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杜奎王丽华张茜谢玥李利军庄启国李峤虹李明章王永志 《资源开发与市场》2022,(6):739-744
为筛选中华猕猴桃(A.chinensis Planch.var.chinensis)与软枣猕猴桃(A.argute(Sieb.&Zucc)Planch.ex Miq.)种间杂交亲本,对两类猕猴桃进行染色体倍性测定、物候期调查和果实感官品质、主要营养成分、耐藏性评价。结果表明:①软枣猕猴桃均为四倍体,中华猕猴桃既有四倍体又有二倍体。②两类猕猴桃的萌芽期、展叶期、花期接近,但软枣猕猴桃果实成熟期和休眠期较中华猕猴桃早。③两类猕猴桃果实感官评价指标呈现差异,中华猕猴桃单果重和可溶性固形物含量均显著高于软枣猕猴桃。④受试材料中,HN-AA-03067的VC含量最高,‘魁绿’可溶性糖含量和糖酸比最高,‘金实1号’耐藏性最好。 相似文献
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塌陷地开发利用现状:馀州煤田位于苏、鲁、豫、皖四省结合部的江苏铜山县境内,含煤面积360km~2。由于长期大量开采煤炭,造成了该区大面积农田和村庄的塌陷,带来了社会、经济、生态等方面的严重问题。到1990年5月底,塌陷面积达9866.7ha,并仍以400~600ha/a 的速度在增加;因此,塌陷地的开发和利用刻不容缓。近几年,各地因地制宜地对部分塌陷地进行了不同程度的开发利用。据1988年统计,总改造面积已达2607.3ha,占总塌陷地的28.6%。其中已用作农田的面积1431ha,占塌陷总面积的15.7%,为已改造利用总面积的54.9%;用作浅水藕的面积146.1ha,占已改造利用总面积的 相似文献
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四川省大蒜的生产与发展对策 总被引:1,自引:0,他引:1
一、四川大蒜的生产利用现状四川大蒜栽培历史悠久,种植量大。主要分布在彭县、郫县、温江、新都、金堂、峨眉、涪陵、达县和西昌等地。据统计,1984年全省大蒜种植面积约5330ha,1985年约6660ha,蒜头总产量5万t。其中彭县种植面积2660ha,蒜头产量约2.2万t。种植大蒜每亩纯收入达250元,较同期种植油菜(每亩纯收入90元)高,因此我省大蒜种植面积 相似文献
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川西北草地位于四川西北部,青藏高原东南缘,地跨甘孜、阿坝2个自治州和凉山州的部分地区,系全国5大牧区之一。川西北草地资源分布广、面积辽阔,现有草地1600多万 ha,约占全省土地总面积的1/4,为全省耕地面积的2倍多。但川西北草 相似文献
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酉阳地处四川东南部,位于武陵山与大娄山之间,属亚热带季风气候,李属植物资源丰富。据对酉阳8个乡的调查,发现有李、杏李两个种,共10个栽培种(栽秧李、桐子李、玉皇李、七麦李、青脆李、空壳李、鸡血李、火烫李、六麦李、火炮李)和3个野生种(苦麦李、酸麦李、野麦李),其调查情况简报如下。1.酉阳李的地方栽培种:①桐子李:占全县李属的24.33%,单株产量20~40kg,最高单株产量70kg,食用采果期7月上中旬。其树势较强,为小乔木,果大,单果重27g,最大单果重50g,果皮、果肉厚1.6cm,纤维较粗,汁多,味酸甜,品质中上等。②栽秧李:占全县李属的23.19%,单株产量40kg,最高单株产量100kg,食用采果 相似文献
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从北至南依次连接冕宁县、西昌市、德昌县和米易县的安宁河流域,具有丰富的光温资源,平均气温14.1~19.4℃,≥10℃的积温4200~7300℃;年日照时数2044~2413h,年总辐射507~590KJ/cm~2;其中中下游区长夏无冬,热量资源为全省之冠。光温生产力达33903~56888kg/ha,增产潜力30228~52410kg/ha,增产潜力指数89.16%~92.13%。但因该流域干雨季节分明,干季降水不到10%,冬干春旱;雨季洪涝成灾,严重限制了光温生产潜力的发挥。自然生产潜力的光能利用率只占光合生产潜力的38%.实行水土综合改良,增加保灌面积和小春复种指数,以及立体开发,是挖掘生产潜力的有效措施。 相似文献
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雅连为毛茛科黄连属植物三角叶黄连(Coptis deltoidea)的根茎,具有清热燥湿,泻火解毒的功效。被《神农本草经》和《本草品汇精要》等列为上品,是最重要的川产道地药材。雅连主产于四川洪雅、峨眉一带,其中洪雅占全国产量的70%以上。洪雅人民很早就对雅连进行了驯化种植。据明代《嘉靖洪雅县志》记载:“雅连出瓦屋诸山,家种者3年1牧。解放后,雅连生产得到了巩固和发展,到70年代全县已有四五个乡种植,总面积达46.7ha,年产量3万多 kg,但近10年雅连生产逐年下降。据洪雅县 相似文献
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田雨金 《中国环境管理干部学院学报》2006,16(1):90-92
考试是高校检测学生学习情况的重要手段,但当前这种手段走入了误区,我们需要反思,我们需要明确教育的终极目标是学生创新能力的培养。只有通过改变旧的观念,进行考试的改革,我们才能达到考试与创新能力培养完美地结合。 相似文献
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Metzidakis I Martinez-Vilela A Castro Nieto G Basso B 《Journal of environmental management》2008,89(2):120-128
There is intensive cultivation of olives on sloping land in Jaen-Granada (Spain), Basilicata (Italy) and Western Crete (Greece). The intensive olive groves here are characterised by a tree density of about 250treesha(-1), yearly fertilisation and pruning, several chemical sprays for pest control, soil tillage once to thrice per year and irrigation up to 2700m(3)ha(-1)yr(-1). Intensive management results in high yields of 3600-6500kgha(-1) but also higher labour costs of 1154-1590euroha(-1)yr(-1), varying per area. The major environmental concerns in this system are related to chemical residues in the fruit, the extinction of useful insects, the depletion of groundwater resources, the pollution of soil and water and the erosion of soil. This paper describes the impact of intensive orchard management on natural resources and gives recommendations for soil and water conservation, reduction of chemicals use and biodiversity enhancement. The specific recommendations for the relevant stakeholders-farmers, technicians, agricultural services and policy makers-are based on the experimental evaluation of different agricultural practices and a socio-economic analysis of local and global production and markets. 相似文献
