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1.
为探究生物刺激素产品在春季花椰菜绿色防控生产中的应用效果,2019年在北京市大兴区开展4种生物刺激素对花椰菜生产的影响试验,比较植株长势、结球率、单球直径、单球质量、品质等指标,以筛选适合推广使用的生物刺激素。结果表明:苗期施用大丽轮枝孢激活蛋白(处理2)可以促进花椰菜苗期生长,推荐用量为苗期施用大丽轮枝孢激活蛋白5000倍液,定植后30 d施用12000倍液;定植后施用大丽轮枝孢激活蛋白(处理6)可以提高花椰菜的产量,推荐定植后7 d和结球前各施用1次大丽轮枝孢激活蛋白6000倍液;采用以上处理方法可以增加花椰菜的维生素C含量,提高品质和安全性。  相似文献   
2.
拟南芥中硝酸盐的吸收、转运和分配是通过硝酸盐转运蛋白(nitrate transporter, NRT)实现的。尽管之前的生物信息学分析推测大豆GmNRT1.2s可能参与共生固氮过程,但尚未开展相应的功能研究。本研究通过对其表达模式分析収现,GmNRT1.2a和GmNRT1.2b分别在根和叶中高表达,且受硝酸盐诱导,在接种根瘤菌与结瘤因子(nodfactors,NFs)后表达量明显升高。功能研究结果显示,过表达GmNRT1.2a或GmNRT1.2b后大豆根瘤数目显著增加。本研究为深入探究GmNRT1.2a和GmNRT1.2b调控大豆共生固氮过程的分子机制提供了一定的数据支持。  相似文献   
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4.
In Ethiopia, inoculation of soybean with rhizobial inoculants is not common practice, but could provide an option to increase grain yields in low nitrogen (N) acidic soils. In these acid soils, the selection of acid tolerant rhizobia is one strategy that may increase the performance of soybean. In this study, rhizobial strains isolated from Ethiopian soils were evaluated for their acid tolerance and symbiotic N fixation efficiency with soybean, in controlled environments. Following this, four isolated rhizobial strains were evaluated in six field experiments in major soybean growing areas of Ethiopia. Inoculation with the commercial strain or with one of two locally sourced isolates, that were developed as inoculants, improved soybean yield. The yield increase due to inoculation with the commercial strain was consistent and greater than other treatments, while the increase due to the two locally sourced strains was comparable to, or greater than, application of 46 kg N/ha in soils, where the resident rhizobial population was ≤1.4 × 103 cfu/g soil. For soils with high background rhizobial populations, there was no response to inoculation. In one of the experimental sites (Bako), the percentage of N fixed (%Ndfa) was 55 for the commercial strain and 35 for the local strain, ES3. This study demonstrated that field validation is a necessary step in the selection of acid-tolerant strains of rhizobia to increase soybean production for Ethiopia.  相似文献   
5.
ABSTRACT

Common bean (Phaseolus vulgaris L.) is relatively poor in dinitrogen (N2) fixation, so selecting compatible host cultivar and Rhizobium strain combinations may offer an improvement. The effectiveness of six rhizobial strains was evaluated using five bean cultivars of bean (three pinto and two black bean) in a growth-room experiment. We subsequently selected the three best strains to assess whether multi-strain inoculation had advantages over single-strain inoculation in growth-room and field experiments. In the first-growth-room experiment, Rhizobium strains UMR 1899, RCR 3618, and USDA 2676 were selected for high nodulation, plant dry weight, shoot nitrogen (N), and N2 fixation. In a second growth-room experiment, the individual strains and a mixture of the three strains generally did not differ in the parameters evaluated. Total shoot N accumulated ranged from 172.9 to 162.8 mg plant?1, of which 32.1% to 33.6% (equivalent to 54.0 to 59.2 mg plant? 1) was fixed. In field experiments, plant biomass and seed N2 fixed did not differ among the inoculants at any site. These results suggest that the three strains were equally effective and that the multi-strain inoculant offered no consistent advantage over the single-strain inoculants.  相似文献   
6.
Abstract

A field experiment was conducted to examine the effects of two organic materials (Bark and Tenporon composts) on the growth, nodulation and nitrogen fixation (measured as acetylene-reducing activity) of soybean plants (Glycine max L.) under acid and saline conditions. These organic materials were incorporated into acid and saline (induced by irrigating the soil with a NaCl solution) soils at 4% rate of application.

These composts tended to improve nodule formation in soybean under acid and saline conditions, especially in the plants treated with Bark compost. Acetylene-reducing activity was significantly (P<0.05) increased by these composts under acid condition.

