共查询到17条相似文献，搜索用时 171 毫秒
1.
对农户水稻熟制决策行为差异及其空间特征的研究是理解水稻熟制动态变化、保障区域粮食安全的关键和提出应对策略的前提。利用野外调研与室内统计分析等方法,以鄱阳湖区为研究区,对研究区402例农户问卷调查数据进行实证研究分析。结果表明:(1)湖区水稻种植呈现南北差异,东南部(进贤县等)双季稻种植处于绝对优势,而西北部(德安县等)以单季稻为主;(2)不同县域的水稻熟制选择差异较大,以双季稻农户为主,占受访农户的63.57%,然而复种指数仍然偏低,仅1.55,且有近三成的农户发生了水稻熟制变更。基于以上研究结果,通过种在哪、谁来种、种什么、怎么种等角度出发,鄱阳湖区应该从提高水稻生产比较效益、促进土地流转及适度规模经营和优化水稻种植环境等方面引导、规范农户水稻种植,提高区域水稻复种指数和粮食供给功能,务实农业供给侧改革,进而实现耕地资源高效、可持续利用。 相似文献
2.
实时监测作物熟制信息对于区域乃至国家粮食安全具有重要意义。以水稻主产区吉泰盆地为例,以TM遥感影像为数据源,采用遥感与GIS技术并结合农业气象数据,建立吉泰盆地水稻物候历,综合运用特征时间窗口与地表水分指数和植被指数等方法,定量提取了2010年吉泰盆地水稻熟制信息,揭示了吉泰盆地单季稻和双季稻分布的数量特征与空间格局。研究表明:1)6月中下旬、7月中下旬和9月下旬是吉泰盆地单季稻和双季稻提取的较好时段,其中,9月下旬为最佳时段;2)2010年吉泰盆地水田和旱地的比例基本相当,耕地主要分布于赣江两侧河谷地带,水田主要位于盆地腹地;3)2010年吉泰盆地水稻种植面积为2 059km2,单季稻和双季稻的比例为1∶12,双季稻分布广泛,单季稻分布较为零散,在盆地周边区县相对集中。 相似文献
3.
农户小规模的农业生产方式已经与我国农业现代化的发展产生冲突,在全国大力推进土地流转和发展农业适度规模经营的背景下,对种植规模与规模效率之间关系的研究就成为了热点。本文利用368份江汉平原水稻种植农户的调查数据,应用"DEA-OLS"两阶段分析方法,对水稻种植的规模效率进行了测算,并考察了种植规模与规模效率之间的关系。结果表明:(1)江汉平原内农户水稻种植的规模普遍较小,平均为0.77公顷,规模效率平均为0.88,规模效率是限制水稻种植综合技术效率增加的主要因素,有88.32%的农户都处在规模报酬递增的阶段。(2)水稻种植规模与规模效率之间确实存在稳定的倒"U"型关系,在考虑户主特征、土地质量和家庭特征的情况下,农户水稻种植规模达到5公顷时,规模效率最大。(3)户主特征因素中,户主年龄对规模效率有显著的负向影响;户主从事非农工作的家庭比户主纯务农的家庭规模效率低。耕地质量因素中,地块的灌溉条件对规模效率有显著的正向影响。家庭特征因素中,使用机械播种的家庭比手工播种家庭的规模效率高3.07%。因此,我们建议当地政府积极推进土地流转,实行阶梯式的规模经营补贴,增加在灌溉条件改善和机械设施普及上的投入,以鼓励农户扩大种植规模,提高规模效率和种植收益,发展适度规模经营。 相似文献
4.
基于三工河流域284份农户抽样问卷调查数据,总结了多因素作用下农户灌溉决策机理。自然因素是导致农户灌溉行为区域差异的根源,农户自身因素影响农户对灌溉和节水的认识,政府决策可有效调控农户决策行为。根据农户灌溉决策机理,选择耕地状况、政策管理、农户素质、家庭经济状况和农户当前灌溉特征5类因素,构建Logistic模型分析多因素与农户节水意愿的关系,得出影响农户选择节水灌溉的主要因子,按影响程度从大到小排序如下：灌溉水价>耕地区位>非农收入比重>耕地归属>农户对滴灌的了解程度>受访者性别>灌水量>家庭劳动力平均年龄>家庭耕地面积,并据此提出鼓励农户选择节水技术的建议。 相似文献
5.
