中国南方调整水稻种植格局——一种水稻生产预先适应气候变化的选择(英文)

Rice planted in southern China accounts for 94% of the total in sown acreage and 88% of the total in production, which matters a lot to Chinese food security. However, due to the prolonged conflict between water availability and rice growth in spatial/temporal distribu-tion, rice production suffers from seasonal drought at acreage of 16%-22%, which compro-mises food production capacity and food security. Focusing on the spatial distribution of seasonal drought with rice and the practices to adapt to it, and based on an analysis of bal-anced water supply for and demand by rice at a growing season scale during 1981-2030, this paper assesses the changing seasonal drought in the process of rice production under the changing climate in the future, and identifies general rice re-cultivation options for climate change adaptation. Some conclusions can be drawn as follows. (1) Rice suggests a decline in seasonal drought, with early season rice (early rice hereafter) by 12,500 km2, middle season rice (middle rice) by 80,000 km2, and in particular late season rice (late rice) by 25,000 km2, which accounts for almost 20% of its cultivated acreage. It is indicated that due to climate change, seasonal drought in major rice producing areas tends to alleviate in general, late season rice in particular. (2) Future climate change brings about a significant impact on the spatial/temporal distribution of water resources in rice producing areas in China. Based on ’pre-designed’ adaptation actions for rice-re-cultivation, the rice cultivation pattern undergoes a significant alteration between 1981-2000 and 2001-2030. In eastern Guizhou and western Hunan, the pattern of single early plus single dry farming is changed into double cropping. In eastern Hunan, the pattern of dry cropping is changed into single early plus single dry farming. In northern Anhui, the pattern of dry farming cropping is changed into middle rice. All this is aimed at a potential adequate availability of water for rice production in the future. (3) Rice re-cultivation patterns developed in this paper help re-balance water demand and supply for rice growth using the spatial analysis tool to adapt rice growth to the changing water avail-ability from spatial perspective, and come up with rice producer-friendly re-cultivation options in response to climate change.     

Change analysis of rice area and production in China during the past three decades

Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.     

镉米之痛

正"民以食为天,国以粮为本。"我国有7000年有水稻种植历史,是世界上水稻品种最早有文字记录的国家。在我国南方,大米一直是长江流域及其以南地区人民的主粮。然而,就是这种每天饭桌必不可少的主食,最近却被曝出安全隐忧,被推到舆论的风头浪尖。5月16日,广州市食品药品监管     

RESEARCH PROGRESS OF FAN-SHAPED PHYTOLITH OF RICE AND RELEVANT ISSUES

在稻作农业起源和传播的研究中,水稻扇型植硅体对于发现、鉴定水稻遗存起到了重要的作用.目前学术界利用扇型植硅体在区分野生稻和栽培稻,粳稻和籼稻方面建立了诸多判别标准,但这些“标准”并没有得到广泛认可.本文从扇型植硅体的发育机理入手,结合前人对水稻扇型植硅体的研究成果和通过对部分现代野生、栽培水稻扇型植硅体的观察分析,认为尽管现代稻属和粳、籼稻扇型植硅体的鉴定特征是比较明确的,但由于野生稻和栽培稻扇型植硅体的区分存在不确定性,限制了扇型植硅体在早期稻作研究中的应用.本文对目前利用扇型植硅体进行水稻农业考古方面存在的问题进行分析,对如何寻找野生稻和栽培稻扇型植硅体的有效区分标准、如何应用新方法新技术提高鉴定准确性等方面进行了探讨.     

