基于多因子分析的高原山区火龙果种植适宜性评价

目的 为针对贵州省复杂的生境背景,改进火龙果种植适宜性评价方法。方法 文章研究选用温度、光照、土壤pH、地形地貌和土地利用等生境因子,构建包括地形、气象、土地利用、生态保护等多因子评价指标体系,通过ArcGIS进行空间叠加分析,并以县域和乡镇空间尺度划分贵州高原山区火龙果种植适宜分区。结果 （1）通过该方法分析显示,至2019年,贵州省火龙果种植适宜区为3.520 5万hm²,次适宜区为5 695hm²,适宜区和次适宜区分别占全省国土面积0.20%和0.03%;（2）罗甸县、望谟县、贞丰县为推荐种植县,适宜综合种植面积分别为1.397 9万hm²、9 060hm²和6 568hm²;册亨县、镇宁县和关岭县为一般种植县,适宜种植面积分别为5 413hm²、3 357hm²和1 123hm²;平塘县、安龙县为分散种植县,可种面积分别为311hm²和1 089hm²;（3）推荐种植县中,适宜区在罗甸县中部和南部、贞丰县东南部、望谟县南部分布较多,涵盖30个乡镇;一般种植县中,适宜区集中于册亨县东部、镇宁县南部、关岭县东南部地区的20个乡镇。结论 该研究的过程中使用了充分考虑贵州高原山区土地资源实际情况的多因子评价,弥补了以往单因子研究的不足,可为为山地农业产业布局和适宜性评价体系的构建提供了参考。     

基于耕地发展权价值的内蒙古耕地数量、质量、生态三位一体保护研究

目的 基于耕地发展权价值的测算,探析内蒙古耕地保护机制。方法 文章通过对内蒙古自治区及其各盟市耕地发展权的测算,结合耕地数量、质量和生态服务价值等数,借助ArcGIS10.2软件、EXCEL软件分析三位一体耕地保护措施。结果 （1）2020年内蒙古自治区31.84%耕地面积满足区域粮食自给,粮食总盈余量为2 263.66万t,折算成盈余耕地面积为777.99万hm²,耕地保护机会成本损失为77.38万元/hm²,耕地发展权最高总价值为6.020 274万亿元。其中用来保障国家粮食安全的耕地面积占55.23%,折算耕地面积为5 113.72万hm²,耕地发展权价值为3 957.11亿元。（2）各盟市中呼和浩特市的耕地保护机会成本最高,为228.32万元/hm²,其次为鄂尔多斯市,172.87万元/hm²,最低是兴安盟,为21.83万元/hm²;国家粮食安全和耕地保护政策背景下,呼伦贝尔市耕地发展权价值最高,为412.52.亿元,其次是赤峰市、通辽市、鄂尔多斯市、向安盟和巴彦淖尔市,分别为317.57亿元、336.89亿元、250.10亿元、212.66和190.58亿元,最小正值为乌兰察布市,为23.92亿元;呼和浩特市、包头市、锡林郭勒盟、乌海市、阿拉善盟5盟市出现耕地赤字,耕地发展权价值测算为“负值”。结论 内蒙古各盟市耕地自给比例和粮食盈亏量差异较大,耕地机会成本和耕地发展权总价值变化大,这与内蒙古自治区耕地分布相对集中,自然资源禀赋和耕地生产力差异较大,以及经济发展和城镇化率不同是分不开的。最后结合各盟市耕地数量、质量、生态价值和耕地发展权价值综合分析并提出耕地三位一体保护措施。     

