Abstract:In this paper, a quantatative remote sensing method for soil erosin losses is briefly introduced, and its operation and application in the mountain and hilly areas of Shandong Province, China are described.Although the model form of this method for monitoring soil erosion losses is the same as that of the (American) RUSLE, the formula and algorithms for model factors are generated from the loss data observed in China.Therefore, the method is more applicable to loss regions in our country and is suitable for personal computers to process the data of GIS and remote sensing.It is a more accurate and practical method compared with the conventional survey method and the qualitative remote sensing method.The results of its application include the total loss of region, the area of different grades of soil loss, the soil erosion map, and the forecast map of soil conservation.The total losses monitored by the quantitative remote sensing method are conformable to the deposition values observed and calculated by hydrometric stations in the 9 reservoir valleys with an average accuracy of 82.96%, showing the accuracy of the monitoring results obtained by this method in Shandong Province (see Table 2).

Abstract:Vertisols were proved in this work to be not modern soils but paleosols from the characteristics of genetic horizons in soil profile, soil ages and environmental changes in terms of pollen analysis, paleontologic fossils and radiocarbon dating.The paleosols have undergone 3 sedimentation-soil formation cycles since late Pleistocene, being weak in the degree of soil development.In fact, the paleosols found in the Huang-Huai-Hai Plain are a superimposed paleosol consisting of calcareous concretion soil horizon, dark soil horizon, topsoil horizon and/or warped horizon.

Abstract:The vertical changes of textural layers along profiles in alluvial soils are a very complicated problem.The vertical changes can be described only qualitatively but have not been quantified for a long time past The characteristics of combination of textural layers in soil profiles greatly influence water transport and solute movement in the soil, so the quantitative description is a foundation for more accurate quantification of water transport and solute movement in field soils.Markov chain theory can be used to characterize the state transition of a dispersed state sequence changing with time (or space).This work used it to study regulations of vertical changes of textural layers along profiles in alluvial soils.The results showed that the vertical changes of textural layers along profiles had Markov characteristic in an alluvial soil region and that its transition probability matrix (TPM) was nearly stable.Meanwhile, the features of combination of soil profile textural layers in the study region were studied by TPMs, entropy group values and similarity measures.Among soil textural layers in the study region, clay layers were predominant, then came sand soil layers, sand loam layers, medium loam layers, light loam layers and heavy loam layers in proper order.The combination patterns of textural layers in soil profiles are mainly clay-sand, sand-clay, clay-sand-clay and sand}lay-sand.

Abstract:Red Soil Resource Information System (RSGIS) made by means of Remote Sensing and Geographic Information System (GIS) plays an important role in survey, evaluation, utilization and management of red soil resource.The RSGIS of Quzhou City, Zhejiang Province (1:250,000) and the RSGIS of Longyou County and Quzhou City, Zhejiang Province (1:50, 000) were made by using Sun workstation and ARC/INFO software respectively.The system design, database establishment technology, system functions, etc.are introduced, focused on developing applied models, such as red soil resource division and mapping, suitability evaluation, erosion risk evaluation, plant utilization zone, etc.The problems on studying of RSGIS and its strategy are also discussed.

Abstract:This paper deals with the E' center's mean life of quartz in the Quaternary red earth developed largely in South China.According to the results of annealing experiments at equitime (ten minutes), the curve of equitime-annealing of the quartz particles was drawn successfully.The curves showed that the E' center of quartz declined quickly from the temperature of 600K to 748K, based on the curve the probable temperatures of isothermal annealing experiments were selected as following: 623, 648, 673, 698 as well as 723K.After each sample's being annealed at the selected temperatures, the ESR intensity was measured at the room temperature respectively.Considering the fitting function of ESR intensity versus the annealing time (minutes), each sample's E' center's mean life at corresponding temperature was acquired.Consequently, from the fitting line of E' center's mean life versus temperatures, we assumed that the E' center's mean life at room temperature would be 3.09×10⁸ years.This study demonstrates that the quartz particle in the red earth of south China is fully suitable to be selected as the specimen for ESR dating.

Abstract:The characteristics of physical fertility evolution under various land use patterns of red soil derived from Quaternary red clay in low-hilly region in the middle subtropics were researched, then the evaluation indexes were selected with cluster analysis and their weight coefficients determined with factor analysis.Results showed that the soil physical fertility in forest and grass land systems was not obviously lower than in cultivated land systems as soil chemical fertility showed.In the systems in Jiangxi Province, the soil physical fertility degraded with the reclamation, which was mainly expressed by the destroy of soil structure, the decrease of soil larger aggregate and microaggregate, the drop of soil aeration and capillary porosity and the uneven-distributed capillaries.However in those systems in Zhejiang Province, it rose with the reclamation.In cultivated land systems, the upland soil physical fertility increased with the cultivation, but the upland crops-rice rotation has a disadvantageous effect.The soil physical fertility in tea garden system was higher than that in citrus orchard.

