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1.
基于田间定位试验研究了种植绿肥和施氮对旱作冬小麦农田土壤酶活性的影响。试验采用绿肥和氮肥双因素完全设计方案,其中绿肥作物在夏季休闲期种植,包括长武怀豆、苏丹草、怀豆+苏丹草混播和裸地休闲（对照）4种处理;氮肥于冬小麦播前施入,包括0、60、120 kg·hm-2共3个水平;观测指标包括土壤β-葡萄糖苷酶、纤维二糖水解酶、乙酰氨基葡萄糖苷酶、亮氨酸氨基肽酶活性。结果表明,与对照相比,休闲期种植怀豆、苏丹草、怀豆+苏丹草混播均显著提高了以上4种土壤总体酶活性,0～10 cm和10～20 cm土层增幅分别达12.9%～59.3%和6.19%～48.8%。土壤β-葡萄糖苷酶和纤维二糖水解酶活性在不同绿肥处理间无显著差异,而种植怀豆较种植苏丹草和混播显著提高了乙酰氨基葡萄糖苷酶和亮氨酸氨基肽酶活性。施氮肥对土壤酶活性具有显著促进作用,且4种土壤酶活性均随着施氮水平提高而增加。氮肥与绿肥对纤维素二糖水解酶活性具有交互影响。黄土高原旱作种植系统休闲期间可以考虑通过种植绿肥作物尤其是豆科绿肥来提高肥力。 相似文献
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填闲作物腐解过程及其对后茬冬小麦产量的影响 总被引：1，自引：0，他引：1
研究了渭北旱塬地区不同填闲作物（长武怀豆（S）、黑麦草（R）及两者1∶1混合（M））翻压和氮肥水平（0、60、120 kg N·hm-2）双因素处理下,填闲作物的腐解规律、碳氮释放动态及对后茬冬小麦产量的影响,并对腐解速率与Olsen模型进行了拟合。结果表明：各填闲作物翻压后腐解规律及碳氮释放特征均表现为“前期快-中期慢-后期加快”,填闲作物腐解规律符合Olsen模型,在第276天各处理累积腐解率均达70%以上。在第0~35天,同一施氮处理下,累积腐解率和腐解速率均表现为S>M>R（P<0.05）;第35天,S、M和R各处理干物质累积腐解率分别达到61.9%、55.5%和47.5%;在0~35 d,施氮对S、M的腐解影响不显著,对R影响显著,35 d后氮肥效应逐渐减弱;填闲作物的腐解同时伴随其碳、氮的快速释放,在第21天,S、M和R碳氮残留率分别达到40%、50%和60%左右。平均来看,S的碳氮释放速率显著高于R,与M无显著差异。与裸地对照相比,翻压填闲作物能够显著提高后茬冬小麦产量,其籽粒产量增加10%~35% （P<0.05）,其中翻压长武怀豆低氮处理和混合翻压低氮处理效果最佳。 相似文献
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依托黄土塬区4 a绿肥填闲种植田间定位试验,开展不同填闲作物对土壤团聚体组成及各组分有机碳在团聚体中分布影响的研究,为阐明填闲种植措施下土壤有机碳库的物理保护机制提供依据。试验设置4个处理,即冬小麦夏闲期种植长武怀豆(SB)、苏丹草(SG)、怀豆/苏丹草混播(Mix)和裸地休闲(CK)。利用干筛法将全土筛分为>5 mm、2～5 mm、0.25～2 mm和<0.25 mm等4个粒级,分别测定土壤和各粒级团聚体中有机碳和颗粒有机碳含量,进而计算团聚体平均重量直径及有机碳贡献率。结果表明：绿肥种植对土壤团聚体分布有显著影响,各绿肥处理均有利于0～10 cm土层土壤团聚体的形成,但对亚表层土壤团聚结构影响较小。与CK相比,在0～40 cm各土层,SB、SG和Mix处理均显著提高土壤有机碳含量、颗粒有机碳含量及团聚体平均重量直径,提高幅度分别为7.9%、8.0%和7.9%,其中SB更有利于表层土壤有机碳的固存,且土壤有机碳和颗粒有机碳含量之间呈显著正相关关系,这两者与团聚体平均重量直径之间均呈显著负相关关系。不同处理下土壤团聚体各有机碳组分含量存在差异,与CK相比,SB和Mix均显著... 相似文献
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旱地夏闲期秸秆覆盖和种植绿肥对冬小麦水分利用及养分吸收的影响 总被引：4，自引：0，他引：4
以夏季裸地休闲为对照,研究了免耕条件下小麦秸秆覆盖和种植豆科绿肥及二者混合对旱地冬小麦产量、作物水分利用、氮磷钾养分吸收的影响。结果表明,秸秆覆盖和种植绿肥对冬小麦籽粒产量和生物量无影响,但秸秆覆盖作物耗水量较对照增加10 mm,种植绿肥则减少11 mm,水分利用效率却无显著变化;夏闲期种植绿肥和秸秆覆盖+种植绿肥使小麦籽粒吸氮量分别降低6.0%和6.6%,差异显著,吸磷量降低5.9%和6.2%,籽粒吸钾量降低了7.9%和7.9%。可见,一年的秸秆覆盖和种植绿肥对冬小麦产量没有显著影响,但秸秆覆盖使小麦生育期耗水量增加而种植绿肥使之降低,种植绿肥和秸秆覆盖+种植绿肥使小麦对氮磷钾养分吸收有所降低。 相似文献
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为了揭示"一年二熟"种植模式的农田土壤水分动态及耗水规律,试验设置了4个不同的"一年二熟"种植模式,测定分析了不同种植模式的土壤水分动态变化、水分满足率、作物耗水强度及作物产量等指标。结果显示:在黄土高原东南部年降雨量达640 mm左右的旱作农田,发展"一年二熟"种植能较好地利用夏闲期的水热资源,不同程度地提高了全年的生物产量、经济产量、水分利用效率,加强了农田物质循环。"冬小麦—大豆"、"冬小麦—玉米"两个种植模式的平均耗水强度仅比"冬小麦—夏闲"(对照)处理高0.07、0.1 mm/d,而"冬小麦—谷子"的耗水量等同于对照。经济效益以"冬小麦—玉米"为最好,土壤水分资源的持续利用性以"冬小麦—谷子"最好,一年二熟在取得显著经济效益的前提下具有可持续性;综合考虑该区的自然资状况,在旱作农田下最优的"一年两熟"种植模式为"冬小麦—玉米","冬小麦—大豆"。 相似文献
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为研究不同土层尤其是深层土壤水对冬小麦耗水的贡献,本文首先对长武黄土塬区300 cm深度土壤水人工标记氘水,并通过测定抽穗期、开花期、灌浆期和乳熟期小麦茎秆水δD值确定冬小麦是否能够利用300 cm深度以下土壤水分;其次通过测定小麦茎秆水、降水和不同土层土壤水δ18O值,分析降水以及不同深度尤其是300 cm以下土层土壤水对冬小麦耗水的贡献。结果表明：长武塬区降水分别贡献了旱作冬小麦抽穗期、开花期、灌浆期和乳熟期耗水的49.2%、30.2%、35.9%和38.2%,土壤水分别贡献了50.8%、69.7%、64.1%和61.8%。50~100 cm、100~150 cm、150~200 cm和200~300 cm土层土壤水贡献了冬小麦抽穗期耗水的17.9%、15.2%、10.0%和7.7%,开花期耗水的24.6%、18.8%、14.0%和12.4%,灌浆期耗水的19.5%,14.4%、10.0%和8.7%,乳熟期耗水的18.6%、13.2%、10.3%和8.3%。冬小麦茎秆水δD值变化表明,冬小麦自灌浆期开始利用300 cm深度以下土壤水分,300~400 cm土层土壤水贡献了冬小麦灌浆期和乳熟期耗水的11.4%和11.5%。可见,深层土壤水分对于冬小麦水分供给具有重要意义,因此生产实践中需要做好夏闲期蓄水保墒措施,以增加雨水入渗量和入渗深度,促使深层土壤水分恢复,保证土壤水库调蓄功能的持续发挥。 相似文献
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黄土高原半湿润区旱地一年两熟复种模式土壤水分效应 总被引：3，自引：0，他引：3
