Abstract:This article deals with the influence of tea plantation on the acidification of yellow-brown earth. The soil pH decreased after planting tea, and the soil tended to be further acidified with the time of growing tea. The decrement of soil pH was higher in upper layers,than in lower layers. The acidification of soil in tea garaen was related to the biological accumulation of aluminium and fluorine by tea trees, to The increade of soil exchangeable aluminium and aluminium complexes, and to the eluviation of basic canons in soils. The contents of aluminium and fluorine in the fallen leaves of tea were 5836-6136 ppm and 469-520 ppm respectively, and the aluminium content in the percolating solution of soil in tea garden decreaed from 0.46-0.55 mg L^-1 in the litter floor to 0.01-0.15 mg L^-1 in the 50 cm deep soil. Aluminium and fluorine cycle in tea garden resulted in not only the increase of Al³⁺ and F^-1 in soil bur also the accumulation of organic complex aluminium in surface soil and aluminium-fluorine complexes in soil exchangeable complexes and soil solution. Therefore, the accumulation of aluminium and fluorine in soils and its hiogeochemical cycle were the main reason fof the acidification of soils in tea gardens.

Abstract:A simulated rainfall study on cultivated red earths derived from red sandstone, phyllite, quaternary red clay in the northen Jianxi P-ovince and cultivated yellow brown earths from Xiashu Loess in the southern Jliansu Province, including six runoff experimental plots, was conducted for measuring water and soil losses in flattish hill region. Determination of some soil physical properties influencing soil erosion, such as soil permeability, was carried out.

Abstract:The world has a total rice-growing area of 9.7 million hectares and a total rice production of 468 million tons, of which Asia constitutes 89.6% and 91.6% respectively. In rice production, there are mainly two cropping systems, i.e., double-cropping rice system (2 or 3 crops a year) and single-cropping rice system (1 or 2 crops a year). With expansion of the rice growing area and changing of the cropping syseem, the proLlem of soil and Water management in the rice-cropping system is becoming more and more prominent which is chiefly refiected in the following 3 aspects: improvement of soil physical propertices, rationalization of irrigtlion and drainage, and coordination of soil nutrients. In rice cultivation, the pudding of cultivated layer and the percolating of plough pan are 2 major problems, to which solutions lie in the adoption of minimum tillage, non-tillage, paddy-upland crop rotation and application of coarser organic mcnures. In the water management and irrigation of paddy fields, different irrigation methods such as shallow irrigation, deep irrigation, moistinb irrigation and sunning are adopted, in light of tlae soil conditions and water requirement of rice.

Abstract:By using the methods of correlation analysis and dissection, the microaggregate composition and cementing substances in black soils and brown forest soils of different fertility levels were studied. The resullts obtained are summarized as follows. The content of >10μm microaggregates and the degree of aggregation of sbil markedly increased with the increase of soil fertility level. The soil constituent affected greatly the formation and distribution of soil microaggregates.

Abstract:This paper deals mainly with the physico-chemical properties and mineral compositions of red earths, lateritic red earths and latosols developed from basalts under different conditions of biological climate. The content of iron oxide in clays from all soils was higher, being 16.98±0.83%. The iron oxides in clay fraction were dominated by hematites and geothites, but those in coarse fraction by magnetites, hemames and anatases. The free degrees(free Fe₂O₃/total Fe₂O₃) of iron oxides of red earths, lateritic red earths and latosols were 53.3±2.2%. 71.1±2.8%, and 82.8±3.1% respecaively, and silica-alumina ration 3.29±0.05, 2.33±0.05, and 1.89±0.03 respectively. The degree of allitic enrichment strengthened with increase of remperature and rainfall. The weathering leached coefficient ba (ba=K₂O+Na₂O-CaO+MgO molecular ration) was used to indicate the weathering intensity of soils. The ba valus of red earths. lateritic red earths and latosols were 0.22±0.01, 0.13±0.002, and 0.05±0.01 respectively.

Abstract:In this paper the clay mineral composition of red earths and yellow earths derived from granites in Guangdong, Jiangxi and Anhui Provinces were studied by using a quantttatwe analysis approach. It will he helpful for explaining mineralogical properties of red earths and yellow earths in different zones of the eastern China are also given in it.

