1998-2008年中国农作物化肥消费的时空分异(英文)     

辛良杰  李秀彬  谈明洪 《地理学报(英文版)》2012,22(4):643-652

The agricultural and land policies in China are always focused on protecting its food supply and security because of the country’s large population and improved diets.The crop production guide ’Take Grain as the Key Link’ prompted peasants to plant grain on most of the agricultural land,leading to the majority of fertilizer being used in grain crops for many years in China.This situation has changed dramatically in recent years.Based on data pertaining to provincial crops sown area and fertilizer use per unit area in 1998 and 2008,the temporal and spatial variations of China’s fertilizer consumption by crops were analyzed at the provincial level,and the results are presented here.(1) Fertilizer consumption in China grew strongly in the last decade,while the growth was mainly attributable to the increase of fertilizer con-sumption by horticultural crops.The fertilizer consumption of grain crops dropped from 71.0% in 1998 to 57.8% in 2008.Thus,it is concluded that the emphasis of fertilizer consumption is shifting toward horticultural crops.(2) There were marked differences in the growth rates of fertilizer consumption from the regional point of view.The national average growth rate of fertilizer consumption was 31.9% during 1998-2008.The western and northeastern parts of the country came close to the national average,while the eastern part was lower,with an average of 13.0%,and central China was much higher(50.8%).The increase of fertilizer consumption in central and west China was higher than the other zones,which already ac-counted for 77.9% of the national total.Thus,it is concluded that the consumption emphasis of chemical fertilizer shifts toward the central and western regions.(3) The decline of fertilizer consumption by grain crops was largely due to the decrease in sown area compared with the increase by vegetable crops attributable to the enlarging sown area;the increase by orchard crops was affected by both expanding the sown area and fertilizer use per unit area.  相似文献   

北美地质演化与钾盐成矿   总被引：3，自引：0，他引：3  

齐文 《地质学报》2010,84(11):1576-1584

北美大陆拥有世界上最大的钾盐矿床,北美大陆的钾盐储量占全球已探明钾盐储量的一半数。本文在总结北美大陆地质构造单元划分、地质演化历史的基础上,重点分析了晚古生代地台沉积序列及其与钾盐矿床形成的关系,指出钾盐主要形成于欠补偿的海相地台型盆地,个别形成于海陆交互相的克拉通边缘地堑/裂谷盆地中;钾盐层主要位于海相台地序列的最后一个旋廻(Kaskaskia序列),以及从台地向前陆盆地转化的过渡阶段(Absaroka序列),当海相台地转化为前陆盆地之后,就不再有钾盐矿床的形成。北美晚古生代钾盐大规模集中成矿作用,也与该时期北美大陆古赤道位置密切相关。钾盐矿床的形成是构造-盆地-古气候等多种因素耦合的结果,钾盐找矿是有章可循的。  相似文献   

The creep of potash salt rocks from Saskatchewan     

E. J. Scott Duncan  Emery Z. Lajtai 《Geotechnical and Geological Engineering》1993,11(3):159-184

Summary The results of creep tests on the Esterhazy-and the Patience-Lake-types of potash salt rocks from Saskatchewan, Canada are presented. The investigations involved over 6 years of time-dependent experiments in uniaxial compression using potash from the Rocanville and the Lanigan mines of the Potash Corporation of Saskatchewan. A creep test at a given load would last from 2 to 8 months, with most tests conducted over a 4-month period.Since the yield stress of both types of potash lies between 9 and 11 MPa, there is very little creep below 11 MPa. Between 11 and 13 MPa, creep strain production increases sharply through plastic deformation. Above about 13 MPa, however, plastic creep is dominated by brittle creep caused by microcracking. As a result, the lateral and volume creep strain curves may then display the transient and the steady-state, or all three stages of creep, while the axial strain, which is not affected by microcracking, usually attenuates for the whole duration.Two different interpretations of the results are offered. Identifying the last (the fourth) month of testing with the steady-state model, the stress dependence of the steady-state rate has been established for both rock types. A unimodal rate model for the axial strain and a bimodal model for the lateral strain are suggested. The alternate interpretation proceeds on the assumption that under 13 MPa, both the axial and the lateral strain can be modelled through the power function formulation of transient strain.  相似文献   

Studies on the effects of polyaspartate protease fertilizer enhancer in the absorptions of soil nutrition and the enzymatic activities of crops     

JIANG Guoliang )  *  YANG Dong )  LIU Yun )  ZHANG Guanghua )  LI Zhongjun )  ZHANG Xinhua ) ) College of Marine Life Sciences  Ocean University of China  Qingdao  P..R.China) Fisheries College  Ocean University of China  Qingdao  P..R.China) Agriculture bureau of Anqiu  Anqiu  P..R.China 《中国海洋大学学报(英文版)》2003,2(1):62-64

1　Introduction　Chinaisboththelargestproducerandthelargestconsumerofchemicalfertilizersintheworld .Since1984 ,Chineseconsumptionofchemicalfertilizerhasincreasedmorethanonetimes ,fromabout 17millionmetrictonsto 35millionmetrictons .However ,dur ingthesameperiod ,theyieldoffoodproductionhasincreasedonlyabout 10 % .Thediscrepancybetweenfertilizerconsumptionandyieldincreasehasindicatedthedrasticdecreaseofthebenefitsofchemicalfertiliz ers .Infact ,theutilizationefficiencyofnitrogenfer tilizerinC…  相似文献   

