Breeding for Africa's new smallholder maize paradigm

This paper describes the evolution of a newly emerging smallholder maize paradigm in southern Africa beginning in 1996. This new paradigm involves the breeding, extension, and adoption of a new generation of open-pollinated ‘flinty’ maize varieties that specifically address the needs of southern African smallholder farmers for seed varieties that can be replanted (recycled) and that resist drought and low fertility problems increasingly common in southern Africa. The described mechanism is the extension and breeding work of the Southern Africa Drought and Low Fertility programme (SADLF) of the Centro Internationale por la Mejoridad de Maize y Trigo (CIMMYT). This paper explains the devolution of southern African maize production in the past two decades from centralized large-scale producers to smallholder farms, signalling a shift in research and plant breeding needs. The research/extension approach described here had profound consequences beyond the technical benefits of screening maize varieties for tolerance to stress; it empowered small-scale farmers to become informed consumers of agricultural technology. The transformation of the smallholder from a passive consumer to one actively seeking the best opportunity and seed to produce food, create economic opportunities and address local social conditions is an important development in the history and sustainability of maize production in southern Africa, and one consistent with modern African history of economic liberalization in the global food economy.     

Adoption of Drought Tolerant Maize Varieties under Rainfall Stress in Malawi

We examine adoption of drought tolerant (DT) maize varieties using a four‐round panel dataset from six districts in Malawi. There is an increase in adoption of DT maize from 3% in 2006 to 43% in 2015 in our data. We focus on the effect of past drought exposure on adoption and the likelihood of DT maize being distributed under the Farm Input Subsidy Programme (FISP). Results show that past exposure to drought increases the probability of DT maize seed being distributed through FISP. Farmers who accessed maize seed subsidy coupons and were previously exposed to late season dry spells are more likely to use the seed subsidy coupon to redeem DT maize seed. The likelihood of adoption and adoption intensity (area under DT maize) are positively influenced by previous early season dry spells and access to seed subsidy. Previous late season droughts also positively affect adoption intensity. On the other hand, area share under DT maize is positively correlated with early season dry spells and past exposure to late season dry spells but negatively related to seed subsidy. FISP in Malawi appears to have stimulated adoption of DT maize directly through subsidy and indirectly through generating farmers’ experiences of the performance of DT varieties under drought conditions.     

湖南油茶干旱指数保险产品优化与费率厘定

目的 气象指数保险具有理赔便捷以及成本低的优点,通过设计气象指数类保险产品以及费率厘定,为农林产品自然灾害风险的有效转移提供新思路。方法 文章基于2007—2019年逐年7—9月湖南省14个市（州）降水量以及油茶籽单产量数据,设计油茶干旱指数保险产品,选择科学的干旱指数指标参数,通过建立关键致灾因子与干旱的关系模型,构建干旱天气指数,对油茶干旱风险进行合理区划,使用Hodrick Prescott Filter（HP滤波）方法分离出气象产量从而测算油茶籽减产率,回归分析油茶籽干旱指数与减产率的相关关系,采用损失率期望值法厘定纯费率。结果 （1）湖南省干旱风险空间分布不均,衡阳市与永州市干旱致灾因子危险性最高,分别为11.41%与11.57%,而张家界市与娄底市相对干旱致灾因子危险性较低,分别为4.87%与6.01%。（2）油茶籽减产率与干旱指数存在着显著（P=0.001）的相关关系,拟合方程为YLR=0.464DI+0.097 3,当干旱指数为0时,其他灾害将会导致油茶籽减产9.73%,干旱指数每增加一个单位,减产率增加0.464个百分点,设置干旱指数为-15%为赔付触发值。（3）湖南油茶干旱指数保险各市（州）的纯费率差异较大,干旱程度越高纯费率越高,纯费率分布在6.49%~14.96%,永州市纯费率最高达到14.96%。结论 根据湖南干旱情况以及油茶空间分布现状,选取油茶籽年产量较高以及干旱风险较大的永州市与衡阳市作为先行市试点,建议政府制定差异化保费财政补贴政策。该产品可以有效转移油茶干旱风险,有助于森林保险公司低成本、高效率完成经济赔偿。     

Books Reviewed

Vosti, Stephen A., and Thomas Reardon, eds. Sustainability, Growth, and Poverty Alleviation: A Policy and Agroecological Perspective.
Swinbank, Alan, and Carolyn Tanner. Farm Policy and Trade Conflict: The Uruguay Round and CAP Reform.
Frisvold, George, and Betsey Kuhn, eds. Global Environmental Change and Agriculture: Assessing the Impacts.     

农户兼业化程度对农业保险偏好的影响机理与实证分析

[目的]随着农业结构调整深入推进,农户的收入来源逐渐多元化,文章通过研究农户兼业化程度对不同类型农业保险偏好的影响,为针对性推广农业保险提供依据和参考。[方法]以湖北、湖南、河南3省粮食主产区的732份农户调查数据为基础,运用Logit模型和多元Logit模型分析农户兼业化程度对保险种类偏好的影响,讨论种植规模在务农收入占比和保险种类选择之间的调节效应,以是否有固定非农工作将农户分为不同类型的兼业农户进行异质性分析。[结果]（1）务农收入占比高的农户偏好传统的物化成本保险,务农收入占比低的农户更喜欢新型指数保险。（2）兼业化程度相同的情况下,大规模农户比小规模农户更愿意保成本、保产量。（3）不同类型的兼业农户保险偏好存在差异,有固定非农工作的兼业农户比没有固定工作的兼业农户更愿意选择新型指数保险。[结论]有必要在务农收入占比高、种植规模大、没有固定非农收入的农户中推广传统的物化成本保险;在务农收入占比低、种植规模小、有固定非农收入的农户中推广新型指数保险。     

