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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2014 Vol. 22, No. 12
Display Method:
2014, 22(12): 1385-1396.
doi: 10.13930/j.cnki.cjea.140744
Abstract:
Household ranch is a basic management unit and complicated production system critical for restoration of grassland ecosystem, conservation of biodiversity and improvement in incomes of farmers and herdsmen. While environment, natural resources, economy, society and management have been included in household ranch, the direction of future studies now includes the quantification, precision, stereotype and marketization of household ranch. Modeling has been important in the production, management and research in household ranch and in minimizing the factors restricting the management and development of household ranch and op-timizing ranch benefits. Several various models and softwares have been developed in the past 20 years in relation to household ranch developement, and used in the simulation of grass growth, animal production, greenhouse gas emission and system manage-ment as well as in operating household ranch system and making management and policy decisions. The main characteristics of household ranch were summarized in this paper based on review of 24 models and comparison of four factors - household ranch production, management, herb growth and greenhouse gas emission. 1) There was a rapid development of models in the area of ani-mal husbandry. 2) Farm models were more comprehensive than household ranch models, especially for dairy and beef farms. 3) The balances in forage, energy and benefit maximization were the basis of the simulations. 4) The model required a range of parameters, most of which were difficult to obtain. 5) There was lack of universal model with a wide scope of application. Based on production condition of household ranches in China, ACIAR, GrassGro and SEPATOU models were fit for household ranches in natural grassland areas and IFSM model was good for intensive farm or enterprise systems. Depending on the current state of grassland and livestock production systems in China, it was necessary to base proven results of research and practice, and interdisciplinary and trans-regional co-operations for household ranch model building and application in China.
Household ranch is a basic management unit and complicated production system critical for restoration of grassland ecosystem, conservation of biodiversity and improvement in incomes of farmers and herdsmen. While environment, natural resources, economy, society and management have been included in household ranch, the direction of future studies now includes the quantification, precision, stereotype and marketization of household ranch. Modeling has been important in the production, management and research in household ranch and in minimizing the factors restricting the management and development of household ranch and op-timizing ranch benefits. Several various models and softwares have been developed in the past 20 years in relation to household ranch developement, and used in the simulation of grass growth, animal production, greenhouse gas emission and system manage-ment as well as in operating household ranch system and making management and policy decisions. The main characteristics of household ranch were summarized in this paper based on review of 24 models and comparison of four factors - household ranch production, management, herb growth and greenhouse gas emission. 1) There was a rapid development of models in the area of ani-mal husbandry. 2) Farm models were more comprehensive than household ranch models, especially for dairy and beef farms. 3) The balances in forage, energy and benefit maximization were the basis of the simulations. 4) The model required a range of parameters, most of which were difficult to obtain. 5) There was lack of universal model with a wide scope of application. Based on production condition of household ranches in China, ACIAR, GrassGro and SEPATOU models were fit for household ranches in natural grassland areas and IFSM model was good for intensive farm or enterprise systems. Depending on the current state of grassland and livestock production systems in China, it was necessary to base proven results of research and practice, and interdisciplinary and trans-regional co-operations for household ranch model building and application in China.
2014, 22(12): 1397-1404.
doi: 10.13930/j.cnki.cjea.140869
Abstract:
The aim of this study was to determine nitrogen use efficiency and reduce environmental pollution caused by excessive use of nitrogen fertilizer in pea/maize intercropping fields in irrigated areas of Hexi Corridor, Gansu Province. To that end, a field experiment was conducted in 2011 to determine the spatial and temporal distributions of soil inorganic N (Nmin) in orthic anthrosol soils under pea/maize intercropping at different N application rates (N 0 kg·hm-2, 75 kg·hm-2, 150 kg·hm-2, 300 kg·hm-2, 450 kg·hm-2). Soil samples were collected in the 0 20, 20 40, 40 60, 60 80, 80 100 and100 120 cm soil layers and Nmin concentrations measured by flow analysis of extracted CaCl2. The results showed that NO3--N was the major form of Nmin in orthic anthrosol soils with a concentration 7.55 times that of NH4+-N. During maize growth season, NO3--N concentration increased by 29.7%, 67.5%, 88.2% and 134.3% respectively under N rates of 75, 150, 300 and 450 kg·hm-2 over no N fertilization treatment. Compared with that after pea harvest, NO3--N concentration decreased by 44.2% after maize harvest. Soil NO3--N concentration in the 0-120 cm soil layer under intercropped pea/maize decreased respectively by 6.1%/5.1% over that of each corresponding monocultured crop. The highest soil Nmin accumulation occurred in the 0-20 cm soil layer at different nitrogen application rates and growth stages. After pea harvest, Nmin accumulation in the 0-60 cm soil layer under intercropped pea/maize respectively decreased by 4.9%/1.9%, and in the 60-120 cm soil layer by 10.8%/9.2% compared with that of each corresponding monocultured crop. After maize harvest, soil Nmin accumulation in the 0-60 and 60-120 cm soil layers under intercropped pea/maize decreased respectively by 28.2%/9.4% and 23.5%/12.5% over each corresponding monocultured crop. Also soil Nmin residue in the 0-60 and 60-120 cm layers under intercropped pea decreased respectively by 4.9% and 10.9% over monocultured pea. The study showed that nitrogen fertilizer application significantly increased soil inorganic nitrogen concentration and accumulation with higher effect on soil NO3--N. Also excessive N application resulted in environmental pollution in the study area. Pea/maize intercropping significantly reduced soil inorganic nitrogen concentration and accumulation. It was obvious that intercropping reduced soil inorganic nitrogen accumulation especially in the later growth stages of the crops.
The aim of this study was to determine nitrogen use efficiency and reduce environmental pollution caused by excessive use of nitrogen fertilizer in pea/maize intercropping fields in irrigated areas of Hexi Corridor, Gansu Province. To that end, a field experiment was conducted in 2011 to determine the spatial and temporal distributions of soil inorganic N (Nmin) in orthic anthrosol soils under pea/maize intercropping at different N application rates (N 0 kg·hm-2, 75 kg·hm-2, 150 kg·hm-2, 300 kg·hm-2, 450 kg·hm-2). Soil samples were collected in the 0 20, 20 40, 40 60, 60 80, 80 100 and100 120 cm soil layers and Nmin concentrations measured by flow analysis of extracted CaCl2. The results showed that NO3--N was the major form of Nmin in orthic anthrosol soils with a concentration 7.55 times that of NH4+-N. During maize growth season, NO3--N concentration increased by 29.7%, 67.5%, 88.2% and 134.3% respectively under N rates of 75, 150, 300 and 450 kg·hm-2 over no N fertilization treatment. Compared with that after pea harvest, NO3--N concentration decreased by 44.2% after maize harvest. Soil NO3--N concentration in the 0-120 cm soil layer under intercropped pea/maize decreased respectively by 6.1%/5.1% over that of each corresponding monocultured crop. The highest soil Nmin accumulation occurred in the 0-20 cm soil layer at different nitrogen application rates and growth stages. After pea harvest, Nmin accumulation in the 0-60 cm soil layer under intercropped pea/maize respectively decreased by 4.9%/1.9%, and in the 60-120 cm soil layer by 10.8%/9.2% compared with that of each corresponding monocultured crop. After maize harvest, soil Nmin accumulation in the 0-60 and 60-120 cm soil layers under intercropped pea/maize decreased respectively by 28.2%/9.4% and 23.5%/12.5% over each corresponding monocultured crop. Also soil Nmin residue in the 0-60 and 60-120 cm layers under intercropped pea decreased respectively by 4.9% and 10.9% over monocultured pea. The study showed that nitrogen fertilizer application significantly increased soil inorganic nitrogen concentration and accumulation with higher effect on soil NO3--N. Also excessive N application resulted in environmental pollution in the study area. Pea/maize intercropping significantly reduced soil inorganic nitrogen concentration and accumulation. It was obvious that intercropping reduced soil inorganic nitrogen accumulation especially in the later growth stages of the crops.
