Vauclin Michel , Han Yong , Xing Guangxi
1989, 26(4):216-323.
Abstract:This paper deals with the study on the types,properties and isomorphic substitution of Fe (Ⅲ) by Al(Ⅲ) of iron oxides in torrid red earths under different arid and hot conditions in youth China by using the Mossbauer spectroscopy.The Mossbauer spectra for the colloidal portion(<2μm) extracted from the surface layer of the four red earths studied indicated that the superharamagnetic state appeared at room remperature and the magnetic splitting six-line spectra was observed significantly at 80K.The resuits fitted with a computer show that hematite and goethite are predominant in iron oxides and commonly occur in small particles,reflecting the feature of tropical and subtropical soils.Also,the proportion of hematite and goethite in soil colloids varies considerably in different dry climates; the drier the soil,the higher the propor ion of hematite.
Chen Zhixiong , Vauclin Michel
1989, 26(4):309-315.
Abstract:Results of soil water content by sampling at 77 nodes of 10×l0m grid (Fig.1) in a flat experiment field of 66×100m2 indicated that the distribution of soil moisture of upper layct (0-45 cm) was normal distribution.The moisture of subsoil (45-90cm) was abnormal distribution which could be due to a clayey layer.with high water capacity hurried there in different thickness The error estimates of the average moisture content of upper layer was 0.024(g/g) when 4 samples were taken.By the analysis of semivariance,it was shown that the spatial stribution of soil moisture was structural (Fig.3).Its correlation range (lag) was about 30m.This spatial structure was stable,which was also proved by the analysis of rank correlation.Therefore,when monitering the soil moisture flutuation,the experimental error would be disreased by choosing the sampling locations at which their moisture content are as close as possible to the average of total values and their distances are corresponding to the correlation range.
Fu Shaoqing , Wang Yongzhen , Zhang Ruying , Zhao Deming
1989, 26(4):324-330.
Abstract:This paper deals with a comparative and collaborative study on determining soil total potassium with three fusion or digestion methods conducted by four labortories.The result showed that the average percentage of soil total K value by NaOH fusion method was 98.5% of the value by Na2CO3 fusion method,and 99.5% of the value by HF digestion method.The precision and accuracy of the three methods were also very close.Therefore,the authors sugBest that the NaOH fusion method can be used in routine work instead of HF digestion meshod for determining soil total potassium.
Ding changpu , Maria De Nobili , B. Ceccanti
1989, 26(4):331-336.
Abstract:Both the peak number and peak current value of water-soluble organic substances for decomposition products of green manures varied with the incubation time and also withthe kind of greea manures.The peak number and current value were the mole and largest after 5-day incubaxion.Astragalus had more peaks and,larger current value than.ribe straw.The latter poloesed one peak after 120-day incubation,but for the former the peak and peak current tended to disappear.
Zhu Zhaoliang , J. R. Simpson , Zhang Shaolin , Cai Guixin , Chen Deli , J. R. Freney , A. V. Jackson
1989, 26(4):337-343.
Abstract:N losses were investigated in the field of calcareous paddy soil by 15N-tracer and micrometeorological mass balance techiques.Results revealed that:1.Total N loss from ammonium bicarbonate and urea broadcast into floodwatcr and incorporated just before transplanting was 72% and 63%,of which 39% and 30% was of ammonia loss which accounted for 54% and 48% of total N loss,respectively.2.The higher N loss from calcareous soil,as compared with acidic one,is primarily due to the higher ammonia loss,because the difference in denitrification loss between the two soils investigated in this series of research was insignif icant.
1989, 26(4):344-352.
Abstract:Status of soil phosphorus and rational application of phosphorus fertilizer were studied by field trials.Results abtained showed that (1) variation of soil total P and available P contents were both increasing from the north to south and the contents of different soils were in the following order:irrigation warped soil>manured loessial soil,cinnamon soil,dark loessial soil>yellow cultivated loessial soil,sieroezm,chestnut soil>seolion sandy soil.
Liu Zhcng , Zhu Qiqing , Tang Lihua
1989, 26(4):353-361.
Abstract:Studies were made on the regularities of content and distribution of boron in soils of China.The total boron content varies from.trace-500ppm,with an average.of 64ppm.There are two markedly different regions which are differentiated by boron content in soils,i.e.soils rich in boron and those poor in this element.The former includes soils of Tibet and other arid inland as well as saline soils; while the later includes the acid soils of South China,e.g.red earth,lateritic red earth,yellow earth,purplish soil,etc,Various loessial soils have a medium amount of total boron and low water-soluble boron.Boron content of paddy soils varies greatly soil acidity exerts a prDfound influence on availability of this elements.
