通过对浅圆仓配套提升机的技术改造解决收储东北玉米进仓破碎问题

通过对进仓提升机的技术改造,把东北玉米进仓破碎率由原来的5％～7％降至3％。     

The Corn Price Surge: Impacts on Rural Mexico

We use an agent-based, general-equilibrium model to explore the impacts of world corn-price increases on land use and income in rural Mexico. In the model, interactions among heterogeneous agents within a local context shape both macro and microeconomic outcomes. Results suggest that subsistence activities allowed agriculture to absorb the shock, limiting the benefits of higher prices for the population while keeping deforestation pressures in check. An estimated 5.7% corn-area expansion by 2008 and wide variation across regions corresponds well with ex-post reports. Agricultural growth led to 0.02% and 3.9% increases in real income for rural households and absentee landholders, respectively.     

A Case of Mistaken Identity? Measuring Rates of Improved Seed Adoption in Tanzania Using DNA Fingerprinting

Studies of improved seed adoption in developing countries are almost always based on household surveys and are premised on the assumption that farmers can accurately self-report their use of improved seed varieties. However, recent studies suggest that farmers’ reports of seed varieties planted, or even whether the seed is local or improved, are sometimes inconsistent with the DNA fingerprinting results of those crops. We use household survey data from Tanzania to test the alignment between farmer-reported and DNA-identified maize seed types planted. In the sample, 70% of maize seed observations are correctly reported as local or improved, while 16% are type I errors (falsely reported as improved) and 14% are type II errors (falsely reported as local). Type I errors are more likely to have been sourced from other farmers, rather than formal channels. An analysis of input use, including seed, fertiliser, and labour allocations, reveals that farmers tend to treat improved maize differently, depending on whether they correctly perceive it as improved. This suggests that errors in farmers’ seed type awareness may translate into suboptimal management practices. The average yield of seed that is correctly identified as improved is almost 700 kg per hectare greater than that of type I errors. This indicates that investments in farmers’ access to information, seed labelling, and seed system oversight are needed to complement investments in seed variety development.     

Climate Risk and Technology Adoption in the Midstream of Crop Value Chains: Evidence from Nigerian Maize Traders

Climate induced events exacerbate food production and distribution risks, posing a threat to global food security. Though many studies focus on farmer adaptation to climate change, there are few studies of actors in the middle of agricultural value chains such as traders, logistics providers, and processors. The activities of these actors, referred to as the ‘hidden middle’, are key determinants of the prices received by farmers and the price and quality of food products for consumers. We explore how climate events and risk perceptions affect the adoption of value‐adding and damage control strategies among maize traders in Nigeria, Africa’s largest economy and most populous country. We find consistent evidence that climate events and climate risk perception discourage the adoption of value‐adding practices including storage. This potentially affects the availability and price of maize for consumers (household and industry) in the lean season. However, once traders store maize, climate risk does not affect the adoption of damage control, but training and social networks do. These findings suggest that actors in the midstream of food value chains are responding to climate change and more attention needs to be paid to these actors to maintain the availability of affordable and safe maize products throughout the year. There is also a need for strategies to reduce the risks of trading activities due to climate change.     

A meta-analysis of community-based studies on quality protein maize

Biofortification, or the improvement of nutritional quality in food crops, is a promising strategy to combat undernutrition, particularly among the rural poor in developing countries. However, traditional methods of impact assessment are inadequate for biofortified crops, as they do not consider their nutritional benefits. Evidence for the nutritional impact of maize varieties with improved protein quality, collectively known as quality protein maize (QPM), was evaluated using meta-analysis of randomized, controlled studies in target communities. A new and generalizable effect size was proposed to quantify the impact of QPM on a key outcome, child growth. The results indicated that consumption of QPM instead of conventional maize leads to a 12% (95% CI: 7–18%) increase in the rate of growth in weight and a 9% (95% CI: 6–15%) increase in the rate of growth in height in infants and young children with mild to moderate undernutrition from populations in which maize is the major staple food. The proposed effect size and use of bootstrapping to determine statistical significance addressed some methodological limitations in the existing studies.     