Origin of high fluoride contents in groundwater of the Santa Maria Formation, Guarany Aquifer System, southern Brazil     

Ari Roisenberg Maria Paula C. Marimon Antonio P. Viero 《中国地球化学学报》2006,25(B08):121-121

Fluoride anomalies （up to 11 mg/L） have been detected in the porous confined Santa Maria Aquifer （Guarany Aquifer System） in the central region of Rio Grande do Sul State, southern Brazil, leading to endemic fluorosis. Two hypotheses are investigated concerning the fluoride origin： contamination by long-term phosphate-fertilizer application due to extensive tobacco plantation or lithogeochemical affiliation from regional rocks. The results are discussed based on statistical and geochemical modeling and stable isotope data of water, nitrate and sulfate. Field monitoring of phreatic and confined aquifer during two years and laboratory leaching and retention experiments were performed. Regional statistical analysis （factorial and cluster analysis） on the basis of 350 wells discriminates four different hydrochemical groups in the confined aquifer, considering magnesium, calcium bicarbonate, sodium chlorinate and sodium bicarbonate as specific parameters. The last two groups reach higher fluoride contents and represent deeper aquifer levels where geochemical modeling shows carbonates （calcite and dolomite） are of super-saturation. The laboratory experiments confirmed that local soils with high CTC and aluminum contents （Udults） represent an efficient geochemical barrier, preserving the aquifer from fluoride contamination and supporting remediation strategies for fluoride removal. δ^18O and δD groundwater data and the local meteoric water line （LMWL） indicate that local precipitation is the main groundwater recharge source in the area.  相似文献   

塔里木盆地西部卤水地球化学特征及成钾远景预测   总被引：13，自引：0，他引：13  

马万栋  马海州 《沉积学报》2006,24(1):96-106

在塔里木盆地的地质发展史上，尤其是在白垩纪和第三纪，经历了多次新特提斯海的海进和海退，带来了大量成盐物质，再加上后期持续干旱的气候条件和适宜的岩相古地理条件，使塔里木盆地沉积了一套厚层石盐岩、膏泥岩、碳酸盐岩以及泥质岩等，为钾盐资源的形成奠定了一定物质基础，同时由于受地质构造和中生代盆地断裂的控制所形成的若干次级盆地，加上适宜的古地理环境，使其具备了钾盐矿床形成的基本条件。通过野外实地考察取样，采集岩盐及卤水样品共300多件，用于实验分析的共142件（卤水43件）。通过对塔里木盆地西部卤水的地球化学特征分析，讨论了寻找钾盐的直接指标K+含量和各种地球化学特征系数，探讨了塔里木盆地的成盐模式、卤水浓缩阶段和成钾可能性，得出:塔里木盆地的钾盐远景区是喀什凹陷和阳霞凹陷；依据溴和硼含量以及各种特征系数值与正常卤水浓缩值比较，可知塔里木盆地是溴和硼等微量元素含量较少的地区，不能完全依靠这些特征参数来判断塔里木盆地的卤水浓缩程度和钾盐资源状况，同时也说明了塔里木盆地是一个成盐环境相对比较复杂的地区。  相似文献   

硅肥在黄河冲积土上的水稻肥效试验研究   总被引：4，自引：1，他引：3  

蔡德龙  钱发军  邓挺  孙启文 《地域研究与开发》1998,17(1):62-64

试验研究结果表明：无论以炼铁水淬渣还是以赤泥为基料生产的硅肥,在河南省黄河冲积平原水稻上施用均获得１５％以上的增产效果,尤以赤泥的基本原料生产的硅肥增产效果最佳。  相似文献   

高钾系列复混喷施肥的研制与应用     

屠兰英 《盐湖研究》1998,(Z1)

所研制的高钾系列复混喷施肥其成份以KNO3为主,含微量营养元素。应用试验表明,该喷施肥具有成本低,肥效高,经济效益显著的特点,具有推广应用价值。  相似文献   

福鼎四季柚与地质背景相关性研究     

林才浩  叶允钧  杨锦发  谢云妹  陈先进  陈月仙 《物探与化探》1997,21(5):339-347

福鼎四季柚是柚类中的一个特殊品种,品质优良。其传统种植区除具有优越的自然地理条件外,其地质背景为白垩系中酸性(英安质、流纹质)火山碎屑岩,为作物提供了较丰富的Ca、Mg、Na、Zn、Mn等营养元素．有利于四季柚的生长。经研究了解了四季柚对多种化学元素的需求,初步确定了四季柚种植土壤元素有效态的适宜含量范围并提出了扩种的最佳地区。做了初步施肥试验,为配方施肥提高抽果产量和品质提供了依据。  相似文献   

排水条件下化肥流失的研究——现状与展望   总被引：14，自引：0，他引：14       下载免费PDF全文

张蔚榛  张瑜芳 《水科学进展》1997,8(2):197-204

探讨排水对化肥流失的影响;减少排水条件下化肥流失的合理施肥措施及排水方式。根据现有研究成果,从排水条件下化肥流失的野外试验研究和数值模拟研究两方面进行了论述,在此基础上提出该项研究需进一步探讨和解决的问题,为该课题的深入研究提供了有利条件。  相似文献