Li Songqin , Wu Bingjun , Wu Guangyun , Luo Chenggang , Hu Wei
1989, 26(4):362-370.
Abstract:Trace element content of 1049 soil samples collected from Simao districtity Yunnan were determined.Results obtained showed that the total contents B and Cu in the soils of Simao are approximately the same as the mean contents in soils of the country,those of Mo,Zn,Mn are lower than the mean values of the country;available B,Mo,Zn are generally deficient,the samples of which the contents of B,Mo and.Zn are below critical values constitute 9l%,77%,and 52% respectively; availaible Cu and Mn are more abundant.Trace element conttnts in soils of Simao vary in a greater range,and they are distributed unevenly,being affected by genetic conditions such as parent materials,.climate relief etc.and genetic procPSS.177 field experiments in 58 sites showed significant of trace element fertilizers on crop yield increase with a the increase rate of 14.1%.
Wu Jinjiang , Xin Shihe , Lin Jingliang
1989, 26(4):371-378.
Abstract:The content of humin and ratio of H/F in surface horizon of soils increases with the following order:original soil (red earth) < percogenic paddy soil < periodically waterlogged paddy soil < gleyed paddy soil.Fed-o/Feo ratio good genetic index for dividing paddy soils developed under different water regimes.This ratio in diagnostic horizon (W) of periodically water logged paddy soil profile is much higher than that in other horizons.The magnetic susceptibility X value of paddy soil is much lower that that of their corresponding orginal soil derived from the same parent materical.
Gong Zitong , Chen Hongzhao , Liu Liangwu
1989, 26(4):379-387.
Abstract:Paleosols of China are divided into buried and relict soils.The buried soils in high-cold region of Tibet Plateau,which are characterized by compact structure,gaily colour,intensive weathering and iron-stained matrix as micromorphological feature,are mostly reserved in tills.In the arid and semi-arid regions of northwest China several layers of buried soils are found within aeolian loess sediments from early to late Pleistocene series due to deep deposition of the loess.In addition,relict soils also occur in the region.Buried soils are dominant in north part of east monsoon region,while in the south part (Qionglei region) can be found paleosols on red weathering crust.The greater changes among the paleosols in the three regions during Quaternary can be compared.
Wang Fusheng , Li Fudi , Chen Huakui
1989, 26(4):388-392.
Abstract:To study the effect of Bradyrhizobium japonicum strain PRC005 inoculation rate on growth of soybean (Glycine max L.Merr.),field experiment was conducted in the University farm soil containing a large quantity of indigenous soybean-nodulating rhizobia,and pot experiment was carried out with the same soil.Number and dry weight of nodules,dry weight and total nitrogen content of plant tops,and seed yield were determined.Neither number and dry weight of nodules nor dry weight and total nitrogen content of plaflt tops were significantly incrsased by different inoculation ratty of soybean grown in the field for both 40 days aad 60 days after planting.
Wang Honggang , Wu Guanyi , Li Huiquan
1989, 26(4):393-400.
Abstract:Mungbean as experimental plant was investigaed by means of sand culture containing three levels of water to determine the influence of VA mycorrhiza on the host plant growth and its water use.The experimental results showed that inoculatlag with VA mycorrhiza was beneficial not only to uptake of phoephorw by plant,but sisa to promoting plant growth.amount of water used by mungbean inoculated with mycorrhiza to produce one gram of dry matter was as low as half of that by controlled plant.It was implied that the efficiency of water used by the host plant inoculated with mycorrhiza was increased by 100%.In this paper,the growth and development of mycorrhizal and non-mycorrhizal plants in three different water levels of sand culture were described.The water consumed by plant growth in the whole growing period was measured and the experimental results were analysed and discussed.
1989, 26(4):401-404.
Abstract:土壤的承载能力是土壤-机器系统的主要参数之一.对于不同类型的土壤,反映其承载能力的荷载与沉陷关系的曲线图形是不相同的.荷载与沉陷曲线图形的多样性,排除了赋予任何普遍有用的数学定义的可能性.
Zhu Youngsuei , Wang Yunxiang , Wan Jianwei
1989, 26(4):405-407.
Abstract:团聚体结构是土壤肥力的基础,它能调节作物生长所需的水分与空气,因此保持良好的土壤结构可促进植物根系的生长,增加对养分的吸收,提高作物产量.60年代初,作者曾用水解聚丙烯腈钠改善土壤结构,效果显著.