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11.
Ethiopia’s irrigation potential is estimated at 3.7 million hectare, of which only about 190,000 ha (4.3% of the potential) is actually irrigated. There is little information on the extent to which the so far developed irrigation schemes have been effective in meeting their stated objectives of attaining food self-sufficiency and eradicating poverty. Therefore, the aim of this paper is to identify the impact of small-scale irrigation on household food security based on data obtained from 200 farmers in Ada Liben district of Ethiopia in 2006. The resulting data was analyzed using Heckman’s Two-step Estimation procedure. Studies elsewhere revealed that access to reliable irrigation water can enable farmers to adopt new technologies and intensify cultivation, leading to increased productivity, overall higher production, and greater returns from farming. Our study findings confirm some of these claims. In the study area about 70% of the irrigation users are food secure while only 20% of the non-users are found to be food secure. Access to small scale irrigation enabled the sample households to grow crops more than once a year; to insure increased and stable production, income and consumption; and improve their food security status. The study concludes that small-scale irrigation significantly contributed to household food security.
Dereje BachaEmail:
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12.
Sweet sorghum (Sorghum bicolor [L.] Moench) is a prospective bioethanol feedstock source. Four high-biomass and sweet sorghum male lines and three grain sorghum female lines were intercrossed using Design II mating. Parents and hybrids were evaluated to (a) identify genetic sources to improve biofuel traits, and (b) determine the inheritance of biofuel and morpho-agronomic traits. Total soluble sugars (TSS) per plant were determined using juice weight (JW) and Brix (°Bx). Plant height (PH), biomass (BM) and stalk diameter (SD) were also measured. Mean hybrid performance for PH, JW, TSS and BM was higher than the male parent means. Three male parents exhibited positive and significant general combining ability (GCA) for at least three traits. Among males, PI185672 showed the highest GCA for PH, °Bx and BM, while No. 08 exhibited the greatest GCA for JW and TSS. Most hybrids exhibited overdominance-driven high-parent heterosis for all traits except SD. Trait broad-sense heritability ranged from 0.71 (BM) to 0.93 (PH). Results revealed that biofuel traits could be substantially improved through breeding, which will contribute to enhanced bioethanol production.  相似文献   
13.

Context

The phenomenon of known as ‘land grabbing’ is not a new process. Especially, since the 1990s, some capital-rich countries have started to buy or lease foreign lands to be able to produce food and biofuels.

Objectives

This article aimed at investigating the (un)sustainability of ‘transnational land deals’ (TLDs) for investors, host governments and local communities. Given the three dimensions of sustainability, the “social acceptability”, “economic viability” and “environmental conservation” of the TLDs have been studied.

Methods

To understand whether and to what extent the TLD is sustainable in each dimension a meta-analysis was conducted on 73 journal articles.

Results

Results showed that tenure arrangements and livelihoods were the main drivers for the matter’s social acceptability. Accordingly, local communities are affected by losing and receiving little or no compensation for their land, and making them have to face the increasing vulnerability of their livelihoods. This results in a win–win–loss situation for investors, host governments and local communities, respectively. Economic (un)sustainability mainly depends on capital flow, infrastructure and employment. This aspect is evidenced as a win for investors and host governments and implies the aforementioned win–win–loss situation. The main aspects of environmental (un)sustainability are considered as biodiversity, ecosystem services, and climate change.

