勤于专研做学问，求真务实为土壤—— 记我国著名土壤学家黄瑞采教授

我国著名土壤学家、农业教育家黄瑞采教授终生致力于土壤科学研究及农业教育事业，为中国土壤科学的发展做出了重要贡献，在土壤地理、土壤发生分类、土壤微形态和农田生态等领域进行了长期的卓有成效的研究。本文着意梳理黄瑞采教授的成长成才过程，希望其“宁劳死于工作，不老死于牖下”的一生能感染新一代科学工作者，引领更多的后继者为中国科学事业发展作出应有的贡献。     

THE PATH OF CARBON IN PHOTOSYNTHESIS. XXXI. THE ROLE OF LECTINS

Radish (Raphanus sativus) and Swiss Chard (Beta vulgaris) seedlings, grown hydroponically, exhibited significantly greater increases in height and weight in medium containing α-mannoside supplemented with calcium and manganese salts, than in control treatments lacking one or more of those components. Furthermore, seeds sown on medium containing α-mannoside plus Ca²⁺and Mn²⁺showed accelerated germination. Calcium and manganese are necessary to maintain the protein conformation of mannose-binding lectins. In the presence of those cations, glycosides displace specific sugars bound to lectins, making them available to support plant growth.     

STUDIES ON THE DECOMPOSITION OF PLANT MATERIAL IN SOIL. IV. THE EFFECT OF RATE OF ADDITION

Different amounts of ryegrass roots and tops, both uniformly labelled with ^{1 4} C, were mixed with soil and allowed to decompose for 155 days under controlled conditions in the laboratory at 25°C. Initially the roots decomposed more slowly than the tops but by 155 days this difference had disappeared. About a third of the added plant C remained in the soil at the end of 155 days, about as much as when the same plant materials were incubated in the same soils for 6 months in the field. To a first approximation, the amount of labelled CO₂–C evolved was directly proportional to the amount of labelled plant C added. This held throughout the incubations. However, a slightly smaller percentage of the added plant C was evolved with small additions than with large, although this effect was on the limits of detection. Slightly more labelled plant C was retained in a soil rich in organic matter (2.43% C) than in an otherwise similar soil with less organic matter (0.97% C).     

RECONNAISSANCE FOR SOIL SURVEY. II. PRE-SURVEY ESTIMATES OF THE INTRICACY OF THE SOIL PATTERN

The best procedure for mapping the soils of an area, and the effort this will require, depend upon the intricacy of its soil pattern. This paper presents one way of describing such intricacy-by a graph of variance against area sampled-and an exploratory attempt to determine its form for OM, N, coarse and fine sand, silt, clay, gravel, available P and K, CEC, exch. Ca, Mg and K, in areas in the Northern Territory of Australia. This confirmed that there are considerable differences between the graphs for different properties and that areas differ very much in the short- and long-range contributions to the total variability of their soil. It demonstrated the inevitable sampling problems in determining the form of variance-area graphs.     

THE CALCAREOUS SOILS OF AZERBAIJAN.

The surface properties of soil carbonate were related to its distribution in thirteen profiles of a catenary sequence of calcareous soils from Azerbaijan. When carbonate surfaces were contaminated by Mg²⁺, ⁴⁵Ca was used as a tracer for Mg²⁺ as well as Ca²⁺, thus enabling the carbonate surface areas to be estimated. These were shown to be inversely and curvilinearly related to soil carbonate contents, but with some abnormality for the three extremely saline/alkaline soils. Na+ does not appear to be specifically adsorbed on carbonate surfaces in the latter. The specific and the total surface areas of carbonate in the surface soils are very sensitive indices of profile development, and are combined with the content and particle-size distribution of carbonate in the profiles to show the variation in soil development along the catenary sequence.     

TRENDS OF SOIL CLASSIFICATION IN TANZANIA I. THE EXPERIMENTAL USE OF THE 7TH APPROXIMATION

A review is made of the trends in soil classification in Tanzania, indicating the need for an alternative to the traditional catena concept. An attempt to use the 7^th Approximation is reported, in view of the demand for high category soil classification, using forty-three typical soil profiles and discussing the particular problems related to placing three intimately studied profiles into the orders Alfisol, Ultisol, and Oxisol. An unrevised version of the 7^th Approximation is not recommended for use in Tanzania. However, by using the central concepts of the system and further defining the soil classes at all levels, the use of the 7^th Approximation could greatly assist in the assessment of the nation's soil resources and the ultimate development of agriculture in this country.     

观赏狼尾草光合特性的研究

用Li-6400便携式光合分析仪测定了观赏狼尾草(Pennisetum alopecuroides L.Spreng)的光合特性。试验结果显示:狼尾草的光合日进程呈“单峰型”,无“午休”现象,最大净光合速率为21.8μmol CO2m-2s-1,出现在13:00。狼尾草的光饱和点为1200μmolm-2s-1,光补偿点为15μmolm-2s-1,表观量子效率为0.05743;CO2饱和点为600μmolmol-1,补偿点在5μmolmol-1左右,羧化效率CE=0.2349。所有数据表明该狼尾草具有典型的C4植物的特性。     

黄河流域土壤研究 1.华北平原土壤概况和改良途径

黄河以北的华北平原,地处北纬36°—40°,东经114°30′—119°间,北起燕山南麓,西止太行山东麓;东至渤海,南至黄河,略呈长方形,由西南缓缓倾向东北,总面积约十二万平方公里。