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1.
以集雨区水量平衡为基础,从分析坡地水文过程入手,以坡地不同生态系统雨水分配、降雨过程地表径流产量、径流过程的土壤及养分流失量为参数,以生产灌溉对集雨的要求、坡地不同生态系统对雨水侵蚀的承载力、坡地雨水运移过程对环境和区域洪涝灾害的影响为约束条件,拟合出红壤丘岗坡地农林复合生态系统构建适宜的土地利用结构:人工林占30%,人工草地占15%,果药茶园占30%,耕地占20%,自然保护区占5%。该用地比例(结构)既满足于地貌单元(集雨区)生态系统利用坡地集雨维持系统水循环平衡的要求,也满足于坡地农林复合生态系统的可持续性保护的要求。  相似文献   

2.
红壤丘岗坡地农业开发利用的问题与对策   总被引:11,自引:0,他引:11  
在综合分析了红壤丘陵区农业水资源和坡土壤资源特性的基础上,提出了红壤丘岗坡地农业开发利用中应采取的五项对策措施,即:1.坡地开发,水利先行;2.改进灌溉技术,提高水资源利用率;3.合理耕作,扩大土壤有效水库溶;4.推广避旱抗旱生态栽培技术;5.改土培肥,提高地力。  相似文献   

3.
台湾山坡地作为农业利用之面积甚为广大,为加强山坡地之保有与利用,促进坡地农业之发展,有关方面近二十多年来大力推展坡地农场机械化。推展坡地农场机械化所行之方法可分为三方面:一为推行坡地机械施工作业,改进施工技术,有效进行水土保持处理,兴建坡地农场基本设施,及改善坡地利用环境;二为改良及研发适于坡地作业之农业机械与机械设施,以节省劳力,增加农业生产,三为建立坡地农场之机械化作业体系,藉整合水土保持,土地利用,作物栽培,及机械作业,以求坡地农业之现代化与永续发展。经由有关单位与人员之协办参与,台湾坡地农场机械化已获致多方面之成效,其最显为:1.使政府各年度山坡地保育利用计划下之水土保持处理与公共设施之工作量得以顺利完成,并保持良好之工作品质。2.已完成改良及研发一系列之坡地农业机械与机械设施,使坡地重要作物之栽培管理作业均得以机械化。3.配合坡地保育利用方式与作物栽培方法,已建立多种坡地农场机械化作业体系,可供农民参考采行。  相似文献   

4.
施用氮肥对温州蜜柑产量和品质的影响   总被引:14,自引:0,他引:14       下载免费PDF全文
刘运武 《土壤学报》1998,35(1):124-128
红壤丘岗坡地桔园,在施用有机肥和磷钾肥的基础上,施用不同量的氮肥后,土壤pH值随着施氮量的增加而下降,呈线性负相关。不同施氮量对柑桔产量的影响具有极显著的差异。施氮后,土壤速效氮,磷,钾和叶片氮,磷,钾含量与产量呈显著或极显著线性相关。  相似文献   

5.
本文介绍了饮马池村坡地建大棚发展山区“霜期”农业的典型,提出坡地大棚是山区坡地资源科学、高效、立体利用的有效途径。  相似文献   

6.
应用层次分析法,在胱氨酸生产废水的治理和利用途径中进行了决策。结果表明,从利用废水提取其它氨基酸、制备氨基酸饲料、生产氨基酸农药、开发氨基酸肥料和直接利用废水灌溉旱坡地等5种资源化途径中,依照技术上简单易行、治理效果好,又具有一定经济效益的原则,选取最优方案为制备氨基酸肥料,其次为利用废水灌溉旱坡地与生产氨基酸饲料。  相似文献   

7.
本研究系藉由水土保持学之理论与分析,对于可能会影响坡地利用的因素加以探讨,并将地区之山坡地游憩区的游憩活动对山坡地水土保持可能造成之冲击作一深入之探讨,进而提出因应之对策,以作为日后划坡地游憩资源及坡地景观资源之参考,此乃本研究之目的是也。  相似文献   

