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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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2013 Vol. 21, No. 4
Display Method:
Soil phosphorous accumulation in long-term P fertilization paddy field and its environmental effects
2013, 21(4): 393-400.
doi: 10.3724/SP.J.1011.2013.00393
Abstract:
The continuous and excessive application of phosphorus (P) fertilizers and manure in intensive agricultural systems have led to soil P accumulation and progressive saturation of soil sorption capacity. This has significantly influenced soil P loss and P accumulation in aquatic ecosystems. The Taihu Lake Region of the Yangtse River Delta has for decades been a highly intensive agricultural production zone in China. Here, applications of chemical fertilizers and farmyard manure have been an effective method of improving soil fertility and productivity. Long-term applications of fertilizers and/or manure, often in excess of immediate plant uptake, have resulted in significant P accumulation and loss in this region. This has considerably increased the potential for eutrophication in the Taihu Lake. The change-point theory (with a soil Olsen-P content threshold above which the potential for significant P loss from soils to water systems occurred) has been considered to be scientific and useful in P management in agricultural soils. Up to date, however, there has been less report with respect to the Olsen-P change-point theory for paddy soils in the Taihu Lake Region. In this study, a long-term (13 years) P fertilization experiment in four P application doses (0 kg·hm-2·a-1, 30 kg·hm-2·a-1, 60 kg·hm-2·a-1 and 90 kg·hm -2·a-1) was conducted in the Taihu Lake Region to evaluate the accumulation of Olsen-P under rice-wheat rotation cropping system. The experiment evaluated the environmental risks caused by P loss from soils to water systems. Topsoil (0~15 cm), surface water and leachates (30 cm and 60 cm) Olsen-P and total P (TP) contents were determined. Furthermore, a split-line regression model was used to estimate the risks of P loss from soils to water bodies and the change-point of soil Olsen-P in the Taihu Lake Region determined. Although, TP concentrations in surface water bodies and in 30 cm leachate significantly increased with increasing application rate of fertilizer-P, no significant increase was observed in the 60 cm leachate. As the risk of P runoff was mainly in the first 9 days after fertilizer-P application, it was advisable to control paddy field drainage during this period. Split-line regression analysis suggested that the change-points of Olsen-P content in surface soil triggering P leaching and runoff were respectively 26.0 mg·kg-1, 24.8 mg·kg-1. Fertilizer-P application at 60 kg·hm-2·a-1 and 90 kg·hm-2·a-1for 13 years resulted in respective soil Olsen-P accumulation of 26.9 mg·kg-1 and 33.2 mg·kg-1, which were all higher than the change-points. TP concentration of 30 cm leachate was also increased significantly. With continuous application of fertilizer-P at 30 kg·hm-2·a-1 for 13 years, soil Olsen-P content remained at (10.1±2.0) mg·kg-1. This was sufficient for optimum rice/wheat growth without any risk of P loss. It was therefore not suitable to continuously apply 60 kg·hm-2·a-1 of fertilizer-P for a long time in paddy fields. The results demonstrated that intermittent fertilizer-P applications at 30 kg·hm-2·a-1 and 60 kg·hm-2·a-1 were suitable for rice-wheat rotation cropping system in the Taihu Lake Region.