2014, 22(12): 1405-1413.
doi: 10.13930/j.cnki.cjea.140921
Abstract:
Ratooning rice, with significant improvement in potential yield, has become a major farming system to raise multiple crop index. Ratooning rice yield is directly related to the rate of ratooning bud germinating into spikes, and thereby enhancing ratooning bud germination is a key element for ratooning rice high yield. Numerous studies on rice eco-physiology have shown that nitrogen application enhances bud development also strongly promotes ratooning bud germination. However, the molecular mechanism of nitrogen application for bud development to promote ratooning bud germination has remained unclear. This paper studied the effects of nitrogen application for bud development on protein expression of ratooning buds of rice and the corresponding physiological characteristics by using comparative proteomics and relative physiological indicators. A total of 20 differentially expressed proteins were detected in different treatments in 2-DE maps of ratooning bud proteome. The proteins involved in energy metabolism, growth regulation, defense response to stress, etc. The results indicated that the expression abundance of nucleoside diphosphate kinase protein involved in energy metabolism was down-regulated and the proteins involved in photosynthesis (probable photosystem Ⅱ oxygen-evolving complex protein and cytochrome b6-f complex iron-sulfur subunit) were up-regulated during ratooning bud germination. Furthermore, protein expressions were higher under nitrogen application treatment than non-fertilization treatment on 7 d and 14 d after nitrogen application for bud development. It suggested that nitrogen application for ratooning bud development significantly slowed the down-regulation of proteins involved in energy metabolism, and promoted the up-regulation of proteins involved in photosynthesis. Thus ratooning buds mediated by fertilization treatment had relatively stronger energy synthesis and photoautotroph capabilities, which better met the needs of energy and material for ratooning bud germination and differentiation. Six protein spots involved in cellular growth and five protein spots involved in resistance were detected and identified in the study. Among them, two protein spots (translationally-controlled tumor protein homolog and actin-depolymerizing factor) were down-regulated and nine protein spots (e.g., germin-like protein, ABA/WDS-induced protein, putative quinone-oxidoreductase QR2, Cu-Zn superoxide dismutase and dirigent-like protein) were up-regulated during the ratooning bud germination. Furthermore, expression abundance of proteins (e.g., ABA/WDS-induced protein and actin-depolymerizing factor on the 7th and 14th day, germin-like protein on the 7th day of fertilization) was lower under nitrogen application treatment than non-fertilization treatment. Proteins (e.g., translationally-controlled tumor protein homolog, putative quinone-oxidoreductase QR2, Cu-Zn superoxide dismutase and dirigent-like protein on the 7th and 14th day, germin-like protein on the 14th day) had higher expressions under fertilization treatment than non-fertilization treatment. It indicated that nitrogen application for ratooning bud development relatively cut down the expression abundance of proteins that inhibited ratooning bud germination. Meanwhile, it increased the expression abundance of proteins related to cell division, elongation and resistance, which promoted the germination of ratooning bud and enhanced the ability to resist adverse conditions. Therefore compared with those under non-fertilization treatment, living bud rate and length of the 2nd to the 5th ratooning bud were significantly higher in nitrogen application treatment. As a result, nitrogen application for bud development significantly improved effective panicle number, seed setting rate and grain yield of ratooning rice, which was aimed at getting high yield and significant improvement in ratooning rice production.
Ratooning rice, with significant improvement in potential yield, has become a major farming system to raise multiple crop index. Ratooning rice yield is directly related to the rate of ratooning bud germinating into spikes, and thereby enhancing ratooning bud germination is a key element for ratooning rice high yield. Numerous studies on rice eco-physiology have shown that nitrogen application enhances bud development also strongly promotes ratooning bud germination. However, the molecular mechanism of nitrogen application for bud development to promote ratooning bud germination has remained unclear. This paper studied the effects of nitrogen application for bud development on protein expression of ratooning buds of rice and the corresponding physiological characteristics by using comparative proteomics and relative physiological indicators. A total of 20 differentially expressed proteins were detected in different treatments in 2-DE maps of ratooning bud proteome. The proteins involved in energy metabolism, growth regulation, defense response to stress, etc. The results indicated that the expression abundance of nucleoside diphosphate kinase protein involved in energy metabolism was down-regulated and the proteins involved in photosynthesis (probable photosystem Ⅱ oxygen-evolving complex protein and cytochrome b6-f complex iron-sulfur subunit) were up-regulated during ratooning bud germination. Furthermore, protein expressions were higher under nitrogen application treatment than non-fertilization treatment on 7 d and 14 d after nitrogen application for bud development. It suggested that nitrogen application for ratooning bud development significantly slowed the down-regulation of proteins involved in energy metabolism, and promoted the up-regulation of proteins involved in photosynthesis. Thus ratooning buds mediated by fertilization treatment had relatively stronger energy synthesis and photoautotroph capabilities, which better met the needs of energy and material for ratooning bud germination and differentiation. Six protein spots involved in cellular growth and five protein spots involved in resistance were detected and identified in the study. Among them, two protein spots (translationally-controlled tumor protein homolog and actin-depolymerizing factor) were down-regulated and nine protein spots (e.g., germin-like protein, ABA/WDS-induced protein, putative quinone-oxidoreductase QR2, Cu-Zn superoxide dismutase and dirigent-like protein) were up-regulated during the ratooning bud germination. Furthermore, expression abundance of proteins (e.g., ABA/WDS-induced protein and actin-depolymerizing factor on the 7th and 14th day, germin-like protein on the 7th day of fertilization) was lower under nitrogen application treatment than non-fertilization treatment. Proteins (e.g., translationally-controlled tumor protein homolog, putative quinone-oxidoreductase QR2, Cu-Zn superoxide dismutase and dirigent-like protein on the 7th and 14th day, germin-like protein on the 14th day) had higher expressions under fertilization treatment than non-fertilization treatment. It indicated that nitrogen application for ratooning bud development relatively cut down the expression abundance of proteins that inhibited ratooning bud germination. Meanwhile, it increased the expression abundance of proteins related to cell division, elongation and resistance, which promoted the germination of ratooning bud and enhanced the ability to resist adverse conditions. Therefore compared with those under non-fertilization treatment, living bud rate and length of the 2nd to the 5th ratooning bud were significantly higher in nitrogen application treatment. As a result, nitrogen application for bud development significantly improved effective panicle number, seed setting rate and grain yield of ratooning rice, which was aimed at getting high yield and significant improvement in ratooning rice production.
2014, 22(12): 1414-1423.
doi: 10.13930/j.cnki.cjea.140610
Abstract:
Precise estimation of maize yield potential would enhance our understanding of crop development and yield formation and thus improve yields. Many crop models have been used in estimating yield potentials, among which the FAO-AEZ model has been shown to be efficient and accurate. However, some parameters of the FAO-AEZ model such as harvest index are set constant which limit estimation precision. Thus in this paper, we developed an optimized FAO-AEZ model to increase yield estimation accuracy. Field experiments were conducted at three ecological zones (Qian'an County, Gongzhuling City and Huadian City) in Jilin Province in 2005-2013. Dry matter accumulation at several developmental stages and grain yield of maize were measured, and then an optimized calculation method integrated with traditional FAO-AEZ model to evaluate maize yield potential. With this new method, harvest index had become a dynamic factor that was adjustable in line with maize development. Moreover, an analytical method for dry matter accumulation was developed under super-high yield production of maize and the model parameters calculated using Logistic model. The results showed a high correlation (P < 0.01) between maize yield and dry matter accumulation parameters. Then using data from independent field experiments in 2012 and 2013 to test the optimized model, low error (both absolute error and relative mean error) was noted. Using nonlinear optimization theory, the optimized model was applied in analysis of potential maize yield in Qian'an County and Huadian City. Compared with traditional FAO-AEZ model, the calculated yield potentials by the optimized model were higher by 17.5% in Qian'an County and by 16.1% in Huadian City. Furthermore, we estimated minimum planting density and dry matter accumulation at different developmental stages using a target yield of 15 000 kg·hm-2. The minimum planting density was 7.7 104 plants·hm-2, 8.2 104 plants·hm-2 and 7.9 104 plants·hm-2 in Qian'an County, Gongzhuling City and Huadian City, respectively. The optimized FAO-AEZ model provided the scientific basis for decision-making before planting and for growth period regulation in order to have super-high-yield maize production. The established model and the results of the analysis could be used to estimate yield potential, high-yield and super-high-yield cultivation in Jilin Province and other regions for maize and other crops.