8.
福建省侵蚀坡地的可持续利用   总被引:5,自引:0,他引:5  
福建省25°以下的未开垦利用的侵蚀坡地,通过多年的开发与整治,不仅有效地控制了水土流失,且建立了水果生产基地。然而,在侵蚀坡地,尤其是在中、强度侵蚀坡地上开垦的果园,土壤肥力尚未得到改善,坡地生态系统仍然较脆弱。因此,在侵蚀坡地果园上必须通过套种绿肥(牧草),以增加园面覆盖和生物归还量,促使土壤肥力的提高和环境条件的改善。研究证明,这是保证侵蚀坡地持续利用的一条根本出路。  相似文献   

9.
宁南黄土丘陵区旱作梯田水分利用率分析   总被引:4,自引:0,他引:4  
依据在宁南黄土丘陵区半干旱气候地带梯田和坡地上进行的作物水分利用比较试验,分析了丰水年与欠水年和高肥与低肥条件下,作物的耗水量和水分利用率。结果表明,梯田丰水年与欠水年作物产量与水分利用率变化小,而坡地大。在高肥条件下,梯田作物耗水量为328.0mm,用水效率为0.227kg/mm;而坡地分别为262.2mm与0.208kg/mm。充分挖掘梯田增产潜力的出路在于增加投肥量。  相似文献   

10.
坡地为集水区的基本单元,坡地水流的成份,分配与流动,影响集水区下游地区之水效应,致坡地水日益受到重视,台湾坡地水研究,起于1950年代,陆续设立坡地水土保持方法径流观测小区,比较坡地不同水土保持方法的地表径流量,1970年,逐步进行坡地径流系数,坡地水模式及影响模式之重要参数因子探讨,背希建立合理的坡地水分析与分析方法,俾利应于寻求适宜的坡地水土保持方法,减缓下游地区灾害。  相似文献   

11.
Potatoes, members of the Solanaceae plant family, serve as major, inexpensive low-fat food sources providing energy (starch), high-quality protein, fiber, and vitamins. Potatoes also produce biologically active secondary metabolites, which may have both adverse and beneficial effects in the diet. These include glycoalkaloids, calystegine alkaloids, protease inhibitors, lectins, phenolic compounds, and chlorophyll. Because glycoalkaloids are reported to be involved in host-plant resistance and to have a variety of adverse as well as beneficial effects in cells, animals, and humans, a need exists to develop a clearer understanding of their roles both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the (a) history of glycoalkaloids; (b) glycoalkaloid content in different parts of the potato plant, in processed potato products, and in wild, transgenic, and organic potatoes; (c) biosynthesis, inheritance, plant molecular biology, and glycoalkaloid-plant phytopathogen relationships; (d) dietary significance with special focus on the chemistry, analysis, and nutritional quality of low-glycoalkaloid potato protein; (e) pharmacology and toxicology of the potato glycoalkaloids comprising alpha-chaconine and alpha-solanine and their hydrolysis products (metabolites); (f) anticarcinogenic and other beneficial effects; and (g) possible dietary consequences of concurrent consumption of glycoalkaloids and other biologically active compounds present in fresh and processed potatoes. An enhanced understanding of the multiple and overlapping aspects of glycoalkaloids in the plant and in the diet will benefit producers and consumers of potatoes.  相似文献   

12.
Tomatoes, a major food source for humans, accumulate a variety of secondary metabolites including phenolic compounds, phytoalexins, protease inhibitors, and glycoalkaloids. These metabolites protect against adverse effects of hosts of predators including fungi, bacteria, viruses, and insects. Because glycoalkaloids are reported to be involved in host-plant resistance, on the one hand, and to have a variety of pharmacological and nutritional properties in animals and humans, on the other, a need exists to develop a better understanding of the role of these compounds both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the history, composition, and nutrition of tomatoes, with special focus on the assessment of the chemistry, analysis, composition, nutrition, microbiology, and pharmacology of the tomato glycoalkaloids comprising alpha-tomatine and dehydrotomatine; their content in different parts of the tomato plant, in processed tomato products, and in wild and transgenic tomatoes; their biosynthesis, inheritance, metabolism, and catabolism; plant-microbe relationships with fungi, bacteria, viruses, insects, and worms; interactions with ergosterol and cholesterol; disruption of cell membranes; tomatine-induced tomatinases, pantothenate synthetase, steroid hydroxylases, and cytokines; and inhibition of acetylcholinesterase. Also covered are tomato-human pathogen relationships and tomatine-induced lowering of plasma cholesterol and triglycerides and enhancement of the immune system. Further research needs in each of these areas are suggested. The overlapping aspects are discussed in terms of general concepts for a better understanding of the impact of tomato glycoalkaloids in the plant in general and in food in particular. Such an understanding can lead to the creation of improved tomatoes and to improved practices on the farm and in the consumption of tomatoes.  相似文献   

