The rise of peri-urban aquaculture in Nigeria

The development of fish farming in Nigeria is traced from the colonial period through decades of mostly subsistence farming to large-scale commercial catfish farming today. Most African countries have encountered difficulties breaking into profitable commercial fish farming; however, Nigeria's strongly growing population at some 150 million and its very high demand for fish positioned the country on a much more strongly market-driven path based on commercial production in peri-urban areas. With investment in good management, selection of the hardy catfish for farming, development of intensively managed fish hatcheries and use of high quality fish feeds, farmers established a new model for raising fish in concrete tanks, which greatly reduced poaching and allowed farmers to get full return on their investment within one year. The paper details costs and benefits. With prospects of good profits, a number of medium-scale investors, invested in farming fish in tanks in ‘fish farming villages’ (also called fish farm estates) located in peri-urban areas near large markets, where several hundred tanks were cooperatively managed. With high demand and market prices, they were able to obtain credit, using professional business plans and security documentation required by lenders.     

政策性农业保险的收入效应分析——来自华中3省的微观调查

目的 农业保险具有防灾减灾的功能,是重要的农村金融工具,体现了惠农富农的政策导向。随着农业保险进入高质量发展阶段,从微观农户层面研究农业保险的收入效应具有重要的现实价值。方法 文章基于2019年湖北、湖南和河南3省808份微观调查数据,运用多元线性回归模型和分位数回归模型,系统分析了农业保险对农户农业收入水平的影响。结果 农业保险会显著增加农户的农业收入水平,在使用工具变量方法处理互为因果问题,PSM方法纠正选择性偏误,以及截尾和缩尾处理后,结论依旧稳健。农业保险对不同收入农户的作用效果存在显著的异质性,随着分位数水平的提高,农业保险的增收效果逐渐减弱。结论 为充分发挥农业保险的保收增收功能,从强政策宣传,提高保险密度与深度;加大财政支持力度,完善保险体系建设;以及实施倾斜性保费补贴和赔偿机制三方面提出相关政策建议。     

农地规模经营能否实现农业增效与农民增收的趋同？

研究目的:探究不同经营规模区间内农业增效与农民增收的趋同性。研究方法:随机前沿函数法、工具变量法。研究结果:(1)伴随着农地经营规模的扩大,小麦生产技术效率和亩均利润均表现出\"倒U型\"变化趋势,处理了内生性后结果依然稳健;(2)当农地经营规模低于134.32亩时,扩大经营规模可以实现农业增效和农民增收的\"双赢\";当农地经营规模处于134.32～169.80亩之间时,扩大经营规模会导致增收不增效的矛盾困境;当农地经营规模超过169.80亩后,技术效率和亩均利润随着经营规模扩大均表现出明显下降趋势。研究结论:推进农地规模经营对于实现农业增效和农民增收仍然具有提升空间。在推进农地经营规模的同时,应兼顾小麦销售与流通的外部环境建设与投资,促进效率与收入尺度下最优经营规模的重合,实现农业增效和农民增收的趋同发展。     

广西甘蔗寒冻害空间反演模型研究

甘蔗寒冻害是蔗糖主产区主要气象灾害之一。大范围、严重的甘蔗寒冻害造成甘蔗产量和蔗糖分含量下降,给广大蔗农及企业带来巨大的经济损失。但受蔗区地形地貌复杂及气象观测台站分布稀疏等因素制约,寒冻害过程影响期间难以获取区域甘蔗实际受害信息,给甘蔗寒冻害过程监测、评估及防灾、减灾措施的实施带来了极大困难。为了实现及时、真实地反演甘蔗产区寒冻害程度,文章基于广西历年冬季寒冻害过程最低气温资料、地理信息数据以及EOS/MODIS卫星资料,采用多元回归法,分别构建基于地理信息、基于地理信息及下垫面信息耦合的最低气温空间推算模型,创建了逐年寒冻害过程最低气温格点数据库。并以2008年辐射型、2010年平流型寒冻害过程为例,将反演结果与实况进行比较,结果表明两种模型反演所得寒冻害空间分布状况均与自动站实况一致,两种模型对平流型寒冻害的模拟效果优于对辐射型寒冻害的模拟。     

From researcher to farmer: partnerships in integrated aquaculture—agriculture systems in Malawi and Cameroon

The potential for integrating aquaculture with agriculture has been widely recognized as a means of improving the use of inputs, diversifying output and economic opportunity, and enabling smallholder producers to maintain and strengthen livelihoods. This paper describes the outcomes of this approach and explains the extent to which it has been taken up and has led to sustained and self-generated capacity. Based in particular on experience in Malawi, Ghana and Cameroon, it also considers implications more widely in the region. The overall picture is that this is a partial and still emerging success story, linked as much with the social and economic drivers surrounding smallholder farmers as with the development support approach adopted.     

Family Composition and Off-Farm Participation Decisions in Israeli Farm Households

This article studies the relationship between the off-farm participation behavior of farm operators and their spouses and the demographic composition of the household. We focus on farm families without parents, siblings or partners, and examine the effects of the existence of elderly children of the farm couple. We find that both the father and the mother tend to reduce their participation in off-farm work as the number of elderly children rises. This result holds even after controlling for observed characteristics. We also find that the effect of elderly children stems from considerations related to both farm production and household production.     

Does maternal employment affect child nutrition status? New evidence from Egypt

Even though maternal employment can increase family income, several studies suggest that it could have adverse consequences on children’s health. In this study, we use a nationally representative sample of 12,888 children, aged 0–5 years from Egypt to examine the impact of maternal employment on child nutritional indicators, namely: stunting, wasting, and being underweight and overweight. We adopted various estimation methods to control for observable and unobservable household characteristics in order to identify the causal effect of maternal employment. These different techniques include, propensity score matching (PSM), OLS regression with controlling for a wide range of individual characteristics, and an instrumental variable two-stage least squares (IV 2SLS) approach. Results of the PSM and OLS suggest that maternal employment is weakly associated with having a malnourished child. On the other hand, the IV 2SLS suggests a stronger and significant association between maternal employment and poor nutritional status among children.     