水稻籽实及其根系土壤中镉含量的相关性研究——以几个金土地工程土地整理区为例

通过对水稻籽实（大米）及其根系土壤中镉含量的相关性研究表明：酸性水稻土壤区域,根系土中的镉与水稻籽实中的镉相关系数为0．971,说明大米中镉积累与土壤环境中镉含量密切相关。碱性水稻土壤区域,水稻根系土中的镉与水稻籽实中的镉相关系数为0．265,大米中镉含量较低,碱性土壤中镉不易活化而原地淀积,则根系土壤中镉对大米中镉的富集贡献小。水稻根系土壤中有机质（Org）与镉相关系数为0．59,也较为显著。土壤中有机质对重金属元素镉具正吸附作用,有机质含量越高,重金属元素镉呈难吝硫化物而原地淀积。     

水稻土中重金属元素Cd、Pb的竞争吸附 ——以长株潭地区水稻土为例

对中国南方的3个水稻土样品进行了Cd、Pb单一离子和混合离子吸附特点的研究。结果表明,3个水稻土样品中Cd、Pb的吸附特点都相似,Langmuir等温方程可很好地描述Cd、Pb的吸附等温线。3个土壤样品中,有较高pH值和较低有机物、CEC浓度、粘土含量、高岭石含量的2个土壤样品对Cd、Pb有较大的吸附量,且其等温吸附拟合的最大吸附量(B)也较大。在两组分混合溶液中,尽管共存离子的存在影响了土壤对单一离子的吸附,同时土壤对Cd的吸附在一定程度上受影响的程度大,但3个土壤样品都表现出对Pb有强的吸附能力。在3个土壤样品中,Langmuir等温方程中Pb的健合能常数(K)都大于Cd的健合能常数(K),混合溶液中的K值高于单一溶液的K值,表明2种金属离子对吸附位点的竞争提高了特定吸附位点的保持力,使金属离子在土壤中特定位点的吸附更加坚固。     

低温对水稻秧苗电导率及可溶性糖含量的影响

在人工气候室6℃和15℃的低温环境下,研究了苗期低温条件下水稻秧苗的生理变化,分析了电导率、可溶性糖指标。结果表明,低温条件下水稻秧苗中电解质大量渗出,可溶性糖含量发生变化。这些生理指标的变化可以如实地反映水稻秧苗受低温胁迫的程度及水稻各品种之间的差异。     

庆安县有机水稻种植气象条件配比及灾害防御

本文利用庆安县1980—2010年气象资料,分析了种植水稻的气象条件,并与1998—2008年水稻平均生育期进行配比,得出当地温度、水分、日照和生态环境的同期配比适宜有机水稻的生长。通过分析气象灾害发生的类型及对有机水稻生产的影响,提出防御措施,为当地水稻生产提供指导。     

我国主要农耕区水稻土有机碳含量分布及影响因素研究

水稻土是我国主要的耕作土壤之一,水稻土有机碳变化与全球气候变化息息相关,因此研究我国主要农耕区水稻土有机碳含量分布特征及影响因素具有重要的现实意义。本文基于全国多目标地球化学调查1：250000土壤数据库,以行政区划分析了水稻土有机碳分布规律,从土壤pH值、年均气温、年均降雨量、耕作方式等角度探讨了其对水稻土有机碳含量...     

云南省元阳县传统水稻梯田的农业土壤评价

作为元阳水稻梯田农业生态系统可持续性评价的一部分,本文调查了箐口流域梯地的自然生物环境,评价了农业土壤的土壤肥力,采用地质—地貌—土壤信息相结合的方法建立了土壤—景观之间的组合模式。研究确定了人为、气候、地形因素为影响土壤形成的主要因素,评价了土壤潜在生产力以及相关的限制因子,并根据FAO体系,确定并划分了主要的土壤类型。研究结果表明：土壤肥力的空间分布相当均一;土壤属酸性,阳离子代换量和养分储量总体较低;农业生态系统在较大程度上受哈尼群众人为活动的影响,成功维持了相对活跃的养分循环系统。目前的研究集中在：（1） 本研究区域在整个哈尼梯田系统中的代表性评价;（2） 田间水平上的养分循环研究;（3） 土壤特性对作物产量的影响;（4） 将田间水平的研究结果应用于更大的空间单元。