13.
黄土丘陵区土地利用变化与地形梯度关系研究   总被引:3,自引:0,他引:3  
土地利用/土地覆被变化(LUCC)是人类活动与自然环境相互作用最直接的表现形式,是反映人类活动程度的重要因子。以彭阳县为例,应用1995年和2014年25m×25m的DEM数据和土地利用现状数据,运用GIS空间分析功能,采用地形位指数以及分布指数定量分析了1995—2014年彭阳县土地利用基于地形梯度的变化特征。结果表明:(1)1995—2014年,彭阳县耕地和未利用地面积大量减少,草地面积大量增加,林地、水域和建筑用地面积均有不同程度的增加;(2)随着地形位的升高,耕地、水域、建筑用地的分布指数逐渐降低,林地和草地的分布指数逐渐升高,未利用地的分布指数先升后降。草地的优势分布区间增加了2个地形位,未利用地的优势分布区间降低了2个地形位;(3)水域的优势度区间集中在低地形位区间,耕地和建筑用地的优势度区间集中于低中地形位区间,林地、草地和未利用地的优势度区间集中于中高地形位区间。  相似文献   

14.
本文分析了小流域水土流失原因、特点基础上,提出提高思想认识,编制水土保持方案,加强水土流失治理,强化水土保持预防监督和管理,普及防灾减灾知识,加大农民对水土保持科技投入,是小流域水土流失治理的主要对策之一。  相似文献   

15.
The serious decline of forest trees in Quebec and adjacent areas of the U.S. parallel those observed in Germany. In certain locations, in both cases, K deficiency is now occurring on glacial tills and outwash soils and is associated with a low concentration of exchangeable K+ and a high molar ratio of exchangeable Ca+ ions to K+ ions in the soil. This deficiency results from the so-called Ca-K antagonism in which an increased concentration of Ca2+ ions blocks the entry of a reduced concentration of K. Mg deficiency is occurring on granitic soils and results from a low concentration of exchangeable Mg2+ and a high molar ratio of A13+ ions to Mg2+ ions. The role of the parent rock, weathering reactions and atmospheric inputs are discussed in relation to the changes that have resulted from the cumulative effect of acid deposition. The changes in storage, transfer and losses of cationic nutrients in soil and trees can explain the development of these imbalances, which are still increasing, and are resulting in these forest declines.  相似文献   

16.
The levels and distributions of petroleum hydrocarbons incoastal waters and sediments of the United Arab Emirates (U. A. E.) along theArabian Gulf and the Gulf of Oman were investigated. Oil concentrations in the waters ofthe U. A. E. were below the 15 μg L-1 and ranged from 1.6 to 13 μg L-1.Petroleum hydrocarbons showed different pattern of distribution in the Arabian Gulf and the Gulf of Oman withmore or less similar values. Horizontal distribution of petroleum hydrocarbons atthe Arabian Gulf showed significant differences between most sites. At the Gulf ofOman, similar oil concentrations were measured at different sites. Meanwhile,vertical distributions of petroleum hydrocarbons indicated higher concentrations atsurface layers of the Arabian Gulf compared to bottom layers. Whereas, more or less similarconcentrations were measured at the Gulf of Oman. The concentration of petroleum hydrocarbons in marinesediments varied from 2.5 to 8.2 μg g-1 (dry sediment weight), with higher concentrations at theArabian Gulf compared to the Gulf of Oman. The pattern of distribution for petroleumhydrocarbons in marine sediments resembled to some extent the distribution of organiccarbon in marine sediments. The study revealed that the concentrations ofpetroleum hydrocarbons in waters and sediments of the investigated area are not highcompared to other areas of the world.  相似文献   

