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Varying atmospheric nitrogen (N) depositions for different crops were observed at Bad Lauchstädt (Saxony‐Anhalt, Germany) when using the ITNI system (ITNI = Integrated Total Nitrogen Input), which is based on the 15N isotope dilution method. These differences were only partly explained by climatic influences. The effects of crops on the atmospheric N deposition measured by the ITNI system are discussed. For this purpose, data of six different plant species recorded in 1998 were re‐analyzed. It was found that the airborne N input is closely correlated with the morphology and metabolism of crops. Daily atmospheric N depositions of 129.0–360.8 g per hectare were measured for the plant species used. The nutritional supply of plants, especially with N, is another factor of influence on the N input from the atmosphere which should be considered. To investigate this aspect, a pot experiment was conducted with the grass Lolium perenne at three different N levels. An increase in the airborne N uptake (corresponding to N fertilization) was observed as biomass production rose. 相似文献
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农作物秸秆资源利用浅析 总被引：14，自引：4，他引：14
中国农作物秸秆综合利用主要集中在能源、饲料和肥料等领域。虽然已取得了一批成果,但就总体而言,与发达国家尚有较大差距。文章指出,中国发展秸秆资源的综合利用,要立足促进农业经济发展和农民增收。首先要解决“四个转变”,重点要研发实用性强,推广简便适用、易操作、农民容易接受的技术,推动农业农村经济的发展。 相似文献
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基于遥感数据与作物生长模型同化的作物长势监测 总被引：6，自引：4，他引：2
遥感观测和作物生长模型模拟是进行农作物长势监测的2种有效手段,并具有较好的互补性,构建二者的同化系统是目前农业遥感研究领域的热点。同化涉及多学科的交叉集成,十分有必要将同化方法中的模型、算法、数据进行集成,构建基础作物模型同化系统平台,降低科学研究和应用的难度。采用模块化结构设计,将同化系统构建所需的主要模型、算法、数据等进行有机结合和无缝集成,实现基于极快速模拟退火算法的遥感数据与CERES-Wheat作物生长模型的同化原型系统构建。此外,通过所开发的系统利用地面高光谱作为遥感数据,通过同化小麦叶面积指数对同化系统进行了检验和初步应用。同化LAI与实测结果较好的拟合度,表明所开发的同化系统基本可行,能为遥感技术与作物模型的基础研究和应用提供一个平台。 相似文献
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以北京地区冬小麦生产为例，介绍了两种作物生长模型——小麦生长模拟模型WheatSM和农业生产模拟系统(小麦模型)APSIM-Wheat在作物生产气候风险评估中的应用研究。在对WheatSM和APSIM-Wheat进行参数调试和验证的基础上，用北京地区1955～2000年的历史时期气候资料，以日为时间步长，进行多年冬小麦生产的模拟，分析不同气候年型下冬小麦产量的风险。其中，利用WheatSM的模拟结果评估了北京地区热害对冬小麦产量造成的风险，结果表明，5月平均气温≥21℃时为灌浆期高温年型，热害造成的减产至少在13.1%以上；利用APSIM-Wheat的模拟结果评估了北京地区干旱造成的冬小麦产量风险，结果表明，当全生育期降水量<100 mm，缺水量>169.40 mm时，北京冬小麦全生育期严重干旱，冬小麦产量在4 t·hm-2以下。以上研究结果符合生产实际，可为北京地区不同气候年型下冬小麦生产的动态决策和减轻灾害损失提供科学依据和技术支持。 相似文献
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E. G. Souza C. L. Bazzi R. Khosla M. A. Uribe-Opazo Robin M. Reich 《Journal of plant nutrition》2016,39(4):531-538
Technological advances in precision agriculture in the last two decades have made yield monitoring and mapping an economically feasible option or practice for farmers. Differentially corrected Global Positioning System (GPS)-equipped yield monitoring system on a combine allows collection of georeferenced yield data which when coupled with a geographic information system (GIS) can generate yield maps via several interpolation techniques. Scientists and practitioners have reported to use multiple different types of interpolation techniques to process yield data. However, one of the aspects that still need to be elucidated is the influence of the different interpolation methods on the quality of the resulting thematic yield maps. The objective of this study was to investigate the influence of three interpolation methods (i.e., inverse of distance, inverse of square distance, and ordinary kriging) commonly used in developing yield maps. An index for the comparison of errors (ICE) was proposed to provide an objective criterion for selecting an experimental variogram model to use with the kriging. Results indicate that inverse distance squared performed slightly better in predicting yields than either inverse distance or ordinary kriging. With a mean absolute difference varying from 0.04 to 0.32 t ha?1 corresponding to a relative deviation from 1.20 to 7.53%, the management decisions can differ in some cases based on the type of interpolation implemented. 相似文献
