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941.
本试验旨在研究日粮中添加不同比例的氨化稻草及精组比例对体外发酵产气规律的影响。以2头安装有永久性瘤胃瘘管的西门塔尔牛作为瘤胃液供体,以未氨化、4%尿素和6%尿素氨化的稻草为粗饲料,分别与精料混合料配制成6种比例日粮,其中精料与粗饲料的比例为0∶100、20∶80、40∶60、60∶40、80∶20、100∶0。采用体外产气法测定各种日粮体外发酵的产气规律。结果表明:同一尿素氨化水平下,随着精料比例增加,产气量显著增加(P<0.05),并且精料∶粗料为100∶0组极显著高于0∶100组(P<0.01);不同尿素氨化水平下,精料∶粗料为40∶60时,4%尿素氨化组48 h产气量显著高于未氨化组(P<0.05),并且高于6%氨化组,而精料∶粗料为0∶100、20∶80、60∶40、80∶20、100∶0时,3种尿素氨化水平产气量之间差异不显著(P>0.05)。表明使用4%尿素对稻草进行氨化处理、日粮精料∶粗料为40∶60时,日粮的可消化性最好。  相似文献   
942.
A field experiment was conducted with sorghum variety CSH-9 in kharif season of 1983 and 1984 to find out the efficiency of coated urea fertilizers over urea alone. The coated urea fertilizers used were neem cake coated urea, neem extract coated urea, coaltar coated urea, 10% didin coated urea along with ordinary urea. Four rates of urea application viz 50, 100, 125 kg N/ha were used along with control in single and split application.
The dry matter yield was recorded to be higher with ordinary urea at initial growth stage of sorghum. However the coated urea fertilizers recorded more dry matter at advancing growth stages. The dry matter accumulation increased with increasing N rates. Split application of N registered higher dry matter. The grain yield was increased due to coating of fertilizers. The neem cake coated urea and 10 % didin coated urea produced highest grain yield which was about 1.5 times more over urea alone. The grain and fodder yields were increased with increasing N rates, the highest yields being with 120 kg N/ha application. N concentration in plant was decreased with advancing growth stage. The concentration, uptake and N recovery were highest with 10% didin coated urea in 1984 and with neem cake urea in 1983. Coated urea fertilizers and split application of N resulted in increasing the N use efficiency over single application.  相似文献   
943.
Abstract. The effect of humic acids on transformation of phosphorus fertilizer was studied in an alkaline soil. Soil P was fractionated following 4 and 15 days incubation after humic acids were applied with phosphorus fertilizer to the soil. The availability of phosphate in the soil and total phosphorus in plants were determined at earing stage and at maturity in a pot experiment, and wheat yield was examined in a field trial. Addition of humic acids to soil with P fertilizer significantly increased the amount of water soluble phosphate, strongly retarded the formation of occluded phosphate and increased P uptake and yield by 25%.  相似文献   
944.
The effects of nitrapyrin (NI), urea (U) and Zn rates on rhizosphere pH, smut incidence (S.I.), dry matter (D.M.), grain yield (G.Y.) and ear leaf N and Zn contents were studied in cemented plots, containing calcareous and non-calcareous soils. Treatments were comprised of 3 U applications (46, 92 and 138 kg N acre−1), combined with 2 NI rates (0 and 0.22 kg acre-1) and 2 levels of Zn (0 and 8 kg acre-1). Corn seeds, cv 'Amoun' were planted in 1993 and 1994 and the seedlings were artificially infected with U. maydis-spores at the 6 and 10 leaf growth stages. Results have shown that corn plants grown in calcareous soil imposed greater advantage in D.M. and G.Y., accompanied by a relatively low smut infection than those grown in non-calcareous soil. Unlike the diversion effects of NI on soil pH and plant Zn content, its application was beneficial for improving yield and plant Zn content. Urea applications decreased the soil pH by 0.6 unit at the highest N rate and exerted stimulatory effects on ear leaf N and Zn contents. By increasing U rate to 138 kg N acre-1, smut severity was increased by 6%. In contrast, by Zn fertilization, smut severity was decreased by 10.3%, accompanied by marked increases in G.Y. and leaf Zn content. Mixed results were detected on S.I. data, when NI was combined with U rates. In the presence of Zn, smut severity was dropped to 20.1% at 138 kg N acre-1. The results also showed that in the absence of Zn supply, S.I. was dominated in NI-treated plants and the reverse was true when Zn was included. Satisfactory results were achieved when 92 kg N acre-1 were combined with 0.22 and 8 kg acre-1 of NI and Zn, respectively.  相似文献   
945.
在戊二醛作用下将刀豆粉交联在尼龙网上,制成脲酶膜,安装在氨电极极头上,即成刀豆组织电极。该电极的特性:电极的电位值与尿素浓度成线性范围在2×10-5~10-1mol/L,斜率58mv,响应时间3~10min。脲酶膜寿命60d。该电极应用在临床上测血清中尿素含量,具有操作简便,快速、准确的特点。回收率为99.3%~98.2%  相似文献   
946.
