To further develop the methods to remotely sense the biochemical content of plant canopies,we report the results of an experiment to estimate the concentrations of three biochemical variables of corn,i.e.,nitrogen(N),...To further develop the methods to remotely sense the biochemical content of plant canopies,we report the results of an experiment to estimate the concentrations of three biochemical variables of corn,i.e.,nitrogen(N),crude fat(EE) and crude fiber(CF) concentrations,by spectral reflectance and the first derivative reflectance at fresh leaf scale. The correlations between spectral reflectance and the first derivative transformation and three biochemical variables were analyzed,and a set of estimation models were established using curve-fitting analyses. Coefficient of determination(R2),root mean square error(RMSE) and relative error of prediction(REP) of estimation models were calculated for the model quality evaluations,and the possible opti-mum estimation models of three biochemical variables were proposed,with R2 being 0.891,0.698 and 0.480 for the estimation models of N,EE and CF concentrations,respectively. The results also indicate that using the first derivative reflectance was better than using raw spectral reflectance for all three biochemical variables estimation,and that the first derivative reflectances at 759 nm,1954 nm and 2370 nm were most suitable to develop the estimation models of N,EE and CF concentrations,respectively. In addition,the high correlation coefficients of the theoretical and the measured biochemical parameters were obtained,especially for nitrogen(r=0.948).展开更多
Nitrogen fertilization is one of the greatest challenges associated with the production of biofuel from corn grain. The objective of this research was to determine the effect of N fertilization on the content and yiel...Nitrogen fertilization is one of the greatest challenges associated with the production of biofuel from corn grain. The objective of this research was to determine the effect of N fertilization on the content and yield of oil, protein, and starch in corn grain. The project was done in Southeast Missouri (USA), from 2007 to 2009 in a silt loam soil. Corn grain contains 3.8-4.2% oil, 6.7%-8.9% protein, 68.0%-70.4% extractable starch, and 76.0%-77.7% total starch. The total starch yield ranged from 2.8 to 7.8 mg.ha1 whereas the extractable starch varied between 2.5 to 7.1 mg-ha1. As the N rate went up, the oil and starch content of the grain decreased, whereas the protein content and the protein, starch, and oil yields increased, reaching their maximum at the N rate corresponding to 179.0 kg N.ha~. The potential ethanol yield varied between 616.2 and 7,035.1 L-ha1 depending on the method of conversion of the starch into ethanol, the year and the N rate (P 〈 0.0001). The negative correlation between N fertilization rate and starch content suggested that when farmers add too much N to their soil to increase grain yield, they reduce the starch content in those grains, and consequently the conversion into bioethanol. Therefore, for biofuel production to be beneficial for both farmers and the power plant owners, an agreement needs to be made with regard to the use of fertilizers.展开更多
Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in b...Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in black soil region in China. In Jilin black soil region, a six treatments study including three corn varieties (transgenic corn, control and local variety) and two sampling locations (in rizhosphere and in between plants) were deployed to study the effect of transgenic corn cultivation and sampling location on densities, species richness and community structure of Collembola. We found that root biomass was marginally decreased in transgenic corn and control variety when compared to local variety. Collembola significantly affected by sampling location treatments. Densities and species richness of collembolans significantly decreased in "between plants" than in "rizhosphere". Densities of Collembola were impacted by corn varieties. In the whole growing season, densities of Collembola significantly decreased in control than in local variety. Collembolans in transgenic variety only slightly decreased in "jointing stage" than local variety. Collembolans adversely affected in "between plants" when compared to "in rhizosphere" in "seeding stage" but not other stages. These variations of collembolans were in lines with the trend of corn root biomass. It is indicated that Collembola variations could be caused by food resources (root biomass) but not corn varieties (transgenic, control and local).展开更多
