Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphati...Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%～33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.展开更多
A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP...A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK＞MNP＞MN＞NPK＞NP＞M＞N＞the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N＞P＞K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.展开更多
Compost of dtherent rates was applied to artificial field plots of a low humic andosol at National Agriculture Research Center (NARC) of Japan for 15 or 28 years, and their effects on the chemical properties of wheat ...Compost of dtherent rates was applied to artificial field plots of a low humic andosol at National Agriculture Research Center (NARC) of Japan for 15 or 28 years, and their effects on the chemical properties of wheat rhisosphere soil and nonrhizosphere soil were measured.Continuous application of compost for 28 years resulted in raise of soil C, N, P, pH and exchangeable bases. The building up of organic matter in the soil occurred slowly A residual effect of the compost on soil chemical properties was still present after 13 years of no application, but this effect was weaker in comparison with that of the continuous application treatments. In the rhizosphere soil, NaHCO3-extracted P and exchangeable Ca were higher than those in the bulk soil. The removal of free organic acid slightly affected the soil pH, especially, the rhizosphere soil pH. The raise of soil pH may result from the increase of exchangeable base by the application of compost.展开更多
Field lysimeter method was employed to investigate the downward movement and leaching of N applied to summer corn (Zea may L.) on dryland soil in Beiling. A N-fertilizer (120 kg N hm-2) and a control treatment were ar...Field lysimeter method was employed to investigate the downward movement and leaching of N applied to summer corn (Zea may L.) on dryland soil in Beiling. A N-fertilizer (120 kg N hm-2) and a control treatment were arranged for the study. Soil solution was collected at depths of 20, 40, 60, 120 and 170 cm,while leachate was collected at the bottom (200 cm) of the lysimeter. The results showed that the downward movement of NO3-N in soil profile was greatly affected by rainfall pattern. The peak of leached NO3-N from both treatments coincided with the peak of the rainfall. In addition, leached NO3-N from both treatments and rainfall were significantly correlated (P<0.05). The amount of leached NO3-N was not great in the N-fertilizer treatment. The results also suggested that N fertilization could cause NO3-N contamination of groundwater during the rainy season.展开更多
Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined ef...Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined effects of VAM, Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity.Vegetative dry matter accumulation was increased by P application and reduced by VAM treatments. Both P and VAM increased grain yield. Zinc concentration and uptake were generally reduced by P addition and VAM infection. There were no antagonistic effects of Zn on P acquisition in the plant. The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.展开更多
Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequentextracting. Localization and distribution of calcium and influence of calcium nutritionon cell ultrastructure were observed by tran...Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequentextracting. Localization and distribution of calcium and influence of calcium nutritionon cell ultrastructure were observed by transmission electron microscopy combined within situ precipitation of calcium with an improved method of potassium pyroantimonatetechnique. Results indicated that spraying calcium solution on surface of young fruitsincreased contents of calcium in all forms. During storage, contents of soluble calciumand pectic calcium declined and those in calcium phosphate, calcium oxalate and calciumsilicate increased. Calcium contents of Red Fuji in all forms were higher than those ofStarkrimson, indicating that calcium accumulating capability of Red Fuji fruits precededthat of Starkrimson. Under transmission electron microscopy, calcium antimonite precipitates(CaAP) was mainly distributed in cell wall, tonoplast, nuclear membrane and nucleoplasm,much more CaAP deposited in vacuole. Calcium deficiency during storage leads to decreaseof CaAP in locations mentioned above, disappearance of compartmentation, and entrance ofCaAP to cytoplasm. Transformation from soluble calcium and pectic calcium to calciumphosphate, oxalate and damages of biomembranes structuraly and functionally resultedfrom calcium deficiency during storage were the crucial causation of physiologicaldisorder.展开更多
Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as ...Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as the effect of Se on cell ultra structure of soybean leaf and nascent root under salt stress. Results showed that appropriate amount of Se addition increased GSH-Px activity in soybean leaves from 0. 810 to 1. 421μmol·g-1 fresh weight·min-1 F = 9.12, and reduced the concentration of MDA from 20.17 to 16.16 μmol·g-1 fresh weight, F = 5.44. Under salt stress,no obvious damage on chloplast membrane was observed in Se treated seedlings,and the structures of chloplast and mitochondrion were integrate,whereas in control (no Se addition),the cell membrane was destroyed seriously,chloplast degraded and mitochondrion disappeared. Compared with control,Se addition increased the dry matter weight of seedling by 2.92% to 21.86%, F =5.97.展开更多