南方水稻复种指数变化对国家粮食产能的影响及其政策启示 总被引：7，自引：1，他引：7
中国南方地区水稻生产的变化对国家粮食安全具有重要影响。本文利用Landsat数据提取1990-2015年南方地区水稻种植制度分布及变化,并分析其对粮食产能的影响。结果表明：① 1990-2015年,水稻复种指数从148.3%下降到129.3%,双季稻改种单季稻（“双改单”）损失的播种面积为253.16万hm2,区域上以长江中下游地区变化最为突出。南方地区水稻种植制度整体呈现由北向南“双退单进”的变化格局;② 1990-2015年,“双改单”导致全国水稻产量减少6.1%,粮食产量减少2.6%。水稻主产区湖南省和江西省以及经济发展较好的浙江省因“双改单”水稻减产幅度较大,均超过13%;③ 充分利用“双改单”稻田的粮食产能相当于新增耕地223.3万hm2,为2001-2015年通过土地整治项目新增耕地总量的54%,是2016-2020年全国新增耕地规划目标的1.7倍,可节省约1674.4亿元新增耕地开垦费用。因此,与其追求低质量的“新”耕地,不如充分利用已有的高质量“旧”耕地,政府应转变耕地占补平衡的考核方式,将因提高复种指数增加的播种面积纳入补充指标。 相似文献
6.
本文借助作物生长计算机模型与模型数学的方法对江苏省丹阳市两种种植制度的气候，土壤生产潜力进行了初步研究。结果表明，模拟的小麦／玉米－晚稻种植制度的气候潜力比小麦－单季稻高３０００ｋｇ／ｈａ左右。玉米的气候产量受降水量的年际变化影响较大。当土壤排水良好时，小麦的气候产量受降水量的影响较小。占丹阳市水稻土类８０％面积的三种水稻土属的自然生产潜力在种植小麦－单季稻两熟时基本上为１３５１０．５ｋｇ／ｈａ… 相似文献
7.
农地边际化过程中农户土地利用行为变化及其对粮食生产的影响 总被引：2，自引：0，他引：2
认识农地边际化过程中农户土地利用行为的变化及其对粮食生产的影响,对正确判断中国的粮食生产形势,制订相关政策以确保粮食安全具有重要意义。基于湖北省咸宁市4县1市1区的23个村组、1252个农户家庭的调查数据,对1981年以来农户土地利用行为变化的特征及其对粮食生产的影响进行分析。结果表明：① 农户用于粮食生产的劳动力与土地面积明显下降,农户用地方式出现“省工性”变化,劳动力被农机要素替代,农业机械、化学肥料与农药等物质投入显著上升。② 主要粮食作物的劳动生产率、土地生产率与商品率分别提高了4.61%、29.69%与50.56%,但区域主要粮食作物的总产量与农户家庭平均粮食占有量却分别下降了10.49%与10.50%,区域粮食安全的保障能力出现弱化。③ 丘陵山区主要粮食作物的“三率”提高幅度高于平原地区,丘陵山区的水稻总产量与家庭占有量均略有提高,但平原地区却出现了明显下降。产粮重心在空间上出现从平原地区向丘陵山区倾斜的现象。④ 稳定主要粮食作物的用地规模,促进农户规模经营,提高土地产出效率,是应对农地边际化作用的关键。从事规模化与专业化粮食生产的农区与农户,应成为国家惠农政策与粮食安全政策重点扶持的对象。 相似文献
8.
农户收入的农区发展环境影响分析——基于河南省1251家农户的调查 总被引：10，自引：1，他引：9
通过对分层随机抽样选取的河南省不同类型的11个村的农户调查和定量分析,发现农户间收入差别很大,村际之间和同村农户之间均如此。全体样本农户收入的基尼系数达0.3936,有的村子已达0.4以上。模型分析表明,农区发展环境因素对农户收入具有重要影响。耕地面积、种植结构、经济基础、乡镇工商业发展水平、城郊区位、交通条件、兼业水平等因素在不同的地形类型和收入类型农户中,对收入提高产生一定的影响。低收入农户中,耕地面积较为重要,而在中等收入农户中,增加了种植结构因素,在高收入农户中,又增加了经济基础、工商水平、城郊区位和交通因素,由此验证了"区域发展阶段不同影响因素有所不同"的理论假设。 相似文献
9.
