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171.
本文依据能量平衡原理和质量守恒定律,提出了作物蒸腾与棵间土壤蒸发的估算模式,并对参数的估算做了详细的分析和讨论。最后利用试验区实测资料,通过田间水热耦合运移的数值模拟,对夏玉米田作物蒸腾棵间土壤蒸发模型及其模拟计算方法进行了验证,结果表明,本文提出的模型和模拟计算方法是有效而实用的。  相似文献   
172.
我国水资源短缺与水资源浪费并存的现象十分严重,而农业用水效率不高,农田灌溉水的利用效率低下就是其中之一。其原因主要是灌溉方式不合理,造成水资源浪费严重、利用效率低下,加剧了水资源的短缺。近年来,国家对节灌技术的发展愈加重视,出现了许多新型的节水灌溉装置,提出基于作物需水机制的远程无线自动化喷灌系统,是以单片机为自动化控制中枢,采用Arduino技术设计,可以实时监测大田不同部分的缺水情况,并对缺水部分田地定点喷灌直至达到适宜含水量范围,从根本上改变了以人为经验为依据的粗犷的灌溉方式,可以节省大量的资源。  相似文献   
173.
北方旱地土壤氮素平衡   总被引:1,自引:0,他引:1  
北方大部分地区的旱地土壤中,农业氮素一般表现亏损,平衡强度约87%;园田土壤氮素略有盈余,平衡强度约123%.~(15)示踪研究表明,旱地土壤主要作物氮素利用率平均为27.04%,土壤残留24.79%,亏缺损失48.17%.园田主要蔬菜氮素和用率平均为29.11%,土壤残留22.67%,亏缺损失48.23%,其间差异很小.北方旱地施用铵态氮化肥主要损失是氨的挥发.影响氨挥发的因素有风速、温度、土壤水分、土壤质地、化肥品种.氮肥深施是防止氨挥发的有效方法.  相似文献   
174.
    
Aluminum toxicity, nutrient imbalance, and reduced microbial activity are the most limiting factors for optimum agronomic productivity in acid soils. A field study was conducted to investigate the impact of micronutrient and liming on soil properties and productivity of groundnut-rapeseed system in an acidic Inceptisol. The impact of six micronutrient (control or no micronutrient, Zn at 5 kg ha−1, B at 1 kg ha−1, Mo at 0.5 kg ha−1, Zn + Mo, and Zn + B + Mo) and two soil amendment (furrow liming at 500 kg ha−1 and no lime addition) treatments were first tested in groundnut and theirs residual effects were assessed on soil properties of succeeding rapeseed crop. Results indicated that liming significantly improved soil pH, soil organic carbon (SOC), available N, P and K, and diethylene triamine penta acetate (DTPA)-extractable micronutrients, soil microbial biomass C and dehydrogenase activity as compared to no-lime. After harvesting groundnut, Mo + Zn + B treated plots maintained the highest SOC content, whereas sole B and Mo treatment had the highest SOC content after harvesting rapeseed. Further, Mo + Zn + B treated plots showed higher contents of soil DTPA-extractable micronutrients as compared to others. The highest groundnut equivalent yield (GEY) of the cropping system (pooled data of 2 years) was obtained with Mo + Zn + B (2.12 Mg ha−1) but remained at par with Zn + Mo (2.02 Mg ha−1). Multivariate principal component analysis indicated that available P was the most prominent soil nutrient with a strong effect on GEY. The results indicated that integrated application of Zn + B + Mo along with liming improves soil properties and agronomic productivity of groundnut-rapeseed cropping system.  相似文献   
175.
基于作物模型的温室环境管理系统设计与实现   总被引:2,自引:1,他引:2  
为改进温室环境管理系统的性能,获取实时动态生成的决策信息,建立了基于作物模型的温室环境管理系统。在借鉴前人先进研究成果的基础上,通过实验建立了简化的温室番茄和黄瓜作物生长模型;其次,通过收集资料和专家经验建立了温室环境管理知识库;最后,应用农业环境实时监测数据,综合利用模型预测和知识推理建立了温室环境管理决策支持系统。通过实际运行表明,系统可实时动态输出室内温度、光照等参数的优化值及其它相关辅助决策信息,通过进一步完善可望取得更好的应用前景。  相似文献   
176.
作物株型相关基因研究进展   总被引:1,自引:0,他引:1  
概述了作物株型的概念及决定作物株型的主要性状如株高、分蘖数、分蘖角度等方面的研究进展,提出:矮化基因的研究是当前株型育种的主要方向,并对基因工程在改进株型中的广阔应用前景进行了阐述。  相似文献   
177.
设施农业是我国农业发展的重要内容,也是我国农业资源高效利用的重要生产模式。在我国设施农业快速发展的同时,其生产决策表现出科学性不足,主要体现为存在明显的盲目性和随意性。构建了农作物组合优化决策模型,采用贪心算法,以最大经济效益为目标,综合考虑风险以及作物轮作等因素,得出了最优生产决策组合方案;通过与优化前种植方案的比较,表明采用决策模型所获得方案的利润有所增加,且全年承担风险更加平稳。因此,对以企业方式进行生产的设施农业单位,可以通过优化组合生产计划,实现经济效益的增加,进而提高生产者的生产积极性和产品的市场竞争力。  相似文献   
178.
