Abstract:The contents of Cu, Be, Zn, Cd, Hg, Sc, La, Pb, As, Se, Cr, Mo, Mn, Co, and Ni in the important soil types of Beijing and Nanjing areas were measured by physical and chemical methods. Data concerning the mean value and the standard deviation of these elements both in various soil types and in the different horizons of each soil profile are given in the tables of the Chinese text. Results of present inveatigation may be summarized as follows. Variations of the content of trace elements of a soil were largely dependent on their parent materials. Soils derived from different parent materials, even belonging to a same soil type, usually show a rather great divergency in background values of trace elements while similarities of the values of trace elements were still perceived in different soil types derived from the same parent material. Present investigation also revealed that soils derived from basic rocks, as a rule, possessed higher back-ground values of trace elements than those from the acidic rocks as shown in the following descending order:basalt. limestone>shale>granite, sandstone.

Abstract:The water regime in cultivated black soils are not only influenced by the climatic factors, but also by the crops. In the black soils under different crops, there were obvious difference in the levels of soil humidity and the residual water in soils after harvest of crops. In wheat fields, an high evapotranspiration intensity with a peak which happened earlier and a maximum annual rate of evapotranspiration were found. But in fields of intertilled crops such as soybean and corn, the evapotranspiration intensity was, lower, the evapotranspiration peak came later and the annual rate of evapotranspiration was smaller. In the same year, soll humidity in wheat fields was lower than that in soybean and corn fields, and the residual soil water in wheat field after harvest was the smallest.

Abstract:The Tai Bai mountain, with a summit of more than 4000 m. above sea level is located in central part of Shangi Province of northwestern China. The annual rainfall of this region averages about 850 mm. A cool and humid.climatic condition prevaiLR at the higher altitude of this mountainous area. Vertical zonality of the soil distribution from the mountain foot to the summit ranges as: Drab soil-Brown soil-Podzolic soil-Soddy podzolic soil-Alpine meadow soil. Investigations on the fractional composition and characteristics of the humus of different soil groups reveal the following results.

Abstract:Shanghai is situated in the Yangtze Delta. The main soil types in this district are greyish-blue lowland rice soil (swamp type),greyish-brown upland rice soil (meadow type),brownish-yellow upland rice soil (meadow type) and salty soil.A preliminary study was made on the contents of available boron and zinc as well as their affecting factors in the soils mentioned above. The samples were collected from 44 localities. The contents of available boron and zire varied greatly. The content of available boron in the plough layer ranged from 0.06 to 3.20 ppm with an average of 0.71 ppm, and that of available zinc ranged from 0.25 to 5.47 ppm with an average of 1.82 ppm. In 80% of the collected samples, the available boron was 1.0 ppm or less;and in 33% of the samples, the available zinc was 1.0 ppm or less.

Abstract:A potentiometric method for the determination of the apparent mean activity of NaCI in saline soils in situ was proposed. A spear-type sodium-selective glass electrode and a spear-type chloride-selective pressed electrode were used. It was found that under ordinary circumstances the equilibrium potential between the electrodes and the soil generally reached within 10 min. after the insertion of the electrode into the soil, the actual time being dependent on the water content and NaCI content of the soil. For most saline soils with a water content near field capacity, the equilibrium time was 2-5 minutes. Prolonged usage may affect the function of the electrodes due to the adhesion of soil colloidal particles on the surface of the chloride-selective electrode and the dehyciration of the sodium-selective electrode. These affects may be avoided by frequent rubbing with fine emery paper and rinsing with water respectively.

Abstract:The present paper mainly deals with the phosphorus status of the soils in the suburbs of Shanghai. Two different methods were employed to extract the different forms of phosphorus in the soils. The results obtained showed that inorganic phos-phorus comprised about 90% of the total phosphorus, and of the inerganic phos-phorus calcium phosphate accounted for more than 50%.70-80% of calcium phos-phate took the forms of rock phosphate. Moreever, determination of the transformation of phosphorus in paddy soil by ³²P labelling method revealed that, after the application of phosphorus fertilizer to the soils, at first, the majority of phosphorus existed in the form of Al-P, then gradually converted to Fe-P, and finally, most of them were transformed into Ca-P. Through comparative study of extraction of available phosphorus in the soils and through field trials, it proved that Olsen's method is suitable for the soils in Shanghai, This article puts forward some sugestions on the application of phosphorus fertiliters to the soil in the suburbs of Shanghai.

Abstract:The effect of certain nitrofication inhibitors, such as 2-chloro-6(trichloromethyl) pyridine and 1-amino-2-thiourea, on the absorption rate of urea, ammonium carbonate, ammonium sulphate and ammonium nitrate by the rice variety Bai-Jin was studied. The rice plant tested was grown in the field plots on a saline light color meadow soil or in bottomless pots filled with the same soil. It was found that the utilization rate of the fertilizer nitrogen by the rice plants and the yield of rice grains were increased to different extent due to the application of nitrofication inhibitors.

Abstract:The clay minerals in two soil profiles of cinnamon soil in %iangshan district of Beijing were studied by chemical analysis, cation exchange capacity determination differential thermal analysis and %-ray diffraction. The results obtained are as follows: 1. The minerals in the clay fraction are composed of illite, strongly hydrated illite, illite-montmorillonite interstratified mineral, hydrobiotite and vermiculite. 2. The transformation sequences of clay minerals in cinnamon are supposed as follow.

Abstract:Composition of soil color is determined by scanning with a reflecto-spectrometer in the visible range. The computation of XYZ color system is based on the data obtained as percentage of reflection at different wavelength. The x, y values given in the color coordinate of the XYZ system are again converted into standard color according to the Munsell's svstem. In order to eliminate the tedious procedures of calculation, the present writers have suggested two tables of "1-9 times XZ coefficient" and "x,y color coordination". By consulting these two tables, it is feasible to denominate the soil colors directly from their spectrometric readings both in the laboratory and in the field. Examples for the method of the denomination of soil color are illustrated in present report.

Abstract:Paddy soils developed from red earth [pH 5.2-5.9, organic matter 1-3.1% and total phosphorus (P) 0.022-0.044%] were used in present experiment. Field experiments applied phosphatic fertilizer were carried out in Jinhua and Quxian area of Zhejiang province. Contents of soil available phosphorus were determined by four conventional egtractants, i.e. 0.511M NaHCO₃ (Olsen),0.025 N HCl+0.03N NH₄F (Bray),0.05 N HCl+0.025 N H₂SO₄ (Nelson) and 0.3 N NaOH+0.5 N Na₂C₂O₄ (Al-Abbas).

Abstract:Investigation on biotiite, muscovite, illite and orthoclase was made by chemioal analysis, X-ray diffraction and electron inicroscopy. Tbe results obtained ate suntutarized as follows.