Abstract:The problem to imitate a camber often needs to be solved in soil survey.So-called imitating camber is to calculate the attribute data of whole grids in research area based on a limited amount of sample attribute data such as elevation data, underground water depth, soil pH.This is a classical mathematical theory problem.This paper gives a new method to imitate camber, which combines fractal theory with digital filtering and is fit to process the complicated case with a separating zone.

Abstract:In the present work, the electrical conductivity of yellow brown earth, brown earth, black soil and latosol suspensions in 10^-4mol/L HCl or 5×10^-5mol/L H₂S0₄ or 10^-4 mol/L H₃P0₄ was measured with an apparatus with adjustable frequency.The results indicated that all the soil suspensions showed a conductivity dispersion phenomenon in all the acids.On all the conductivity-frequency curves a plateau region with a larger range of frequency appeared.

Abstract:Organic acids were added into soil, to study the effects of organic acids on mobilization of cadmium in soil and its uptake by wheat plant (Triticum aestivum L.).It was shown that organic acids could mobilize soil Cd, the sequences of mobilizing ability of organic acids were followed EDTA>wheat root exudate>citric acid>malic acid>water.However, EDTA decreased Cd content in shoot, and wheat root exudate collected under Fe-deficient stress significantly increased Cd content in shoot.Compared to the control, citric acid and malic acid also increased Cd content in shoot.

Abstract:The uptake selectivity, transport and compartmentation of ions in wheat and sugar beet irrigated with brackish water were studied under field conditions.S_K,Na (K/Na selectivity) increased gradually in the stem, sheath, leaf and husk of wheat but decreased gradually in the roots and seed of wheat and in the roots and leaves of sugar beet with increasing NaCl content in irrigation water.S_Cl,Na (Cl/Na selectivity) was reduced in the all parts of wheat and sugar beet with increasing NaCl content of irrigation water.S_K,Na and S_Cl,Na in the aerial parts were higher than those in the root of wheat but lower than or equal to those in the root of sugar beet.These results indicated that ion transport from root to aerial parts of wheat was much different from that of sugar beet.The selective uptake and transport of ions by wheat and sugar beet made Na and Cl distribute mainly in the parts, i.e., the stem and sheath of wheat and the dead leaves of sugar beet, which have little effect on their growth and yields.

Abstract:By using the ³²P isotopic tracer method, experiments have been conducted to investigate phosphorus transport in three different forms of four types of soils in Shaanxi Province.It is found that: (1) Phosphorus can hardly break through the soil column in experiment, as the retardation factor,R, is larger than 1 in most cases, particularly in soils rich in clays and calcium carbonate.After eliminating CaCO₃ from the soil, the value of R will decrease.(2) While rising temperature makes the value of R increase and the value of diffusion-dispersion coefficient, D, decrease; and (3) It is viable to use the CXTFTT program for calculation of phosphorus transport parameters.

Abstract:Adsorption reactions of aluminum on Na-montmorillonite have been studied in the temperature range of 293.15K-338.15K, and at initial pH of Al solution of 2, 3, 4, respectively.The effects of pH and temperature on the adsorption isotherm are discussed on the basis of experimental results.H⁺ adsorption on the clay edges, OH^- adsorption and the degree of hydrolysis of Al³⁺ adsorbed on the clay surface are estimated.The adsorption mechanism of trivalent ions with clay is also discussed.

Abstract:Fourier transform infrared spectroscopy (FTIR) was directly applied to study the decomposition process of corn straw residue (CSR).The result showed that FTIR spectra could indicate the dynamic changes of organic components during the deeomposition process of CSR With the progress of CSR decomposition,hydroxyl, ketonic carbonyl, methyl, methylene, methine and aliphatic compounds decreased, but aromatic compounds increased.This meant that the carbohydrates and aliphatic compounds decomposed quickly and lignin decomposed slowly.The inorganic elements, especially silicon, were reduced from the CSR and accumulated as oxides and some other inorganic elements were reacted with carboxyls to form carboxylates.In the process of decomposition, carboxyl existed as carboxylic ions, most carbohydrates and aliphatic compounds were oxidized to CO₂ and H₂O, the proteins and amino acids were decomposed to CO₂, NH₄⁺,NO₃^- and amides, and the lignin were decomposed to hydroquinones.As far as the differences between the leaf and the stem during the decomposition process of CSR, methoxy increased in the leaf, however, no significant changes were observed in the stem; the organic silicon compounds and lignin decomposed significantly in the leaf, but the change was little in the stem; undecomposed leaf didn't contain carboxylic ions, on the contrary, carboxylic ions existed in undecomposed stem.During the decomposition process of CSR, addition of N fertilizer promoted the decomposition progress of CSR. The chemical analyses showed that the humification index when the leaf and stem were mixed and decomposed was higher than that when the leaf and stem were decomposed separately.