The continuous and excessive application of phosphorus (P) fertilizers and manure in intensive agricultural systems have led to soil P accumulation and progressive saturation of soil sorption capacity. This has significantly influenced soil P loss and P accumulation in aquatic ecosystems. The Taihu Lake Region of the Yangtse River Delta has for decades been a highly intensive agricultural production zone in China. Here, applications of chemical fertilizers and farmyard manure have been an effective method of improving soil fertility and productivity. Long-term applications of fertilizers and/or manure, often in excess of immediate plant uptake, have resulted in significant P accumulation and loss in this region. This has considerably increased the potential for eutrophication in the Taihu Lake. The change-point theory (with a soil Olsen-P content threshold above which the potential for significant P loss from soils to water systems occurred) has been considered to be scientific and useful in P management in agricultural soils. Up to date, however, there has been less report with respect to the Olsen-P change-point theory for paddy soils in the Taihu Lake Region. In this study, a long-term (13 years) P fertilization experiment in four P application doses (0 kg·hm-2·a-1, 30 kg·hm-2·a-1, 60 kg·hm-2·a-1 and 90 kg·hm -2·a-1) was conducted in the Taihu Lake Region to evaluate the accumulation of Olsen-P under rice-wheat rotation cropping system. The experiment evaluated the environmental risks caused by P loss from soils to water systems. Topsoil (0~15 cm), surface water and leachates (30 cm and 60 cm) Olsen-P and total P (TP) contents were determined. Furthermore, a split-line regression model was used to estimate the risks of P loss from soils to water bodies and the change-point of soil Olsen-P in the Taihu Lake Region determined. Although, TP concentrations in surface water bodies and in 30 cm leachate significantly increased with increasing application rate of fertilizer-P, no significant increase was observed in the 60 cm leachate. As the risk of P runoff was mainly in the first 9 days after fertilizer-P application, it was advisable to control paddy field drainage during this period. Split-line regression analysis suggested that the change-points of Olsen-P content in surface soil triggering P leaching and runoff were respectively 26.0 mg·kg-1, 24.8 mg·kg-1. Fertilizer-P application at 60 kg·hm-2·a-1 and 90 kg·hm-2·a-1for 13 years resulted in respective soil Olsen-P accumulation of 26.9 mg·kg-1 and 33.2 mg·kg-1, which were all higher than the change-points. TP concentration of 30 cm leachate was also increased significantly. With continuous application of fertilizer-P at 30 kg·hm-2·a-1 for 13 years, soil Olsen-P content remained at (10.1±2.0) mg·kg-1. This was sufficient for optimum rice/wheat growth without any risk of P loss. It was therefore not suitable to continuously apply 60 kg·hm-2·a-1 of fertilizer-P for a long time in paddy fields. The results demonstrated that intermittent fertilizer-P applications at 30 kg·hm-2·a-1 and 60 kg·hm-2·a-1 were suitable for rice-wheat rotation cropping system in the Taihu Lake Region.
2013, 21(4): 401-408.
doi: 10.3724/SP.J.1011.2013.00401
Abstract:
A pot experiment was conducted in a rain-light shad to provide scientific basis for citrus nitrogen nutrient and fertilizer management via analysis of the effects of different nitrogen forms and ratios [NO3--N∶NH4+-N at 100∶0 (CaNO3·4H2O 42.16 g·pot-1), NO3--N∶NH4+-N at 75∶25 (CaNO3·4H2O 31.62 g·pot-1 and NH4HCO3 7.06 g·pot-1), NO3--N∶NH4+-N at 50∶50 (CaNO3·4H2O 21.08 g·pot-1 and NH4HCO3 14.12 g·pot-1), NO3--N∶NH4+-N at 25∶75 (CaNO3·4H2O 10.54 g·pot-1 and NH4HCO3 21.19 g·pot-1), and NO3--N∶NH4+-N at 0∶100 (NH4HCO3 28.25 g·pot-1 or CO(NH2)2 10.71 g·pot-1)]. Also the daily changes in photosynthetic rates (Pn), photosynthetic pigments (Chal. a, Chl. b, Car.) contents, light compensation point (LCP) and light saturation point (LSP) of Newhall navel orange grafted in trifoliate orange were analyzed. The results showed that under the mixed dose of NO3--N and NH4+-N at the ratio of 75∶25, contents of Chl. a, Chl. b and Car. and Pn were significantly higher than those under other nitrogen sources treatments. Pn, Tr, WUE and Gs of Newhall navel orange at 10:00 reached highest values with 4.81 μmol(CO2)·m-2·s-1, 2.30 mmol(CO2)·m-2·s-1, 2.09 and 0.09 mol·m-2·s-1, respectively. The contents of Chl. a, Chl. b and Car., and Pn , Tr, WUE and Gs all decreased with increasing NH4+-N/NO3--N ratio. Under sole NO3--N (NO3--N∶NH4+-N=100∶0), Pn was 3.53 μmol(CO2)·m-2·s-1, significantly lower than that under mixed NO3--N and NH4+-N dose (NO3--N∶NH4+-N=75∶25). Under the sole CO(NH2)2, the contents of Chl. a, Chl. b and Car. and Pn were lowest, and Pn was only 3.07 μmol(CO2)·m-2·s-1. No significant differences were noted in Newhall navel orange Pn under the sole NH4+-N and CO(NH2)2. Also no significant differences were noted in LCP and LSP of Newhall navel orange among different nitrogen resources treatments. Both points were respectively maintained at 861.51 μmol·m-2·s-1 and 10.09 μmol·m-2·s-1. Mixed dose of NO3--N and NH4+-N at the ratio of 75∶25 was beneficial to Newhall navel orange in terms of Pn improvement.