基于GIS的河南省小麦区域节肥减排潜力评价

目的 为研究河南省小麦节肥减排潜力。方法 文章基于农业统计数据、2 063份农户小麦调研数据和1 582组小麦田间试验数据,采用ArcGIS系统分析河南省农户习惯管理下小麦氮磷钾肥施用量及区域间差异,评价不同区域与推荐施肥相比的节肥潜力;应用生命周期评价（life cycle assessment,LCA）方法,定量河南省及不同区域小麦温室气体（greenhouse gas,GHG）减排潜力及区域性差异,为我国农业可持续发展和环境保护提供科学依据。结果 （1）河南省农户小麦习惯施氮量平均198 kg/hm²（174~259 kg/hm²）,其中东部和北部相对较高,中部和南部较低;在节氮量方面,小麦单位面积节氮量平均为42 kg/hm²,在县域水平上差异很大,整体上由南往北逐渐增加。（2）农户小麦习惯施磷量平均为121 kg/hm²（64~210 kg/hm²）,呈现北高南低、中部高低交错。平均单位面积节磷量为16 kg/hm²,以15~55 kg/hm²范围内的区域所占比例最大。（3）全省农户小麦钾肥习惯施用量平均50.4 kg/hm²,变化范围19~112 kg/hm²,施钾量普遍偏低,东部和北部及信阳南部县市施钾量仅19~35 kg/hm²;小麦节钾量范围为-45~62 kg/hm²,平均为-15 kg/hm²,有71.4%的县市需要增施钾肥。（4）在节肥总量方面,河南省小麦氮磷钾节肥总量分别为23.10万t、8.88万t、-5.31万t。（5）河南省小麦GHG减排总量为348.65万t CO₂ eq,单位面积温室气体减排潜力整体呈现出由南向北逐渐增加的趋势,范县、辉县、濮阳等县市的单位面积减排潜力可高达>1 000 kg CO² eq/hm²。结论 在当前河南省小麦施肥状况下,推荐施肥具有很大的节肥和减排潜力,但也表现出很强的区域性差异,根据不同区域小麦习惯施肥量和推荐量,确定节肥减排目标并制定相关措施,对小麦生产中资源节约和环境保护有重要意义。     

吉林省农户玉米种植与施肥现状调查

目的 明确吉林省不同生态区农户玉米种植与施肥现状,为区域玉米栽培和养分管理的进一步优化提供依据。方法 文章采用抽样调查方法,于2014年在吉林省44个县市开展农户调查,共收回有效问卷5 142份。调查内容主要包括：玉米品种、产量水平、种植面积和密度、播种和收获期、养分来源、施肥时期及方式、肥料种类和施用量等。结果 吉林省农户种植与施肥条件下玉米产量平均为9.1 t/hm²,东部湿润山区、中部半湿润平原区和西部半干旱平原区产量平均分别为8.1、10.1和8.0 t/hm²。全省农户共选用玉米品种526个,使用率前6的品种占比46.7%,播种期集中在4月下旬至5月上旬（占86.0%）,收获期集中于10月上中旬（占89.0%）。单户种植面积大多在1~3 hm²（占62.3%）,平均2.9 hm²,种植密度集中在5.5万~6.5万株/ hm²（占58.0%）,平均5.7万株/ hm²。全部参与调研的农户均施用化肥,但增施有机肥比例仅3.5%,东、中、西部地区分别为6.0%、1.9%和4.0%。化肥品种以单施复合肥和复合肥—单质肥配施为主,中部地区大多为单施复合肥,东、西部地区大多为复合肥与单质肥配施。全省农户的氮（N）、磷（P₂O₅）、钾（K₂O）养分投入量平均分别为244.6、130.8和104.4 kg/hm²,氮磷钾养分比例平均为1∶0.53∶0.43。施肥方式上,全省一次性施肥和分次施肥（基肥+追肥）方式分别占53.5%和46.5%。各区域中,中部地区农户的玉米养分投入量和一次性施肥比例（平均为540.6 kg/hm²和77.9%）远高于东、西部地区（平均为429.3、401.2 kg/hm²和22.4%、36.1%）。结论 现阶段吉林省农户玉米产量水平较高,但种植和施肥过程中还存在很多问题,需进一步加强针对区域尺度的玉米优化栽培和高产高效养分管理研究及技术推广,因地制宜地促进玉米产业绿色优质可持续发展。     

果园生草复合种养循环模式效应分析基于云南泸西县果园比较研究

目的 探讨果园生草复合种养循环模式的经济与生态环境综合效应,促进果园生草模式的多元应用。方法 文章通过实地调研获取2019年云南省泸西县果园生产数据,运用生态循环理论,系统分析果—草—畜（羊）复合种养循环模式,并利用生态系统价值评估模型测算复合种养和清耕种植两种模式的生态系统服务价值,对比两种模式的经济与生态环境的综合效应。结果 在经济效益上,复合种养模式比清耕种植模式节约化肥6 496元/hm²、农药426元/hm²,分别降低肥料成本18%,农药成本19%;同时,果园生草替代外购饲料减少饲料成本1.956 0万元/hm²,提高经济效益4.439 9万元/hm²。生态效应上,复合种养模式增加生态系统服务价值32%,通过减少化肥及农药投入降低环境成本33%,由此果园综合效应提高4.998 2万元/hm²。结论 果园生草复合种养循环模式将果业、草业、畜牧业有机融合,实现了农业资源高效利用,同时节肥、节药、节饲效果显著,是一种生态与经济协调发展的果园生态循环模式。     