Soil erosion is one of the most important problems in the Loess Plateau of China affectingsustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed tomeasure soil erosion rates under ...Soil erosion is one of the most important problems in the Loess Plateau of China affectingsustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed tomeasure soil erosion rates under conventional tillage practices using field-simulated rainfall.Field rainfall experiments were carried out to compare previous results from laboratoryrainfall simulations on the same soil for interrill conditions. Although in the laboratoryexperiments, a strong correlation was found between the stream power of the runoff water andthe unit sediment load, this sediment transport equation overestimated the field rainfallsimulation results. Another sediment transport equation derived by Nearing et al. for rillerosion was in better agreement with the results of the field experiments, although it alsooverestimated these values. The measured sediment load values during the field rainfallsimulations were also lower than those found during field experiments on the same soil but witha loosened surface layer. This difference indicates the importance of soil physical conditionof surfce like soil structure and aggregate size, which may contribute to the discrepancybetween the field and laboratory experiment results.展开更多
A field trial was carried out to investigate phosphorous (P) absorption, grain quality and yield between high oil corn and common corn. The results indicated that high oil corn var.Tongyou 1 obtained lower highest P a...A field trial was carried out to investigate phosphorous (P) absorption, grain quality and yield between high oil corn and common corn. The results indicated that high oil corn var.Tongyou 1 obtained lower highest P absorption rate (HAR) and later occurring date of HAR, in comparison with common corn var. Simi 25. The highest HAR and the earliest occurring date of HAR was obtained by the treatments of P45 and P75 in Tongyou 1 and Simi 25 separately; while the total amount of P accumulated by maize plant was achieved by P105 treatment in both varieties. P in grain relied mainly on root uptake at maturation that accounted for 85.7-96.8% and 79.3-84.3% for Tongyou 1 and Simi 25, respectively. Tongyou 1 contained more oil and protein contents, but less starch content with lower grain yield. P application at appropriate rate enhanced contents of protein and fatty acid, but the increment of starch content was neglectable. Acknowledgements This study was financed by the National Key Tech- nologies R & D Program (2004BA520A13), P.R.China.展开更多
A pot experiment was conducted in the growth chamber on Saskatchewan soils with dfferent texture todeterniine the K release status and wheat K demand. The relationship between K uptake and soil availableK extracted by...A pot experiment was conducted in the growth chamber on Saskatchewan soils with dfferent texture todeterniine the K release status and wheat K demand. The relationship between K uptake and soil availableK extracted by cation exchange membrane (CEM-K) and the effect of K fertilizer on wheat growth and soilavailable K was also evaluated. Theatments of 0, 60 and 120 mg K/kg were applied to sandy, low and highK loamy and clay soils. The highest yields were achieved with the application of 120 mg K/kg in sandysoil and 60 mg K/kg in other soils. On the whole, the clay soil contributed K more than other soils fromslowly available fraction. Regression revealed a linear relationship between the soil available K extractedby NH_4OAc(Ka) and CEM-K in suspensions (r=0.93). Results also showed that CEM-K in burial and insuspensions were different not only in the amount but also in correlation with Ka or K uptake.展开更多
An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four...An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10 to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil Water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on elemental sulfur-oxidizing potentiality of soils.展开更多
The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang, Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods including reduced tillage...The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang, Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods including reduced tillage(RT), no-till(NT), 2 crops/year(2C), subsoiling(SS), and conventional tillage(CT)were compared to determine the effects of tillage methods on soil water conservation, water availability, and wheat yields in a search for better farming systems in the areas. The NT and SS showed good effects on water conservation. The soil water storage increased 12 - 33 mm with NT and 9-24 mm with SS at the end of summer fallow periods. The soil evaporation with NT and SS decreased 7-8 mm and 34 - 36 mm during the fallow periods of 1999 and 2001, respectively. Evapotranspiration(ET)with NT and SS increased about 47 mm during wheat growth periods of 2000 to 2001. Treatment RT and 2C had low water storage and high water losses during the fallow periods. The winter wheat yields with conservation tillage practices were improved in the 2nd year, increased by 3, 5 and 8% with RT, NT and SS, respectively, compared with CT. The highest wheat yields were obtained with subsoiling, and the maximum economic benefits from no-till. All conservation tillage practices provided great benefits to saving energy and labors, reducing operation inputs, and increasing economic returns. No-till and subsoiling have shown promise in increasing water storage, reducing water loss, enhancing water availability, and saving energy, as well as increasing wheat yield.展开更多
文摘Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%～33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.