云南不同土壤类型人工草地施肥研究刍议   总被引:5,自引:0,他引:5  
  相似文献   
947.
为探讨包膜复混肥在油菜上的应用效果,实现高产高效栽培,于2010—2011 年以‘湘油1613’油菜品种为材料,在湖南省2 个地方设计小区试验,研究2 种施肥条件对油菜农艺性状及产量的影响。结果表明:在普通复混肥处理的基础上,包膜复混肥提高油菜产量平均达到10.23%,提高了油菜大部分性状的变异程度,仅有每角果粒数的变异性低于普通复混肥处理,其中地上部干重变异系数达到最大值0.58,千粒重的变异最小。包膜复混肥对根干重的变异性程度的提高达到最大值0.24,对产量变异程度的改变最小,仅有0.02,可以认为包膜复混肥能够改善油菜的生长形态,获得高产的同时可以起到稳产的效果。与普通复混肥相比,包膜复混肥提高了各性状之间以及各性状与产量之间的相关性,因此通过包膜复混肥提高油菜产量,主要加强了对性状株高、分枝数、茎干重、角果皮干重、每株角果数的提高。包膜复混肥处理的前2 个主成分累积贡献率达到85.49%,分别代表了油菜的整体生长状况与角果性状的信息,普通复混肥处理的前3 个主成分累积贡献率达到89.00%,分别代表了主茎性状与产量的信息,角果性状的信息和主茎与千粒重的信息。不同施肥条件下,各性状的重要程度发生改变,施用包膜复混肥条件下,茎干重、角果皮干重、产量、株高、主茎节数、每株角果数具有较大的重要程度,应进行重点选择,可作为施用包膜复混肥料的条件下评价油菜生长状况与产量的指标。  相似文献   
948.
In 2006, the influence of different rates of applied mineral fertilizers and their combinations with bacterial inoculants [nitrogen (N)–fixing Klebsiella planticola and Enterobacter spp.] on the number of microorganisms from the N cycle in a Cambisol and the yield of maize was evaluated in this study. The results obtained implied that high rates of mineral fertilizers brought about an increase in the number of fungi and a decrease in the number of Azotobacter spp., oligonitrophiles, ammonifiers, and nitrifiers in soil. Combined application of microbial inoculants and low rates of mineral fertilizers resulted in the greatest increase in the number of Azotobacter spp., oligonitrophiles, and ammonifiers in soil. The greatest number of soil nitrifiers, as well as the grain yield of maize studied, were determined in the variants where combinations of the microbial inoculants and low and high rates of mineral fertilizers were applied.  相似文献   
949.
ABSTRACT

The effect of different sources of nitrogen fertilizers (organic fertilizers and urea) and zeolite under different irrigation regime on the qualitative traits of sunflower seeds was investigated by a trial, in 2014 and 2015 in Iran with split factorial on a randomized complete block design with three replications. Main plots consisted of irrigation regimes (irrigation after unloading 40%, 60% and 80% of available soil water (ASW)). The sub-plots consisted of factorial combinations of three nitrogen fertilizer treatments (100% organic, integrated treatment and 100% chemical treatment) and three levels of zeolite (10, 5 and 0 ton ha?1). Farmyard manure and urea were the organic and chemical sources of nitrogen, respectively; integrated treatment included 50% organic +50% chemical nitrogen. The percentage of nitrogen required by urea was set in a way that 100% of the required nitrogen could be provided by urea. The maximum diameter and stems height as well as the performance of the oil and protein by application of zeolite were measured in terms of the lack of stress in the first and second year, respectively. In sum, it can be concluded that the severe water stress can reduce the percentage of unsaturated fatty acids. In the first year, oleic acid and linoleic acid were decreased by 22% and 7%, respectively; while in the second year, they were reduced by 27% and 6.8%. Stearic acid also declined in the first and second years by 50% and 52%, respectively. However, an increase was observed for palmitic acid of sunflower. In both years, the application of organic fertilizer increased linoleic acid and oleic and improved the quality of sunflower seed oil. Under favorable irrigation conditions, organic fertilizers could be advantageous; while organic fertilizers and zeolite can be helpful under drought stress conditions.  相似文献   
950.
根据天津武清地区设施菜田施肥状况,进行不同缓控释氮肥在设施菠菜上的试验探究,分析不同氮肥在菠菜的长势、产量、收益等方面的差异及对土壤环境的影响。结果表明,施用促根剂包膜尿素的菠菜667 m2产量和667 m2净收益最高。对于不同氮肥,无包膜尿素的硝态氮含量在土层表现上明显下移;有包膜尿素中,除高分子聚合物包膜尿素,其余尿素包膜中均有活性物质,起到增效作用,施用前期效果好,但高分子聚合物包膜尿素的肥效期长,施用后期还会继续释放。因此,选用适当缓控肥料非常必要。本研究对提高氮肥利用率与不同作物增产增效具有重要意义。  相似文献   
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