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Sesbania rostrata in pure and amended Pb/Zn tailings. About 90% of seeds of S. rostrata germinated in pure Pb/Zn tailings, which contained high concentrations of Pb, Zn, Cu, and Cd. Although seedling growth suffered
from the adverse environment of Pb/Zn tailings, they became established on tailings stands, in the greenhouse, as well as
on the actual tailings dam, and completed their life cycle in 4 months. Dry matter production and nitrogen accumulation was
3200 kg/ha and 69.4 kg/ha, respectively in the actual tailings dam. Applying inorganic fertilizer to Pb/Zn tailings led to
no obvious improvement in growth and nodulation of S. rostrata, while tailings amended by river sediment or domestic refuse rich in organic matter improved the growth and nodulation of
the species. Azorhizobium caulinodans survived and formed N-fixing stem and root nodules in S. rostrata grown in pure Pb/Zn tailings with a nodule biomass exceeding 300 mg fresh matter per plant. 相似文献
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Nutrient bioassimilation capacity of aquacultured oysters: quantification of an ecosystem service 总被引:1,自引:0,他引:1
Like many coastal zones and estuaries, the Chesapeake Bay has been severely degraded by cultural eutrophication. Rising implementation costs and difficulty achieving nutrient reduction goals associated with point and nonpoint sources suggests that approaches supplemental to source reductions may prove useful in the future. Enhanced oyster aquaculture has been suggested as one potential policy initiative to help rid the Bay waters of excess nutrients via harvest of bioassimilated nutrients. To assess this potential, total nitrogen (TN), total phosphorous (TP), and total carbon (TC) content were measured in oyster tissue and shell at two floating-raft cultivation sites in the Chesapeake Bay. Models were developed based on the common market measurement of total length (TL) for aquacultured oysters, which was strongly correlated to the TN (R2 = 0.76), TP (R2 = 0.78), and TC (R2 = 0.76) content per oyster tissue and shell. These models provide resource managers with a tool to quantify net nutrient removal. Based on model estimates, 10(6) harvest-sized oysters (76 mm TL) remove 132 kg TN, 19 kg TP, and 3823 kg TC. In terms of nutrients removed per unit area, oyster harvest is an effective means of nutrient removal compared with other nonpoint source reduction strategies. At a density of 286 oysters m(-2), assuming no mortality, harvest size nutrient removal rates can be as high as 378 kg TN ha(-1), 54 kg TP ha(-1), and 10,934 kg TC ha(-1) for 76-mm oysters. Removing 1 t N from the Bay would require harvesting 7.7 million 76-mm TL cultivated oysters. 相似文献
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Jo HK 《Journal of environmental management》2002,64(2):115-126