A pot experiment was conducted in a rain-light shad to provide scientific basis for citrus nitrogen nutrient and fertilizer management via analysis of the effects of different nitrogen forms and ratios [NO3--N∶NH4+-N at 100∶0 (CaNO3·4H
2013, 21(4): 409-415.
doi: 10.3724/SP.J.1011.2013.00409
Abstract:
Anaerobic ammonium oxidizing (anammox) bacteria of phylum Planctomycetes origin have been identified to be responsible for N removal in terrestrial and aquatic environments through combined NH4+ oxidation and NO2 reduction. Anaerobic ammonium oxidation mediated by anammox bacteria has been noted to be a key process of biogeochemical N cycle in various ecosystems. It was also possible to have anammox processes in flooded paddy fields because of the low oxygen habitat conditions. To investigate the existence of anammox bacteria and the bacteria community diversity response to applied N fertilizer in paddy fields, anammox bacteria community structures in paddy fields were investigated with the aid of denaturing gradient gel electrophoresis and cloning sequencing by assay 16S rRNA gene in the third year of N fertilizer experiment in the field. DGGE images of 16S rRNA gene in surface or root-zone soil showed rich anammox bacteria in paddy soils. The numbers of DGGE band in the images of surface soil or root-zone soil under high N level treatment [N3: 225 kg(N)·hm-2] were greater than those under other N levels [N2: 150 kg(N)·hm-2, N1: 75 kg(N)·hm-2 and CK: without fertilizer]. The Shannon-Wiener index based on the number and density of DGGE band showed significantly (P < 0.05) higher diversity of anammox bacteria in surface soil or root-zone soil under N3 treatment than N2, N1 or CK treatments. At the same time, Shannon-Wiener index of anammox bacteria in surface soil was markedly (P < 0.05) higher than in root-zone soil under N3 treatment. Redundancy discriminate analysis (RDA) based on 16S rRNA gene DGGE profiles showed significant correlation (P = 0.006) of anammox bacteria community structure in surface soils of paddy fields with different levels of N fertilizer application. RDA plot depicted that anammox bacteria community structure in surface soil under N3 treatment obviously differed from that under N1 or CK treatment. Furthermore, 18 DNA sequences cloning from DGGE band was obtained and logged in GenBank. The findings demonstrated that anammox bacteria community structure in paddy soils strongly responded to intensive N fertilizer use especially in surface paddy soils. Anammox bacteria possibly played a critical role in N cycle in paddy soil ecosystem.