长江流域稻田生态系统的水分和养分转换过程 总被引：4，自引：0，他引：4
田间模拟施肥进步和灌溉模式的定位试验在中国科学院桃源农业生态试验站进行。结果表明施肥制度和水分管理模式显著地影响水分和养分的转化过程和生产效益。单施N的产量效应为4.5 kg/kg,而NP或NPK配施养分总的产量效应分别为8.8 kg/kg和8.0 kg/kg;有机物料循环的增产率为56.8%,在有机物料循环的基础上配施NPK化肥最大的增产率可达到80.1%;化肥应用的进步可使水稻产量增长62.5%或通过施肥实现的水稻产量中由于化肥应用所占的贡献份额为38.4%,有机无机肥配合水稻产量增长80.1%,或通过施肥达到的产量中有机无机肥配合所占的份额为44.4%。本区双季稻年灌溉需水量为5838 m3/hm2,年变异C.V = 8.3%。晚稻灌溉占全年的71%,7~9月是灌溉需水高峰期,占全年灌溉量的68%。生产灌溉效率 (灌溉水量与产量之比)：生物量3.67 kg/m3,精谷量1.48 kg/m3。常规管理田间水分分配为：蒸散占1/2,翻耕整地占1/6,植物构成占1/21,田间渗漏占1/14,其它环境耗水 (维持) 占1/5。耕灌雨养管理翻耕整地和田间渗漏比例过高。不同灌溉处理试验表明：双季稻生产的灌溉,以早稻保持水层灌溉,晚稻按需配额灌溉的模式比较适宜。 相似文献
10.
中国东北农业生产适应气候变化的行为经济学解释 总被引：2，自引：0，他引：2
利用调查问卷和入户访谈的方法,以中国东北地区11个调查点为研究区.对554户农户进行调查研究.从行为经济学的视角出发,把农业实践者的粮食种植行为作为一种农业经济行为,分析20世纪80年代气候变暖以来,农业实践者在农业种植决策中的行为过程及其与传统经济学理性行为之间的差异.结果显示,在不确定条件下,农业决策行为符合行为经济学的一般规律,在认知偏差和思维定式等因素的影响下,会系统地偏离传统经济学理论,产生非理性行为,从而导致适应与变化之间存在时滞现象:①受启发式认知偏向的影响,农业实践者在作物种类选择、种植计划制定和粮食出售时间确定等方面均表现为非理性的特点:②受中国具体国情和农业生产固有特点的影响,出于"保障生活能够继续"的考虑,农业实践者判断"获得"和"损失"的参照点通常很低,对作物品种选择的行为更倾向于保守. 相似文献
11.
This paper examines the spatial characteristics of farmer/household behaviors in regional rice cropping systems (RCS), and the results provide necessary information for developing strategies that will maintain regional food security. Through field study and statistical analysis based on 402 households questionnaires finished in 2014-2015 in the Poyang Lake Region (PLR) of China, we arrived at two main conclusions. First, single- and double cropping rice were found across the study area, but showed a general distribution trend, with double cropping rice in the southeast part (especially in Jinxian county) and single cropping rice in the northwest (particularly in De’an county). Second, the household decisions concerning RCS varied in different parts of the PLR, but double cropping was the dominant type, with about 63.57% of the respondent households in the PLR cultivating double cropping rice. However, the multiple-cropping index of paddy rice was only 1.55. About 3% of interviewed households had altered their RCS during this period. Based on these findings, the local governments should guide farmers’ paddy field cultivation behaviors by increasing the comparative efficiency of rice production, promoting appropriate scale operations and land conversion, as well as optimizing rice growing conditions to improve the multiple cropping index and enhance food provision. Finally, land-use efficiency and more sustainable use of land resources should be improved. 相似文献
12.
Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems.Yet,it is always affected by external factors,like agricultural policies.Since 2004,seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China.So far,few studies have investigated the ef-fects of these policies on the rice cropping systems.In this study,based upon the long-term field survey information on paddy rice fields,we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region(PLR),China.The results revealed that:(1) from 2004 to 2010,the decrement of paddy rice field was 46.76 km2 due to the land use change.(2) The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields.NDVI curves of single cropping rice fields showed one peak,while NDVI curves of double cropping rice fields displayed two peaks an-nually.NDVI of fallow field fluctuated between 0.15 and 0.40.NDVI of the flooded field during the transplanting period was relatively low,about 0.20±0.05,while NDVI during the period of panicle initiation to heading reached the highest level(above 0.80).Then,several temporal windows were determined based upon the NDVI variations of different rice cropping systems.(3) With the spatial pattern of paddy rice field and the NDVI threshold within optimum tem-poral windows,the spatial variation of rice cropping systems was very obvious,with an in-creased multiple cropping index of rice about 20.2% from 2004 to 2010.The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR,China. 相似文献
13.