These composts also tended to improve shoot growth under acid and saline conditions, presumably due to the improvement of the soil moisture status of the soils and nutrient uptake. These results suggest that the growth of soybean could be improved by the application of organic matter under acid and saline conditions.  相似文献   
7.
A glasshouse study was undertaken to investigate the effects of the copper fungicide Kocide 101 and its residues in soil on the growth, nodulation and nitrogen fixation of beans (Phaseolus vulgaris L.). The soil used was a sandy clay loam classified as Typic Rhodustalf. The bean variety SUA 90 was used as test crop. The bean rhizobia strains CIAT 899, PV, and a local isolate were used. Kocide 101 applied at the recommended rate (equivalent to 1.7 mg kg‐1 soil) had no significant negative effects on the growth, nodulation or nitrogen fixation of bean plants. Higher levels of Kocide 101 significantly (P < 0.05) reduced plant growth, nodulation and nitrogen fixation. The bean plants inoculated with the “local isolate”; rhizobia had the highest dry matter weights, nodule numbers and nodule dry weights, and also had more N fixation. They were followed by those inoculated with the PV, strain and, lastly, those inoculated with CIAT 899. The growth and nodulation of bean plants were still curtailed by the Kocide 101 residues four months after the fungicide was first applied to the soil. Therefore, occurrence of high levels of Kocide 101 in soils can have long‐term effects on the performance of the bean‐rhizobia symbiosis.  相似文献   
8.
Abstract

Methyl jasmonate (MeJA) has recently been shown to act as a plant-to-bacteria signal. We tested the hypothesis that pre-induction of Rhizobium leguminosarum bv. phaseoli cells with genistein and/or MeJA would at least partially overcome the negative effects of low root zone temperature (RZT) on bean nodulation, nitrogen fixation and plant growth. Otebo bean plants were grown at constant air temperature (25oC) and two RZT regimes (25 and 17oC) and inoculated with R. leguminosarum bv. phaseoli pre-induced with MeJA and/or genistein. Our results indicate that low RZT inhibited nodulation, nitrogen fixation and plant growth. The plants growing at low RZT began fixing nitrogen seven days later compared to those at higher RZT. The low RZT plants had fewer nodules, lower nodule weight, less N fixation, slower plant growth, fewer leaves, smaller leaf area, and less dry matter accumulation comared to plants at a higher RZT. Rhzobium leguminosarum bv. phaseoli cells induced with genistein and/or MeJA enhanced bean nodulation, nitrogen fixation and growth at both optimum and suboptimum RZTs. The results of this study indicate that MeJA improves bean nitrogen fixation and growth at both optimum and suboptimum RZTs, and can be used alone or in combination with genistein to partially overcome the low RZT induced inhibitory effects on nodulation and nitrogen fixation.  相似文献   
9.
An on-farm field experiment was conducted on an acidic soil to investigate the effects of combined use of lime and deficient nutrients on herbage yield of alfalfa (Medicago sativa L.). Omitting lime and limiting nutrients led to elevated concentrations of aluminium (Al), iron (Fe), and manganese (Mn) in alfalfa leaves and stems and caused severe reductions in herbage yield of alfalfa. Combined use of lime (2 t ha?1) and nutrients [phosphorus (P): 20 kg ha?1, sulfur (S): 20 kg ha?1, zinc (Zn): 4 kg ha?1, and boron (B): 2 kg ha?1] had the maximum increase in groundcover, root biomass, nodulation, leaf retention, leaf-to-stem ratio, herbage yield, crude protein, and nutrient composition of alfalfa. These beneficial effects were due to raised soil pH; improved calcium (Ca), P, S, Zn, and B nutrition; and reduced Al, Mn, and Fe toxicity. Aluminium and all the nutrients except copper (Cu) were more concentrated in alfalfa leaves than stems.

Aluminum concentration was about three times greater in the lower leaves than in upper leaves. Lower leaves also had much greater concentrations of Ca, Mg, K, S, Fe, Mn, Cu, and B compared with upper leaves. In contrast, P and Zn concentrations were greater in the upper leaves than in lower leaves. Results suggest that the combined use of lime and all the limiting nutrients may realize potential beneficial effects of alfalfa on acidic soils where more than one essential nutrient is deficient. This may increase growth potential, nitrogen contributions, and groundcover by alfalfa and reduce soil erosion and runoff.  相似文献   
10.
Low availability of phosphorus (P) and potassium (K) in acidic soil is a major constraint for crop production. Therefore, a field study was conducted to determine the effects of K and P on nodulation, productivity, and nutrient uptake of cowpea (Vigna unguiculata L. Walp) under rainfed conditions. The K and P were subjected to main and subplots, respectively with 100, 75, and 50% of fertilizer application. The growth and yield attributes were better using 100% K with 100% P. However, 100% K resulted in 20.9 and 16.9% greater green pod and stover yield than 50% K. Similarly, 100% P recorded 20.2 and 15.6% greater green pod and stover yield than 50% P. Uptake of nutrients such as nitrogen (N), P, and K followed the trend of greater to lower, 100% > 75% > 50%, in order for K and P. Similarly, nutrient-use efficiencies and production efficiency followed the trend of nutrient uptake.  相似文献   
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