Abstract:The present paper deals mainly with the adsorption characteristics of magnesium ion in soil and the effect of exchangeable magnesium on some physical properties of soil.The experimental results Indicate that the effect of anions of magnesium salts on magnesium ion to intrude into soil absorbing complex was in the order of CO₃^2- > SO₄^2- > Cl^-.Accompanied by sodium ion,magnesium ion was more easily adsorbed by calcaxeous soil containing magnesium carbonate than when it exists alone in soil solution with a low saliniiy Sodium ion was more easily adsorbed by soil in NaCl-MgCl₂ solution than in NaCl-CaCl₂ solurion when salinity and SAR were given.

Abstract:The oxidation-reduction pomntials (intensity Factor) and reducing substances(capacity factor) in some soils of the Dinghu Mountain, the Jianfeng Mountain and the Nada region wire determined in situ with electrochemical methods.It was found that the oxidation-reduction regime in soils changed regularly with the variation of the vertical plant conuuunity.

Abstract:Both laboratory analysis and pot experiments in greenhouse were conducted by using four typical soils widely distributed in Zhejiang province and rye as testing plant to study the relationship between plant-availability of P and characteristics of phosphate desorption in soils The results obtained demonstrated that P uptake of rye plant was correlated more significantly with desorbed-P than with Olsen-P or Bray 1-P. What is more interesting is that the plant-absorbed P was much more compatible with desorbed-P than with Olsen-P or Bray 1-P in quantity,dinder various levels of P intensity. The Q-l relationship of either P uptake of rye plant or desorbed-P against P intensity fitted much better with the Langmuir equation than that of Olsen-P or Bray 1-P against P intensity as far as the four tested soils are concerned. It suggested that plant-availability of phosphorus in soil was essentially related with phosphate desorption behavior. The maximum buffering capacity of desorption (MBCD) obtained from the Langmuir equation mas found to explain well the variability in the recovery percentage of the applied fertilizer P by rye plant on different soils. Compared with the maximum buffering capaeity of adsorption (MBCA), MBCD is a better physico chemical index for evaluating the plant-availability of phosphorus in soils. However, it seems that the equilibrium buffering capacity of desorption rnay become the most promising index for diagnosing soil P status.

Abstract:To study phosphorus in orgamt wastes four kinds of ping excrete and two kinds of cattle and chicken excretes were collected for a laboratory study and a greenhouse pot experiment of rice plant on a paddy soil derived from Quaternary red clay. The pots without pho-sphorus fertilizer and with chemical phosphorus fertilizer were taken as controls in the experiment.

Abstract:Loessal soils are one of maln soil types in the northern part of China. They are widely distributed over Shanxi, shaanxi, Nei Monggol, Gansu, Ningxia, Qinghai and Henan provinces, with a calcareous reaction and pH of 7.5-8.5 and low content of organic matter. The yeild of crops in the soil regions is low because of drought and erosion.In comparison with the average contents of soils in the whole China, the contents of the total Zn and Mn of the soils in the loessal region are lower, Mo is very low, B is medium and Cu is slightly higher. The contents and distribution of trace elements in the soils have some regularities, which are affected by parent material, climate, topography and soil properties. The contents of Zn, Mn, Cu and Fe in soils increase with the increasing of soil clay particles from the nouthwest to the southeast. The content of B in the soils derived from river alluvium is higher than that in the soils derived from loess. And the content of Mo in the soils derived from loessal materials is the highest.

Abstract:The enrichment capability of native zinc by iron oxide, manganese oxide and organie matter in 18 soils of the eastern China were studied with the sequential extraction fractionation procedure. Soils used incaude 5 acid soils, 5 neutral soils and 8 calcareous soils which are derived from 11 kinds of parent materials from south to north in China. The enrichment capability of native zinc by per unit soil components is different from enrichment capacity of soil components, and a comparative study of them were conducted.

Abstract:前人从气候、地形、生物等外力因素的影响入手,对土壤中微量元素的分布、迁移及其转化的地球化学规律进行了大量有益的工作。但是,对于地质构造体与土壤中微量元素分布的关系,构造运动对土壤中微量元素迁移及富集的影响,即内力作用方面,几乎完全缺乏研究。

Abstract:长期以来,人们总想寻找一个更为适合的土壤有效钼测试方法,其主要原因有两个,一方面常规方法如Tamm液提取法提取的土壤有效钼往往偏高,在许多缺钼的酸性土壤的测试中,该法提取的土壤钼量不能较好地反映植物需钼的实际情况^[1]。另一方面,土壤有效铝含量极低,普通的分析方法在测定土壤有效铝时,很不容易做到准确、快速。