Precise estimation of maize yield potential would enhance our understanding of crop development and yield formation and thus improve yields. Many crop models have been used in estimating yield potentials, among which the FAO-AEZ model has been shown to be efficient and accurate. However, some parameters of the FAO-AEZ model such as harvest index are set constant which limit estimation precision. Thus in this paper, we developed an optimized FAO-AEZ model to increase yield estimation accuracy. Field experiments were conducted at three ecological zones (Qian'an County, Gongzhuling City and Huadian City) in Jilin Province in 2005-2013. Dry matter accumulation at several developmental stages and grain yield of maize were measured, and then an optimized calculation method integrated with traditional FAO-AEZ model to evaluate maize yield potential. With this new method, harvest index had become a dynamic factor that was adjustable in line with maize development. Moreover, an analytical method for dry matter accumulation was developed under super-high yield production of maize and the model parameters calculated using Logistic model. The results showed a high correlation (P < 0.01) between maize yield and dry matter accumulation parameters. Then using data from independent field experiments in 2012 and 2013 to test the optimized model, low error (both absolute error and relative mean error) was noted. Using nonlinear optimization theory, the optimized model was applied in analysis of potential maize yield in Qian'an County and Huadian City. Compared with traditional FAO-AEZ model, the calculated yield potentials by the optimized model were higher by 17.5% in Qian'an County and by 16.1% in Huadian City. Furthermore, we estimated minimum planting density and dry matter accumulation at different developmental stages using a target yield of 15 000 kg·hm-2. The minimum planting density was 7.7 104 plants·hm-2, 8.2 104 plants·hm-2 and 7.9 104 plants·hm-2 in Qian'an County, Gongzhuling City and Huadian City, respectively. The optimized FAO-AEZ model provided the scientific basis for decision-making before planting and for growth period regulation in order to have super-high-yield maize production. The established model and the results of the analysis could be used to estimate yield potential, high-yield and super-high-yield cultivation in Jilin Province and other regions for maize and other crops.
2014, 22(12): 1424-1432.
doi: 10.13930/j.cnki.cjea.140830
Abstract:
The loss of nitrogen and phosphorus due to excessive fertilizer application has become a major form in agricultural non-point pollution. In order to explore the impact of different planting patterns (conventional cultivation, green rice-frog ecosystem, organic rice-frog ecosystem) on nitrogen and phosphorus loss, a field experiment was conducted and the characteristics of nitrogen and phosphorus in surface water, runoff, leakage as well as rice yield differences analyzed in three paddy ecosystems. The results showed that among the paddy ecosystems, the order of average concentration of total nitrogen (TN) in surface water was: conventional cultivation (18.87 mg·L-1) > green rice-frog ecosystem (8.98 mg·L-1) > organic rice-frog ecosystem (8.20 mg·L-1). Compared with conventional cultivation, green rice-frog ecosystem and organic rice-frog ecosystem decreased TN loss during rice growth season by 15.27% and 25.76%, respectively. The TN runoff loss was in the following order: green rice-frog ecosystem > conventional cultivation > organic rice-frog ecosystem. NH4+-N was the main form of TN runoff. The order of TN leaching loss of was conventional cultivation > green rice-frog ecosystem > organic rice-frog ecosystem, with NO3--N as the main form of TN leaching. Also the ratio of total TN loss to nitrogen fertilizer use in the three treatments was in the range of 1.25%-2.38%, all less than 3%. Average total phosphorus (TP) concentration of surface water was in the following order: organic rice-frog ecosystem (0.82 mg·L-1) > green rice-frog ecosystem (0.64 mg·L-1) > conventional cultivation (0.37 mg·L-1). Total loss of TP was in the order of: organic rice-frog ecosystem > green rice-frog ecosystem > conventional cultivation. Then the order of proportion of total loss of phosphorous fertilizer was: green rice-frog ecosystem > conventionally cultivation treatment > organic rice-frog ecosystem, most of which was dissolved phosphorus. The order of rice yield under the three treatments was: conventional cultivation > organic rice-frog ecosystem > green rice-frog ecosystem. Compared with conventional cultivation, yield under green rice-frog ecosystem and organic rice-frog ecosystem decreased respectively by 19.33% and 8.15%. Research results showed that organic rice-frog ecosystem and green rice-frog ecosystem effectively controlled nitrogen and phosphorus loss in paddy fields although production decreased. Production quality and economic benefits of organic rice-frog ecosystem were better than those of green rice-frog ecosystem and conventional cultivation treatment. The requirements for organic rice-frog ecosystem were higher than those for green rice-frog ecosystem and conventional cultivation treatment.
The loss of nitrogen and phosphorus due to excessive fertilizer application has become a major form in agricultural non-point pollution. In order to explore the impact of different planting patterns (conventional cultivation, green rice-frog ecosystem, organic rice-frog ecosystem) on nitrogen and phosphorus loss, a field experiment was conducted and the characteristics of nitrogen and phosphorus in surface water, runoff, leakage as well as rice yield differences analyzed in three paddy ecosystems. The results showed that among the paddy ecosystems, the order of average concentration of total nitrogen (TN) in surface water was: conventional cultivation (18.87 mg·L-1) > green rice-frog ecosystem (8.98 mg·L-1) > organic rice-frog ecosystem (8.20 mg·L-1). Compared with conventional cultivation, green rice-frog ecosystem and organic rice-frog ecosystem decreased TN loss during rice growth season by 15.27% and 25.76%, respectively. The TN runoff loss was in the following order: green rice-frog ecosystem > conventional cultivation > organic rice-frog ecosystem. NH4+-N was the main form of TN runoff. The order of TN leaching loss of was conventional cultivation > green rice-frog ecosystem > organic rice-frog ecosystem, with NO3--N as the main form of TN leaching. Also the ratio of total TN loss to nitrogen fertilizer use in the three treatments was in the range of 1.25%-2.38%, all less than 3%. Average total phosphorus (TP) concentration of surface water was in the following order: organic rice-frog ecosystem (0.82 mg·L-1) > green rice-frog ecosystem (0.64 mg·L-1) > conventional cultivation (0.37 mg·L-1). Total loss of TP was in the order of: organic rice-frog ecosystem > green rice-frog ecosystem > conventional cultivation. Then the order of proportion of total loss of phosphorous fertilizer was: green rice-frog ecosystem > conventionally cultivation treatment > organic rice-frog ecosystem, most of which was dissolved phosphorus. The order of rice yield under the three treatments was: conventional cultivation > organic rice-frog ecosystem > green rice-frog ecosystem. Compared with conventional cultivation, yield under green rice-frog ecosystem and organic rice-frog ecosystem decreased respectively by 19.33% and 8.15%. Research results showed that organic rice-frog ecosystem and green rice-frog ecosystem effectively controlled nitrogen and phosphorus loss in paddy fields although production decreased. Production quality and economic benefits of organic rice-frog ecosystem were better than those of green rice-frog ecosystem and conventional cultivation treatment. The requirements for organic rice-frog ecosystem were higher than those for green rice-frog ecosystem and conventional cultivation treatment.