秋季叶面喷肥对红地球葡萄生长及果实品质的影响   总被引:2,自引:0,他引:2  
【目的】研究秋季叶面喷肥对红地球葡萄树体生长和果实品质及产量的影响,从而获得最佳秋季喷肥配方,为红地球葡萄优质丰产栽培提供理论依据。【方法】于2012-10在陕西渭南红地球葡萄果实采收后,以喷清水为对照,设置4个不同配方叶面喷肥,每10d喷施1次,共喷施3次,在2013年春季测定不同处理红地球葡萄萌芽期冬芽的纵横径,于新梢生长期测定新梢直径及长度,于花蕾期测定花粉生活力及叶面积,于果实成熟期测定果实的外观品质、营养品质和产量。【结果】与对照相比,各喷肥处理使红地球葡萄的冬芽纵、横径,新梢直径、长度及叶面积和花粉生活力等均有不同程度的提高,增幅分别为12.15%~43.81%,1.84%~32.24%,8.08%~11.86%,26.62%~68.56%,3.23%~9.81%,13.68%~58.50%。各喷肥处理的百粒质量和百粒体积分别较对照增加10~20g,2.1~11.9cm3;各喷肥处理果蒂拉力和硬度分别为6.87~7.21N,3.90~4.58kg/cm2,均低于对照(7.72N,4.60kg/cm2)。各喷肥处理的可溶性固形物、Vc含量、糖酸比分别较对照高0.7%~2.1%,0.012 5~0.248 8mg/hg,9.343 6~16.070 3,且可滴定酸含量均低于对照。各喷肥处理的总产量增幅为21.47%~57.25%,其中处理4和处理5的总产量增幅都达到57%左右。【结论】与其他喷肥处理相比,处理4和处理5可以有效促进红地球葡萄树体生理生长、改善果实品质及提高果实产量。处理4(第1次.1.5%磷肥+0.6%铁肥+0.5%钙肥;第2次.2.0%磷肥+2.0%铁肥+1.0%钙肥;第3次.2.0%磷肥+2.0%铁肥+1.0%钙肥)和处理5(第1次.1.5%磷肥+0.6%镁肥+0.5%锌肥;第2次.2.0%磷肥+2.0%镁肥+1.0%锌肥;第3次.2.0%磷肥+2.0%镁肥+1.0%锌肥)是较好秋季喷肥配方。  相似文献   
179.
辽北水稻纹枯病和稻曲病防控效应研究   总被引:1,自引:0,他引:1  
对水稻纹枯病和稻曲病进行了防控效果试验。结果表明,以全防病处理作为对照,产量损失率表现为全不防病不防纹枯病不防稻曲病,分别为5.53%,5.11%和2.79%;在孕穗期和乳熟期时,防治纹枯病有助于降低纹枯病的病情指数;不防治稻曲病的穴发病率、穗发病率、结实减退率及产量损失率因品种不同差异较大。生产中应重点对水稻纹枯病和个别品种稻曲病进行防治。  相似文献   
180.
    
This paper describes the effects of elevated CO2 (550 and 680 μl l−1) and O3 (60 nl l−1 O3 as an 8 h mean), alone or in combination, on canopy development and senescence in potato (Solanum tuberosum L. cv Bintje) across a range of European agro-climatic conditions. The assessments were made within the European CHIP project (CHanging climate and potential Impacts on Potato yield and quality) that was conducted for two growing seasons (1998 and 1999) in free air CO2 enrichment systems (FACE) and open-top chamber facilities (OTCs) at seven European sites. A comparison of chambered and unchambered experimental plots was included to examine the effects of chamber enclosure. Phenological growth stages, plant height, leaf area index (LAI) and the number of green and yellow leaves were recorded non-destructively throughout the growing season and by a destructive intermediate harvest at maximum leaf area (MLA). In the dynamic growth analysis CO2 and O3 effects were studied over three developmental stages: canopy expansion, full canopy and canopy senescence. Chamber enclosures promoted potato crop development (taller plants, more leaves) during the initial growth stages and led to a faster decline of LAI and a higher number of yellow leaves. The growth in ambient plots varied between sites and seasons, as did the scale of the treatment responses. Despite the large background variation, some overall treatment effects could be detected across all sites. Both levels of increased CO2 reduced final plant height in comparison to ambient concentrations, which indicates a premature ending of the active plant growth. At the stage of full canopy and crop senescence the average number of green leaves was significantly (P<0.05) decreased by 680 μl l−1 CO2 (OTC experiments) and LAI showed the same tendency (P=0.07). As there was however no indication of a decreased leaf formation during initial growth and at full canopy, this must have been due to an earlier leaf fall. In the FACE experiments LAI had already began to decline at the stage of full canopy at 550 μl l−1 CO2 but not in ambient CO2 (DAE×CO2, P<0.05). These observations strongly indicated that elevated CO2 induced a premature senescence during full canopy. O3 did not have an overall detrimental effect on crop development during initial growth nor at full canopy, but did induce a faster reduction of LAI during crop senescence (DAE×O3, P<0.05). Final plant height was not affected by O3. There were few CO2×O3 interactions detected. There was a suggestion (P=0.06) that O3 counteracted the CO2-induced decrease of green leaves at full canopy, but on the other hand during crop senescence the decline of LAI due to elevated O3 was faster at ambient compared to elevated CO2 (P<0.05). These responses of canopy development to elevated CO2 and O3 help to explain the treatment responses of potato yield within the CHIP project at sites across Europe.  相似文献   
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