Anaerobic ammonium oxidizing (anammox) bacteria of phylum Planctomycetes origin have been identified to be responsible for N removal in terrestrial and aquatic environments through combined NH4+ oxidation and NO2 reduction. Anaerobic ammonium oxidation mediated by anammox bacteria has been noted to be a key process of biogeochemical N cycle in various ecosystems. It was also possible to have anammox processes in flooded paddy fields because of the low oxygen habitat conditions. To investigate the existence of anammox bacteria and the bacteria community diversity response to applied N fertilizer in paddy fields, anammox bacteria community structures in paddy fields were investigated with the aid of denaturing gradient gel electrophoresis and cloning sequencing by assay 16S rRNA gene in the third year of N fertilizer experiment in the field. DGGE images of 16S rRNA gene in surface or root-zone soil showed rich anammox bacteria in paddy soils. The numbers of DGGE band in the images of surface soil or root-zone soil under high N level treatment [N3: 225 kg(N)·hm-2] were greater than those under other N levels [N2: 150 kg(N)·hm-2, N1: 75 kg(N)·hm-2 and CK: without fertilizer]. The Shannon-Wiener index based on the number and density of DGGE band showed significantly (P < 0.05) higher diversity of anammox bacteria in surface soil or root-zone soil under N3 treatment than N2, N1 or CK treatments. At the same time, Shannon-Wiener index of anammox bacteria in surface soil was markedly (P < 0.05) higher than in root-zone soil under N3 treatment. Redundancy discriminate analysis (RDA) based on 16S rRNA gene DGGE profiles showed significant correlation (P = 0.006) of anammox bacteria community structure in surface soils of paddy fields with different levels of N fertilizer application. RDA plot depicted that anammox bacteria community structure in surface soil under N3 treatment obviously differed from that under N1 or CK treatment. Furthermore, 18 DNA sequences cloning from DGGE band was obtained and logged in GenBank. The findings demonstrated that anammox bacteria community structure in paddy soils strongly responded to intensive N fertilizer use especially in surface paddy soils. Anammox bacteria possibly played a critical role in N cycle in paddy soil ecosystem.
2013, 21(4): 416-425.
doi: 10.3724/SP.J.1011.2013.00416
Abstract:
To investigate the effect of irrigation and fertilization on photosynthetic physiology of super rice, a pot experiment was conducted using super rice "Zhongzheyou 1" as experimental crop. The study analyzed the photosynthetic physiology parameters [net photosynthetic rate,Pn; intercellular CO2 concentration, Ci; photosynthetic light response curve and photosynthetic pigment contents of chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), total chlorophyll content (TCC)] of rice under three irrigation methods [controlled irrigation (CIR), intermittent irrigation (IIR) and flood irrigation (FIR)] and three fertilization levels [non-fertilization (F0), low fertilization (FL) and high fertilization (FH)]. It also conducted correlation analysis for Pn and chlorophyll contents. The results showed that compared with FIR, CIR and IIR treatments (saving-water irrigation methods) significantly increased Pn. It, however, failed to significantly enhance Ci at the jointing, heading and milking stages. Both CIR and IIR increased light saturation point (LSP) by 9.2%~36.8% at the jointing and heading stages and apparent quantum yield by 6.7%~31.5% respectively at the three growth stages, while they decreased light compensation point by 3.2%~12.8% at the jointing, heading and milking stages. Compared with FIR, CIR respectively increased the contents of Chl a, Chl b, Car and TCC by 19.1%~76.3%, 44.5%~98.5%, 31.5%~117.4% and 45.4%~145.0% at the jointing, heading and milking stages. IIR treatment respectively enhanced the contents of Car and TCC by 4.2%~45.8% and 31.5%~117.4% at the three growth stages. Under the three irrigation treatments, photosynthetic indices and photosynthetic pigment contents were higher under fertilization than non-fertilization treatments. High fertilization also resulted in higher photosynthetic indices and photosynthetic pigment content than low fertilization. Correlation analysis showed significant correlation between Pn and photosynthetic pigments contents, which correlations were influenced by growth stages. CIR and IIR improved photosynthetic capacity under strong light, and adaptability to weak light; and significantly increased light utilization rate. Compared with FIR, CIR and IIR increased photosynthetic pigment content but delayed photosynthetic pigment degradation. It was concluded that CIR and IIR treatments enhanced photosynthetic capacity, improved the photosynthetic light response curve and increased photosynthetic pigment contents. In terms of fertilization rate, high fertilization increased photosynthetic capacity of "Zhongzheyou 1" under saving-water irrigation treatments.