以冬小麦—夏闲种植模式为对照,比较了不同作物种植模式的土壤水分动态、作物耗水量及作物产量等指标。研究了旱地"一年两熟"种植模式的农田土壤水分动态及耗水规律,揭示了不同种植模式对土壤水分的影响机理。结果表明:旱地一年两熟种植模式具有较好的水分利用效率和经济效益,4种一年两熟种植模式的水分利用效率和经济效益较对照分别高48.4%~107.5%和62.3%~119.2%;发展旱地复种对土壤水分的影响程度有限,各复种处理与对照相比,水分差异主要存在于1 m以下的深层土壤;冬小麦—芝麻、冬小麦—大豆、冬小麦—玉米3种作物模式的全季度耗水强度仅较对照分别高0.05、0.07和0.09 mm/d。综合经济效益及土壤水分可利用性分析,冬小麦—玉米模式的经济产量、收益最佳,冬小麦—大豆则为水分生产效益次佳,但显著降低了对土壤水分的消耗。 相似文献
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青海东部浅山旱地土壤水分状况及其作物利用研究 总被引：5，自引：1，他引：5
在青海东部浅山地区以裸地为对照进行小麦、马铃薯、豌豆、胡麻等4种作物的田间土壤水分蓄积消耗试验,研究浅山地区旱地土壤水分给源、贮水量、垂直分布以及作物利用情况。结果表明:浅山地区土壤水分主要的给源为大气降水。裸地土壤贮水量增量仅为62mm,不利于降雨的蓄积;种植作物能够充分利用降雨;0～100cm土层范围土壤水分以20～40cm土层最高;当地主要作物的耗水系数为小麦898.5,马铃薯760.5,豌豆和胡麻高于2140。 相似文献
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陇东黄土高原半干旱区降雨年际变化较大,且年内分布不均,果园种草实践的优化不仅有助于减少干旱季节牧草对果园土壤水分过度消耗,还会促进其生态涵养效应的更好发挥。为探究种植不同牧草对旱作果园土壤水分季节动态的影响。试验设置4个处理,分别为在苹果园行间种植鸭茅、白三叶和混播牧草(鸭茅和白三叶)及清耕果园。结果表明:春季轻度干旱条件下,种植鸭茅和豆-禾混播牧草会降低果园土壤水分,但种值白三叶对果园土壤水分影响不显著;在夏季经历长期干旱之后,种植牧草显著降低了果园各土层的水分含量;整个生长季种植鸭茅、混播牧草和白三叶果园的蒸散量分别比清耕果园高45.3 mm、55.4 mm和0.7 mm,由此可知,在陇东黄土高原半干旱区苹果园内,不宜种植鸭茅等高耗水的禾本科植物,但可以种植白三叶等耗水少的豆科植物来改善果园环境。该研究结果对于陇东黄土高原旱作果园生草实践的改进具有一定的指导意义。 相似文献
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Light is an important resource that crops and weeds compete for and so increased light interception by the crop can be used as a method of weed suppression in cereal crops. This research investigated the impact of altered availability of photosynthetically active radiation (PAR) (from crop row orientation or seeding rate) on the growth and fecundity of Lolium rigidum. Wheat and barley crops were sown in an east–west (EW) or north–south (NS) direction, at a high or low seeding rate, in three field trials in 2010 and 2011 (at Merredin, Wongan Hills and Katanning, Western Australia). The average PAR available to L. rigidum in the inter‐row space of EW crops compared with NS crops was 78% to 91% at crop tillering, 39% to 56% at stem elongation, 28% to 53% at boot/anthesis and 41% to 59% at grain fill. Reduced PAR in the EW crop rows resulted in reduced L. rigidum fecundity in five of the six trials (average of 2968 and 5705 L. rigidum seeds m?2 in the EW and NS crops). Availability of PAR was not influenced by seeding rate, but the high seeding rate reduced fecundity in three of the six trials (average of 3354 and 5092 seeds m?2 in the crops with high and low seeding rate). Increased competitive ability of crops (through increased interception of PAR or increased crop density) was highly effective in reducing L. rigidum fecundity and is an environmentally friendly and low cost method of weed suppression. 相似文献
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Journal of Plant Diseases and Protection - Crop sequence patterns are considered as those schemes farmers apply within a single field to succeed crops over time, regardless of whether the same crop... 相似文献
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农田冬季覆盖作物对土壤有机碳含量和主作物产量的影响 总被引：3，自引：0，他引：3
从冬闲覆盖作物对土壤有机碳的固定及覆盖作物对主作物产量的影响等方面对国内外有关覆盖作物环境改良机理的最新研究结果进行了总结分析。认为,长期轮作覆盖作物可以增加土壤有机碳,提高微生物的活性,而且对主作物的产量提高有不同程度的促进作用。 相似文献
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Erich-Christian Oerke Heinz-Wilhelm Dehne 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(3):203-215
