‐grain price ratio, which we interpret as evidence of a commercial orientation even on household farms. However, despite the dramatic increase in the number of hybrids sold and the breadth of seed suppliers as seed markets liberalize, an older hybrid still dominates national demand.     

Modelling the impact of the ‘fast track’ land reform policy on Zimbabwe's maize sector

Zimbabwe has recently gone through a widely criticised land reform process that is argued to be the cause of subdued agricultural production. This paper attempts to present a counterfactual picture of the maize market in Zimbabwe had land reform been managed appropriately. The counterfactual is developed through a partial equilibrium framework in order to quantify the impact of the land reform programme. This, to our knowledge, is the first attempt at applying a partial equilibrium framework to an analysis of the impact of land reform. The results of the post-2000 land reform policy simulation showed that actual total maize output was lower than what could have been produced if it was under a pre-2000 land reform system. The study validates the assertion that land reforms contributed to the contraction of output. These results suggest the need for a well planned and executed land reform process, which can still play an important role in output growth and food security.