To investigate the effect of irrigation and fertilization on photosynthetic physiology of super rice, a pot experiment was conducted using super rice "Zhongzheyou 1" as experimental crop. The study analyzed the photosynthetic physiology parameters [net photosynthetic rate,Pn; intercellular CO2 concentration, Ci; photosynthetic light response curve and photosynthetic pigment contents of chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), total chlorophyll content (TCC)] of rice under three irrigation methods [controlled irrigation (CIR), intermittent irrigation (IIR) and flood irrigation (FIR)] and three fertilization levels [non-fertilization (F0), low fertilization (FL) and high fertilization (FH)]. It also conducted correlation analysis for Pn and chlorophyll contents. The results showed that compared with FIR, CIR and IIR treatments (saving-water irrigation methods) significantly increased Pn. It, however, failed to significantly enhance Ci at the jointing, heading and milking stages. Both CIR and IIR increased light saturation point (LSP) by 9.2%~36.8% at the jointing and heading stages and apparent quantum yield by 6.7%~31.5% respectively at the three growth stages, while they decreased light compensation point by 3.2%~12.8% at the jointing, heading and milking stages. Compared with FIR, CIR respectively increased the contents of Chl a, Chl b, Car and TCC by 19.1%~76.3%, 44.5%~98.5%, 31.5%~117.4% and 45.4%~145.0% at the jointing, heading and milking stages. IIR treatment respectively enhanced the contents of Car and TCC by 4.2%~45.8% and 31.5%~117.4% at the three growth stages. Under the three irrigation treatments, photosynthetic indices and photosynthetic pigment contents were higher under fertilization than non-fertilization treatments. High fertilization also resulted in higher photosynthetic indices and photosynthetic pigment content than low fertilization. Correlation analysis showed significant correlation between Pn and photosynthetic pigments contents, which correlations were influenced by growth stages. CIR and IIR improved photosynthetic capacity under strong light, and adaptability to weak light; and significantly increased light utilization rate. Compared with FIR, CIR and IIR increased photosynthetic pigment content but delayed photosynthetic pigment degradation. It was concluded that CIR and IIR treatments enhanced photosynthetic capacity, improved the photosynthetic light response curve and increased photosynthetic pigment contents. In terms of fertilization rate, high fertilization increased photosynthetic capacity of "Zhongzheyou 1" under saving-water irrigation treatments.
2013, 21(4): 426-431.
doi: 10.3724/SP.J.1011.2013.00426
Abstract:
The North Yin Mountain Region (NYMR), the main potato production region in Inner Mongolia, is highly limited in water resources. Water-saving cultivation techniques have therefore been increasingly used in this region in recent years. To evaluate the effects of different irrigation methods on water and nutrient use efficiency and the eco-environmental benefits of potato cultivation, field experiments were conducted in 2009-2010 in the Wuchuan Region of NYMR, Inner Mongolia. The field experiment was consisted of four different irrigation patterns - flood irrigation (FI), ground sprinkler (GS), drip irrigation (DI) and under-mulch-drip irrigation (UMDI). The irrigation patterns were compared in terms of potato tuber yield, water and nutrient use efficiency, net economic income and soil inorganic nitrogen residue. The results showed that UMDI increased potato yield over conventional farm practice FI, GS and DI by 35.7%, 26.0% and 12.9%, water use efficiency by 200.2%, 91.8% and 23.7% and net economic income by 37.7%, 30.1% and 10.7%, respectively. Nitrogen fertilizer partial factor productivity under UMDI was respectively 50.6 kg·kg-1, 39.8 kg·kg-1 and 22.0 kg·kg-1 higher than those under FI, GS and DI. Also phosphorus fertilizer partial factor productivity under UMDI was respectively 126.6 kg·kg-1, 99.4 kg·kg-1 and 55.0 kg·kg-1 higher than those under FI, GS and DI. Then potassium fertilizer partial factor productivity under UMDI was respectively 42.3 kg·kg-1, 33.2 kg·kg-1 and 18.4 kg·kg-1 higher than those under FI, GS and DI. Soil inorganic nitrogen residue in the 60~120 cm soil layer after potato harvest was 102.95 kg·hm-2 under FI, which was 0.36, 1.11 and 1.28 times higher than those under GS, DI and UMDI, respectively. The above results suggested that DI and UMDI not only saved water resources, but also enhanced potato yield, nutrient use efficiency and net economic income in the research area. This was critical for reducing the risk of environmental pollution due to nitrogen leaching. It was therefore important to intensify DI and UMDI irrigation patterns in potato fields in the NYMR for higher yields, resources use efficiencies and low environmental pollution risks.
