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1.
本文详细阐述了中国和越南4个村蔬菜生产中的肥料施用情况,概述了施用肥料的种类、施用时间和施用数量。评价了影响肥料施用的因素,比较了施肥量和蔬菜从土壤中带出的养分量。在研究区域,农户施用了50多种肥料,施氮量间于0~700kg/hm^2。肥料施用时间因蔬菜种类和地区不同而不同。氮的施用量主要受作物种类影响。大部分中国蔬菜的氮、磷施用量过大,而钾肥施用量不足;相对而言,越南蔬菜的局部养分平衡比中国的情况好一些。因此,局部的养分平衡显示了不同蔬菜种类、不同季节和不周村社的养分投入量和养分输出量有很大区别。  相似文献   
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Needles from a series of wild yews (Taxus baccata L.) from Sardinia were investigated for their contents of 10-deacetyl baccatin III (DAB-III, 1), paclitaxel (Taxol) (2) and taxine (3). Despite a common geographical origin, ample variation of the taxoid profile was discovered, and several samples were surprisingly devoid of all terpenoid markers above. This finding is unprecedented within the European yew, while the general lack of taxine might rationalize the observation that most plants investigated are actively and impunently browsed by goats.  相似文献   
4.
Summary Salt tolerance in pepper (Capsicum annuum L.) is described in terms of yield, mortality and root weight. Significant differences in absolute and in relative salt tolerance were demonstrated between Tunisian varieties. Relative salt tolerance of Beldi was found to be due to its root system which remained unreduced under stress condition; local adaptation could be involved. D'hirat showed interesting levels of absolute salt tolerance and low mortality. An ECw-value \s-> 7.63 dS/m was critical for almost all characters observed, with reductions of approximately 50%. Fruit weight and shoot-root ratio were not significantly affected by high salt concentrations of the irrigation water.  相似文献   
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A pathogenetic role of the renin-angiotensin-aldosterone system has been implicated in cats in both systemic arterial hypertension and hypokalemic myopathy. Yet, measurement of plasma aldosterone concentrations (PACs) and plasma renin activity (PRA) has not unequivocally pointed to hyperaldosteronism as a cause of these conditions. To obtain appropriate reference ranges, this study included a large number (130) of healthy house cats of different breeds without a history of recent illness and plasma concentrations of urea and creatinine below the upper limit of the respective reference ranges. In addition, the pituitary-adrenocortical axis was studied by measuring plasma concentrations of adrenocorticotropic hormone (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), and cortisol. Reference ranges for PACs (110-540 pmol/L; 40-195 pg/mL), PRA (60-630 fmol/L/s; 0.3-3 ng/mL/h), and the aldosterone to renin ratio (ARR) (0.3-3.8) were very similar to those established in the same laboratory for humans in a supine position. No breed differences were found. The ARRs in neutered cats were significantly higher than in intact cats, primarily because of low PRA in neutered cats. The ARRs of cats > or = 5 years of age were significantly higher than those of cats < 5 years of age. The plasma concentrations of ACTH, alpha-MSH, and cortisol did not correlate significantly with PAC. Thus, although blood sampling was performed in cats in nonstandardized positions and was associated with a wide variation of stress responses, the references ranges of PAC, PRA, and ARR were similar to the relatively narrow limits established for humans under standardized conditions. The effects of neutering and aging on PRA and ARR warrant further investigation.  相似文献   
6.
1. A total of 2560 male and female Ross broilers were raised to 42 days of age in a 2 × 2 treatment factorial arrangement experiment to investigate the influence of different degrees of physical activity and dietary energy on broiler performance, abdominal fat content, carcase yield and sensory quality.

2. Vertical fans were used to force the treatment birds to walk 3 to 4 times as far as the normal activity birds; birds were fed a normal and a high energy diet (12.55 compared with 13.81 MJ ME/kg) with the same energy/protein, energy/lysine and energy/methionine + cystine ratios.

3. High activity birds had greater body weight ( + 4.1%), food intake ( + 5.1%) and ME intake ( + 5.1%) than normal activity birds. Birds receiving high energy diet had a lower food conversion and food intake than birds receiving normal energy diet. There were no significant differences in body weight or ME intake between birds with different diets.

4. Slaughter yields, both absolute and relative to live body weight, were affected by activity or dietary energy to varying degrees. Breast meat was increased with more activity. The absolute weight of abdominal fat was independent of activity and in males the relative weight of abdominal fat was decreased in high activity birds.

5. Different degrees of activity and dietary energy had only minor influences on broilers' sensory quality.  相似文献   

7.
ABSTRACT The virulence of Meloidogyne hapla, M. chitwoodi, and M. fallax was studied on genotypes of Solanum spp. in a greenhouse. Juveniles of 11 M. hapla race A isolates, 3 M. hapla race B isolates, and 5 mono-female lines of a M. hapla race A isolate were inoculated on S. chacoense, S. hougasii, and S. sparsipilum. Juveniles of eight M. chitwoodi isolates, five M. fallax isolates, and six mono-female lines of a M. chitwoodi isolate were inoculated on S. bulbocastanum, S. chacoense, S. hougasii, S. stoloniferum, and S. tuberosum. Virulence was expressed as nematode reproduction 8 weeks after inoculation. Nematode reproduction was estimated by the number of egg masses and, in one experiment, by the number of hatched second-stage juveniles per inoculated juvenile. Considerable variation in virulence and resistance was observed among M. hapla isolates and plant genotypes, respectively. The M. hapla isolate-plant species interaction was highly significant. The response to M. chitwoodi ranged from susceptible (S. tuberosum and S. chacoense) to highly resistant (S. bulbocastanum and S. hougasii). S. tuberosum was susceptible to M. fallax, whereas all four wild species were resistant. In contrast to M. hapla, no significant isolate-plant genotype interaction was obtained for M. chitwoodi or M. fallax, indicating no or little intraspecific variation in virulence. M. chitwoodi juveniles in species mixtures with M. fallax isolates appeared to be able to break the resistance of S. bulbocastanum and S. hougasii. Significant differences among mono-female lines of M. hapla and M. chitwoodi were observed, indicating heterogeneity of pathogenicity within meiotic parthenogenic Meloidogyne populations.  相似文献   
8.
动物福利在养猪生产中占据着越来越重要的地位。通过对动物福利进行立法以对养猪生产者进行更多限制是一种不能永远持续的趋势。荷兰Wageningen大学从事家畜研究的Hans Spoolder博士解释了结果将如何满足。  相似文献   
9.
在整个荷兰,可以找到大约15家使用两层式猪舍进行养猪的猪场。尽管因为社会原因备受批评,但这种饲养方式向生产者提供了许多益处。  相似文献   
10.
The Sistan Delta in Iran is located at the end of a closed basin with nearly 100% of the supply coming from Afghanistan. This supply is supporting irrigated agriculture in the area and is the source for the lake system around the delta. These Hamoun lakes are ecological very valuable wetlands; a number of them are registered as Ramsar sites. The Iranian government tries to improve the living conditions of the people in the area, among others by providing infrastructure for irrigated agriculture. Further development of the irrigated area will mean less water for the Hamouns with resulting lower average water coverage of the lakes. This will not only endanger the ecosystem that the Hamouns support but also the livelihoods of the people that depend on the goods and services that the lakes provide. This paper describes a study that has been carried out to support decision making on potential development schemes in the delta. The non-availability of data from Afghanistan requires the development of various tools and the use of remote sensing techniques to enable to make estimates for the river flow that Iran can expect from Afghanistan. An IWRM approach has been used for the balancing of interests involved. Some preliminary conclusions are described.  相似文献   
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