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141.
Comparison of energy consumption and economic performance of organic and conventional soybean production——A case study from Jilin Province,China
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Modern agriculture heavily depends on energy consumption, especially fossil energy, but intensive energy input increases the production cost for producers and results in environmental pollution.Organic agricultural production is considered a more sustainable system, but there is lack of scientific research on the energy consumption between organic and conventional systems in China.The analysis and comparison of energy use between the two systems would help decision-makers to establish economic, effective and efficient agricultural production.Thus, the objectives of the present study are to analyze energy inputs, outputs, energy efficiency, and economic benefits between organic and conventional soybean(Glycine max(L.) Merrill) production.A total of 24 organic farmers and 24 conventional farmers in Jilin Province, China, were chosen for investigation in 2010 production year.Total energy input was 71.55 GJ ha–1 and total energy output was 96.18 GJ ha–1 in the organic system, resulting in an energy efficiency(output/input) of 1.34.Total energy input was 9.37 GJ ha–1 and total energy output was 113.4 GJ ha–1 in the conventional system, resulting in the energy efficiency of 12.1.The huge discrepancy in energy inputs and respective efficiencies lies in the several times higher nutrient inputs in the organic compared to the conventional production system.Finally, the production costs ha–1 were 33% higher, and the net income ha–1 25% lower in the organic compared to the conventional soybean production system.It is recommended to improve fertilizer management in organic production to improve its energetic and economic performance. 相似文献
142.
John Kormla Nyameasem Reiner Ruser Christof Kluß Christoph Essich Mareike Zutz Martin ten Huf Caroline Buchen-Tschiskale Heinz Flessa Hans-Werner Olfs Friedhelm Taube Thorsten Reinsch 《Grass and Forage Science》2023,78(3):338-358
The effect of slurry application techniques and slurry N stabilizing strategies on nitrous oxide emission from grasslands is poorly understood and, therefore, can result in large uncertainties in national/regional inventories. Field experiments were, thus, conducted to estimate the effect of different fertilization techniques on nitrous oxide (N2O) emissions. Fertilizer was applied (135–270 kg N ha−1 year−1) as calcium ammonium nitrate (CAN), untreated or treated cattle slurry. The slurry was either treated with sulfuric acid (target pH = 6.0), applied using trailing shoes or treated with 3,4-dimethyl pyrazole phosphate and applied via slot injection. N2O fluxes were sampled using the closed chamber technique. Cumulative N2O emissions ranged 0.1–2.9 kg N ha−1 year−1 across the treatment, sites and years. The N application techniques showed inconsistent effects on soil mineral N content, cumulative N2O emission and N yield. The fertilizer replacement value of slurry was low due to low N use efficiencies at the sites. However, a close positive relationship (r = 0.5; p = .013) between slurry value and biomass yield was observed, highlighting the benefit of high slurry value on crop productivity. N2O-N emission factors were low for all treatments, including CAN, but were 2–6 times higher in 2019 than in 2020 due to lower precipitation in 2020. Variations in N2O emission were largely explained by soil and climatic factors. Even with the low N2O emissions, this study highlights the benefit (significant mitigation of N2O emissions) of replacing the increasingly expensive chemical fertilizer N with input from slurry under favourable conditions for denitrification. 相似文献
143.