The North Yin Mountain Region (NYMR), the main potato production region in Inner Mongolia, is highly limited in water resources. Water-saving cultivation techniques have therefore been increasingly used in this region in recent years. To evaluate the effects of different irrigation methods on water and nutrient use efficiency and the eco-environmental benefits of potato cultivation, field experiments were conducted in 2009-2010 in the Wuchuan Region of NYMR, Inner Mongolia. The field experiment was consisted of four different irrigation patterns - flood irrigation (FI), ground sprinkler (GS), drip irrigation (DI) and under-mulch-drip irrigation (UMDI). The irrigation patterns were compared in terms of potato tuber yield, water and nutrient use efficiency, net economic income and soil inorganic nitrogen residue. The results showed that UMDI increased potato yield over conventional farm practice FI, GS and DI by 35.7%, 26.0% and 12.9%, water use efficiency by 200.2%, 91.8% and 23.7% and net economic income by 37.7%, 30.1% and 10.7%, respectively. Nitrogen fertilizer partial factor productivity under UMDI was respectively 50.6 kg·kg-1, 39.8 kg·kg-1 and 22.0 kg·kg-1 higher than those under FI, GS and DI. Also phosphorus fertilizer partial factor productivity under UMDI was respectively 126.6 kg·kg-1, 99.4 kg·kg-1 and 55.0 kg·kg-1 higher than those under FI, GS and DI. Then potassium fertilizer partial factor productivity under UMDI was respectively 42.3 kg·kg-1, 33.2 kg·kg-1 and 18.4 kg·kg-1 higher than those under FI, GS and DI. Soil inorganic nitrogen residue in the 60~120 cm soil layer after potato harvest was 102.95 kg·hm-2 under FI, which was 0.36, 1.11 and 1.28 times higher than those under GS, DI and UMDI, respectively. The above results suggested that DI and UMDI not only saved water resources, but also enhanced potato yield, nutrient use efficiency and net economic income in the research area. This was critical for reducing the risk of environmental pollution due to nitrogen leaching. It was therefore important to intensify DI and UMDI irrigation patterns in potato fields in the NYMR for higher yields, resources use efficiencies and low environmental pollution risks.
2013, 21(4): 432-439.
doi: 10.3724/SP.J.1011.2013.00432
Abstract:
Stem sap flow is a valuable plant water transportation parameter, meticulously indicating crop inner body water budget and driving natural growth of plants. Basic research on stem flow has not been completely enough in guiding dryland farming operations. It is therefore important to determine how stem flow reflects crop water balance under different cultivation models and to determine the relationship between water transport, cultivation pattern and environmental conditions. Sap flow rates of maize (Zea mays L.) under two cultivation patterns (traditional treatmentⅠ: "Shendan 16" at 45 000 plant·hm-2 and N 225 kg·hm-2 without mulching; improved treatmentⅡ: "Zhengdan 958" at 60 000 plant·hm-2 and N 225 kg·hm-2 and P2O5 112.5 kg·hm-2 with mulching) were continually measured by stem flow gauges (operated on heat balance method) along with combined environmental factors such as solar radiation, air temperature, and relative humidity to analyze variations in maize transpiration in the Loess Plateau. The results showed obvious maize sap flow rates in rhythm of daily variation as same as the radiation. Plants under treatment I had higher stem flow rate than those under treatmentⅡ. The maximum daily sap flow rates of maize were at tasseling stage, with values dropping at latter growth stages under the two cultivation treatments. This variation was also coincident with leaf area index. From tasseling to waxing stage, maize transpiration under treatmentsⅠandⅡwere respectively 115.18 mm and 119.47 mm. Compared with treatmentⅠ, soil evaporation under treatmentⅡdecreased by 39.2%. This implied that treatmentⅡoptimized the ratio of soil evaporation to maize evapotranspiration and improved WUE of the crop. Plant sap flow rates were affected by varied environmental factors, among which solar radiation was a critical meteorological factor. Daily sap flow rate per maize was significantly correlated with solar radiation, air temperature, vapor pressure deficit and relative humidity under both cultivation treatments.
