Abstract:A cinnamon soil and a lime concretion black soil from Huang-Hai-Hai Plain of China and a Palouse silty loan from eastern part of Washington state of U.S.A. were mixed with wheat streiw (¹⁵N labelled and unlabelled) and nitrogen fertilizer (¹⁵N labelled and unlabelled) in different. rotes and incubuted under 20℃ and 30℃ for 7 weeks to investi;ate the transformation of fertilizer-N and straw-N. More than 70% even all of the mineral N was immobilized in the soils incubated only with straw or low rate of N fertilizer under 200C or 300C after 1 week; and immobilization was dominant in the soils during the imubation from 2nd to the week. While Iess N immobilized in soils ineubated with lihlmr rate of N fertilizer after 1 week;and part of the immobilized N was mineralized in the soils incubated under 30℃ during the perind from 2nd to 7th week. It seemes that the immobilization rate of N in the soils decreased with the increase of fertilizer-N added. At the end of incubation 10-50% of fertilizer-N appeared as miniral-N in the soils with higher rates of N fertilizer. About 50-60% of the fertilizer-N and similar range of straw-N appeared as HCl hydrolpzable N. The immobilization rate decreased with the inerease of organiu matter and total nitrogen contens of the soils and the raising of incubation temperature.

Abstract:The present paper deals with the ages of ealcrareaus concretions in soils using radiocarbon dating method and.the relationship between the age and chemical composition of the calcareous concretions. The factors effecting the genesis of the calcareous concretions, such as ground water, class material weathered from limestone and human activities are discussed.

Abstract:In this paper, experiments of phosphate sorption and buffering capacity of the soils collected from the suburbs of Shenghai were conducted, and the phosphate adsorptics index and phosphate fertilizer index were studied. Results obtained showed that phosphate sorption indices calculated from Freundlich, Tempkin and Langmuir equations were closely related with the types and properties of the soils, they could be regarded as an iutportant index for sodl fertility."Phosphate fertilizer index" that reflects buffering capacity of soils was closely related with roil organic matter content, clay content, active Al content and pH value. Results also showed that the adsorption maxima (X_m),P adsorbed at 0.2 ppm and phosphate fertilizer were in a descending order waterlogged paddy soil>stagnating paddy soil>percolating paddy soil>permeable paddy soil>sandy permeable paddy soil.

Abstract:Results of field experiment applying sweet clovers, wheat straw anti heat in black soil showed that there were significant differences among the ratcs of decompositiun of the oganic materials. The decomposition rate of sweet clover was greater than these of the other two organic materials, and that of peat was the lowcet either in tlic black soil of Harbin or in that of Keshan. The humification coefficient of peat in the soil was the highest, that of wheat straw the second, and that of sweet clover the lowest. Experimental results also showed that application of the organic materials incremnd the contents of humus and nutrients, improved the retention oblity of the soil fo.r nutrient.s, and increased the total C and additional complexing degree of organo-complexes in soil. It was also found that the content of loosely cambineci humus was increased, that of closely-combined humus was decreased, and the humus was activated by application of onganic meterials, and the colloidal characteristics and the fertility art the black soil were improved.

Abstract:The contents of trace elements in soils of Henan Province are lower than the average values in soils of China. Owing to diverse parent materials and soil types, the contents of trace elements in the soil fluctuate greatly. The soils are mostly deficient in available B and available Mo. However, the Zn content which belon ges to lower level as compared with other regions varies with different parent materials and soil foaming conditions.The distribution of trace elements in profile varies with elements and soil types, soil pH value is the most important factors affeecting the available availability of trace elements in soil. Available Zn and NIn contents in soil decreases with the increase of pH value, while Mo trends in the contrary way.

Abstract:The relationship between modules of rupture and moisture content, of three clayey soils within a suction range of 1-15 bars was studied. The results showed that the turning points of moisture content for rupture modules of latosol, red earth amd yellow earth were 25.3%,15.3% and 15.7% respectively. According to the characteristic curves of these soils, taking the moisture contents of the soils at 8 bar as the critical values of the turning point, their errors were less than 1% (dry weight percent) as compared with the measurements. As compared with other 14 typical characteristic curves published in literature, it is suggested that this critical value would be suitable for most sails with the errors less than 2% (dry weight percent).Owing to the turning point of the moisture content far modules of rupture at which the pressure to break down the soil clad increases sngnificantly, this critical value of soil moisture content could be considered as a parameter for the lower limit of sail tillage.

Abstract:This paper deals with the genetic chracteristics of brown earth in Shandang province, in comparison with cinnlamon soil. The browen earth having been named Shan-Bong brown earth, in fact, includs tow groups, i.e. brown earth and cinnamon soil. The brown earth is widely distributed in Shandong peninsula, while the cinnamon soil is spreaded in the northwest part of this province. And in the transitional area the two groups of soils are often distributed as complex association.

Abstract:Cold spring paddy soils are the low yielded soils with puddling soil layer formed under strongly reducing condition induced by persistent submergence. Experiment results showed that low ing the ground-water level by deep ditch drainage and controlling the rice disease by applying potassium fertilizer are the effective measures for the improvement of the soils.

Abstract:The intact section of the acient weathering crust in Sichuan Basin can be delimited inW three strata, i.e, those of elastic clay (the 3rd stratum)，the elastic brccia-clastic clay (the 2nd stratum) and the elastic breccia (the 1st stratum).The silt content of the ancient weathering crust is lower by about 15%, the fine clay content higher by more than 80% and the plastic index higher by 2.44-3.02% than those of the purplish soils derived from purple rock in the same region. The ancient weathering crust is relatively stronger in the accumulation of Si, Al, Fe and Ti and leathing of Ca, Mg, K and Na, as compared with its parent rocks underlying.

Abstract:The present paper deals the application of the cluster analysis method in the basic categories of classification for salt-affected soils on the basis of the analytical data of forty profiles. The results obtained are: 1. According to the coefficients of distance matrix among the samples, the seven genera originally classified can beg reclassified into five genera at 0.08 distance level through cluster analysis.

Abstract:随着工业发展,煤和石油热力能源的消耗与日俱增,多环芳烃(简称PAH)类化合物,主要是在燃烧不完全时产生。它们排放到大气中与各种类型的尘埃结合在一起,颗粒较大的则随不同风向和风力降到地面,进入土壤,造成土壤污染。因此测定土壤中的PAH,了解它的状况,进而探测它的迁移、转化、归宿等具有一定意义。

Abstract:我们曾发现,苏州地区的某些水稻土的耕层土壤,pH值可低至5.0-5.5,有些土壤的交换性Ca/Mg比值亦明显下降^[2,3]。黄棕壤在添加有机物质并淹水培育后,使其交换性镁含量增加和交换性钙含量下降^[1],而试样的pH值与交换性钙镁总量之间,出现显著的正相关(r=0.837,n=10)。

Abstract:水平排水在防治改良盐碱土中已得到广泛的应用,但在地形低洼、地下水出流不畅,水平排水不能有效地降低地下水位的地区,采用垂直排水可获得较好的效果。我们根据在陕西省洛惠渠两年抽水冲洗脱盐试验证明,垂直排水具有脱盐深度深、脱盐效率高、冲洗过程短、占地面积少、冲洗定额小等优点。