宁夏玉米和小麦干旱风险评价研究

[目的]分析宁夏23年(1993—2016年)玉米和小麦干旱时空分布格局及演变趋势,探讨各县玉米和小麦的干旱风险成因及关键作用因子,以期为宁夏县级作物防旱抗灾工作提供科学依据。[方法]本文基于成灾综合评价法,从干旱对玉米和小麦种植的危险性、玉米和小麦在干旱环境下的暴露性、玉米和小麦种植在干旱胁迫下的脆弱性和区域农业抗旱能力4个方面选取指标构建作物干旱风险模型,利用1981—2016年气象数据资料及玉米、小麦生育期资料、玉米小麦产量和面积等数据,分析计算宁夏各地区的玉米和小麦的干旱风险。[结果] 23年间(1993—2016年)宁夏玉米和小麦干旱风险整体上呈逐步上升趋势,玉米干旱风险上升趋势明显,最高达到45%。而小麦干旱风险趋势较平缓,干旱风险水平在30%～40%之间。品种间的差异主要在于干旱危险性指数和暴露性指数间差异较大,玉米干旱暴露度高,生育期较长,潜在蒸散量大,降水无法供应生育期内的需水量,因而玉米干旱风险较大。从空间分布来看,小麦干旱风险高值区分布范围较广,由于小麦生育期在雨季初期,降水量较少,且种植面积大,因而受旱面积较大。各县(市)玉米和小麦危险性、暴露性指数权重均在0. 3以上,是导致玉米和小麦干旱风险较高的主要原因。[结论]因此调整种植比例,减少小麦的种植面积,加强农村脱贫,增加农民收入,是减少干旱危害的有效措施。     

水产养殖保险应用类型的比较研究

我国现阶段所开展的水产养殖保险主要有两种类型,一种是传统型,即以实际损失程度为理赔依据的水产养殖保险;另一种是创新型,目前主要以气象指标发生程度为理赔依据的水产养殖保险。两种类型的水产养殖保险在险种设计、运营管理和承保理赔方式等方面存在着显著的差异,应用条件及适用范围也存在较大不同。论文通过比对两种类型的水产养殖保险的特征与利弊,结合我国现有的水产养殖品种和养殖模式,重点对其应用范围进行了分析,并提出了有关建议,以期能对相关机构推进水产养殖保险工作提供参考。     

高粱品种生态适应性综合评价指标体系的构建与应用

[目的]高粱是我国重要的多用途旱地经济作物,生产区域广,生态条件复杂,栽培方式多样,因此,构建高粱品种生态适应性评价指标体系对品种选择、种植规划等具有重要指导意义。[方法]文章通过文献研究、生产调研和专家问卷调查,利用层次分析法,构建品种生态适应性评价的指标体系的层次结构;利用德尔菲法,利用橙子办公软件设计调查问卷,借助专家微信群对各指标的相对重要性进行专家问卷调查,使用SPSSAU优序图法,计算各指标权重。[结果]根据反复征询意见,确定了各项指标的判分原则和标准,按综合得分将高粱品种生态适应性分为适应（≥90分）、较适应（76～89分）和不适应（≤75分）3类。根据所建评价方法对适应性评价试验中6个代表性品种,对其在6个地区的表现进行综合打分评价。[结论]证明结果符合实际。     

Insuring Against Losses from Transgenic Contamination: The Case of Pharmaceutical Maize

Concerns about the risk of food supply contamination have limited the development and commercialization of certain pharmaceutical plants. This article develops an insurance pricing model that helps translate these concerns into a cost-benefit analysis. The model first estimates the physical dispersal of maize pollen subject to a number of weather parameters. This distribution is then validated with the limited amount of currently available field trial data. The physical distribution is then used to calculate the premium for a fair-valued insurance policy that would fund the destruction of possibly contaminated fields. The flexible framework can be readily adapted to other crops, management practices, and regions.     

皖东地区旱涝预测与分析研究

统计了皖东地区500年间旱涝次数,发现该地区具有较强的旱涝灾害连发性,集中性和近20或30年一遇规律性,后半世纪较前半世纪多发旱涝灾害,以及定量计算和推测每个年代的具体年份旱涝发生的可能性,认为防灾减灾工作应加强旱涝年代人际研究。     

基于MODIS数据的辽西北地区玉米干旱脆弱性评价研究

传统区域作物脆弱性的研究主要基于气象资料、作物生长观测资料和社会经济统计资料,忽略了作物对极端事件的反应在时空分布上的差异性。众多研究表明,植被指数能够表征水分胁迫下的植被特征,在对旱情的表达上比常规的间接方法更为直接,监测精度更高。研究以辽西北地区2006年玉米干旱为例,基于MODIS数据计算植被状态指数VCI和温度条件指数TCI,根据二者在旱情表达上不同的侧重和研究目的,确定模型参数,构建辽西北地区玉米干旱脆弱性模型,计算玉米干旱脆弱性,并将玉米干旱脆弱性划分为4级,借助GIS技术绘制辽西北地区玉米各生育阶段干旱脆弱性的空间分布图。结果表明,随着时间的推移,辽西北地区玉米干旱脆弱性空间分布也在发生着变化。研究实现了玉米干旱脆弱性在时间变化和空间分布上的差异变化描述,为区域因地制宜地制定防灾减灾规划提供科学依据。