基于ARIMA模型的中国玉米单产潜力分析

在中国玉米单产的AEZ(农业生态区划)模型潜力基础上,运用ARIMA(自回归单整移动平均)模型,基于1949—2018年数据预测2023年前中国玉米单产.结果表明:2019、2020、2021、2022和2023年中国玉米单产分别为6293、6458、6627、6801和6979 kg/hm2,分别是AEZ模型潜力上限...     

A paradigm shift in African agricultural research for development: the role of innovation platforms

To demonstrate the development impact of their outputs, agricultural research and development (R&D) organizations used to focus on the efficiency and effectiveness of technologies. In recent years, innovation systems thinking has started to address institutional and organizational barriers to technological change in African agriculture. The main approach used has been the multi-stakeholder innovation platform (IP). This paper analyses the requirements for improving the competence and skills of IPs actors in agricultural value chains, food systems, and natural resource management. As case studies, it uses IPs in the maize and cassava value chains that were initiated in the dissemination of new agricultural technologies in Africa (DONATA), in both West and Central Africa, and made reference to the rice IPs facilitated by AfricaRice. Yields and incomes in maize and cassava IPs significantly increased and inter-actor relationships and behavioural change among the diverse social and economic operators were enhanced. This achievement built on three capacity development interventions: (i) learning workshops that sensitized and informed technocrats and policy-makers and nurtured their involvement and ownership, (ii) competence and skill training of IP facilitators and practitioners, and (iii) coaching and mentoring of these facilitators and practitioners. To better facilitate IPs, facilitators and practitioners need to learn to observe, recreate, test, and perfect the IP process and value chain approach. Practicable tools that can be visualized and put into practice by the IP actors are essential. The DONATA on which the paper is based has been invaluable in terms of experiential learning.     

冻融稳定型羟丙基糯玉米淀粉的制备及特性研究

以糯玉米淀粉为原料,制备冻融稳定型羟丙基淀粉。并对淀粉乳浓度、环氧丙烷浓度、反应温度、反应时间、氢氧化钠浓度、硫酸钠浓度对羟丙基淀粉的冻融稳定性和分子取代度的影响进行了研究。确定制备冻融稳定型羟丙基淀粉的最佳工艺参数为：淀粉乳浓度40％,环氧丙烷浓度12％,反应温度50℃,反应时间25h,氢氧化钠浓度1.3％,硫酸钠浓度14％。同时对羟丙基糯玉米淀粉的透明度和抗老化特性进行了研究。随淀粉冻融稳定效果的增加,其淀粉的透明度和抗老化性均增加。     

Evaluating the effectiveness of inter-regional trade and storage in Malawi’s private sector maize markets

This paper evaluates the effectiveness of the private sector maize marketing system in Malawi using threshold autoregression models. Two dimensions of maize market performance are evaluated: (1) inter-regional trade and spatial price transmission; and (2) storage and seasonal price relationships. In both cases, threshold autoregression models which account for nonlinearities predicted by economic theory are applied. Results indicate that spatial price transmission and seasonal price patterns in private sector maize markets in Malawi are generally consistent with long-run competitive inter-regional trade and storage behavior, and that in most cases shocks to long-run equilibrium are arbitraged away quickly. This suggests the private sector in Malawi is generally doing a good job of transporting maize from surplus to deficit regions and smoothing maize consumption between harvests.     

Climate Smart Agriculture? Assessing the Adaptation Implications in Zambia

We examine a set of potentially climate smart agricultural practices, including reduced tillage, crop rotation and legume intercropping, combined with the use of improved seeds and inorganic fertiliser, for their effects on maize yields in Zambia. We use panel data from the Rural Incomes and Livelihoods Surveys merged with a novel set of climatic variables based on geo‐referenced historical rainfall and temperature data to explore the changing effects of these practices with climatic conditions. We estimate the impacts on maize yields, and also on the exhibition of very low yields and yield shortfalls from average levels, as indicators of resilience, while controlling for household characteristics. We find that minimum soil disturbance and crop rotation have no significant impact on these yield outcomes, but that legume intercropping significantly increases yields and reduces the probability of low yields even under critical weather stress during the growing season. We also find that the average positive impacts of modern input use (seeds and fertilisers) are significantly conditioned by climatic variables. Timely access to fertiliser emerges as one of the most robust determinants of yields and their resilience. These results have policy implications for targeted interventions to improve the productivity and the resilience of smallholder agriculture in Zambia in the face of climate change.