The Effect of Nitrogen and Phosphorus Fertilization on the Nitrogen Absorption by Sunflowers

Little is known about the effect of fertilization on the N uptake of sunflowers. A 4² factorial trial with 0, 60, 120 and 180 kg N ha⁻¹ and 0, 15, 30 and 45 kg P ha⁻¹ was conducted over three years. The N content and concentration of leaves, stems and capitula were determined at three growth stages. High N levels increased the N content and concentration of all plant parts at all growth stages sharply. High P levels increased the N content of all plant components through better growth. P has an inconsistent effect on N concentration but tended to decrease it. After flowering the crop assimilated 20 to 25 % of the total N. This implies that N applied can still be applied and utilized by the crop at a late stage. This should be substantiated by further research.     

Effect of Low Night Temperatures on Photosynthetic Activity of the Maize Seedlings (Zea mays L.)

Night chilling (5 °C) subsequently lowered photosynthetic intensity in the leaves of maize seedlings at 20 °C through an increase in leaf diffusive resistance brought on by lower tissue water content in morning hours. A more significant increase in leaf diffusion resistance was observed when soil temperature was lowered than in the case of lower air temperature.
The unfavorable effect of soil and air cooling temperature on photosynthesis was limited by air saturated with water vapour. However, as a result of lowering the night temperature from 5 °C to 1 °C, the efficiency of the protective influence of higher atmospheric humidity was decreased. This demonstrates that the participation of factors unrelated to plant water status in inhibiting photosynthesis increases with lower night temperatures.
An additional reason for inhibited photosynthesis following cool nights was a decrease in chlorophyll accumulation, below 50 μg per 1 cm² of leaf area.     

Some Comments on Gerechte Designs

In a companion paper we derived the correct analysis for gerechte designs with uncorrected errors. Here we show that this correct analysis cannot be justified by the usual randomization argument. However, when the regions are rectangular there is a randomization procedure which validates an analysis with three separate error terms. We also outline other developments in design and analysis that may be more satisfactory.     

Matching spatial databases and quantitative models in land resource assessment

Abstract. Good land management needs information about land resources and the processes taking place in the landscape. In practical land evaluation this information is often expressed in terms of land qualities. The original survey data are stored in geographical information systems where they can be used to estimate the values of appropriate land qualities. Land qualities are complex attributes of land used in planning that may be derived from the original attributes through empirical threshold or regression models, or from process-based deterministic or stochastic simulation models. In order to improve estimates of the distribution of land qualities in space and time, and hence to improve planning decisions, the models require data with a much better spatial resolution than is usually available. The problems and dangers associated with the ad hoc linkage of simulation models and GIS are discussed. Particular attention needs to be paid to the problems of error propagation and costs and benefits when using models.     

A quantitative study of Eimeria infections of goats from central Spain.

A survey on coccidial infections in goats from central Spain was carried out. Fifty-five goat farms from 28 localities belonging to the three bioclimatic subregions of the area were visited. Individual samples (702) were obtained from the rectum of 130 young (under 1 year of age) and adult (572 over 1 year of age) goats. Coproscopical analyses showed a 100% prevalence and a moderate average intensity (7606.48 +/- 17918.78 Eimeria oocysts per gram of faeces), although wide variations were seen among herds and among individuals within each goat flock. Statistical analysis showed a strong age-related reduction in oocysts output in goats up to 4 years of age. The intensity of coccidial infections (young and adult goats, herds) was independent of the prevailing bioclimatic conditions. Heavier infections in young goats were found in bigger herds, whereas adult goats from these same big flocks (over 300 animals) showed the lowest oocyst output. Under our conditions, neither the female restocking rate nor the age structure seemed to play a significant role in the intensity of the Eimeria infections.     