Two variants of diet composition were prepared to evaluate the susceptibility of ECBs to CrylAb toxin as follows: 1) 38-0600 Stonefly Heliothis Diet mixed with purified CrylAb protein and 2) 38-0600 Stonefly Heliot...Two variants of diet composition were prepared to evaluate the susceptibility of ECBs to CrylAb toxin as follows: 1) 38-0600 Stonefly Heliothis Diet mixed with purified CrylAb protein and 2) 38-0600 Stonefly Heliothis Diet mixed with lyophylized leaves of Bt maize MON 810-YieldGard. A method of sample preparation and extraction of Bt toxin for reproducible ELISA quantification were optimized. The qualitative DAS-ELISA kit from Agdia was optimized for use in quantitative analysis of Cry lAb toxin. The mortality of ECB larvae from the laboratory strain on the diet with CrylAb toxin did not differ significantly from the mortality on the diet with Bt maize leaves with the same rate of Cry lAb toxin. Similarly, the mortality of the ECB larvae from the field population on the diet with Bt maize leaves did not differ significantly from the mortality of ECB larvae from the laboratory strain on the same type of diet. Therefore, the incorporation of Bt maize leaves into the diet did not influence the efficacy of CrylAb toxin against ECBs. Using this method, a susceptibility of one field population of ECBs from the Czech Republic to CrylAb toxin was determined (LC50 of 2.16 μg of Cry 1Ab g^-1 of diet).展开更多
Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was use...Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was used as the test crop. Its DM yield was determined. The browse materials had higher total N and narrower C:N ratio than the maize material. Calliandra material had higher levels of insoluble fiber (ADF), fiber bound N (ADFN) and lignin. Application of the browse and maize materials raised C, N, and C:N ratio of the soil in which they were applied compared to the control soil. The treated soils maintained higher levels of C and N and a narrower C:N ratio up to the third crop. Amaranthus DM yield was highest (P 〈 0.05) with browse treatments. Treatment with maize material did not have DM yield advantage over the control soil. Treatments with browse materials could have given higher yields because the materials had more N and fermentation could not only have increased the proportion of soluble N, but also degradability of the materials, thus making the N and other nutrients in the fermented materials available for plant growth. DM yield was highest (P 〈_ 0.05) with the first and third crops but lowest (P 〈 0.05) with the second crop. Plant growth in the second crop could have coincided with high demand for the N by the soil micro-organisms decomposing the added materials. During the third crop, decomposition of the readily degradable components of the added materials could have been complete and the N became available for plant growth. DM yield dropped (P 〈 0.05) with the fourth crop as the available N could have been depleted from the soil for plant growth.展开更多
Aims Long-term determination of root biomass production upon land-use conversion to biofuel crops is rare.To assess land-use legacy influences on belowground biomass accumulation,we converted 22-year-old Conservation ...Aims Long-term determination of root biomass production upon land-use conversion to biofuel crops is rare.To assess land-use legacy influences on belowground biomass accumulation,we converted 22-year-old Conservation Reserve Program(CRP)grasslands and 50+-year-old agricultural(AGR)lands to corn(C),switchgrass(Sw)and restored prairie(Pr)biofuel crops.We maintained one CRP grassland as a reference(Ref).We hypothesized that land-use history and crop type have significant effects on root density,with perennial crops on CRP grasslands having a higher root biomass productivity,while corn grown on former agricultural lands produce the lowest root biomass.Methods The ingrowth core method was used to determine in situ ingrowth root biomass,alongside measurements of aboveground net primary productivity(ANPP).Ancillary measurements,including air temperature,growing season length and precipitation were used to examine their influences on root biomass production.Important Findings Root biomass productivity was the highest in unconverted CRP grassland(1716 g m?2 yr?1)and lowest in corn fields(526 g m?2 yr?1).All perennial sites converted from CRP and AGR lands had lower root biomass and ANPP in the first year of planting but peaked in 2011 for switchgrass and a year later for restored prairies.Ecosystem stability was higher in restored prairies(AGR-Pr:4.3±0.11;CRP-Pr:4.1±0.10),with all monocultures exhibiting a lower stability.Root biomass production was positively related to ANPP(R2=0.40).Overall,attention should be given to root biomass accumulation in large-scale biofuel production as it is a major source of carbon sequestration.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 40271078)the Basic Research Program of Science and Technology Department of China (No. 2003DEA2C010-13)