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作物模型研究与应用中存在的问题 总被引：18，自引：4，他引：14
该文以CERES-Wheat、Maize模型为例,系统阐述了作物模型的研究与应用发展情况,分析了模型当中仍然存在的问题,指出在冠层结构与作物光能截获计算方法和作物水分、养分对生长过程的胁迫机理与定量方法方面需要深入的实验研究,以探索其机理,提高模型模拟预测性能.该文强调指出目前绝大多数的作物模型是空间一维的田间尺度模型,借鉴区域生物地球化学循环模拟方法或与分布式水文模型耦合进行尺度扩展开发区域尺度作物模型,既是区域水、土资源评价与管理的应用需求,也将能促进作物模型发展并发挥更大作用. 相似文献
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Volkhard Gerd Scholz Monika Heiermann Jürgen Kern Antje Balasus 《Archives of Agronomy and Soil Science》2013,59(8):805-837
Crops cultivated as feedstock for energy conversion processes (energy crops) could cover about 5% of the total energy demand of the European Union. Therefore, cultivation, harvest, processing, and finally utilisation of feedstock are required to be sustainable minimising environmental pressures and maximising environmental benefits. This contribution will give a comprehensive view on the environmental impacts of cultivating conventional energy crop species like cereals, rape seed and maize and of the hitherto uncommon species such as willow and poplar. Generalisations of environmental relevant parameters are deduced based on literature surveys as well as on results from own long-term experiments at Leibniz-Institut für Agrartechnik institute. These parameters include biomass yield and energy yield, demand for water, fertiliser and pesticides as well as other environmentally relevant substances, emission of nitrous oxide and depletion and enrichment of soil carbon. In addition, recent results regarding energy balances and CO2-balances are presented and discussed. It can be concluded that energy crops specified for ligno-cellulose utilisation are preferable to oil, sugar and starch containing crops. In the first case the whole plant biomass can be used. Furthermore, biodiversity is increased and nitrogen demand and nitrous oxide emissions are decreased. Finally, in context with conventional and especially future energy technologies it is possible to obtain high CO2-mitigation potentials. Energiepflanzen, also für die energetische Nutzung angebaute Kulturpflanzen, können ca. 5% des Energiebedarfs der Europäischen Union decken. Voraussetzung ist, dass Anbau, Ernte, Aufbereitung und die anschließende Nutzung dieser Pflanzen umweltverträglich erfolgen, d.h. negative Umweltwirkungen minimiert und positive maximiert werden. Der vorliegende Beitrag gibt einen Überblick über die Umweltwirkungen von konventionellen Energiepflanzen wie Getreide, Raps und Mais sowie bisher eher selten angebauten Arten wie Pappel und Weide. Auf Basis von Literaturrecherchen und langjährigen eigenen Untersuchungen werden verallgemeinerungsfähige Aussagen zu Biomasse- und Energieerträgen, zu Wasser-, Düngemittel- und Pflanzenschutzmittelbedarf sowie zu umweltrelevanten Inhaltsstoffen, Lachgasemissionen und Entzug bzw. Anreicherung von Kohlenstoff im Boden getroffen. Darüber hinaus werden die Ergebnisse aktueller Energie- und CO2-Bilanzen vorgestellt und diskutiert. Zusammenfassend wird festgestellt, dass für Ligno-Zellulose-Nutzung vorgesehene Energiepflanzen i. allg. vorteilhafter sind als die Öl, Zucker und Stärke liefernden Pflanzen, weil von ihnen die gesamte oberirdische Pflanzenmasse genutzt werden kann, die Artenvielfalt größer und Stickstoffbedarf und Lachgasemissionen häufig geringer sind, und weil in Zusammenhang mit konventionellen und insbesondere mit künftigen Energietechnologien hohe CO2-Minderungsraten je Hektar erreicht werden. 相似文献