Carbon dioxide is an important greenhouse gas and a major agent of climate change. This study quantified carbon (C) emissions from energy consumption and C storage and uptake by greenspace for three cities in middle Korea: Chuncheon, Kangleung, and Seoul. Carbon emissions were estimated using C emission coefficients for fossil fuels consumed. Carbon storage and uptake by woody plants were computed applying biomass equations and radial growth rates. The soils in Chuncheon were cored to analyze organic C storage. Annual C emissions were 37.0 t/ha/yr in Kangleung, 47.2 t/ha/yr in Chuncheon, and 264.9 t/ha/yr in Seoul. Mean C storage by woody plants ranged from 26.0 to 60.1 t/ha for natural lands within the study cities, and from 4.7 to 7.2 t/ha for urban lands (all land use types except natural and agricultural lands). Mean annual C uptake by woody plants ranged from 1.60 to 3.91 t/ha/yr for natural lands within the cities, and from 0.53 to 0.80 t/ha/yr for urban lands. There were no significant differences (95% confidence level) between the cities in C storage and uptake per ha for urban lands. Organic C storage in Chuncheon soils (to a depth of 60 cm) averaged 31.6 t/ha for natural lands and 24.8 t/ha for urban lands. Woody plants stored an amount of C equivalent to 6.0-59.1% of total C emissions within the cities, and annually offset total C emissions by 0.5-2.2%. Carbon storage in soils was 1.2 times greater than that by woody plants in Chuncheon. The C reduction benefits of woody plants were greater in Chuncheon and Kangleung, where areal distribution of natural lands was larger and the population density lower than in Seoul. Strategies to increase C storage and uptake by urban greenspace were explored. 相似文献
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The East Usambara Mountains, recognized as one of the 25 most important biodiversity hot spots in the world, have a high degree
of species diversity and endemism that is threatened by increasing human pressure on resources. Traditional slash and burn
cultivation in the area is no longer sustainable. However, it is possible to maintain land productivity, decrease land degradation,
and improve rural people’s livelihood by ameliorating cultivation methods. Improved agroforestry seems to be a very convincing
and suitable method for buffer zones of conservation areas. Farmers could receive a reasonable net income from their farm
with little investment in terms of time, capital, and labor. By increasing the diversity and production of already existing
cultivations, the pressure on natural forests can be diminished. The present study shows a significant gap between traditional
cultivation methods and improved agroforestry systems in socio-economic terms. Improved agroforestry systems provide approximately
double income per capita in comparison to traditional methods. More intensified cash crop cultivation in the highlands of
the East Usambara also results in double income compared to that in the lowlands. However, people are sensitive to risks of
changing farming practices. Encouraging farmers to apply better land management and practice sustainable cultivation of cash
crops in combination with multipurpose trees would be relevant in improving their economic situation in the relatively short
term. The markets of most cash crops are already available. Improved agroforestry methods could ameliorate the living conditions
of the local population and protect the natural reserves from human disturbance. 相似文献
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Extending livestock grazing to the steep slopes has led to unstable grazing systems in the East African Highlands, and new
solutions and approaches are needed to ameliorate the current situation. This work was aimed at studying the effect of livestock
grazing on plant attributes and hydrological properties. The study was conducted from 1996 to 2000 at the International Livestock
Research Institute at Debre Ziet Research Station. Two sites were selected: one at 0–4% slope, and the other at 4–8% slope.