文摘To further develop the methods to remotely sense the biochemical content of plant canopies,we report the results of an experiment to estimate the concentrations of three biochemical variables of corn,i.e.,nitrogen(N),crude fat(EE) and crude fiber(CF) concentrations,by spectral reflectance and the first derivative reflectance at fresh leaf scale. The correlations between spectral reflectance and the first derivative transformation and three biochemical variables were analyzed,and a set of estimation models were established using curve-fitting analyses. Coefficient of determination(R2),root mean square error(RMSE) and relative error of prediction(REP) of estimation models were calculated for the model quality evaluations,and the possible opti-mum estimation models of three biochemical variables were proposed,with R2 being 0.891,0.698 and 0.480 for the estimation models of N,EE and CF concentrations,respectively. The results also indicate that using the first derivative reflectance was better than using raw spectral reflectance for all three biochemical variables estimation,and that the first derivative reflectances at 759 nm,1954 nm and 2370 nm were most suitable to develop the estimation models of N,EE and CF concentrations,respectively. In addition,the high correlation coefficients of the theoretical and the measured biochemical parameters were obtained,especially for nitrogen(r=0.948).
文摘Nitrogen fertilization is one of the greatest challenges associated with the production of biofuel from corn grain. The objective of this research was to determine the effect of N fertilization on the content and yield of oil, protein, and starch in corn grain. The project was done in Southeast Missouri (USA), from 2007 to 2009 in a silt loam soil. Corn grain contains 3.8-4.2% oil, 6.7%-8.9% protein, 68.0%-70.4% extractable starch, and 76.0%-77.7% total starch. The total starch yield ranged from 2.8 to 7.8 mg.ha1 whereas the extractable starch varied between 2.5 to 7.1 mg-ha1. As the N rate went up, the oil and starch content of the grain decreased, whereas the protein content and the protein, starch, and oil yields increased, reaching their maximum at the N rate corresponding to 179.0 kg N.ha~. The potential ethanol yield varied between 616.2 and 7,035.1 L-ha1 depending on the method of conversion of the starch into ethanol, the year and the N rate (P 〈 0.0001). The negative correlation between N fertilization rate and starch content suggested that when farmers add too much N to their soil to increase grain yield, they reduce the starch content in those grains, and consequently the conversion into bioethanol. Therefore, for biofuel production to be beneficial for both farmers and the power plant owners, an agreement needs to be made with regard to the use of fertilizers.
文摘Transgenic corn was modified to combat lepidopteran pests, herbicide and other deteriorate environmental factors. However, fewer studies concerned the effects of transgenic corn cultivation on the soil Collembola in black soil region in China. In Jilin black soil region, a six treatments study including three corn varieties (transgenic corn, control and local variety) and two sampling locations (in rizhosphere and in between plants) were deployed to study the effect of transgenic corn cultivation and sampling location on densities, species richness and community structure of Collembola. We found that root biomass was marginally decreased in transgenic corn and control variety when compared to local variety. Collembola significantly affected by sampling location treatments. Densities and species richness of collembolans significantly decreased in "between plants" than in "rizhosphere". Densities of Collembola were impacted by corn varieties. In the whole growing season, densities of Collembola significantly decreased in control than in local variety. Collembolans in transgenic variety only slightly decreased in "jointing stage" than local variety. Collembolans adversely affected in "between plants" when compared to "in rhizosphere" in "seeding stage" but not other stages. These variations of collembolans were in lines with the trend of corn root biomass. It is indicated that Collembola variations could be caused by food resources (root biomass) but not corn varieties (transgenic, control and local).