近24年三峡水库库尾重庆市江津区耕地利用碳汇及碳足迹变化

目的 碳排放增长引发的全球气候变暖等问题日益受到社会各界的关注,耕地作为碳源和碳汇双重作用载体,剖析其碳排放演进特征显得极为重要。方法 文章基于1997—2020年重庆市江津区耕地利用变更数据和农业数据等,对农作物生育过程中碳吸收及生产过程中的碳排放做了分类测算。结果 （1）江津区耕地利用碳排放、碳吸收、碳汇均成增长趋势,与1997年相比,碳排放增加了3.46万t,涨幅高达86.86%,碳排放强度涨幅为91.18%,主要碳源是农业化肥施用和农膜使用;（2）碳吸收增加了50.30万t,涨幅为27.31%,碳吸收强度涨幅为30.78%,蔬菜、水稻和其他粮食作物的碳吸收贡献比最大;由于碳吸收远大于碳排放,碳汇值均为正值,与1997年相比涨幅为26%,碳汇强度涨幅为29.50%;碳足迹与单位面积碳足迹比1997年相比均为增加态势,碳足迹增加0.11万hm²,涨幅为42.31%,单位面积碳足迹增加了0.011hm²/hm²,涨幅为45.45%,但24年间净碳足迹值均为负值。结论 近24年间重庆市江津区耕地利用处于碳生态盈余状况。     

中国马铃薯农户种植意愿及其空间差异

目的 探究不同区域农户马铃薯种植意愿的影响因素及其差别,能够提高农户种植马铃薯的能动性与积极性,为马铃薯主粮化进程提供决策参考。方法 文章基于1 261个农户样本调研,运用条件价值评估法和多元回归模型,从农户个体禀赋、生产经营、社会资源、市场认知、政策需求五个方面对农户支付与受偿意愿进行分析,在此基础上探讨影响马铃薯种植意愿的主要因素,再比较分析典型产区马铃薯种植影响因素。结果 马铃薯农户种植受偿意愿均值为4 069.5元/hm²,支付意愿均值为724.5元/hm²;马铃薯农户种植意愿受各项成本收益、农户受教育程度、家庭收入、社会资源、市场信息认知及政府补贴的影响较大;北方种植因素受规模和利润率的主导,南方更多受到家庭生产经营特征的综合影响。结论 个体决策影响群体决策,群体决策影响整体马铃薯种植空间格局变化。区域内农户采取基于种植约束、成本收益和政策支持的种植方案选择,通过有限区域范围的无限趋同决策,产生不同程度的种植集聚、产业集聚和市场集聚,进而影响马铃薯种植空间格局变化。     

基于最小阻力模型的村域土地资源优化利用布局研究——以栾川县三川镇部分村庄为例

目的 通过对土地资源利用功能适宜性评价,结合土地利用现状分析,对乡村土地资源利用格局进行优化。方法 文章以栾川县三川镇部分村庄为例,构建土地资源生产、生活和生态功能分类指标体系,运用MCR模型对村域土地资源利用功能适宜性进行评价,通过分析土地资源利用现状与功能适宜性分区之间的冲突,制定相应的土地资源空间布局优化策略。结果 （1）根据MCR模型模拟结果,根据适宜性将研究区土地资源划分为生态保护区、限制开发区、后备开发区、优先开发区等4种类型分区;（2）根据土地利用现状与其适宜性之间的矛盾,可将生产功能区内碎片化的农用地、采矿用地和生活空间内零星建设用地优化为生态发展用地和对生态环境具有涵养作用的农业发展用地。优化后的生活用地面积减少了7.86hm²,工矿用地减少49.14hm²,生产用地中的农业用地增加20.11hm²,生态功能用地增加了36.89hm²,实现了农业生产用地集中连片、生活用地集约高效、生态用地充分保障的优化目标;（3）运用MCR模型模拟划定的土地资源分布格局呈现明显的圈层结构,并与当地的自然条件、区位条件相吻合,可为乡村规划和空间重构提供理论指导。结论 通过村域土地资源空间布局优化,实现乡村土地资源生产、生活和生态功能区协调有序,对推进乡村协调发展,落实乡村振兴战略具有重要意义。     

