Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to e...Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.展开更多
Made teas and typical tea-grown soils in Sichuan and Chongqing were collected to investigate soil nutrients, related soil properties and tea quality. The tea-grown soils in Sichuan and Chongqing are distributed mainly...Made teas and typical tea-grown soils in Sichuan and Chongqing were collected to investigate soil nutrients, related soil properties and tea quality. The tea-grown soils in Sichuan and Chongqing are distributed mainly in mountainous areas. The high annual precipitation (over 1100 mm), precipitous soil slopes, low cohesion among soil particles and high soil porosity suggested that intensive erosion and leaching might occur in these soils. Moreover, they were very acidic and poor in mineral nutrients such as N, P, K, Ca and Mg except S. The average content of total S was 20.40 g kg-1, much higher than that of organic matter in these soils, revealing that S in the tea-grown soils existed mainly in inorganic forms and very little in organic forms. Water-extractable S accounted for only a small amount of total S, which showed that most parts of sulfur in these soils were insoluble in W8ter. K and S varied greatly in made teas. The concentrations of N and P, however, varied little in these teas even though they differentiated significantly in the tea-grown soils. The high concentration of nitrogen in made teas could result in the high free amino acids and low polyphenol of teas. Significantly positive correlation was established between potassium and polyphenol in made teas. Teas with high ratio of phenol to free amino acids were usually good in taste and appearance.展开更多
Investigations were conducted to quantify litterfall, and litter and nutrient accumulation in forest floor, and to acquire information on litter decomposition and nitrogen and phosphorus release patterns in three diff...Investigations were conducted to quantify litterfall, and litter and nutrient accumulation in forest floor, and to acquire information on litter decomposition and nitrogen and phosphorus release patterns in three different subalpine coniferous forests, a plantation （P1）, a secondary forest （SF）, and a primitive forest （PF）, in western Sichuan, China. The litter trap method was used to evaluate litterfall with the litterbag method being utilized for litter decomposition. Seasonal patterns of litterfall were similar in the three forests, with two peaks occurring in September-November and March-May. The plantation revealed an annual litterfall of 4.38 x 103 kg ha-1, which was similar to those of SF and PF, but P1 had a lower mass loss rate and a higher C/N ratio. The C/N ratio may be a sound predictor for the decomposition differences. N concentrations of leaf litter in both the secondary forest and primitive forest increased first and then decreased, and the percentages of their final/initial values were 108.9% and 99.9%, respectively. P concentration in the three forests increased by the end of the study. The results of litterfall and decomposition indicated that in the plantation the potential to provide nutrients for soil organic matter was similar to those of SF and PF; however, its slower decomposition rate could result in a somewhat transient accumulation of litter in the forest floor.展开更多
Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability...Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability beach-bar sandstone reservoir of Es4 in Dongying sag. The results indicated the reservoir has the characteristics of middle-low pores,low-permeability,low compositional and structural maturity,and thin throat. The low-permeability is mainly due to sedimentation (fine particles and argillaceous inter beds) and diagenesis (compaction,cementation,and dissolution). The cementation reduced the physical property of the reservoir mainly by carbonate cementation,quartz autogeny and enragement,and autogeny clay. Clay minerals usually jam the pores by filling holes,close-fitting the wall of hole,bridging,wrapping grains,and separate attaching the pores and so on. The dissolution is insufficient so as not to improve the porosity and permeability of the reservoir obviously. So it is also an important factor of forming low-permeability reservoir.展开更多
基金Supported by Special Fund of Modern Agricultural Industry Technology System(No.CARS-22)Special Fund of Major Industry Technology of Sichuan Economic and Trade Commission(No.2008NC00365)+1 种基金Excellent Paper Fund of Sichuan Academy of Agricultural Sciences(No.2011JYGC-LWJJ-07)Special Fund of Sichuan Financial Genetic Engineering(No.2011JYGC-QNJJ-021)~~
文摘Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.
基金Project supported by the Dept. of Agricultural Science, Potassium Commercial Association, Azote, France and the Municipal Scienc
文摘Made teas and typical tea-grown soils in Sichuan and Chongqing were collected to investigate soil nutrients, related soil properties and tea quality. The tea-grown soils in Sichuan and Chongqing are distributed mainly in mountainous areas. The high annual precipitation (over 1100 mm), precipitous soil slopes, low cohesion among soil particles and high soil porosity suggested that intensive erosion and leaching might occur in these soils. Moreover, they were very acidic and poor in mineral nutrients such as N, P, K, Ca and Mg except S. The average content of total S was 20.40 g kg-1, much higher than that of organic matter in these soils, revealing that S in the tea-grown soils existed mainly in inorganic forms and very little in organic forms. Water-extractable S accounted for only a small amount of total S, which showed that most parts of sulfur in these soils were insoluble in W8ter. K and S varied greatly in made teas. The concentrations of N and P, however, varied little in these teas even though they differentiated significantly in the tea-grown soils. The high concentration of nitrogen in made teas could result in the high free amino acids and low polyphenol of teas. Significantly positive correlation was established between potassium and polyphenol in made teas. Teas with high ratio of phenol to free amino acids were usually good in taste and appearance.
基金Project supported by the National Natural Science Foundation of China (No. 30530630)the Major State Basic Research and Development Program of China (No. G2000046802-05)the National Key Technologies Research and Development Program of China during the Tenth Five-Year Period (No. 2001BA606A-05)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KSCX1-02)
文摘Investigations were conducted to quantify litterfall, and litter and nutrient accumulation in forest floor, and to acquire information on litter decomposition and nitrogen and phosphorus release patterns in three different subalpine coniferous forests, a plantation （P1）, a secondary forest （SF）, and a primitive forest （PF）, in western Sichuan, China. The litter trap method was used to evaluate litterfall with the litterbag method being utilized for litter decomposition. Seasonal patterns of litterfall were similar in the three forests, with two peaks occurring in September-November and March-May. The plantation revealed an annual litterfall of 4.38 x 103 kg ha-1, which was similar to those of SF and PF, but P1 had a lower mass loss rate and a higher C/N ratio. The C/N ratio may be a sound predictor for the decomposition differences. N concentrations of leaf litter in both the secondary forest and primitive forest increased first and then decreased, and the percentages of their final/initial values were 108.9% and 99.9%, respectively. P concentration in the three forests increased by the end of the study. The results of litterfall and decomposition indicated that in the plantation the potential to provide nutrients for soil organic matter was similar to those of SF and PF; however, its slower decomposition rate could result in a somewhat transient accumulation of litter in the forest floor.
基金Project P06012 supported by the Key Research Project of SINOPEC
文摘Core and cast sections observation and description,and logging,scanning electron microscope and core lab analysis data etc. were applied to the present research of the characteristics and mechanism of low permeability beach-bar sandstone reservoir of Es4 in Dongying sag. The results indicated the reservoir has the characteristics of middle-low pores,low-permeability,low compositional and structural maturity,and thin throat. The low-permeability is mainly due to sedimentation (fine particles and argillaceous inter beds) and diagenesis (compaction,cementation,and dissolution). The cementation reduced the physical property of the reservoir mainly by carbonate cementation,quartz autogeny and enragement,and autogeny clay. Clay minerals usually jam the pores by filling holes,close-fitting the wall of hole,bridging,wrapping grains,and separate attaching the pores and so on. The dissolution is insufficient so as not to improve the porosity and permeability of the reservoir obviously. So it is also an important factor of forming low-permeability reservoir.