2014, 22(12): 1433-1439.
doi: 10.13930/j.cnki.cjea.141030
Abstract:
Dew, a crucial element of water cycle in farmland ecosystems, plays an important role in water and nutrient balance in paddy field. As a form of wet deposition, dew is a major pathway for the flow of acidic pollutants from the atmosphere to the biosphere. Acidic dew can damage protective surfaces of leaves, interfere with guard cells and poison plant cells. With dew as a surfactant by nutrient adherence to leaves, recognition of dew as an important factor of nutrient uptake is particularly significant. Dew, as a nutrient input, has always been ignored. Identifying the nutrients in dew is necessary to determine the significance of leaf dew in agricultural practices. The goals of this study were to investigate pH and essential nutrients [ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and phosphate (PO43--P)] in paddy dew and to explore the role of dew in nutrition availability to rice. To this end, in situ dew samples in paddy field were collected from the early July to early October of 2013 at the Sanjiang Plain Paddy Experimental Station (47°35′N, 133°31′E) of Chinese Academy of Sciences. The leaf dew samples were collected 30 min before sunrise on heavy dew days and a total of 22 dew samples were collected directly on rice leaves. A conservative unit area of actual dewfall estimated by LAI in paddy field was 28 mm in 2013. Dew was accounted for 8.3% of total rainfall during the period of study. NO3--N concentration in dew was significantly (P< 0.05) greater than NH4+-N and PO43--P concentrations. Based on statistical analysis, pH affected PO43 -P and NH4+-N concentrations of dew in paddy field. Dew contained more NH4+-N, NO3--N and PO43--P than rain. pH of dew was in the range of 5.34 7.10 with a mean of 6.37, which was not strong enough to cause damage to rice leaves in paddy field. The higher concentrations of N and P in dew were attributed to dry deposition on wet surfaces and variations in composition at high-altitude (cloud level) and low-altitude (ground level) aerosols and gases, to which the dew and rain were exposed. The contribution of leaf dew to rice growth was limited because of its limited condensation time. The deposition amounts of NH4+-N, NO3--N and PO43--P in the 28 mm dewfall from July to October in the paddy field were respectively 0.11 kg·hm-2, 0.22 kg·hm-2 and 0.04 kg·hm-2. Although nutrients were in low concentration in the dew, dew-nutrient supply was long-term. Leaf dew was not temporal, while the foliar fertilizer was evaporative. Thus leaf dew contributed more nutrients to paddy field that subsequently enhanced significant rice growth. The deposition amount of NH4+-N, NO3--N and PO43--P of dew were about 100 times as much as that of foliar fertilization. In addition, dew condensation on both sides of the leaf enhanced more effective uptake of nutrients. Therefore N and P in dews in paddy fields were other significant source nutrients. Dew was an important pathway for the nutrient transfer in paddy fields.
Dew, a crucial element of water cycle in farmland ecosystems, plays an important role in water and nutrient balance in paddy field. As a form of wet deposition, dew is a major pathway for the flow of acidic pollutants from the atmosphere to the biosphere. Acidic dew can damage protective surfaces of leaves, interfere with guard cells and poison plant cells. With dew as a surfactant by nutrient adherence to leaves, recognition of dew as an important factor of nutrient uptake is particularly significant. Dew, as a nutrient input, has always been ignored. Identifying the nutrients in dew is necessary to determine the significance of leaf dew in agricultural practices. The goals of this study were to investigate pH and essential nutrients [ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and phosphate (PO43--P)] in paddy dew and to explore the role of dew in nutrition availability to rice. To this end, in situ dew samples in paddy field were collected from the early July to early October of 2013 at the Sanjiang Plain Paddy Experimental Station (47°35′N, 133°31′E) of Chinese Academy of Sciences. The leaf dew samples were collected 30 min before sunrise on heavy dew days and a total of 22 dew samples were collected directly on rice leaves. A conservative unit area of actual dewfall estimated by LAI in paddy field was 28 mm in 2013. Dew was accounted for 8.3% of total rainfall during the period of study. NO3--N concentration in dew was significantly (P< 0.05) greater than NH4+-N and PO43--P concentrations. Based on statistical analysis, pH affected PO43 -P and NH4+-N concentrations of dew in paddy field. Dew contained more NH4+-N, NO3--N and PO43--P than rain. pH of dew was in the range of 5.34 7.10 with a mean of 6.37, which was not strong enough to cause damage to rice leaves in paddy field. The higher concentrations of N and P in dew were attributed to dry deposition on wet surfaces and variations in composition at high-altitude (cloud level) and low-altitude (ground level) aerosols and gases, to which the dew and rain were exposed. The contribution of leaf dew to rice growth was limited because of its limited condensation time. The deposition amounts of NH4+-N, NO3--N and PO43--P in the 28 mm dewfall from July to October in the paddy field were respectively 0.11 kg·hm-2, 0.22 kg·hm-2 and 0.04 kg·hm-2. Although nutrients were in low concentration in the dew, dew-nutrient supply was long-term. Leaf dew was not temporal, while the foliar fertilizer was evaporative. Thus leaf dew contributed more nutrients to paddy field that subsequently enhanced significant rice growth. The deposition amount of NH4+-N, NO3--N and PO43--P of dew were about 100 times as much as that of foliar fertilization. In addition, dew condensation on both sides of the leaf enhanced more effective uptake of nutrients. Therefore N and P in dews in paddy fields were other significant source nutrients. Dew was an important pathway for the nutrient transfer in paddy fields.
2014, 22(12): 1440-1445.
doi: 10.13930/j.cnki.cjea.140781
Abstract:
Corn seedlings are often harmed by wind and wind-blown sand flowing in semi-arid, wind-sand areas of west of Northeast China in spring. In order to understand the physiological response mechanism of corn seedlings to wind and wind-blown sand damages, net-wind and wind-blown sand experiments were conducted in the spring of 2013 in Horqin Sand Land of eastern Inner Mongolia. The experiments included six wind speed treatments [0 m·s-1 (CK), 6 m·s-1, 9 m·s-1, 12 m·s-1, 15 m·s-1 and 18 m·s-1] and six wind-sand flow strengths [0 g·cm-1·min-1 (CK), 1.00 g·cm-1·min-1, 28.30 g·cm-1·min-1, 63.28 g·cm-1·min-1, 111.82 g·cm -1·min-1 and 172.93 g·cm-1·min-1, which were corresponding to the above wind speeds]. The results showed that with increasing wind speed in the net-wind experiment, MDA content and POD activity apparently increased. Also membrane permeability, SOD and CAT activities, and soluble sugar and proline contents fluctuated with changing wind speed. Compared with CK, SOD activities in 12 18 m·s-1 treatments and POD activities in 6 m·s-1 and 12 18 m·s-1 treatments, CAT activities in 6 m·s-1 and 12 m·s-1 treatments, soluble sugar content in 6 m·s-1 treatment and prolin content in 18 m·s-1 treatment increased significantly. With increasing wind speed under the wind-sand flow experiment, MDA content, SOD activity and soluble sugar content apparently decreased, membrane permeability and POD activity increased significantly, CAT activity and proline content did not significantly change. The only exception was for proline content in 18 m·s-1 treatment where wind-blown sand strength reached 172.93 g·cm-1·min-1. The results suggested that while the 10 min net-wind blow had no significant effect on cell membranes of corn seedlings, wind-blown sand stress caused significant damage to seedling membrane structure. POD played an important role in protecting seedling cell membranes against damage of wind and wind-blown sand stress. Also proline played an osmotic adjustment role under 18 m·s-1 net-wind and wind-blown sand stress.
Corn seedlings are often harmed by wind and wind-blown sand flowing in semi-arid, wind-sand areas of west of Northeast China in spring. In order to understand the physiological response mechanism of corn seedlings to wind and wind-blown sand damages, net-wind and wind-blown sand experiments were conducted in the spring of 2013 in Horqin Sand Land of eastern Inner Mongolia. The experiments included six wind speed treatments [0 m·s-1 (CK), 6 m·s-1, 9 m·s-1, 12 m·s-1, 15 m·s-1 and 18 m·s-1] and six wind-sand flow strengths [0 g·cm-1·min-1 (CK), 1.00 g·cm-1·min-1, 28.30 g·cm-1·min-1, 63.28 g·cm-1·min-1, 111.82 g·cm -1·min-1 and 172.93 g·cm-1·min-1, which were corresponding to the above wind speeds]. The results showed that with increasing wind speed in the net-wind experiment, MDA content and POD activity apparently increased. Also membrane permeability, SOD and CAT activities, and soluble sugar and proline contents fluctuated with changing wind speed. Compared with CK, SOD activities in 12 18 m·s-1 treatments and POD activities in 6 m·s-1 and 12 18 m·s-1 treatments, CAT activities in 6 m·s-1 and 12 m·s-1 treatments, soluble sugar content in 6 m·s-1 treatment and prolin content in 18 m·s-1 treatment increased significantly. With increasing wind speed under the wind-sand flow experiment, MDA content, SOD activity and soluble sugar content apparently decreased, membrane permeability and POD activity increased significantly, CAT activity and proline content did not significantly change. The only exception was for proline content in 18 m·s-1 treatment where wind-blown sand strength reached 172.93 g·cm-1·min-1. The results suggested that while the 10 min net-wind blow had no significant effect on cell membranes of corn seedlings, wind-blown sand stress caused significant damage to seedling membrane structure. POD played an important role in protecting seedling cell membranes against damage of wind and wind-blown sand stress. Also proline played an osmotic adjustment role under 18 m·s-1 net-wind and wind-blown sand stress.