三维生态足迹视角下江西省自然资本可持续利用演化及其驱动因素

目的 文章以三维生态足迹视角对江西省自然资本可持续利用演化及动力机制进行研究,以期为实现“高经济水平,高自然资本存量”的可持续发展状态提供参考。方法 通过三维生态足迹模型计算自然资本,并用GWR模型识别可持续性驱动因素的空间异质性。结果 （1）从时间序列上：全省自然资本整体呈现先增长后下降的趋势;从内部组分构成看,生物账户是存量资本消耗的主要方式,耕地和林地是流量资本占用的主要方式。（2）从空间格局上：足迹深度空间格局表现为西部＞南部＞东部,其中新余市最高达13.264hm²/人,鹰潭市最低为2.717hm²/人;足迹广度在0.460～0.526hm²/人波动,空间格局表现为西部＞东部＞北部,其中鹰潭市最大值为0.860hm²/人,萍乡市最小值为0.199hm²/人;自然资本可持续利用综合分区表现为中部低于四周地区。（3）自党的十八大以来,江西省自然资本可持续利用整体呈现变好趋势,通过定量回归分析发现,引起自然资本可持续利用空间差异的主要原因是生态足迹强度、城市化率、生态承载力,且这3个因素在空间上有不同的表现模式。结论 该省的人均生态足迹、人均生态赤字和足迹深度、足迹广度的变化整体呈现先增长后下降的趋势,大力提升东、中部自然资本流量是实现区域协调发展的必由之路。要以降低生态足迹强度,提高生态承载力和控制城市化速率三项因素入手,以期实现江西省资源环境和社会经济可持续发展。     

考虑有效劳动力影响的花椒种植型新型经营主体土地适度规模研究

目的 受地形因素制约,山区地块小、坡度大、基础设施薄弱,短时间内较难实现大规模机械替代劳动力,加之青壮年劳动力外流日益增多,农村剩余劳动力成为影响新型经营主体规模经营的关键因素。探索有效劳动力约束下新型经营主体适度规模的“度”,对推进山区农业现代化进程具有重要意义。方法 文章基于江津区现代农业园区138户花椒种植新型经营主体的微观调研数据,衡量区域环境及劳动力个体特征等多因素叠加影响下新型经营主体的有效劳动力数量,进而评价劳动力约束下经济—社会—生态3个维度新型经营主体的综合效益,并以综合效益最大化为目标构建计量经济模型确定最优劳均经营规模,分析其规模经济。结果 （1）不同类型新型经营主体的有效劳动力数量具有明显差异,从多到少依次为农民合作社（13.03人）、农业企业（10.74人）、家庭农场（4.11人）、种养大户（3.15人）;（2）不同类型新型经营主体综合效益差异显著,从高到低依次为农业企业（18.12）、农民合作社（13.66）、家庭农场（8.89）、种养大户（7.56）;（3）研究区单个有效劳动力的劳均最优适度经营规模为2.64 hm²/人,兼顾不同经营主体的有效劳动力数量,户均最优适度经营规模从大到小依次为农民合作社（34.39 hm²）、农业企业（28.35 hm²）、家庭农场（10.85 hm²）、种养大户（8.32 hm²）。研究区当前达到最优适度经营规模的新型经营主体数量偏少,仅15.9%,其中包括6.5%的农民合作社、5.1%的家庭农场、2.9%的农业企业、1.4%的种养大户。结论 随着花椒种植新型经营主体土地经营规模的增加,单位土地面积的生产成本降低,与拟合最优规模的倒“U”型特征相符,即目前处于规模报酬递增阶段。该文旨在识别有效劳动力约束下各类花椒种植新型经营主体的土地适度规模,以助于推动山区培育新型经营主体,发展农业适度规模经营。     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式，发挥地质工作优势，推进低碳清洁能源的开发利用创新和技术进步，紧紧依托地质工作的人才、技术和行业优势，加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况，积极加强后备和应紧水源勘查。按照“两种资源，两个市场”的思路，通过实施中外合作勘查项目，以境外勘查工作为载体和平台，实施引进来和走出去战略，为天津市经济社会发展提供地质技术支撑。     

Trust-A monolithic panacea in land use planning?