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Crop rotation and the maintenance of plant residues over the soil can increase soil water storage capacity. Root access to water and nutrients depends on soil physical characteristics that may be expressed in the Least Limiting Water Range (LLWR) concept. In this work, the effects of crop rotation and chiselling on the soil LLWR to a depth of 0.1 m and crop yields under no‐till were studied on a tropical Alfisol in São Paulo state, Brazil, for 3 yr. Soybean and corn were grown in the summer in rotation with pearl millet (Pennisetum glaucum, Linneu, cv. ADR 300), grain sorghum (Sorghum bicolor, L., Moench), congo grass (Brachiaria ruziziensis, Germain et Evrard) and castor bean (Ricinus comunis, Linneu) during fall/winter and spring, under no‐till or chiselling. The LLWR was determined right after the desiccation of the cover crops and before soybean planting. Soil physico‐hydraulic conditions were improved in the uppermost soil layers by crop rotations under zero tillage, without initial chiselling, from the second year and on, resulting in soil quality similar to that obtained with chiselling. In seasons without severe water shortage, crop yields were not limited by soil compaction, however, in a drier season, the rotation with congo grass alone or intercropped with castor resulted in the greatest cover crop dry matter yield. Soybean yields did not respond to modifications in the LLWR. 相似文献
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Dalia Feiziene Virginijus Feiza Virmantas Povilaitis Agne Putramentaite Daiva Janusauskaite Vytautas Seibutis 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(1):36-51
There have been few long-term field studies on greenhouse gases measurement in organic crop rotations under temperate climatic conditions. Little is known about the extent to which the share of legumes in a crop rotation of organic farming affects the potentials for CO2 emission and soil organic carbon sequestration. The current study was aimed to investigate soil physicochemical state and soil net CO2 exchange rate in diverse organic crop rotations with different crop species and proportions of legumes. Four 5-year duration crop rotations were investigated. The best soil sustainability of the arable layer was found in a crop rotation enriched with red clover (Trifolium pratense L.). This rotation resulted in the highest soil mesoporosity and the lowest microporosity, ensured the best supply of plant-available water and revealed high soil resistance to dry conditions. Red clover secured the highest soil organic C sequestration, caused the increase in reserves of total N and available K, and slackened the decrease of soil-available P sources. Red clover-based cropping system exhibited the highest soil net CO2 exchange rate during five experimental years. The effect of crop rotation, consisting of phacelia (Phacelia tanacetifolia Benth.), peas (Pisum sativum L.) and yellow lupin (Lupinus luteus L.), on soil sustainability was weaker than the effect of rotation with red clover. Non-legume rotations, i.e. binary (two-crop) rotation and the crop rotation involving four spring and one winter species, can be regarded as miners of soil nutrient resources rather than contributors. These rotations did not promote soil sustainability because the soil lost large amounts of macronutrients and caused 26–33% lower soil net CO2 exchange rate, compared with leguminous rotations. For future, it could be recommended for ecological farming to rely more on crop rotations with red clover to improve ecosystems functioning. 相似文献
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N.R. Hulugalle T.B. Weaver L.A. Finlay J. Hare P.C. Entwistle 《Soil & Tillage Research》2007,93(2):356-369