光照对“星布罗”肉用仔鸡的生长发育及胰腺内分泌细胞结构和功能的影响

将72只日龄为14d的“星布罗”肉用仔鸡随机分为实验和对照两组,每组36只。实验组接受强度为151x的1L:3D间歇性白炽灯光照,对照组为自然光照。两组的饲喂条件相同。结果:与对照组相比,实验组体重略高而料肉比略低,实验组鸡胰腺A、B细胞的内分泌颗粒减少,A颗粒粒芯周围出现大致均匀的晕轮,B颗粒粒芯呈现不典型的针状、棒状或环状,PP细胞的内分泌颗粒明显增大、增多,胞浆中的粗面内质网、高尔基复合体和线粒体等数量增多。两组鸡的D细胞无明显差异。34日龄的实验组鸡血浆胰岛素含量明显高于对照组,且与体重呈正相关。     

澳洲坚果引种试种研究初报

澳洲坚果无性系从１９７９年开始引入中国，并在南亚热带作物研究所（南亚所）试种，现已在南亚热带地区七省扩大试种达２００ｈｍ＾２，各地生长均良好，已有少量结果。南亚所植区澳洲坚果１３龄树平均单株年产已达６ｋｇ（壳果），抗寒性良好，在－４℃时仍未受害，病虫害不严重（曾发生过花序枯萎病、速衰病、茎干溃疡病），但风害严重。澳洲坚果的适生温度在１０℃－３０℃，以最冷月（１）平均气温≤１０℃，年降雨量在１０００     

Plasma triglyceride concentration during intravenous infusions of propofol and Intralipid in sheep

Plasma triglyceride concentrations were measured in sheep given Intralipid or propofol, which is carried in a vehicle very similar to 10% Intralipid. A bolus dose was administered followed immediately by an infusion of the same agent for 2 h. In the animals that received propofol, the measured concentration increased by a mean amount of 3.39 mmol/l when the infusion rate was l ml/min (Group Pl) and by 7.13 mmol/l when it was 2 ml/min (Group P2). When 10% Intralipid was administered and infused at 1 ml/min (Group I10), the measured concentration increased only by 0.95 mmol/l. One hour after stopping the infusion, the excess of measured concentration over baseline had decreased in the Pl and I 10 groups to 0.52 and 0.13, respectively, of the corresponding maximum excess. The method adopted for measuring plasma triglycerides is widely used in hospitals; however, an incidental observation revealed that it is inappropriate in the presence of injections of propofol or Intralipid. Despite this, evidence and argument are presented to support the conclusion that, with propofol, plasma triglyceride concentrations increased more rapidly during the infusions and returned to baseline more slowly than with a corresponding amount of Intralipid.     

抓具抓取轨迹曲线及其绘制

在设计和研究抓具系统的功能和各种特性时,首先必须对抓具颚爪的抓取曲线进行研究。本文分析和论述了抓具的抓取轨迹曲线、影响抓取轨迹曲线的因素以及抓取曲线的绘制。     

Die Wurzelentwicklung von Zuckerrübenpflanzen auf einem Sandlöß-Standort und ihre Bedeutung für die Stickstoffernährung

Root development of sugar beet plants on a sandy loess site with regard to nitrogen nutrition.
Root development of sugar beet plants in a sandy loess soil (Haplic Phaeozem) was observed from the early seedling stage up to harvest by measuring at first the greatest vertical and lateral extension of the root systems of single plants and later the rooting density of the whole plant stands (auger method, profile wall method).
During the seedling stage not only the subsoil, but also large parts of the topsoil between the plants remained unoccupied by the root systems. In this phase the greatest lateral extension of single roots reaches nearly the length of the greatest leaf of the plant. With the closure of the canopy the rooting density in the topsoil accounts to 1–2 cm cm⁻³.
In summer roots penetrate to a depth of 100–150 cm with rooting densities of 0.1 to 1 cm - cm⁻³. Thus, the plants gain not only access to water reserves, but sometimes meet remarkable amounts of nitrate which under the relatively dry conditions of the region tends to accumulate in 60–120 cm depth and – when taken up by the beet plants in the late stage of growth – affects crop quality negatively.