Actual and potential crop losses of eight major food and cash crops have been estimated by evaluating data from literature and field experiments. Total losses were calculated from yield reductions due to pathogens, animal pests and weeds on a regional, continental and global level. Since 1965, worldwide production of most crops has increased considerably. Simultaneously, crop losses in wheat, potatoes, barley and rice increased by 4 to 10 percent, in maize, soybean, cotton and coffee losses remained unchanged or slightly decreased. The efficacy of crop protection practices was calculated as the percentage of potential losses prevented by control. The efficacy is highest in cotton (55 percent), it reaches only 34 to 38 percent in the food crops rice, wheat and maize. The variability among cropping areas is high: In Western Europe, 61 percent of potential crop losses is prevented, in North America and Oceania 44, in all other regions 38 percent. Due to the small share of Western Europe in worldwide production of 8 percent, the efficacy of actual crop protection worldwide is only 40 percent.In view of population growth and rising food demand crop production has to be increased substantially. As potential loss rates often increase with attainable yields high productivity largely depends on effective crop protection management. Scenarios for the production of food crops by the year 2025 in developed and in developing countries are given. Recent and future developments in crop protection can contribute to establish sustainability in agriculture and to preserve natural resources. However, although effective control methods have been developed for most biotic yield constraints, the use of crop protection products is regulated by economic considerations rather than by food demand. 相似文献
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Limonard T. 《European journal of plant pathology / European Foundation for Plant Pathology》1983,89(1-2):74-74
European Journal of Plant Pathology - 相似文献
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B. Ney M. O. Bancal P. Bancal I. J. Bingham J. Foulkes D. Gouache N. Paveley J. Smith 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(3):561-580
Plant tolerance to biotic stresses (mostly limited here to fungal pathogens and insects) is the ability of a plant to maintain performance in the presence of expressed disease or insect herbivory. It differs from resistance (the capacity to eliminate or limit pests and pathogens by genetic and molecular mechanisms) and avoidance (the ability to escape infection by epidemics). The ways to tolerance of pests and diseases are multiple and expressed at different scales. The contribution of organs to the capture and use of resources depends on canopy and root architecture, so the respective locations of disease and plant organs will have a strong effect on the crop’s response. Similarly, tolerance is increased when the period of crop sensitivity lies outside the period within which the pest or pathogen is present. The ability of the plant to compensate for the reduced acquisition of resources by the production of new organs or by remobilization of reserves may also mitigate biotic stress effects. Numerous examples exist in the literature and are described in this article. Quantification of tolerance remains difficult because of: (i) the large number of potential mechanisms involved; (ii) different rates of development of plants, pests and pathogens; and (iii) various compensatory mechanisms. Modelling is, therefore, a valuable tool to quantify losses, but also to prioritize the processes involved. 相似文献