Information on the effects of growing cotton (Gossypium hirsutum L.)-based crop rotations on soil quality of dryland Vertisols is sparse. The objective of this study was to quantify the effects of growing cereal and leguminous crops in rotation with dryland cotton on physical and chemical properties of a grey Vertisol near Warra, SE Queensland, Australia. The experimental treatments, selected after consultations with local cotton growers, were continuous cotton (T1), cotton–sorghum (Sorghum bicolor (L.) Moench.) (T2), cotton–wheat (Triticum aestivum L.) double cropped (T3), cotton–chickpea (Cicer arietinum L.) double cropped followed by wheat (T4) and cotton–wheat (T5). From 1993 to 1996 land preparation was by chisel ploughing to about 0.2 m followed by two to four cultivations with a Gyral tyne cultivator. Thereafter all crops were sown with zero tillage except for cultivation with a chisel plough to about 0.07–0.1 m after cotton picking to control heliothis moth pupae. Soil was sampled from 1996 to 2004 and physical (air-filled porosity of oven-dried soil, an indicator of soil compaction; plastic limit; linear shrinkage; dispersion index) and chemical (pH in 0.01 M CaCl2, organic carbon, exchangeable Ca, Mg, K and Na contents) properties measured. Crop rotation affected soil properties only with respect to exchangeable Na content and air-filled porosity. In the surface 0.15 m during 2000 and 2001 lowest air-filled porosity occurred with T1 (average of 34.6 m3/100 m3) and the highest with T3 (average of 38.9 m3/100 m3). Air-filled porosity decreased in the same depth between 1997 and 1998 from 45.0 to 36.1 m3/100 m3, presumably due to smearing and compaction caused by shallow cultivation in wet soil. In the subsoil, T1 and T2 frequently had lower air-filled porosity values in comparison with T3, T4 and T5, particularly during the early stages of the experiment, although values under T1 increased subsequently. In general, compaction was less under rotations which included a wheat crop (T3, T4, T5). For example, average air-filled porosity (in m3/100 m3) in the 0.15–0.30 m depth from 1996 to 1999 was 19.8 with both T1 and T2, and 21.2 with T3, 21.1 with T4 and 21.5 with T5. From 2000 to 2004, average air-filled porosity (in m3/100 m3) in the same depth was 21.3 with T1, 19.0 with T2, 19.8 with T3, 20.0 with T4 and 20.5 with T5. The rotation which included chickpea (T4) resulted in the lowest exchangeable Na content, although differences among rotations were small. Where only a cereal crop with a fibrous root system was sown in rotation with cotton (T2, T3, T5) linear shrinkage in the 0.45–0.60 m depth was lower than in rotations, which included tap-rooted crops such as chickpea (T4) or continuous cotton (T1). Dispersion index and organic carbon decreased, and plastic limit increased with time. Soil organic carbon stocks decreased at a rate of 1.2 Mg/ha/year. Lowest average cotton lint yield occurred with T2 (0.54 Mg/ha) and highest wheat yield with T3 (2.8 Mg/ha). Rotations which include a wheat crop are more likely to result in better soil structure and cotton lint yield than cotton–sorghum or continuous cotton. 相似文献
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《国际水土保持研究(英文)》2022,10(1):75-85
Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff (Eragrostis tef [Zucc.]) production in Ethiopia. A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia, to investigate the effects of two tillage practices (reduced tillage [RT] and conventional tillage [CT]), two planting methods (row planting [RP] and broadcast planting [BP]), and two compaction options (with [+T] and without [–T] trampling) on soil loss and teff yields in a split-split plot arrangement. Sediment concentration ranged from 0.01 to 5.37 g L?1 (mean, 0.25 g L?1) in our study. Accordingly, the estimated total (August–October) soil loss ranged from 0.2 to 0.5 t ha–1 (mean, 0.3 t ha–1). The sediment concentration and total soil loss were significantly influenced (P < 0.05) by tillage, planting methods, and trampling only in the third monitoring