文摘Two variants of diet composition were prepared to evaluate the susceptibility of ECBs to CrylAb toxin as follows: 1) 38-0600 Stonefly Heliothis Diet mixed with purified CrylAb protein and 2) 38-0600 Stonefly Heliothis Diet mixed with lyophylized leaves of Bt maize MON 810-YieldGard. A method of sample preparation and extraction of Bt toxin for reproducible ELISA quantification were optimized. The qualitative DAS-ELISA kit from Agdia was optimized for use in quantitative analysis of Cry lAb toxin. The mortality of ECB larvae from the laboratory strain on the diet with CrylAb toxin did not differ significantly from the mortality on the diet with Bt maize leaves with the same rate of Cry lAb toxin. Similarly, the mortality of the ECB larvae from the field population on the diet with Bt maize leaves did not differ significantly from the mortality of ECB larvae from the laboratory strain on the same type of diet. Therefore, the incorporation of Bt maize leaves into the diet did not influence the efficacy of CrylAb toxin against ECBs. Using this method, a susceptibility of one field population of ECBs from the Czech Republic to CrylAb toxin was determined (LC50 of 2.16 μg of Cry 1Ab g^-1 of diet).
文摘Fermented Callliandra, Gliricidia and Leucaena browses and maize material (milk stage) were applied to the soil to determine their effect on soil productivity. Hopi Red Dye Amaranthus (Amaranthus cruentus) was used as the test crop. Its DM yield was determined. The browse materials had higher total N and narrower C:N ratio than the maize material. Calliandra material had higher levels of insoluble fiber (ADF), fiber bound N (ADFN) and lignin. Application of the browse and maize materials raised C, N, and C:N ratio of the soil in which they were applied compared to the control soil. The treated soils maintained higher levels of C and N and a narrower C:N ratio up to the third crop. Amaranthus DM yield was highest (P 〈 0.05) with browse treatments. Treatment with maize material did not have DM yield advantage over the control soil. Treatments with browse materials could have given higher yields because the materials had more N and fermentation could not only have increased the proportion of soluble N, but also degradability of the materials, thus making the N and other nutrients in the fermented materials available for plant growth. DM yield was highest (P 〈_ 0.05) with the first and third crops but lowest (P 〈 0.05) with the second crop. Plant growth in the second crop could have coincided with high demand for the N by the soil micro-organisms decomposing the added materials. During the third crop, decomposition of the readily degradable components of the added materials could have been complete and the N became available for plant growth. DM yield dropped (P 〈 0.05) with the fourth crop as the available N could have been depleted from the soil for plant growth.
基金Support for this research was provided by the Great Lakes Bioenergy Research Center,U.S.Department of Energy,Office of Science,Office of Biological and Environmental Research(Awards DE-SC0018409 and DE-FCO2-07ER64494)by the National Science Foundation Long-term Ecological Research Program(DEB 1832042)at the Kellogg Biological Station,and by Michigan State University AgBioResearch.
文摘Aims Long-term determination of root biomass production upon land-use conversion to biofuel crops is rare.To assess land-use legacy influences on belowground biomass accumulation,we converted 22-year-old Conservation Reserve Program(CRP)grasslands and 50+-year-old agricultural(AGR)lands to corn(C),switchgrass(Sw)and restored prairie(Pr)biofuel crops.We maintained one CRP grassland as a reference(Ref).We hypothesized that land-use history and crop type have significant effects on root density,with perennial crops on CRP grasslands having a higher root biomass productivity,while corn grown on former agricultural lands produce the lowest root biomass.Methods The ingrowth core method was used to determine in situ ingrowth root biomass,alongside measurements of aboveground net primary productivity(ANPP).Ancillary measurements,including air temperature,growing season length and precipitation were used to examine their influences on root biomass production.Important Findings Root biomass productivity was the highest in unconverted CRP grassland(1716 g m?2 yr?1)and lowest in corn fields(526 g m?2 yr?1).All perennial sites converted from CRP and AGR lands had lower root biomass and ANPP in the first year of planting but peaked in 2011 for switchgrass and a year later for restored prairies.Ecosystem stability was higher in restored prairies(AGR-Pr:4.3±0.11;CRP-Pr:4.1±0.10),with all monocultures exhibiting a lower stability.Root biomass production was positively related to ANPP(R2=0.40).Overall,attention should be given to root biomass accumulation in large-scale biofuel production as it is a major source of carbon sequestration.