Abstract:Seasonal drought is one of the main constraints to agricultural development of upland in the area of red soil of China.The responses of crops under five farming systems to drought stress are reported in this paper.The differences of water potentials between air and crop leaves were about 100 times higher than those between crop leaves and soil in the surface layer of 10cm.The differences between the latter were around 100 times higher than those between soils in the layers of lOcm and 70cm as well.The differences of water potentials were lower in the treatments of minimum tillage and narrow ridge tillage than those in the treatments of conventional tillage and wide ridge tillage respectively, indicating the serious water stress in former treatments.The results of diurnal variation of water potentials in soil-plant-atmosphere continuum (SPAQ indicated that peanut is more tolerant to drought than soybean and corn.Leaf water potential decreased with the increase of soil water potential and its relationship could be expressed by binomial equations.In the treatments of ridge tillage, leaf water potential was more related to the water potential of soil in deeper layers than to that of soil surface in the treatment of minimum tillage.Water potentials of soils or leaves increased with the increase of soil and air temperatures respectively.The effect of temperature on water potentials of soils and leaves were affected by farming practices and crop communities.Results showed that seasonal drought in the region is caused by integration of water stress and high temperature.

Abstract:Horizontal spatial variations of nitrification-denitrification in soil and its ecological factors in the soil of rice rhizosphere were determined by the eco-modeling technique and cutting method.Results indicated that the potential nitrification and denitrification intensities in soils decreased with increase in distance from the rice root interface.The potential nitrification intensity in soil dropped down sharply with increase in distance, but the potential denitri6cation intensity changed moderately, because the nitrifying bacteria are strict aerobic-autotrophic microorganisms and the denitrifying bacteria are facultative anaerobes.The amount of available carbon in soil and the ratio of that to the amount of available nitrogen reduced with increase in distance from the root interface, but the amount of available nitrogen increased.The amount of nitrosofying bacteria was larger in the zones of 10-20mm and 20-30mm from the root interface than that of 0-10mm due to the competitive absorption of nitrogen.

Abstract:The effect of persistence, degradation dynamics of DBP (Dibutyl phthalate) and DEHP (di(2-ethylhexyl) phthalate) on core growth were studied in this work.Results showed that DBP and DEHP remainede in soil increased with experimental temperature raised, especially for DEHP.The remained amount of pathalate plasticizers decreased with the increase of soil water contend The degradation of these two chemicals in the soil can be described by the the first order kinetic equation of C=C₀e^-kt.The degradation of DEHP was strongly affected by environmental factors.Although DBP degraded faster than DEHP, the dependence of its degradation in soil on environmental fators was much smaller than that of DEHP.Results also indicated that the activities of soil micro organisms played a very mportant role in PAEs degradation in soil.Increase in activities of soil micro-organisms would accelerate the PAFs degradation rates and reduce the pollution of PAFs to soils.Results of field experiment with these two chemicals showed that a high dose of them restricted the growth of vegetable to some extent, especially for DBP.Meanwhile, it was also concluded that DBP and DEHP decreased the vegetable yield silghtly and reduced the Vc contents of eatable parts of vegetables.

Abstract:现在对植物利用土壤磷的研究不仅限于传统的“有效磷,观点.根际土壤磷被根系活化、耗竭的作用相当明显^[1,2],并且植物不同基因型的这种作用也存在着差异.蒋柏藩、顾益初报道了石灰性土壤无机磷分级体系^[3]和分级方法^[4],并将Ca-P细分为Ca₂-P,Ca₈-P和Ca₁₀-P,这一分级方法也适合于中性土壤.本文应用根盒培养技术,在黑土和黑钙土上研究玉米根际对各形态无机磷的活化以及肥料磷的利用.

Abstract:蒸渗仪(Lysimeter)是一种装满土壤、置于田间地下的反映自然环境、表面裸露或生长有植物的容器,以及用一定方式测定向上或向下离开土体的水和其它物质运移及转化值的装置.它起始于17世纪^[1],在最近的几十年间,随着机械电子学、土壤物理学、计算机等学科的发展和相互交叉渗透,使得对蒸渗仪的研究和应用不断深人,蒸渗仪的结构、精度和功能等方面得到了较大的改进和提高.

Abstract:闽东南沿海丘陵地上的赤红壤早地存在着一个普遍的问题,即是农业生态环境较恶劣,土壤有机质的含量相当低,土壤肥力性状很差,这也是生产上急需解决的间题.为了保持和提高土壤库中物质和能量的贮量水平,提高土壤肥力^[1-3],首先必须提高土壤有机质含量,这是土壤肥力的稳定指标.因此本试验试图寻找适合在沿海赤红壤上提高土壤有机质含量的几种途径,以便推广应用,从而提高作物产量增加经济效益.