美国替代农业的现状及评价

1 替代农业的由来美国在实现了其农业的机械化、化学化以后,极大地提高了农产品的产量和生产效率,成为世界上少数几个粮食、农产品出口国之一。自1940年以来,随着时间的推移,尤其是五十、六十年代常规农业生产大量使用化肥、农药等,造成了环境的污染,过度的机械化耕作、翻耕,使水土流失,养分遭受损失,七十年代初期的石油危机,使这种以大量消耗石油能为主要特征的生产方式受到冲击。人类对环境污染危及人体健康、资源衰竭的认识的提高,也使这种常规的农业生产方式受到了挑战,因而近十年来出现了一种从自然界物质,能量循环的观点出发,以生物学的过程和手段来替代农业生产中引起污染、有害健康、造成     

发展生态农业 实现可持续发展

生态农业是指围绕农业生产系统的资源利用和病虫害及杂草控制问题,通过不用或者尽可能少用来自外界的化肥和农药等化学物质,充分发挥农业系统内部的物质和能量循环机能,实现农业系统的可持续发展。生态农业是一种绿色产业,具有以下显著的特点:1.生态农业强调农业生态系统的总体     

西欧化肥市场考察与启示

尽管西欧各国农业发展道路与我国并不完全相同,但是化肥对于农业生产的重要意义却大体相当。西欧农业发展在依靠机械化解决农业劳动力不足的同时,同样需要依靠施用化肥来提高作物产量。西欧实践表明,只有在政府正确引导和干预下,化肥市场运行才能真正实现与农业生产发展和生态环境保护有效结合。一、西欧化肥市场历史变迁和发展现状(一)西欧化肥市场历史变迁。西欧17国目前拥有1·45亿公顷农业耕地,其中约59·1%的农业耕地用于农作物生产。化肥市场发展对西欧农业生产发展起着重要的支撑作用,同时西欧化肥市场变迁也折射出西欧农业政策的重…     

我国农业区主要粮食作物化肥施用情况分析——化肥施用核算与相对适宜度评价

随着我国农业现代化水平的不断提升,农业生产普遍采用集约化发展模式。但化肥尤其是氮肥在农业生产中的过度施用,对农业环境产生了严重的负面影响,农业面源污染已然成为水体富氧化的主要原因。基于此,以全国平均水平为对照指标,采用“区域化肥（氮肥）施用负荷”和“化肥（氮肥）施用相对适宜度”评价化肥和氮肥施用对我国九个农业区的环境影响程度,作为不同地区化肥和氮肥施用的参考,是科学、合理施用化肥,缓解我国农业环境压力的重要举措。     

用循环经济理念谋划现代农业

一、建设现代农业是我国农业发展的方向 1．现代农业的特征与发展要求。现代农业是与传统农业相对应的农业形态,是以广泛应用现代科学技术、普遍使用现代生产工具、全面实行现代经营管理为本质特征和主要标志的发达农业。现代农业的主要特征是集约利用资金和能源,弱化了农业生产对土地和劳动力的依赖,以投入大量无机能量——化肥、农药、燃料、电力等来维持农业生态系统平衡。     

河南省粮食核心区建设的农业保险问题探析

农业保险可以有效降低风险,能够为农业发展提供有力的保障。作为我国第一粮食生产大省的河南省,虽然粮食生产已连续多年位居全国第一,但农业保险在河南省的发展却不尽如人意。河南省政府于2010年通过了《河南省粮食生产核心区建设规划》,要建设粮食生产核心区,农业保险将发挥着不可替代的重要作用。本文将对河南省粮食核心区建设中的农业保险问题进行探讨。     

中国农业化肥施用量增长原因分解及其削减潜力分析

改革开放以来,中国农业经济取得了巨大增长,但农业化肥过度施用给农业的可持续发展带来了严重挑战,理清造成农业化肥施用量增长的根源,有助于制定相应措施实现农业化肥"减量化"目标。文章利用指标分解法分析了中国农业化肥施用量的增长原因,并探究了农业化肥施用量的削减潜力。结果显示:(1)单位面积化肥施用量增加是引起我国农业化肥施用量增长的主要原因,其贡献率高达67.5%;而播种面积扩张、作物种植结构变化的贡献率依次为28.9%和0.7%;(2)我国农业化肥施用量存在巨大的削减潜力,降低单位面积化肥施用量、耕地轮作休耕均能降低农业化肥施用量。最后,基于研究结论提出相关措施建议以降低我国农业化肥施用量。     

俄乌冲突对世界及我国食物安全的影响与应对策略

在俄乌冲突影响下,国际农产品出口下滑,乌克兰农作物产量面临下降、农产品出口减少,俄罗斯化肥和能源等产品出口受限,国际食品和化肥等农业生产资料价格急剧上涨,能源价格上涨可能传导至全球食品价格上涨,全球食物供应紧张局势加剧。受国际市场影响,我国化肥、农用柴油、饲料粮和食用植物油价格普遍上涨,种养业的生产成本显著增加。为防范地缘冲突和国际食物危机对我国的影响,应确保口粮绝对安全,树立大食物观,着力破解饲料粮短缺问题,全面提升我国油料生产能力。为此,我国应加大粮食生产支持力度,大力推进饲料粮减量替代,加强油料政策支持和科技创新,构建农业新发展格局、统筹国内国际两个大局,科学引导食物消费。     