2014, 22(12): 1446-1452.
doi: 10.13930/j.cnki.cjea.140489
Abstract:
The effect of temperature on pear flower development is a prerequisite for using bees in pear pollination. In this study, the main varieties of Pyrus bretschneideri cv. 'Dangshansuli' and P. bretschneideri cv. 'Yali' served as pollination test materials. Three temperatures (8 ℃, 12 ℃ and 20 ℃) were set to explore the dynamic blossoming and stigma receptivity of 'Dangshansuli', and pollen release, pollen germination, pollen tube growth of 'Yali', and other indicators to lay the theoretical basis for the reasonable use of bee pollination of pears. The results showed that at 8 ℃, the required time for flower opening of 'Dangshansuli' exceeded 144 h. Also the time for stigma receptivity delayed to 112 h and that for pollination persistence shortened. The time for pollen release of 'Yali' extended to 230 h. Pollen germination rate at 8 ℃ was less than that at 20 ℃ (P< 0.05). After culturing for 96 h, the number of pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 84, 55 and 43. At 12 ℃, the time for flower opening of 'Dangshansuli' was 114 h, and strong stigma receptivity occurred 88 h later. The time for total pollen release of 'Yali' was 158 h. While pollen germination at 12 ℃ was faster than that at 8 ℃, the pollen germination rate was significantly lower than that at 20 ℃ (P < 0.05). After culturing for 96 h, the number of pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 111, 105 and 92. When temperature was 20 ℃, the required time for the blossoming of 'Dangshansuli' was 44 h. Stigma receptivity was strong and pollination persistence time reached 120 h. The required time for total pollen release of 'Yali' was 64 h and pollen germination rate was high. After culturing for 96 h, the number pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 121, 120 and 119. The temperature of 20 ℃ was more suitable for pear growth and pollination by bees than 12 ℃ and 8 ℃. The present study laid the scientific basis for future studies on biological characteristics of pear blossoming at different temperatures. It also laid the foundation for practical application of honeybee pollination technology in pear farms.
The effect of temperature on pear flower development is a prerequisite for using bees in pear pollination. In this study, the main varieties of Pyrus bretschneideri cv. 'Dangshansuli' and P. bretschneideri cv. 'Yali' served as pollination test materials. Three temperatures (8 ℃, 12 ℃ and 20 ℃) were set to explore the dynamic blossoming and stigma receptivity of 'Dangshansuli', and pollen release, pollen germination, pollen tube growth of 'Yali', and other indicators to lay the theoretical basis for the reasonable use of bee pollination of pears. The results showed that at 8 ℃, the required time for flower opening of 'Dangshansuli' exceeded 144 h. Also the time for stigma receptivity delayed to 112 h and that for pollination persistence shortened. The time for pollen release of 'Yali' extended to 230 h. Pollen germination rate at 8 ℃ was less than that at 20 ℃ (P< 0.05). After culturing for 96 h, the number of pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 84, 55 and 43. At 12 ℃, the time for flower opening of 'Dangshansuli' was 114 h, and strong stigma receptivity occurred 88 h later. The time for total pollen release of 'Yali' was 158 h. While pollen germination at 12 ℃ was faster than that at 8 ℃, the pollen germination rate was significantly lower than that at 20 ℃ (P < 0.05). After culturing for 96 h, the number of pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 111, 105 and 92. When temperature was 20 ℃, the required time for the blossoming of 'Dangshansuli' was 44 h. Stigma receptivity was strong and pollination persistence time reached 120 h. The required time for total pollen release of 'Yali' was 64 h and pollen germination rate was high. After culturing for 96 h, the number pollen tubes arriving at the top, middle and base of styles of 'Dangshansuli' was respectively 121, 120 and 119. The temperature of 20 ℃ was more suitable for pear growth and pollination by bees than 12 ℃ and 8 ℃. The present study laid the scientific basis for future studies on biological characteristics of pear blossoming at different temperatures. It also laid the foundation for practical application of honeybee pollination technology in pear farms.
2014, 22(12): 1453-1459.
doi: 10.13930/j.cnki.cjea.140796
Abstract:
Although the birth of ecological chicken industry was greeted with great enthusiasm, unreasonable feeding density has largely killed plant cover, exposed hill slopes bare and damaged the ecology. How to use the land resource and shade environment under trees has become a major problem requiring an urgent solution. A total of 441 healthy 45-week-old layer hens were randomly divided into 7 groups to study the effects of density and feed supplement rate on layer production and yolk cholesterol content under grazing conditions. Hens of groups 1?6 were reared under jujube/alfalfa wood. Treatments were set at feed supplement rates of 50% and 70% of free ingestion and at densities of 100, 250 and 400 hens per 667 m2. The 7th group of hens was reared in cages with free ingestion. Each plot area was 62 m2, 3 replicas set up for each group and 3 plots of each group used for rotation grazing. Preliminary trial period was 7 days while normal trial period was 70 days. The results showed that while density and feed supplement interaction had significant effects on egg laying rate (P < 0.01), it had no significant effect on egg weight and feed/egg ratio. Egg weight, egg laying rate and feed/egg ratio were not significantly different between cage-reared hens with free ingestion and 70% feed supplement with density of 100 hens per 667 m2 (P > 0.05). However, in cage-reared hens with free ingestion, egg laying rate was significantly higher than in other treatments (P > 0.05), egg weight significantly higher than in 50% feed supplement with density of 100 hens per 667 m2 (P > 0.05), and feed/egg ratio significantly lower than in 50% feed supplement with density of 100 hens per 667 m2(P < 0.05). The interaction between feed supplement and density had no significant effect on yolk weight, yolk cholesterol content and egg cholesterol content (P > 0.05). However, hen density had significant effect on egg cholesterol content (P < 0.01). Yolk weight of cage-reared hens with free ingestion was significantly higher than that of hens reared under 50% feed supplement and density of 100 hens per 667 m2 (P < 0.01). Yolk cholesterol content and egg cholesterol content of cage-reared hens with free ingestion were significantly higher than those of hens reared under 50% and 70% feed supplements and density of 100 hens per 667 m2 (P< 0.05). Pasture cover was highest for treatment with 70% feed supplement and density of 100 hens per 667 m2. Thus the culture mode with 70% feed supplement and density of 100 hens per 667 m2 was better for layer production, yolk cholesterol content and pasture protection.