year. RT reduced soil loss by 19% relative to that of CT, whereas RP resulted in a 13% reduction in soil loss over BP. The ?T plots showed a 15% reduction in soil loss as compared to + T plots. Results revealed significant increase in soil total carbon and nitrogen in RT and –T. Less soil loss and greater teff grain yield were obtained in plots with improved agronomic practices (RT and RP) compared to conventional ones (CT and BP). Based on our findings we conclude that the use of RT, RP, and –T practices can effectively minimize soil loss without any crop yield penalty. 相似文献
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Nitrate leaching from organic arable crop rotations: effects of location, manure and catch crop 总被引：4，自引：0，他引：4
Abstract. Nitrate leaching from crop rotations supporting organic grain production was investigated from 1997 to 2000 in a field experiment at three locations in Denmark on different soil types. Three experimental factors were included in the experiment in a factorial design: (1) proportion of N2 -fixing crops in the rotation (crop rotation), (2) catch crop (with and without), and (3) manure (with and without). Three, four-course rotations were compared, two at each location. The nitrate leaching was measured using ceramic suction cells. Leaching losses from the crop rotation with grass–clover green manure and without catch crops were 104, 54 and 35 kg N ha−1 yr−1 on the coarse sand, the loamy sand, and the sandy loam, respectively. There was no effect of manure application or time of ploughing-in the grass–clover green manure crop on the accumulated nitrate leaching from the entire rotation. Catch crops reduced nitrate leaching significantly, by 30–38%, on the sandy soils. At all locations catch crops reduced the annual averaged nitrate concentration to meet drinking water quality standards in the crop rotation with green manure. On the coarse sand there was a time lag between the onset of drainage and the start of N-uptake by the catch crop. 相似文献
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污泥农用对土壤和作物重金属累积及作物产量的影响 总被引：20，自引：2，他引：20
以3 a定位试验为基础,比较3种不同处理的污泥肥料（消化污泥、污泥堆肥及污泥复混肥）农田施用下土壤养分、土壤和作物籽粒中Mn、Cu、Zn、Pb、Cd 5种重金属的积累以及作物产量的变化情况,以阐明污泥农用对土壤及作物的影响。研究表明,3种污泥肥料提高了土壤中氮素和有机质的含量;与空白和普通化肥处理相比,3种污泥肥料增加了土壤中Mn和Cu的含量,而对土壤交换态重金属含量没有显著影响;3种污泥处理均增加了小麦籽粒中Zn的含量;相对普通化肥处理,3种污泥肥料处理对小麦和玉米产量均无显著影响。合理施用污泥肥料可以有效地提高作物产量;污泥肥料施用对土壤重金属有一定累积效应,但短期施用对土壤比较安全。 相似文献
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作物产量差研究与展望 总被引：7，自引：0，他引：7
作物实际产量与潜在产量间存在较大差距,地区间甚至同一地区不同田块间作物产量也存在显著差异,这种现象在世界范围内的农业生产中广泛存在.缩小该差距对于提高粮食产量,确保粮食安全具有重要意义.本文在阐述开展作物产量差研究重要性和必要性的基础上,从产量差的内涵、研究尺度的扩展及分析方法等方面介绍了目前国内外有关作物产量差的研究进展,并综述了作物生长模拟模型在产量差研究中的应用,最后分析了目前作物产量差研究中存在的问题和不足之处,并探讨了未来作物产量差研究的发展方向. 相似文献
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作物产量潜力极限研究 总被引：14，自引：1，他引：14
应用模型模拟方法研究近5 0年来主要作物产量演变趋势结果表明,作物长期进化过程中产量演变遵循S曲线增长规律,目前主要作物产量处于S曲线驻点(最快增长值点)左右,种植效益已开始下降,进一步提高产量日益困难,作物产量将不断接近其极限,多数作物未来产量潜力极限约为目前产量的2～3倍。提高作物产量潜力途径主要包括加强农田水利建设、提高作物育种手段、强化作物栽培措施、优化投入和改善作物生长的大环境等 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(6):609-618
Abstract Samples of wheat plants from 5 selected villages of Ludhiana (Punjab, India) were analysed for P, K, Ca, Mg, Zn, Cu, Fe and Mn. The dominant nutritional deficiencies are found to be those of zinc and copper. The extent of hidden hunger is in the order of Zn > Mg > Cu > K. The low concentrations of Zn and Cu are ascribed to the inherent poor fertility status associated with the lighter texture and low organic matter content. The data suggest that the low concentrations of Mg may be due to high availability of K in some soils. A sharp decline in the higher concentrations of P, K, Mg and Zn with the advancement in the growth stage suggests the importance of stage of growth at the sampling time in evaluating the leaf analysis data. 相似文献