文摘A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK＞MNP＞MN＞NPK＞NP＞M＞N＞the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N＞P＞K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.
文摘Compost of dtherent rates was applied to artificial field plots of a low humic andosol at National Agriculture Research Center (NARC) of Japan for 15 or 28 years, and their effects on the chemical properties of wheat rhisosphere soil and nonrhizosphere soil were measured.Continuous application of compost for 28 years resulted in raise of soil C, N, P, pH and exchangeable bases. The building up of organic matter in the soil occurred slowly A residual effect of the compost on soil chemical properties was still present after 13 years of no application, but this effect was weaker in comparison with that of the continuous application treatments. In the rhizosphere soil, NaHCO3-extracted P and exchangeable Ca were higher than those in the bulk soil. The removal of free organic acid slightly affected the soil pH, especially, the rhizosphere soil pH. The raise of soil pH may result from the increase of exchangeable base by the application of compost.
文摘Field lysimeter method was employed to investigate the downward movement and leaching of N applied to summer corn (Zea may L.) on dryland soil in Beiling. A N-fertilizer (120 kg N hm-2) and a control treatment were arranged for the study. Soil solution was collected at depths of 20, 40, 60, 120 and 170 cm,while leachate was collected at the bottom (200 cm) of the lysimeter. The results showed that the downward movement of NO3-N in soil profile was greatly affected by rainfall pattern. The peak of leached NO3-N from both treatments coincided with the peak of the rainfall. In addition, leached NO3-N from both treatments and rainfall were significantly correlated (P<0.05). The amount of leached NO3-N was not great in the N-fertilizer treatment. The results also suggested that N fertilization could cause NO3-N contamination of groundwater during the rainy season.
文摘Vesicular-arbuscular mycorrhizal (VAM) fungi have been credited with improving the groWth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. The combined effects of VAM, Zn and P application on the growth and translocation of nutrients in wheat were investigated using a calcareous soil marginal in P and Zn concentrations. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity.Vegetative dry matter accumulation was increased by P application and reduced by VAM treatments. Both P and VAM increased grain yield. Zinc concentration and uptake were generally reduced by P addition and VAM infection. There were no antagonistic effects of Zn on P acquisition in the plant. The role of VAM in enhancing the translocation of Zn and P from root to grain would be beneficial to seed setting and yield.
文摘Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequentextracting. Localization and distribution of calcium and influence of calcium nutritionon cell ultrastructure were observed by transmission electron microscopy combined within situ precipitation of calcium with an improved method of potassium pyroantimonatetechnique. Results indicated that spraying calcium solution on surface of young fruitsincreased contents of calcium in all forms. During storage, contents of soluble calciumand pectic calcium declined and those in calcium phosphate, calcium oxalate and calciumsilicate increased. Calcium contents of Red Fuji in all forms were higher than those ofStarkrimson, indicating that calcium accumulating capability of Red Fuji fruits precededthat of Starkrimson. Under transmission electron microscopy, calcium antimonite precipitates(CaAP) was mainly distributed in cell wall, tonoplast, nuclear membrane and nucleoplasm,much more CaAP deposited in vacuole. Calcium deficiency during storage leads to decreaseof CaAP in locations mentioned above, disappearance of compartmentation, and entrance ofCaAP to cytoplasm. Transformation from soluble calcium and pectic calcium to calciumphosphate, oxalate and damages of biomembranes structuraly and functionally resultedfrom calcium deficiency during storage were the crucial causation of physiologicaldisorder.
文摘Experiments were conducted to study the effects of selenium (Se) on glutathione peroxidase(GSH-Px) activity and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in soybean seedling, as well as the effect of Se on cell ultra structure of soybean leaf and nascent root under salt stress. Results showed that appropriate amount of Se addition increased GSH-Px activity in soybean leaves from 0. 810 to 1. 421μmol·g-1 fresh weight·min-1 F = 9.12, and reduced the concentration of MDA from 20.17 to 16.16 μmol·g-1 fresh weight, F = 5.44. Under salt stress,no obvious damage on chloplast membrane was observed in Se treated seedlings,and the structures of chloplast and mitochondrion were integrate,whereas in control (no Se addition),the cell membrane was destroyed seriously,chloplast degraded and mitochondrion disappeared. Compared with control,Se addition increased the dry matter weight of seedling by 2.92% to 21.86%, F =5.97.