湖南凤凰茶田汞矿区土壤-水稻系统中汞的传输及其健康风险 总被引：3，自引：0，他引：3
通过野外系统采样和室内分析,研究了湖南凤凰县茶田汞矿区耕层土壤及水稻中Hg的含量分布以及土壤-水稻系统中Hg的传输和分配。结果表明:由于地质成因和人为采选矿活动导致矿区土壤及作物中Hg大量富集,与对照区相比,矿区耕作土壤、稻根、稻秆、稻米中Hg平均含量分别增加了267.6倍、8.6倍、5.8倍和2.3倍。土壤中的有机-硫化态Hg同稻根、稻秆、稻米中Hg含量间均呈现显著正相关性,但整体而言,Hg由土壤→稻根以及稻根→稻米的富集/迁移系数较低,移动性弱。矿区稻米Hg平均含量为0.09±0.04μg/g,与国家粮食卫生标准(GB2762–2005)的限值(0.02μg/g)相比,超标达4.5倍。当地居民终生平均每天摄入的Hg量为0.75μg/(kg.d),超过WHO推荐的可耐受剂量[0.71μg/(kg.d)],面临较大的健康风险。对矿区中多种元素研究发现,稻米中Hg、Pb、Se共同富集,其复合污染机制的研究亟待开展。 相似文献
14.
元代前期省域耕地面积重建 总被引：7，自引：1，他引：6
基于历史文献资料重建区域历史时期土地利用/覆被变化,对深入研究区域生态环境效应、充实全球历史土地利用数据集等均具有重要意义。本文通过对元代（1271-1368年）屯田与屯户、垦田与户口等册载数据及相关史料的梳理与分析,提出了户均屯田数与户均垦田数的转换关系,构建了元代省域耕地面积估算方法,重建了至元二十七年（1290年）研究区省域耕地面积。结果表明：① 元代户均屯田数和户均垦田数均具有明显北高南低的特征,这种区域差异性是南北方地区自然条件和种植制度等差异的客观反映,而地域一致性则是户均屯田数配拨以该地户均垦田数为参照的具体表征。② 在省域尺度上,户均屯田数与户均垦田数存有一定偏差,其南北方地区的修订系数分别为1.23和0.65。③ 元代至元二十七年研究区耕地总量为535.4×106今亩,垦殖率为6.8%,人均耕地面积为6.7今亩;其中,境内北方地区耕地面积约占57.8%,垦殖率为6.6%,人均耕地面积为15.6今亩;南方地区约占42.2%,垦殖率为7.1%,人均耕地面积为4.1今亩。④ 黄河中下游的腹里地区、淮河流域的河南行省、长江中下游地区的江浙、江西及湖广行省和西南地区的云南行省是元代至元年间耕地的主要分布区。 相似文献
15.
Understanding the spatial and temporal variations of cropping systems is very important for agricultural policymaking and food security assessment, and can provide a basis for national policies regarding cropping systems adjustment and agricultural adaptation to climate change. With rapid development of society and the economy, China’s cropping structure has profoundly changed since the reform and opening up in 1978, but there has been no systematic investigation of the pattern, process and characteristics of these changes. In view of this, a crop area database for China was acquired and compiled at the county level for the period 1980-2011, and linear regression and spatial analysis were employed to investigate the cropping structure type and cropping proportion changes at the national level. This research had three main findings: (1) China’s cropping structure has undergone significant changes since 2002; the richness of cropping structure types has increased significantly and a diversified-type structure has gradually replaced the single types. The single-crop types—dominated by rice, wheat or maize—declined, affected by the combination of these three major food crops in mixed plantings and conversion of some of their planting area to other crops. (2) In the top 10 types, 82.7% of the county-level cropping structure was rice, wheat, maize and their combinations in 1980; however, this proportion decreased to 50.7% in 2011, indicating an adjustment period of China’s cropping structure. Spatial analysis showed that 63.8% of China’s counties adjusted their cropping structure, with the general change toward reducing the main food types and increasing fruits and vegetables during 1980-2011. (3) At the national level, the grain-planting pattern dominated by rice shifted to coexistence of rice, wheat and maize during this period. There were significant decreasing trends for 47% of rice, 61% of wheat and 29.6% of maize cropping counties. The pattern of maize cropping had the most significant change, with the maize proportion decreasing in the zone from northeastern to southwestern China during this period. Cities and their surroundings were hotspots for cropping structural adjustment. Urbanization has significantly changed cropping structure, with most of these regions showing rapid increases in the proportion of fruit and vegetables. Our research suggests that the policy of cropping structural adjustment needs to consider geographical characteristics and spatial planning of cropping systems. In this way, the future direction of cropping structural adjustment will be appropriate and scientifically based, such as where there is a need to maintain or increase rice and wheat cropping, increase soybean and decrease maize, and increase the supply of fruit and vegetables. 相似文献
16.