基于韦伯二重合理性的农户生态耕种行为分析

目的 基于韦伯二重合理性理论框架,通过对传统农业大省江西省农户生态耕种行为理性的评价,分析农户生态耕种行为主要因素的影响规律,为农户生态耕种激励政策的制定提供参考。方法 文章以江西省农户为调查对象,采取分层抽样和随机抽样相结合的方式选取样本农户,针对户主或是参与农业经营决策的家庭主要成员开展访谈和问卷调查相结合的入户调查。利用获取的1 488份有效问卷数据,通过层次分析-熵值定权法确定农户生态耕种理性评价指标权重并进行评价,得出农户生态耕种行为理性的评价值。运用Order-Probit模型分析二重合理性理论框架下农户生态耕种行为的工具理性、价值理性及其交互以及其他主要因素的影响规律。结果 （1）样本农户平均采纳生态耕种行为4.735项,工具理性评价均值为0.546 8,价值理性评价均值0.354 2,丘陵区农户生态耕种行为工具理性和价值理性值比平原、山地区更高。（2）当前,工具理性在农户生态耕种行为采纳上起到消极的抑制作用,价值理性起到积极的促进作用,而二重合理性的冲突减弱了农户生态耕种采纳率。（3）家庭劳动力占比越高、耕地收入占比的提高,农户采取生态耕种行为的可能性越高,而促进小农户向新型农业现代经营主体的转变是提高农户生态耕种行为采纳的有效途径之一。（4）农户保留仅供自家消费的耕地说明其对耕地生产的安全性持有疑虑,更加愿意进行生态耕种以保持耕地和农产品健康。结论 需要积极落实生态农产品的补偿,完善有关法规制度和质量监管,实现生态耕种的产品价值,以达到农户追求效益的工具理性与耕地保护的价值理性之间的协调统一。     

土地财政对土地利用效率的影响

研究目的:分析土地财政对土地利用效率的影响。研究方法:在机理分析的基础上利用土地财政滞后一期和土地管理政策作为工具变量进行回归分析。研究结果:(1)政府追求土地财政最大化的目标必然导致对土地市场的干预,从而影响土地利用效率;(2)土地财政对土地利用效率的影响为倒\"U\"型,超出6.38拐点的土地财政对土地利用效率的影响由正转负;(3)作为土地财政的重要运作方式,商住用地和工业用地出让的相对价差对土地利用效率的影响为倒\"U\"型;(4)土地财政对不同城市土地利用效率的影响具有差异性,在二线城市和五线城市最为显著;政府重大经济政策的实施会改变土地财政对土地利用效率的影响。研究结论:应正视土地财政的积极作用,并通过深化改革,采取有效措施来解决其存在的负面效应。     

农户扩大经济林种植规模意愿及规模水平影响因素分析——以浙江省为例

以Probit、Tobit回归模型为主要工具,利用浙江省236户农户调查数据,实证分析了农户扩大经济林种植规模意愿及规模水平的影响因素。研究结果表明:户主年龄、受教育程度、家庭人口数、是否参与标准化项目以及对经济林发展前景判断对农户扩大经济林种植规模意愿及规模水平有显著影响;而经济发展水平只对农户扩大经济林种植规模意愿有显著影响,家庭人均收入和家庭非农收入占比只对农户扩大经济林种植规模水平有显著影响。最后,提出相应的对策建议:加大经济林宣传力度,提高农户种植积极性;完善补贴政策,保障经济林的持续经营;加强经济林质量监督,提高农户经济林收入。     

Sequential Adoption of Site-Specific Technologies and Its Implications for Nitrogen Productivity: A Double Selectivity Model

This paper analyzes the sequential decision to adopt two site-specific technologies, soil testing and variable rate technology, and the impact of adoption on nitrogen productivity. The results indicate that while farm location was a key variable influencing adoption of soil testing, farm size, human capital, and innovativeness of farmers had a significant impact on adoption of variable rate technology in four Midwestern states. A double selectivity model applied to correct for sample selection bias shows that adoption leads to significant gains in nitrogen productivity for farms with below average soil quality but statistically insignificant gains for farms with above average soil quality.     

Incentives and disincentives for diversified agroforestry systems from different actors’ perspectives in Bolivia

Even though diversified agroforestry systems can provide sustainable livelihoods and a resilient production of different goods, adoption remains limited in Bolivia. We examine major obstacles to agroforestry adoption and possible incentives proposed by farmers and civil-society organizations, and relate them to governance and international mechanisms that might play a role in agroforestry adoption. Market access for produce from diversified agroforestry remains difficult, as does its processing and transport. Moreover, farmers have difficulties in achieving the quantities and homogenous quality demanded by markets in the major cities. But most importantly, farmers and civil-society organizations saw little government support, although ‘ecological production in harmony with Mother Earth’ is prescribed by law and the constitution. Agroforestry farmers needed support most urgently in the initial phase, when investment costs are high and returns low. They suggested affordable credits, subsidies for diversified farming systems, and insurance against fire. We identified important albeit small steps towards developing markets for agroforestry products, but government support – mostly in the form of diesel subsidies, materials, and infrastructure – mainly benefitted large-scale monocultures and cattle ranching. In response to this, interviewees opted for strengthening farmers’ organizations, for demanding support with the help of civil-society organizations, and for disseminating best practices.