Juliane Lilienfein Wolfgang Wilcke Reiner Zimmermann Pedro Gerstberger Glein M. Araújo Wolfgang Zech 《植物养料与土壤学杂志》2001,164(5):487-495
The removal or burning of the biomass which frequently includes main roots results in significant nutrient losses from the Brazilian savanna, the Cerrado. To estimate these losses, we quantified above‐ and belowground plant biomass and total nutrient storage in biomass and soil of a typical Cerrado. Dominant tree species in the layer > 2 m were Pouteria torta (MART. ) RADLK ., Ouratea spectabilis (MART .) ENGL ., Roupala montana AUBL ., Byrsonima coccolobifolia H.B. et K., Dalbergia miscolobium BENTH ., Kielmeyera coriacea MART ., and Caryocar brasiliense CAMBESS . which together represented 70 % of the biomass of the > 2 m layer. In the 0.5—2 m tree layer, many different species were found of which Ouratea hexasperma (ST .‐HIL .) BAILL . representing 33 % of the biomass in the 0.5—2 m layer was most abundant. The dominant shrub species were Miconia holosericea DC., Hortia brasiliana VAND . ex DC., Myrcia rostrata DC., Parinari obtusifolia HOOK . f., and Campomanesia velutina BLUME , contributing 93 % to the total shrub biomass. Total aboveground plant biomass was 22.7 Mg ha—1, total belowground plant biomass was 30.4 Mg ha—1. The tree layer > 2 m comprised the largest proportion of the aboveground biomass (64.6 %) > grass/herb (13.0 %) > shrub layer (11.6 %) > tree layer 0.5—2 m (10.8 %). Three quarters of the fine root biomass (17.6 Mg ha—1) were located in the upper 0.3 m of the soil. The element storages (in kg ha—1) were C: 10900, N: 173 N, P: 20, K: 51, Ca: 66, Mg: 20, S: 25, Fe: 10, Mn: 4.2, Zn: 0.35, and Al: 27 in the aboveground biomass, C: 12900, N: 214 N, P: 14, K: 41, Ca: 52, Mg: 10, S: 33, Fe: 2060, Mn: 2.9, Zn: 0.60, and Al: 648 in the belowground biomass, and C: 55400, N: 3510 N, P: 631, K: 366, Ca: 86, Mg: 75, S: 529, Fe: 159000, Mn: 124, Zn: 49, and Al: 434000 in the soil (0—0.3 m). If the above‐ and belowground biomass was completely removed from the Cerrado ecosystem losses would range from 5 % of the total nutrient storage for P to 58 % for Ca referred to a lower ecosystem boundary at 0.3 m mineral soil depth. 相似文献
144.
Analyses of phosholipid fatty acids (PLFA) and phospholipid etherlipids (PLEL) revealed differences in size and structure of microbial communities in the three soil zones of a potato field: ridge (RS), uncompacted interrow (IS), and tractor‐compacted interrow soil (CS). The quantity of phosholipid biomarker concentrations (= microbial biomass) showed large differences among different zones, when lipid contents were related to fresh soil volume instead of soil dry matter. Compaction of interrow soil caused an increase in bacterial and eukaryotic biomass, expressed as total PLFA concentration, as well as an increase in total archaeal biomass, expressed as total PLEL concentration and caused a decrease in the fungi‐to‐bacteria ratio. Due to the higher waterfilled pore space (an indirect measure for reduced O2 availability) in CS, a more pronounced anaerobic microbial community was estimated than in IS, which serves as an explanation for the elevated N2O fluxes in this soil zone. Apart from the effect of O2 availability, microbial communities, especially populations of aerobic bacteria, ascinomycetes, fungi, algae, protozoa, and aerobic archaea responded to organic matter composition in the individual zones. Only in RS PLEL derived cyclic isoprenoids were found, which presumably indicate root‐colonizing archaea. Following principal component analyses of specific biomarker profiles, the assumed substrate effect had the strongest influence on the differences in microbial community structure between the three soil zones. 相似文献
145.
Encystation and expression of cyst antigens by Giardia lamblia in vitro 总被引:20,自引:0,他引:20
F D Gillin D S Reiner M J Gault H Douglas S Das A Wunderlich J F Sauch 《Science (New York, N.Y.)》1987,235(4792):1040-1043
The cyst form of Giardia lamblia is responsible for transmission of giardiasis, a common waterborne intestinal disease. In these studies, encystation of Giardia lamblia in vitro was demonstrated by morphologic, immunologic, and biochemical criteria. In the suckling mouse model, the jejunum was shown to be a major site of encystation of the parasite. Small intestinal factors were therefore tested as stimuli of encystation. An antiserum that reacted with cysts, but not with cultured trophozoites was raised in rabbits and used as a sensitive probe for differentiation in vitro. Cultured trophozoites that were exposed to bile salts showed a more than 20-fold increase in the number of oval, refractile cells that reacted strongly with anticyst antibodies, and in the expression of major cyst antigens. Exposure to primary bile salts resulted in higher levels of encystation than exposure to secondary bile salts. These studies will aid in understanding the differentiation of an important protozoan pathogen. 相似文献
146.
147.
Mirsafaei Liaosadat Reiner Željko Shafabakhsh Rana Asemi Zatollah 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(3):307-315
Plant Foods for Human Nutrition - Cardiovascular disease (CVD) is a worldwide health problem with growing up rates of mortality and morbidity. Many risk factors, including high blood pressure,... 相似文献
148.
149.
Reiner Bonde 《American Journal of Potato Research》1942,19(7):131-133
150.