17.
Asulam reaching the soil either directly as spray drift or as rain washings from bracken fronds would, due to its rapid mobility in soil, be expected to leach down the soil profile into the drainage water and thereby contaminate streams and water catchments. The mobility of asulam in soil is influenced by pH, where undissociated asulam will leach less rapidly than the associated form (asulam pKa 4·82). This is particularly relevant in the case of bracken as it can grow satisfactorily over a wide range of pH values (3·6 – 7·6). Adsorption coefficients expressed as Kd values [(μg asulam/g soil)/(μg asulam/ml solution)] were 2·54, 1·94 and 0·96 at pH readings of 4·0, 4·3 and 4·9 respectively. Another factor involved, the breakdown of asulam, was shown to be temperature dependent, 30·95, 7·65 and 2·50% remaining after 28 days at 5, 18 and 25°C respectively, thus underlining the influence of geographical regions and climatic conditions on asulam behaviour.  相似文献   

18.
灵石县水土保持世行贷款项目涉及12个乡(镇),19条流域,总面积l206km^2。1999年1月开始实施,五年间计划完成综合治理面积115.58km^2,至2003年5月底前,共完成治理面积108.16km^2,占计划的93.6%。项目在实施过程中,严格实行工程、内业和财务的规范化管理,其主要经验是:强化组织领导,加强技术培训,创新治管机制,严格督查奖惩。  相似文献   

19.
Abstract

The Kujawy and Pomorze Province with 127 rural and municipal-and-rural communes in 19 districts is a typical agricultural region, with the highest plant farming intensity in Poland. The diversity and dominance of crop plantations in the agroecosystems in communes were calculated based on percentage share of 21 kinds of crops in the cropland structure. The algorithms applied in ecological research of biodiversity were used: the Shannon–Weaver diversity index (H’) and Simpson's dominance index (λ). The diversity (H’) of crops in arable land in the Kujawy and Pomorze Province ranges from 1.68 to 2.54. The diversity of crop plantations in the region was bigger in the communes in which there are: better soil, a higher share of arable land in the agricultural acreage and cropland in the arable land as well as with a higher share of barley, corn for grain and sugar beet in the cropland structure. The highest dominance index (λ) for crops in the whole province is 0.291. The index of dominance of agricultural crops in this region increases with an increase in the share of: woodland in the total area, meadows and pasture in the agricultural acreage and rye in the cropland structure.  相似文献   

20.
Twenty fertilization experiments were set up in 1985 and 1986 in the Vosges mountains, using mostly calcareous or Mg fertilizers, in order to verify whether fertilization can attenuate defoliation and yellowing recently recorded in Silver fir and Norway spruce. In the Ardennes, a fertilization experiment set up in Norway spruce stands prior to the appearance of yellowing was assessed. In these areas, the total acid deposition is about 2 kg eq H+ ha–1 yr–1. Nitrogen deposition is much more important in the Ardennes (52 kg N ha–1 yr–1 in form of wet and dry deposition) than in the Vosges (16 kg N ha–1 yr–1). The results in the eight adult stands showed no uniform reaction to the treatments. Spontaneous improvement, further deterioration independently of the treatment, as well as a positive reaction to fertilization were observed. Additional N or P fertilization sometimes had a beneficial effect on Ca or Mg treatments. The selection of the stands with the best response turns out to be difficult, as the nutrient contents of needles alone seem not to be a satisfactory criterion for selection. Young plantations reacted positivley to the treatments. Soluble Mg fertilizer leads to an immediate response. Low solubility Ca-Mg fertilizers (Ca-Mg lime) did not produce reactions until three years after the application. In the Ardennes, in a 40 yr old spruce stand suffering from severe Mg deficiency, a Ca and Ca-phosphate fertilization applied 5 yr before yellowing appeared had positive effects on crown density, discoloration and wood production. Conversely, a single N fertilization in this experiment, as well as in a young plantation in the Vosges, had a marked negative effect on Mg nutrition, even at low levels.  相似文献   

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