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Mansoor Sarani Mostafa Oveisi Hamid Rahimian Mashhadi Hassan Alizade Jose Luise Gonzalez‐Andujar 《Weed Biology and Management》2014,14(3):198-208
Field experiments were conducted in Iran in order to determine the interactions between the tillage system and crop rotation on weed seedling populations and crop yields from 2002 to 2005. No tillage, shallow tillage and deep tillage were the main plots and three crop sequences comprising continuous wheat (W‐W), wheat–canola–wheat–canola (C‐W) and wheat–safflower–wheat–safflower (S‐W) were the subplots. Bromus japonicus, Carthumus lanatus, Polygonum aviculare, Lolium temulentum and Avena ludoviciana were found to be the dominant species. The initial weed population in 2002 was estimated at 65 seedlings per m2 and B. japonicus (～35 seedlings per m2) was the most abundant species, followed by A. ludoviciana and L. temulentum. The dominant weed species mostly did not favor the combination of S‐W and C‐W with any tillage type. For the B. japonicus population, S‐W in combination with moldboard plowing indicated the lowest seedling population. In conclusion, the crop sequence in combination with tillage would help to control troublesome weed species. Safflower and canola were determined to be effective in reducing the grass weeds. The inclusion of these crops in rotation also increased the total revenue of the cropping systems because of the higher sale price of canola and safflower. 相似文献
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C. D. van Loon 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(Z2):231-240
Relatively large amounts of pesticides are needed to control diseases and pests in modern, intensive potato production. Integrated crop management offers a way of reducing the need for pesticides. It aims to reduce costs and improve the quality of the product and of the production methods, while maintaining soil fertility and the quality of the environment. The components of integrated crop management are described. Prevention of diseases and pests has high priority. If diseases or pests are present, non-chemical control methods are preferred and chemical control is based on economic criteria and the monitoring of the soil and crops. The contribution of integrated crop management to the control of two important fungal diseases, late blight (Phytophthora infestans), and stem canker (Rhizoctonia solani) and of one pest, potato cyst nematode (Globodera spp..) is described. The prospects for further development of integrated crop protection are discussed. 相似文献
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免耕对粮食作物产量的影响 总被引：1，自引：0，他引：1
通过北京郊区大田调查和定点试验观测,对比研究了免耕覆盖与传统耕作两种措施下作物长势和产量差异,探讨了免耕覆盖技术推广实施中存在的问题.结果表明:与传统翻耕相比,免耕覆盖作物出苗和成熟更晚;免耕冬小麦出苗和生长初期,麦苗密度可低于传统翻耕32%;免耕覆盖玉米出苗和长势往往好于传统翻耕,出苗密度可高于传统翻耕约20%.与传... 相似文献