Although the birth of ecological chicken industry was greeted with great enthusiasm, unreasonable feeding density has largely killed plant cover, exposed hill slopes bare and damaged the ecology. How to use the land resource and shade environment under trees has become a major problem requiring an urgent solution. A total of 441 healthy 45-week-old layer hens were randomly divided into 7 groups to study the effects of density and feed supplement rate on layer production and yolk cholesterol content under grazing conditions. Hens of groups 1?6 were reared under jujube/alfalfa wood. Treatments were set at feed supplement rates of 50% and 70% of free ingestion and at densities of 100, 250 and 400 hens per 667 m2. The 7th group of hens was reared in cages with free ingestion. Each plot area was 62 m2, 3 replicas set up for each group and 3 plots of each group used for rotation grazing. Preliminary trial period was 7 days while normal trial period was 70 days. The results showed that while density and feed supplement interaction had significant effects on egg laying rate (P < 0.01), it had no significant effect on egg weight and feed/egg ratio. Egg weight, egg laying rate and feed/egg ratio were not significantly different between cage-reared hens with free ingestion and 70% feed supplement with density of 100 hens per 667 m2 (P > 0.05). However, in cage-reared hens with free ingestion, egg laying rate was significantly higher than in other treatments (P > 0.05), egg weight significantly higher than in 50% feed supplement with density of 100 hens per 667 m2 (P > 0.05), and feed/egg ratio significantly lower than in 50% feed supplement with density of 100 hens per 667 m2(P < 0.05). The interaction between feed supplement and density had no significant effect on yolk weight, yolk cholesterol content and egg cholesterol content (P > 0.05). However, hen density had significant effect on egg cholesterol content (P < 0.01). Yolk weight of cage-reared hens with free ingestion was significantly higher than that of hens reared under 50% feed supplement and density of 100 hens per 667 m2 (P < 0.01). Yolk cholesterol content and egg cholesterol content of cage-reared hens with free ingestion were significantly higher than those of hens reared under 50% and 70% feed supplements and density of 100 hens per 667 m2 (P< 0.05). Pasture cover was highest for treatment with 70% feed supplement and density of 100 hens per 667 m2. Thus the culture mode with 70% feed supplement and density of 100 hens per 667 m2 was better for layer production, yolk cholesterol content and pasture protection.
2014, 22(12): 1460-1468.
doi: 10.13930/j.cnki.cjea.140299
Abstract:
The objective of this study was to elucidate the role of temperature in antioxidation mechanism of eight wheat cultivars differing in salt tolerance. The eight cultivars seedlings were cultured in nutrient solutions at normal (20 ℃ / 25 ℃) and low (10 ℃ / 15 ℃) temperature conditions. The wheat cultivars were set under 150 mmol·L-1 NaCl stress condition for 48 h at the third leaf stage of the seedlings. Then reactive oxygen species (ROS) accumulation, antioxidant enzyme activity and electrolyte leakage (EK) were examined in the eight wheat cultivar seedlings. The results showed that the activities of SOD, POD, CAT and APX in salt-tolerant cultivars increased significantly, and were higher than those of salt sensitive cultivars under salt stress with normal temperature condition. As for salt sensitive cultivars, salt stress only enhanced APX activity. Accumulated ROS and EK in salt sensitive cultivar seedlings were higher than those in salt-tolerant cultivar seedlings. For drought-tolerant cultivars, the values of above parameters were between those of salt-tolerant and salt-sensitive cultivars. Under low temperature, GR activity of all the experimental cultivars increased by 2?3 folds under salt stress compared with that of non-salt-stress treatments. While CAT and APX activities in salt-tolerant cultivars increased significantly, SOD, POD and APX activities in drought-tolerant cultivars obviously improved under salinity stress conditions. Also in salt-sensitive cultivars, SOD and POD activities enhanced markedly under salinity stress conditions. The response of antioxidative enzymes to salt stress under low temperature was different from that under normal temperature. Under low temperature, SOD and POD activities were inhibited in salt-tolerant cultivars seedlings. The excessive ROS induction was stopped mainly by enhanced activities of APX and GR, two key enzymes of ascorbic acid-GSH cycle. For drought-tolerant and salt-sensitive cultivars, salinity stress obviously increased SOD, POD and GR activities, as well as GR activity. As a result of the interaction of antioxidative en-zymes, different scopes of ROS accumulation and EK in wheat cultivars with different levels of salt tolerance reduced under low temperature conditions compared with normal temperature condition.
The objective of this study was to elucidate the role of temperature in antioxidation mechanism of eight wheat cultivars differing in salt tolerance. The eight cultivars seedlings were cultured in nutrient solutions at normal (20 ℃ / 25 ℃) and low (10 ℃ / 15 ℃) temperature conditions. The wheat cultivars were set under 150 mmol·L-1 NaCl stress condition for 48 h at the third leaf stage of the seedlings. Then reactive oxygen species (ROS) accumulation, antioxidant enzyme activity and electrolyte leakage (EK) were examined in the eight wheat cultivar seedlings. The results showed that the activities of SOD, POD, CAT and APX in salt-tolerant cultivars increased significantly, and were higher than those of salt sensitive cultivars under salt stress with normal temperature condition. As for salt sensitive cultivars, salt stress only enhanced APX activity. Accumulated ROS and EK in salt sensitive cultivar seedlings were higher than those in salt-tolerant cultivar seedlings. For drought-tolerant cultivars, the values of above parameters were between those of salt-tolerant and salt-sensitive cultivars. Under low temperature, GR activity of all the experimental cultivars increased by 2?3 folds under salt stress compared with that of non-salt-stress treatments. While CAT and APX activities in salt-tolerant cultivars increased significantly, SOD, POD and APX activities in drought-tolerant cultivars obviously improved under salinity stress conditions. Also in salt-sensitive cultivars, SOD and POD activities enhanced markedly under salinity stress conditions. The response of antioxidative enzymes to salt stress under low temperature was different from that under normal temperature. Under low temperature, SOD and POD activities were inhibited in salt-tolerant cultivars seedlings. The excessive ROS induction was stopped mainly by enhanced activities of APX and GR, two key enzymes of ascorbic acid-GSH cycle. For drought-tolerant and salt-sensitive cultivars, salinity stress obviously increased SOD, POD and GR activities, as well as GR activity. As a result of the interaction of antioxidative en-zymes, different scopes of ROS accumulation and EK in wheat cultivars with different levels of salt tolerance reduced under low temperature conditions compared with normal temperature condition.
2014, 22(12): 1469-1475.
doi: 10.13930/j.cnki.cjea.140871
Abstract:
The method of application of biocontrol microorganism is important for a successful biocontrol of crop diseases. An experiment was carried out to screen microorganisms and analyze their application methods in biocontrol of rice sheath blight. The T12 fungus screened was identified as Trichoderma asperellum. The applications of conidia powder (CP), organic fertilizer adsorbed mycelia (MA) and solid-state fermentation product (SS) of T. asperellum T12 were compared on effectiveness in biocontrol of sheath blight. SS exhibited best biocontrol efficacy, which was 89.5%. The cfus (colony forming unit) of T. asperellum adhering to sclerotia of Rhizoctonia solani in the soil was significantly higher in MA and SS treatments than in the control and CP treatments (P > 0.05). The MA and SS application methods enhanced the growth of T. asperellum along rice sheath. On the 60th day, 100th day and 130th day after rice transplanting, T. asperellum population on leaf and sheath surfaces of rice indicated that the best and worst treatments were respectively CP and MA. R. solani population on leaf and sheath surface in the control treatment increased from 41 cfu·g-1 to 272 cfu·g-1 (P > 0.05), higher than that in the other treatments (P > 0.05). R. solani population in SS treatment was significantly lower than that in MA and CP treatments (P > 0.05). Compared with control treatment, all the three application methods induced higher enzyme activities of chitinase and β-1,3-glucanase (P > 0.05), while SS and MA induced longer disease resistance than CP. Therefore T. asperellum T12 application in solid-state fermentation production was considered the best application method for biocontrol of rice sheath blight.
The method of application of biocontrol microorganism is important for a successful biocontrol of crop diseases. An experiment was carried out to screen microorganisms and analyze their application methods in biocontrol of rice sheath blight. The T12 fungus screened was identified as Trichoderma asperellum. The applications of conidia powder (CP), organic fertilizer adsorbed mycelia (MA) and solid-state fermentation product (SS) of T. asperellum T12 were compared on effectiveness in biocontrol of sheath blight. SS exhibited best biocontrol efficacy, which was 89.5%. The cfus (colony forming unit) of T. asperellum adhering to sclerotia of Rhizoctonia solani in the soil was significantly higher in MA and SS treatments than in the control and CP treatments (P > 0.05). The MA and SS application methods enhanced the growth of T. asperellum along rice sheath. On the 60th day, 100th day and 130th day after rice transplanting, T. asperellum population on leaf and sheath surfaces of rice indicated that the best and worst treatments were respectively CP and MA. R. solani population on leaf and sheath surface in the control treatment increased from 41 cfu·g-1 to 272 cfu·g-1 (P > 0.05), higher than that in the other treatments (P > 0.05). R. solani population in SS treatment was significantly lower than that in MA and CP treatments (P > 0.05). Compared with control treatment, all the three application methods induced higher enzyme activities of chitinase and β-1,3-glucanase (P > 0.05), while SS and MA induced longer disease resistance than CP. Therefore T. asperellum T12 application in solid-state fermentation production was considered the best application method for biocontrol of rice sheath blight.