粮食生产中化肥投入的影响因素研究——基于Durbin模型的分析

粮食生产中化肥施用量提高带来的环境问题日益严重,要减少化肥的施用量首先要理清化肥施用的影响因素。利用空间Durbin模型(SDM),设置邻接空间、地理距离、经济空间三种权重矩阵,采用Spatial Regression ModelPartial Derivatives方法,以2004—2016年省级面板数据为研究样本,分析了我国化肥施用强度分布的空间特征及影响因素。研究表明:(1)化肥施用强度具有显著的区域差异性和空间依赖性;(2)劳动力投入、农业技术人员数量、化肥的销售价格对化肥投入存在抑制作用,粮食销售价格、各省经济发达程度、农民的文化水平对化肥投入存在促进作用;(3)未来我国化肥减量的压力比较大,压力主要在粮食主产区。     

中国粮食生产要素之间的替代关系研究——基于劳动力成本上升的背景

论文采用1991~2013年中国粮食生产的相关投入与价格数据,基于超越对数成本函数的影子替代弹性估计方法,实证分析了劳动力成本上升背景下我国粮食生产的要素需求与替代关系,研究发现:(1)我国粮食生产的要素需求正处在理性的价格调节区间,要素价格仍然是调节要素需求的经济杠杆;与劳动力和化肥相比,机械投入对价格变化更为敏感,更容易受自身价格变化的冲击。(2)农业机械与劳动力存在明显的替代关系,且替代关系越来越强。这说明在劳动力成本快速上升的情形下,利用机械替代劳动可以大幅减少农业劳动投入,特别是可以有效缓解劳动力选择性转移带来的劳动力结构性短缺问题。(3)化肥与劳动也存在明显的替代关系,但替代关系稳中略降。经济激励是农户决策的首要考量因素,在劳动力成本快速上升的背景下,选择多量少次的施肥方式、增施化肥并减少农家肥投入,用化肥替代劳动成为农户的理性选择。     

Organic Farming for Sustainable Agricultural Production. A Brief Theoretical Review and Preliminary Empirical Evidence

The basic premise of this paper is that modern agricultural production is not sustainable in view of the high cost of chemical inputs (notably fertilizers and pesticides) used and their detrimental effects on the environment. Some of these effects are briefly discussed in this paper. The possibility of adopting organic farming as a means of promoting sustainable agriculture has been the main objective of this investigation.The results of the experiment carried out at the Chepkoilel campus farm, Moi University, Kenya to demonstrate the differences between the yields and returns to organic manure and chemical fertilizers show that high yields are obtained from the use of organic manure. The high yields are also shown to be obtained in subsequent years after the application of the organic manure. This is cheaper than the application of chemical fertilizers. Maximum yields are obtained from a combination of organic manure and chemical fertilizers. Organic manure has the added advantage of providing more healthy vegetables for human consumption and ensuring optimum soil fertility for sustainable production.     

The Use of Organic vs. Chemical Fertilizer with a Mineral Losses Tax: The Case of Dutch Arable Farmers

The paper focuses on farm-level nitrogen fertilization strategies of Dutch arable farmers for analyzing the substitution of organic fertilizers (manure) with chemical fertilizers. The model developed investigates the impact of the major parameters affecting the inferiority of manure compared with chemical fertilizers, including the low availability and non-uniformity of the nitrogen in manure, and the low level and high non-uniformity of plant-available nitrogen supplied via manure. The sensitivity of the optimal fertilization decisions and its associated environmental impact to product price, manure cost, and environmental tax is also examined. The theoretical analysis is applied to a representative Dutch grower of ware potatoes in the northern part of the Netherlands. The results suggest that in the absence of a subsidy the representative farmer will prefer to apply nitrogen only via chemical fertilizers.     

Modeling technological bias and factor input behavior in China's wheat production sector

Over the past three decades, China has implemented reforms in the agricultural sector in an attempt to increase efficiency and food security. However, China now faces a number of environmental degradation problems, in part, caused by her past agricultural reforms. In this paper we estimate, using a provincial-based panel dataset, a third-order translog cost function for China's grain production sector over the period 1990–2011. Results from the estimation, including estimated elasticities of demand for and substitution of factors, suggest that labor and capital are substitutes. This arises because the increasing cost of labor, induced by urbanization and the growth of the manufacturing sector, has lead to a substitution of machinery for labor in the production of wheat. The results are consistent with current government policies to encourage via subsidies and agricultural mechanization, which we show to be technically, a substitute for labor. We further conclude this will create an additional bonus of reducing the amount of fertilizer that is needed to efficiently and securely produce wheat in China, as the new capital is more efficient at fertilizer distribution.     