Although trust research has been extensive and substantial, the constitution and actual merits of trust in land use planning remain nebulous. What do participants of a local land use planning process actually mean when they say they trust the planning committee? How important is participants’ trust in the planning committee in shaping their perceptions of the planning process and their cooperation in it? To explore the everyday meaning of trust in the specific context of local land use planning, semi-structured interviews with the participants of a local planning project in Switzerland were conducted (n = 9). Based on these results, the constitution and the relevance of trust in the responsible planning committee among a wider circle of participants were assessed (n = 66). The results show that participants trust the planning committee if they perceive its members as competent, honest, open, fair, reliable, reciprocating, respectful and committed. Interestingly, a considerable part of trust in the planning committee hinges explicitly on whether the committee incorporates the personal interests of the participant. Trust is indeed vital to participants’ belief that a meaningful discussion and cooperation with the members of the planning committee is possible. However, trust is neither a guarantee for people's approval of planning decisions nor for their cooperation. One implication of the findings is that in order to evaluate trust-building practice comprehensively, it is necessary to first understand the specific everyday meaning of trust for ‘real people’ in real planning processes.     

Agricultural Land in Vietnam: Markets Tempered by Family, Community and Socialist Practices

Since the late 1980s, markets involving agricultural land have emerged in the Socialist Republic of Vietnam. One major reason is that collective farms, previously a central feature of the country's political economy, ended. And a major reason for that was villagers' everyday politics gnawed the underpinnings of the collectives until they collapsed. Rural households, for the most part, wanted to farm separately. Today they do. Land is not privatized, however. Farming households have land use rights, not ownership. This tempers markets, as do other conditions arising from contending schools of thought in Vietnam about how land should be used, distributed and regulated.     

Conservation agriculture (CA) in Tanzania: the case of the Mwangaza B CA farmer field school (FFS), Rhotia Village,Karatu District,Arusha

This project was initiated to promote conservation agriculture (CA) in Tanzania so as to improve the food security and rural livelihood of small- and medium-scale farmers through the scaling-up of CA as a sustainable land management (SLM) tool as well as increasing the numbers of SLM-CA farmer field schools (FFS) in communities. The project had two phases from 2004 to 2010. It was funded by a Government of Germany trust fund and implemented by the Food and Agriculture Organization of the United Nations (FAO) and the Ministry of Agriculture in Tanzania. The project pilot districts include Arumeru (Arusha and Meru Councils), Karatu, Babati, Hanang and Moshi districts. CA has been shown to offer positive elements that could contribute to fighting hunger and poverty.     

Successful Practices in California Wine Exporting

Abstract

California is one of the world's largest wine producers, yet it has exported only a small portion of its products. Many US wineries want to pursue opportunities in foreign markets but only a few are actually doing this successfully. Therefore, this study attempts to identify the successful practices of 12 California wineries that have achieved their financial targets and other export goals. A qualitative research design of in-depth interviews was employed. Results indicate that there are 5 major success factors, with the two most important being the foreign partner relationship and top management vision and commitment to exporting.     

Time Allocation Decisions Associated with Job Market Preparation: Undergraduate Perceptions versus Market Realities

A survey of agribusiness firms identifies characteristics associated with above average starting salary offers in the allied fields of agribusiness, agricultural economics, business, and economics. A complementary survey is made of students at Texas A&M University and University of Georgia. Results show that firms value work experience and leadership experience more than students do, whereas students value raising grade point average and interview preparation more than do firms. Students seeking a firm's maximum starting salary offer will need to enhance academic performance with substantial work experience and leadership experience.     

Developments in the Doha Round and WTO dispute settlement: some implications for EU agricultural policy

Progress in the Doha Round is assessed against the changes tothe common agricultural policy (CAP) brought about by the Fischlerreforms of 2003–2004, and that proposed for sugar. Anelimination of export subsidies could place EU exports of processedfoods at a competitive disadvantage because of high sugar andmilk prices. Provided the single payment scheme falls withinthe green box, the likely new limits on domestic support shouldnot be problematic for the post-Fischler CAP. However, an ambitiousmarket access package could open up EU markets and bring pressurefor further reform. If there is no Doha agreement, existingprovisions will continue to apply, but without the protectionof the Peace Clause; and increased litigation is likely. FurtherCAP reform is to be expected.