2014, 22(12): 1476-1483.
doi: 10.13930/j.cnki.cjea.140868
Abstract:
To investigate the effect of photoperiod on growth and development of two color morphs of pea aphid [Acyrthosiphon pisum (Harris)], red and green color morphs of pea aphid were treated with different photoperiods (10L∶14D, 16L∶8D and 22L∶2D) under different light intensities [low (103 μmol·m-2 s-1), middle (212 μmol·m-2 s-1) and high (313 μmol·m-2 s-1)]. Instars developmental duration, weight difference, mean relative growth rate per day (MRGR) measured. The results showed that at 10L∶14 D photoperiod, the duration of the 4th instar of green color morph prolonged by 0.21 d compared with that of red color morph. While development duration of green color morphs delayed under low light intensity (P < 0.05), there were no significant differences in weight difference and in MRGR between red and green color pea aphid morphs. At 16L∶8D photoperiod, the duration of the 3rd instar of red color morph prolonged by 0.52 d and the development duration of red color morphs also delayed under low light intensity (P < 0.05), compared with those of green color morphs. There were also no significant differences in weight difference and MRGR between red and green color morphs under low light intensity (P > 0.05). At 22L∶2D photoperiod, the durations of the 2nd, and 4th instar of red color morphs prolonged respectively by 0.12 d and 0.22 d under low light intensity (P < 0.05) compared with those of the green color morphs. There were also no significant differences in development duration, weight difference and MRGR between red and green color morphs of pea aphid under low light intensity (P > 0.05). At 10L∶14D photoperiod, weight difference and MRGR of green color morphs decreased respectively by 6.76% and 14.63% compared with those of red color morphs under middle light intensity (P < 0.05). At 16L∶8D photoperiod, the duration of the 1st, 2nd, and 4th instar of green color morphs prolonged respectively by 0.23 d, 0.60 d and 0.33 d under middle light intensity (P < 0.05). Also green color morphs development duration delayed while weight difference decreased by 28.84% and MRGR decreased by 37.21% compared with those of red color morphs under middle light intensity (P < 0.05). At 22L∶2D photoperiod, the developmental duration of red color morphs delayed while MRGR increased by 12.00% compared with green color morphs under middle light intensity (P < 0.05). At 10L∶14D photoperiod, the duration of the 4th instar of green color morph prolonged by 0.58 d over that of red color morph (P < 0.05), while at 16L∶8D photoperiod, the duration of the 1st instar of green color morphs prolonged by 1.63 d under high light intensity (P < 0.05). At 22L∶2D photoperiod, devel-opmental duration of red color morphs delayed (P < 0.05) while there were no significant differences in weight difference and MRGR between red and green color morphs under high light intensity (P > 0.05). In summary, longer photoperiods had positive effect on growth and development of the two color morphs of pea aphid. Moreover, stronger light intensity and shorter light cycle significantly delayed development of the two color morphs of pea aphids. Therefore the growth and development of pea aphids was influenced by light intensity, photoperiod and color morph pattern. It was therefore recommended to develop more efficient mechanisms to further study the characteristics of color morph of pea aphids.
To investigate the effect of photoperiod on growth and development of two color morphs of pea aphid [Acyrthosiphon pisum (Harris)], red and green color morphs of pea aphid were treated with different photoperiods (10L∶14D, 16L∶8D and 22L∶2D) under different light intensities [low (103 μmol·m-2 s-1), middle (212 μmol·m-2 s-1) and high (313 μmol·m-2 s-1)]. Instars developmental duration, weight difference, mean relative growth rate per day (MRGR) measured. The results showed that at 10L∶14 D photoperiod, the duration of the 4th instar of green color morph prolonged by 0.21 d compared with that of red color morph. While development duration of green color morphs delayed under low light intensity (P < 0.05), there were no significant differences in weight difference and in MRGR between red and green color pea aphid morphs. At 16L∶8D photoperiod, the duration of the 3rd instar of red color morph prolonged by 0.52 d and the development duration of red color morphs also delayed under low light intensity (P < 0.05), compared with those of green color morphs. There were also no significant differences in weight difference and MRGR between red and green color morphs under low light intensity (P > 0.05). At 22L∶2D photoperiod, the durations of the 2nd, and 4th instar of red color morphs prolonged respectively by 0.12 d and 0.22 d under low light intensity (P < 0.05) compared with those of the green color morphs. There were also no significant differences in development duration, weight difference and MRGR between red and green color morphs of pea aphid under low light intensity (P > 0.05). At 10L∶14D photoperiod, weight difference and MRGR of green color morphs decreased respectively by 6.76% and 14.63% compared with those of red color morphs under middle light intensity (P < 0.05). At 16L∶8D photoperiod, the duration of the 1st, 2nd, and 4th instar of green color morphs prolonged respectively by 0.23 d, 0.60 d and 0.33 d under middle light intensity (P < 0.05). Also green color morphs development duration delayed while weight difference decreased by 28.84% and MRGR decreased by 37.21% compared with those of red color morphs under middle light intensity (P < 0.05). At 22L∶2D photoperiod, the developmental duration of red color morphs delayed while MRGR increased by 12.00% compared with green color morphs under middle light intensity (P < 0.05). At 10L∶14D photoperiod, the duration of the 4th instar of green color morph prolonged by 0.58 d over that of red color morph (P < 0.05), while at 16L∶8D photoperiod, the duration of the 1st instar of green color morphs prolonged by 1.63 d under high light intensity (P < 0.05). At 22L∶2D photoperiod, devel-opmental duration of red color morphs delayed (P < 0.05) while there were no significant differences in weight difference and MRGR between red and green color morphs under high light intensity (P > 0.05). In summary, longer photoperiods had positive effect on growth and development of the two color morphs of pea aphid. Moreover, stronger light intensity and shorter light cycle significantly delayed development of the two color morphs of pea aphids. Therefore the growth and development of pea aphids was influenced by light intensity, photoperiod and color morph pattern. It was therefore recommended to develop more efficient mechanisms to further study the characteristics of color morph of pea aphids.
2014, 22(12): 1484-1490.
doi: 10.13930/j.cnki.cjea.140412
Abstract:
Golden apple snail (Pomacea canaliculata) was included in the first class of blacklisted invasive alien species in China. In a 48-day period of intermittent drought experiment with different drought-flooding intervals, drought-flooding treatments were carried out to examine changes in growth, antioxidant capacity and digestive enzyme activities of P. canaliculata. The results showed that intermittent drought significantly reduced the increase rate of weight without obviously influencing survival rate of snails. Snails compensated growth mainly by increasing food consumption during re-feeding period under flooding conditon. When intermittent drought duration was extended to 8 days, compensatory growth started by increasing feed intake and enhanced food conversion ratio. Except for the activity of superoxide dismutase (SOD) in 4-day interval treatment, intermittent drought treatments with short intervals (1 4 days) improved SOD and catalase (CAT) activities in hepatopancreas while decreasing the content of malondialdehyde (MDA) in snails. However, SOD and CAT activities in 8-day interval treatment were lower than those of the control group, but MDA content was not significantly different compared with the control. The levels of glutathioneperoxidase (GSH-PX) and glutathione-S- transferase (GST) in the liver of snail dropped down under different intermittent drought stress treatments while glutathione (GSH) content remained unchanged. Except for lipase activity under 1-day interval treatment, intermittent drought treatments also improved amylase and lipase activities on different levels in the stomach of snails. In conclusion, snails enhanced feed intake, food conversion ratio, antioxidant capacity and digestive enzyme activity to protect them from the intermittent drought stress. However, this form of stress significantly influenced normal feeding and growth processes of snails. The findings pointed to the possibility to control snail occurrence and to decrease its damage by periodically regulating water levels in paddy fields.