The treatments were: (1) no grazing (control); (2) light grazing, 0.6 animal unit months per hectare (aum/ha); (3) moderate
grazing, 1.8 aum/ha; (4) heavy grazing, 3.0 aum/ha; (5) very heavy grazing, 4.2 aum/ha; (6) initially plowed and continuously
very heavily grazed, 4.2 aum/ha. The result showed that species richness, infiltration rate, bare ground, and soil loss significantly
varied with grazing pressure. Species richness was higher in grazed plots compared to nongrazed plots. Biomass yield improved
on heavily grazed plots as cow dung accumulated over years. Cynodon dactylon plant species persisted with livestock grazing pressure in both sites. Infiltration rate improved and soil erosion declined
in all treatments after the first year. 相似文献
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Woodard KR French EC Sweat LA Graetz DA Sollenberger LE Macoon B Portier KM Rymph SJ Wade BL Prine GM Van Horn HH 《Journal of environmental quality》2003,32(3):996-1007
In northern Florida, year-round forage systems are used in dairy effluent sprayfields to reduce nitrate leaching. Our purpose was to quantify forage N removal and monitor nitrate N (NO3(-)-N) concentration below the rooting zone for two perennial, sod-based, triple-cropping systems over four 12-mo cycles (1996-2000). The soil is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzip-samment). Effluent N rates were 500, 690, and 910 kg ha(-1) per cycle. Differences in N removal between a corn (Zea mays L.)-bermudagrass (Cynodon spp.)-rye (Secale cereale L.) system (CBR) and corn-perennial peanut (Arachis glabrata Benth.)-rye system (CPR) were primarily related to the performance of the perennial forages. Nitrogen removal of corn (125-170 kg ha(-1)) and rye (62-90 kg ha(-1)) was relatively stable between systems and among cycles. The greatest N removal was measured for CBR in the first cycle (408 kg ha(-1)), with the bermudagrass removing an average of 191 kg N ha(-1). In later cycles, N removal for bermudagrass declined because dry matter (DM) yield declined. Yield and N removal of perennial peanut increased over the four cycles. Nitrate N concentrations below the rooting zone were lower for CBR than CPR in the first two cycles, but differences were inconsistent in the latter two. The CBR system maintained low NO3(-)-N leaching in the first cycle when the bermudagrass was the most productive; however, it was not a sustainable system for long-term prevention of NO3(-)-N leaching due to declining bermudagrass yield in subsequent cycles. For CPR, effluent N rates > or = 500 kg ha(-1) yr(-1) have the potential to negatively affect ground water quality. 相似文献
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Bittman S Hunt DE Kowalenko CG Chantigny M Buckley K Bounaix F 《Journal of environmental quality》2011,40(2):393-401
Removing solids from slurry manure helps balance nutrients to plant needs and may increase soil infiltration rate toreduce loss of ammonia. The long-term effects of applying the separated liquid fraction (SLF) of dairy slurry with surface banding applicators are not well known. This 6-yr study compared the yield, N recovery, and stand persistence of tall fescue (Festuca arundinacea Schreb.) receiving SLF at 300 (SLF300) and 400 (SLF400) kg ha(-1) yr(-1) of total ammoniacal N (TAN); whole dairy slurry (WS) at 200 (WS200), 300 (WS300), and 400 (WS400) kg TAN ha(-1) yr(-1); and mineral fertilizerat 300 kg N ha(-1) yr(-1). The slurries were applied four times per year by surface banding, a technique that reduces ammonia emission and canopy contamination. Grass yield and N uptake were significantly higher for SLF300 than WS300 atequivalent rates of TAN. At similar total N, yield and N uptake were much greater for SLF than WS (2 Mg DM ha(-1) and 75 kg N ha(-1), respectively). Apparent total N recoverywas 63% greater for SLF300 than WS300 due to less ammonia loss and less immobile N. The apparent recovery of total N was 31% higher for Fert300 than for SLF300. Yield and N uptake for SLF300 and WS300 were similar in Harvests 1 and4, but SLF had higher values under hot and dry conditions in Harvests 2 and 3. Using SLF rather than WS will increase crop yield and allow higher application volumes near barns, whichwill reduce hauling costs. 相似文献
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The structure and advancement of woody vegetation was studied in a semi-arid rangeland of southern Ethiopia under three land-use systems (communal land, a government ranch and a traditional grazing reserve enclosure) and along a distance gradient (near, middle and far) from water sources. A total of 54 woody plant species were identified. Based on the subjective opinions of the pastoralists, 85% of the identified woody plants have forage values to livestock. Cadaba farinsoa, Ormocarpum trichocarpum, Rhus natalensis, Acacia brevispica, Cordia gharaf and Hibiscus sparseaculeatus were reported to have fair to good palatability. Tree equivalent (TE) density of all woody plants combined was greater (P <0.01) in the government ranch (1) 188 TE ha(-1)) and the communal land (1083 TE ha(-1)) than in the traditional grazing reserve (419 TE ha(-1)), whereas this did not vary significantly (P >0.05) along the distance gradient from water. The most important encroaching woody plant species in the study areas were in descending order: Commiphora africana, Acacia drepanolobium, A. brevispica, Acacia. tortilis, Grewia tembensis and Lannea floccosa. The density of individual encroaching woody plant species along the distance gradient from water was not consistent. All encroaching woody species had the highest TE density in the communal land. The prevalence of these species followed the pattern of intensity of use within the communal grazing area. Most of the woody species had the highest abundance in the height class >0-2m regardless of land use and distance gradient from water. This study investigated the advance of severe woody encroachment in the communal and government sites as well as along the distance gradient from water. Some of the important contributing factors that can be suggested are heavy grazing pressure (in both the communal and government sites), expansion of cultivation and reduced mobility of livestock due to settlement of the pastoralists in the communal land. 相似文献