Elasticities of substitution between energy and non-energy inputs in China power sector

Energy substitution is considered as a key process to determine the economic outcome of decisions related to energy and environment policies. The sign and magnitude of energy substitution have been widely debated, and the results are divergent. This paper applies the translog cost function specification to estimate factor share equations based on the energy and non-energy inputs, whose coefficients are used to observe the energy degree of substitutability with the other traditional inputs for power industry in China. The results suggest that energy is the least price sensitive among three production factors. The four types of input elasticities (cross-price, Morishima's, Allen and McFadden's shadow elasticity of substitution) show that there are substantial substitution possibilities between energy and capital, while energy and labor have weak substitution. The findings imply that for power industry in China, to reduce energy consumption, more capital should be invested. With respect to labor, though, it appears less energy-saving potential.     

Long-run estimates of interfuel and interfactor elasticities

Meta-analyses of interfuel and capital-energy elasticities of substitution show that elasticity estimates are dependent on the type of data − time series, panel, or cross-section − and the estimators used. Econometric theory suggests that the between estimator might generate the best estimates of long-run elasticities but no existing estimates of elasticities of substitution have used it. Alternatively, Chirinko et al. argued in favor of estimating long-run elasticities of substitution using a long-run difference estimator. We provide estimates of China’s interfuel and interfactor elasticities of substitution using the between and long-run difference estimators. To address potential omitted variables bias, we add province level inefficiency and national technological change terms to our regression model. The results show that demand for coal and electricity in China is very inelastic, while demand for diesel and gasoline is elastic. With the exception of gasoline and diesel, there are limited substitution possibilities among the fuels. Substitution possibilities are greater between energy and labor than between energy and capital. The results are quite different to some previous studies for China but coincide well with the patterns found in meta-analyses for long-run estimates of elasticities of substitution.     

农业有机废弃物能源化对化学农业负外部性纠正研究

针对化学农业的负外部性,利用能值理论建立了基于农业生态需求的农业外部性分析模式。理论分析表明,在兼顾粮食产量目标时,农业有机废弃物能源化、生态化可以从源头纠正化学农业的负外部性。以涟水县高沟镇为例的实证分析表明,通过60%的化肥替代,农业有机废弃物能源化可以纠正85.49%的化学农业负外部性。较之“税费”“标准”“行政监管”等手段,通过产业政策手段将农业补贴政策聚焦于农业有机废弃物能源化生态补偿是一种科学性与现实性较强的政策选择。     

Testing causality among five fertilizer prices

This article identifies the causal relationships among the prices of five fertilizers using both asymptotic Wald test and resampling (bootstrap) techniques. Monthly data for urea, muriate of potash, rock phosphate, diammonium phosphate and triple super phosphate between 2008 (March) and 2016 (March) are used for the analysis. Results show that the urea price Granger causes all other fertilizer prices. The results of the study are significant in understanding the price dynamics and identify the reference fertilizer price that is useful for the fertilizer industry, farmers and government.     

中国钢铁行业能源内部的替代弹性分析

本文运用中国钢铁行业滞后一期的产出代替劳动和资本变量,把钢铁行业能源投入要素分解为煤炭、石油、天然气和电力的投入,建立了一个超越对数生产函数模型,用岭回归估算了中国钢铁行业各能源品种投入要素的产出弹性、替代弹性。结果表明:煤炭与石油、煤炭与天然气、煤炭与电力的替代弹性在1左右,中国钢铁行业可通过用石油、天然气、电力替代煤炭来实现其行业全要素能源效率的提高。     

山东省能源要素产出弹性、替代弹性的实证研究——基于超越对数生产函数的岭回归估计

构建了一个包含煤炭、石油、天然气和电力4种能源投入要素及时间趋势变量的超越对数生产函数,实证检验了1979—2009年山东省各能源要素的产出弹性、替代弹性及技术进步差异。结果表明:自改革开放以来,山东省的能源要素投入系统存在中性技术进步,技术进步率呈逐年递增趋势;山东省各能源要素的产出弹性逐年提高,按其均值由高到低排序依次是电力、石油、煤炭和天然气;1979—2009年期间煤炭与石油、煤炭与电力、石油与电力以及天然气与电力的替代弹性均大于1,石油与天然气的替代弹性虽然小于1,但自2000年后逐渐增大;山东省各能源要素的技术进步差异较小,按能源要素的技术进步率由高到低排序依次是煤炭、石油、电力和天然气。     

Economic diversity, development capacity and sustainable development of China

China's economic growth over the past several decades has been among the highest in the world. It has been fueled by cheap fossil fuel energy so energy consumption has risen rapidly, but there are signs that negative feedbacks in the form of waste and inefficiency may affect future development. If energy throughput exceeds the capacity of the environment to process the inevitable waste from production then the development may not be sustainable. We calculate economic diversity using an energy flow network analysis method to explore the relationships of development policy, energy use, efficiency and sustainable development. China and its provinces are presented as a case study and the development status of each province in China is presented. China's development policy does not appear to be sustainable over the period 1985–1998 because of unsustainable energy consumption trends and declining economic diversity. An energy consumption tax is proposed for increasing diversity and dealing with increasing energy consumption in China.