Ecological compensation for winter wheat abandonment in groundwater over-exploited areas in the North China Plain 总被引：5，自引：1，他引：4
Xue Wang Xiubin Li Liangjie Xin Minghong Tan Shengfa Li Renjing Wang 《地理学报(英文版)》2016,26(10):1463-1476
The land fallow policy was adopted by central and local governments to encourage the abandonment of water-intensive crops, such as winter wheat, in groundwater over-exploited areas. At the same time, since the 1990s, many households in the North China Plain (NCP) have chosen to replace the winter wheat and summer maize double-cropping system with the spring maize single-cropping system. Therefore, it is crucial to identify target land parcels for winter wheat abandonment and to design reasonable and proper standards for ecological compensation prior to the implementation of the land fallow policy in the NCP. In this study, multi-level logit models were used with household survey data in order to detect determinants across land parcel, household and village levels on household cropping system decisions; the opportunity costs for winter wheat abandonment were also calculated using cost–benefit analysis. The results show that: (1) land quality and irrigation condition at parcel level are two essential elements influencing household cropping system decisions. Nearly 70% of the total area of poor land and more than 90% of the total area of unirrigated land has suffered winter wheat abandonment. Target land parcels for the land fallow policy should be those that are irrigated and of high quality. (2) There were no significant differences between net profits from spring maize and summer maize under similar farming conditions, and the opportunity cost for winter wheat abandonment should be equal to the net profit of winter wheat. (3) The primary purpose of the land fallow policy is to induce groundwater recovery and restoration as a preliminary stage. A higher level of 350 yuan/mu is recommended as subsidy for ecological compensation at this stage. Later, the primary purpose of the policy should be a transition to a balance between exploitation and supplementation of water resources, and a lower level of 280 yuan/mu is recommended as a subsidy at this stage. 相似文献
17.
近50多年来澜沧江流域农业灌溉需水的时空变化 总被引：3，自引：1，他引：2
利用澜沧江流域云南境内8 个气象站1950s-2007 年的逐月气象数据,现状作物种植、农业耕作、田间水分管理等资料,应用Mann-Kendall 法和R/S 分析法,探索50 多年来流域区的干湿变化、农业灌溉定额转折变化趋势及分布规律。结果表明：年、季平均温度普遍地显著升高,降水量干季增加、湿季减少;大部分地区的参照作物腾发量ET0在年度及干、湿季都呈增加趋势,仅在流域中段大理、剑川、耿马的部分时段为减少,干湿指数大多数地区都是降低;水稻及农业综合灌溉需水定额从流域上游到下游逐渐呈减少、增-减并存到增加的趋势。气象因子、ET0、干湿指数、水稻灌溉及农业综合灌溉定额发生转折变异现象都集中在澜沧江中下段的耿马、思茅、景洪、勐腊等地,且时间系列的转折变异点在1960s-1990s 的各个时期均有出现。水稻灌溉定额随纬度方向变化的相关系数为0.513,随海拔高程变化为0.610,最高值出现在维西,最低值为勐腊;农业综合灌溉定额受作物种植结构和水稻种植面积的影响较大,二者相关系数达到0.826,但其与纬度、海拔的变化规律不明显,最高值在大理,最低值在维西。灌溉定额在小范围内的多样性变化,表明在纵向岭谷特殊环境对地表水汽输送、气温和气流场分布等的“通道-阻隔”作用下,澜沧江河谷农业灌溉需水量时空变化的复杂性。 相似文献