Conclusions

According to the results, both host governments and local communities experience loss. This results in a win–loss–loss status of the TLDs. The major challenge remains in establishing good land governance, which can guarantee the benefits to local people and their access to land.
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14.
The in vitro activity of 15 antimicrobial agents against clinical isolates of Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Pasteurella spp. and Streptococcus canis from dogs was investigated. For Staphylococcus spp., the highest frequency of resistance was observed for penicillin, followed by ampicillin, tetracycline and chloramphenicol. The highest frequency of resistance in E. coli isolates was recorded for tetracycline and streptomycin. Pasteurella spp. and S. canis had the highest resistance rate for tetracycline and chloramphenicol. Most isolates showed full susceptibility to low-level resistance to colistin, florfenicol and fluoroquinolones. Further studies using larger number of isolates from both healthy and diseased dogs would provide a broader picture of antimicrobial resistance at a national level and promote prudent use of antimicrobial agents in companion animals.  相似文献   
15.
This paper summarizes results from 8 years (1996–2003) of eddy covariance-based ecosystem CO2 exchange measurements at the Borden Forest Research Station (44°19′N, 79°56′W). The site represents a mid-latitude, 100-year-old, mixed deciduous and coniferous forest dominated by red maple, aspen and white pine. The years 1996 and 1997 were relatively cold, had a late spring and received below average photosynthetic photon flux density (PPFD). This contrasts with an early spring, warmer soil and air temperatures during 1998–1999, and with distinctly wet year of 2000 and dry years of 2001–2003. The combination of early spring, warmer air and soil temperature and relatively high level of PPFD was associated with higher net ecosystem productivity (NEP) that peaked during 1999. Photosynthetic capacity was reduced and NEP showed a mid-growing season depression during the dry years of 2001–2003. Annual average ecosystem respiration (R) determined from a light response model was 30% less than R derived from a logistic respiration equation, relating night time CO2 flux and soil temperature. However these independently determined R values were well correlated indicating that the site is unaffected by fetch and spatial heterogeneity problems. Based on the combined 8 years of growing season daytime data, an air temperature of 20–25 °C and a vapor pressure deficit (VPD) of 1.3 kPa were found to be the optimal conditions for CO2 uptake by the canopy. Over the 1996–2003 period, the forest sequestered carbon at an average rate of 140 ± 111 gC m−2 y−1. The corresponding gross ecosystem photosynthesis (GEP) and R over this period were 1116 ± 93 gC m−2 y−1 and 976 ± 68 gC m−2 y−1, respectively. The annual carbon sequestration ranged from 19 gC m−2 in 1996 to 281 gC m−2 in 1999. However, these estimates were sensitive to frictional velocity threshold () used for screening data associated with poor turbulent mixing at night. Increasing from 0.2 m s−1 (based on the inflection point in the nighttime CO2 flux vs. u* relationship) to 0.35 m s−1 (determined using a selection algorithm based on change-point detection) modified the 8-year mean NEP estimate from 140 ± 111 gC m−2 y−1 to 65 ± 120 gC m−2 y−1. Both approaches show that the Borden forest was a low to moderate sink of carbon over the 8-year period.  相似文献   
16.
Fusarium species causing maize kernel rot are major threats to maize production, due to reduction in yield as well as contamination of kernels by mycotoxins that poses a health risk to humans and animals. Two-hundred maize kernel samples, collected from 20 major maize growing areas in Ethiopia were analyzed for the identity, species composition and prevalence of Fusarium species and fumonisin contamination. On average, 38 % (range: 16 to 68 %) of maize kernels were found to be contaminated by different fungal species. Total of eleven Fusarium spp. were identified based on morphological characteristics and by sequencing the partial region of translation elongation factor 1-alpha (EF-) gene. Fusarium verticillioides was the dominant species associated with maize kernels (42 %), followed by F. graminearum species complex (22.5 %) and F. pseudoanthophilium (13.4 %). The species composition and prevalence of Fusarium species differed among the areas investigated. Fusarium species composition was as many as eight and as few as four in some growing area. The majority of the maize samples (77 %) were found positive for fumonisin, with concentrations ranging from 25 μg kg?1 to 4500 μg kg?1 (mean: 348 μg kg?1 and median: 258 μg kg?1). Slight variation in fumonisin concentration was also observed among areas. Overall results indicate widespread occurrence of several Fusarium species and contamination by fumonisin mycotoxins. These findings are useful for intervention measures to reduce the impact of the main fungal species and their associated mycotoxins, by creating awareness and implementation of good agricultural practices.  相似文献   
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