文摘Soil erosion is one of the most important problems in the Loess Plateau of China affectingsustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed tomeasure soil erosion rates under conventional tillage practices using field-simulated rainfall.Field rainfall experiments were carried out to compare previous results from laboratoryrainfall simulations on the same soil for interrill conditions. Although in the laboratoryexperiments, a strong correlation was found between the stream power of the runoff water andthe unit sediment load, this sediment transport equation overestimated the field rainfallsimulation results. Another sediment transport equation derived by Nearing et al. for rillerosion was in better agreement with the results of the field experiments, although it alsooverestimated these values. The measured sediment load values during the field rainfallsimulations were also lower than those found during field experiments on the same soil but witha loosened surface layer. This difference indicates the importance of soil physical conditionof surfce like soil structure and aggregate size, which may contribute to the discrepancybetween the field and laboratory experiment results.
文摘A field trial was carried out to investigate phosphorous (P) absorption, grain quality and yield between high oil corn and common corn. The results indicated that high oil corn var.Tongyou 1 obtained lower highest P absorption rate (HAR) and later occurring date of HAR, in comparison with common corn var. Simi 25. The highest HAR and the earliest occurring date of HAR was obtained by the treatments of P45 and P75 in Tongyou 1 and Simi 25 separately; while the total amount of P accumulated by maize plant was achieved by P105 treatment in both varieties. P in grain relied mainly on root uptake at maturation that accounted for 85.7-96.8% and 79.3-84.3% for Tongyou 1 and Simi 25, respectively. Tongyou 1 contained more oil and protein contents, but less starch content with lower grain yield. P application at appropriate rate enhanced contents of protein and fatty acid, but the increment of starch content was neglectable. Acknowledgements This study was financed by the National Key Tech- nologies R & D Program (2004BA520A13), P.R.China.
文摘A pot experiment was conducted in the growth chamber on Saskatchewan soils with dfferent texture todeterniine the K release status and wheat K demand. The relationship between K uptake and soil availableK extracted by cation exchange membrane (CEM-K) and the effect of K fertilizer on wheat growth and soilavailable K was also evaluated. Theatments of 0, 60 and 120 mg K/kg were applied to sandy, low and highK loamy and clay soils. The highest yields were achieved with the application of 120 mg K/kg in sandysoil and 60 mg K/kg in other soils. On the whole, the clay soil contributed K more than other soils fromslowly available fraction. Regression revealed a linear relationship between the soil available K extractedby NH_4OAc(Ka) and CEM-K in suspensions (r=0.93). Results also showed that CEM-K in burial and insuspensions were different not only in the amount but also in correlation with Ka or K uptake.
文摘An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10 to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil Water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on elemental sulfur-oxidizing potentiality of soils.
文摘The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang, Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods including reduced tillage(RT), no-till(NT), 2 crops/year(2C), subsoiling(SS), and conventional tillage(CT)were compared to determine the effects of tillage methods on soil water conservation, water availability, and wheat yields in a search for better farming systems in the areas. The NT and SS showed good effects on water conservation. The soil water storage increased 12 - 33 mm with NT and 9-24 mm with SS at the end of summer fallow periods. The soil evaporation with NT and SS decreased 7-8 mm and 34 - 36 mm during the fallow periods of 1999 and 2001, respectively. Evapotranspiration(ET)with NT and SS increased about 47 mm during wheat growth periods of 2000 to 2001. Treatment RT and 2C had low water storage and high water losses during the fallow periods. The winter wheat yields with conservation tillage practices were improved in the 2nd year, increased by 3, 5 and 8% with RT, NT and SS, respectively, compared with CT. The highest wheat yields were obtained with subsoiling, and the maximum economic benefits from no-till. All conservation tillage practices provided great benefits to saving energy and labors, reducing operation inputs, and increasing economic returns. No-till and subsoiling have shown promise in increasing water storage, reducing water loss, enhancing water availability, and saving energy, as well as increasing wheat yield.