Golden apple snail (Pomacea canaliculata) was included in the first class of blacklisted invasive alien species in China. In a 48-day period of intermittent drought experiment with different drought-flooding intervals, drought-flooding treatments were carried out to examine changes in growth, antioxidant capacity and digestive enzyme activities of P. canaliculata. The results showed that intermittent drought significantly reduced the increase rate of weight without obviously influencing survival rate of snails. Snails compensated growth mainly by increasing food consumption during re-feeding period under flooding conditon. When intermittent drought duration was extended to 8 days, compensatory growth started by increasing feed intake and enhanced food conversion ratio. Except for the activity of superoxide dismutase (SOD) in 4-day interval treatment, intermittent drought treatments with short intervals (1 4 days) improved SOD and catalase (CAT) activities in hepatopancreas while decreasing the content of malondialdehyde (MDA) in snails. However, SOD and CAT activities in 8-day interval treatment were lower than those of the control group, but MDA content was not significantly different compared with the control. The levels of glutathioneperoxidase (GSH-PX) and glutathione-S- transferase (GST) in the liver of snail dropped down under different intermittent drought stress treatments while glutathione (GSH) content remained unchanged. Except for lipase activity under 1-day interval treatment, intermittent drought treatments also improved amylase and lipase activities on different levels in the stomach of snails. In conclusion, snails enhanced feed intake, food conversion ratio, antioxidant capacity and digestive enzyme activity to protect them from the intermittent drought stress. However, this form of stress significantly influenced normal feeding and growth processes of snails. The findings pointed to the possibility to control snail occurrence and to decrease its damage by periodically regulating water levels in paddy fields.
2014, 22(12): 1491-1497.
doi: 10.13930/j.cnki.cjea.140931
Abstract:
Multiple cropping rotation system has been an important measure for development of recycling agriculture management. Energy conversion and material recycling have constituted the basic functions of ecosystems and the most important researches on farmland ecosystems. In order to investigate the advantages of multiple cropping rotation farming systems, a field experiment was carried out to analyze the characteristics of energy conversion and material recycling in continuous cropping and crop rotation systems in paddy ecosystems in Nanchang, Jiangxi Province. The results showed that multiple cropping rotation system improved energy conversion and material recycling in paddy ecosystems. In terms of energy conversion, average gross primary productivity, total energy investment, solar energy utilization and auxiliary energy output-input ratio of multiple cropping rotation treatments were respectively 31.35%, 4.90%, 31.36% and 25.04% higher than those of continuous cropping system. In terms of material recycling, K nutrient utilization was significantly higher than continuous cropping. N and P output/input of every treatment was less than 1, showing that N and P maintained a positive balance in paddy ecosystems. However, the smaller K input than output in paddy systems showed serious loss of K in the system. Thus multiple cropping rotation system improved energy conversion and material recycling in rice cultivation regions in South China. Multiple cropping rotation system not only induced a state of virtuous cycle in farmland ecosystems, also promoted the development of circular agriculture.
Multiple cropping rotation system has been an important measure for development of recycling agriculture management. Energy conversion and material recycling have constituted the basic functions of ecosystems and the most important researches on farmland ecosystems. In order to investigate the advantages of multiple cropping rotation farming systems, a field experiment was carried out to analyze the characteristics of energy conversion and material recycling in continuous cropping and crop rotation systems in paddy ecosystems in Nanchang, Jiangxi Province. The results showed that multiple cropping rotation system improved energy conversion and material recycling in paddy ecosystems. In terms of energy conversion, average gross primary productivity, total energy investment, solar energy utilization and auxiliary energy output-input ratio of multiple cropping rotation treatments were respectively 31.35%, 4.90%, 31.36% and 25.04% higher than those of continuous cropping system. In terms of material recycling, K nutrient utilization was significantly higher than continuous cropping. N and P output/input of every treatment was less than 1, showing that N and P maintained a positive balance in paddy ecosystems. However, the smaller K input than output in paddy systems showed serious loss of K in the system. Thus multiple cropping rotation system improved energy conversion and material recycling in rice cultivation regions in South China. Multiple cropping rotation system not only induced a state of virtuous cycle in farmland ecosystems, also promoted the development of circular agriculture.
2014, 22(12): 1498-1508.
doi: 10.13930/j.cnki.cjea.140498
Abstract:
This paper proposed the Contingent Valuation Method (CVM) for estimating cultivated land protection externality. The proposed CVM was based on reconstruction of cultivated land utilization benefit system and defined cultivated land protection externality. The paper discussed in detail specific techniques of sample size and distribution, determination of leading technology, pay/compensation interval setting, hypothetical market scenario setting, evasion of deviation, pretreatment of survey data, and results validity/reliability tests. The results showed that ecological and social benefits of cultivated lands included public goods with mixed classes across categories. These classes were provided by joint ventures between the pure positive externalities and the private sector (mainly farmers). This could be estimated by using CVM and other non-market valuation methods. The willingness to pay of interviewee for this service was heavily restricted and influenced by their levels of socioeconomic development. The recognition of ecological and social benefits of cultivated lands of farmers and urban residents formed the main causality factor for the differences in payment ratio between urban residents and rural farmers. Urban residents were more familiar with ecological and social benefits of cultivated lands than rural/farm households. This was probably a key factor influencing the willingness to pay for ecological services. Farm households preferred voluntary labor as mean of payment, while both money and voluntary labor were more preferred by urban residents. The probable reason for this was that farm households had more leisure time than urban residents. Unitary cultivated land protection externality for Jiaozuo City was 1.91×108 Yuan·a-1 and the cultivated land protection externality per unit area of cultivated land was 993.7 Yuan·hm-2·a-1 base on CVM. CVM validity and reliability test was a critical element of CVM theory, method and practice. This was obtained through questionnaire optimization, pre-survey, questionnaire revision, rational inquiry, comparative analysis of different estimation methods, and repeated tests of the same method. The test results showed it was reliable and valid to use CVM estimating the cultivated land protection externality.
This paper proposed the Contingent Valuation Method (CVM) for estimating cultivated land protection externality. The proposed CVM was based on reconstruction of cultivated land utilization benefit system and defined cultivated land protection externality. The paper discussed in detail specific techniques of sample size and distribution, determination of leading technology, pay/compensation interval setting, hypothetical market scenario setting, evasion of deviation, pretreatment of survey data, and results validity/reliability tests. The results showed that ecological and social benefits of cultivated lands included public goods with mixed classes across categories. These classes were provided by joint ventures between the pure positive externalities and the private sector (mainly farmers). This could be estimated by using CVM and other non-market valuation methods. The willingness to pay of interviewee for this service was heavily restricted and influenced by their levels of socioeconomic development. The recognition of ecological and social benefits of cultivated lands of farmers and urban residents formed the main causality factor for the differences in payment ratio between urban residents and rural farmers. Urban residents were more familiar with ecological and social benefits of cultivated lands than rural/farm households. This was probably a key factor influencing the willingness to pay for ecological services. Farm households preferred voluntary labor as mean of payment, while both money and voluntary labor were more preferred by urban residents. The probable reason for this was that farm households had more leisure time than urban residents. Unitary cultivated land protection externality for Jiaozuo City was 1.91×108 Yuan·a-1 and the cultivated land protection externality per unit area of cultivated land was 993.7 Yuan·hm-2·a-1 base on CVM. CVM validity and reliability test was a critical element of CVM theory, method and practice. This was obtained through questionnaire optimization, pre-survey, questionnaire revision, rational inquiry, comparative analysis of different estimation methods, and repeated tests of the same method. The test results showed it was reliable and valid to use CVM estimating the cultivated land protection externality.
Editor-in-chief：LIU Changming
Competent Authorities：Chinese Academy of Sciences
Sponsored by：Institute of Genetics and Developmental Biology, Chinese Academy of Sciences; China Ecological Economics Society
Organizer：Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
ISSN 2096-6237
CN 13-1432/S
- Chinese core periodicals
- Core Chinese Sci-Tech Periodicals
- China's Top Science and Technology Periodicals
- Covered by Chinese Science Citation Database (CSCD)
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