Stem sap flow is a valuable plant water transportation parameter, meticulously indicating crop inner body water budget and driving natural growth of plants. Basic research on stem flow has not been completely enough in guiding dryland farming operations. It is therefore important to determine how stem flow reflects crop water balance under different cultivation models and to determine the relationship between water transport, cultivation pattern and environmental conditions. Sap flow rates of maize (Zea mays L.) under two cultivation patterns (traditional treatmentⅠ: "Shendan 16" at 45 000 plant·hm-2 and N 225 kg·hm-2 without mulching; improved treatmentⅡ: "Zhengdan 958" at 60 000 plant·hm-2 and N 225 kg·hm-2 and P2O5 112.5 kg·hm-2 with mulching) were continually measured by stem flow gauges (operated on heat balance method) along with combined environmental factors such as solar radiation, air temperature, and relative humidity to analyze variations in maize transpiration in the Loess Plateau. The results showed obvious maize sap flow rates in rhythm of daily variation as same as the radiation. Plants under treatment I had higher stem flow rate than those under treatmentⅡ. The maximum daily sap flow rates of maize were at tasseling stage, with values dropping at latter growth stages under the two cultivation treatments. This variation was also coincident with leaf area index. From tasseling to waxing stage, maize transpiration under treatmentsⅠandⅡwere respectively 115.18 mm and 119.47 mm. Compared with treatmentⅠ, soil evaporation under treatmentⅡdecreased by 39.2%. This implied that treatmentⅡoptimized the ratio of soil evaporation to maize evapotranspiration and improved WUE of the crop. Plant sap flow rates were affected by varied environmental factors, among which solar radiation was a critical meteorological factor. Daily sap flow rate per maize was significantly correlated with solar radiation, air temperature, vapor pressure deficit and relative humidity under both cultivation treatments.
2013, 21(4): 440-447.
doi: 10.3724/SP.J.1011.2013.00440
Abstract:
Starch is a major photosynthate and quality index for winter wheat. Planting density influences the growth and development of winter wheat through factors, such as, thermal, light, temperature, etc. This in turn influences the generation, development and transportation of photosynthate to wheat grains which eventually determine wheat yield and quality. Chlorophyll density is strongly related with spectral parameters and accumulated starch. Thus, chlorophyll density was used to serve as a link between canopy spectra and starch accumulation in this study. The aim of the study was to explore suitable density for forecasting accumulated starch content for the purpose of building a model for the accurate forecasting of starch accumulation via spectral remote sensing. In this study, "Jing 9549" winter wheat cultivar was cultivated in 2009 and the "Jing 9549", "Le 639" and "Chang 4738" cultivars cultivated in 2010 at planting densities of 3.0×106 plant·hm-2, 4.5×106 plant·hm-2, 6.0×106 plant·hm-2, 7.5×106 plant·hm-2, 9.0×106 plant·hm-2. In the field experiments, canopy spectral, chlorophyll density and starch accumulation of winter wheat were measured in the five different planting densities. The accuracy of the monitoring model with NDVI (1 200 nm, 670 nm) was highest (0.920 6) at 7.50×106 plant·hm-2 wheat planting density. The model was verified with data for the cultivation period of 2009 to 2010. The result showed a strong agreement with a correlation coefficient of 0.954 2. The 7.5×106 plant·hm-2 density was the most reasonable planting density for monitoring starch accumulation in winter wheat. Also the data for the five densities were integrated to construct a multi-density simulation model. The multi-density model accuracy was 0.883 1 and its relative error (RE) was also the lowest (0.905 4). Thus to some extent, the multi-density simulation model was widely applicable and practically significant. The spectral remote sensing monitoring model for observed optimum density and accumulated starch at different wheat planting densities gave the theoretical basis and guidance for large-scale monitoring of wheat quality from space.
Starch is a major photosynthate and quality index for winter wheat. Planting density influences the growth and development of winter wheat through factors, such as, thermal, light, temperature, etc. This in turn influences the generation, development and transportation of photosynthate to wheat grains which eventually determine wheat yield and quality. Chlorophyll density is strongly related with spectral parameters and accumulated starch. Thus, chlorophyll density was used to serve as a link between canopy spectra and starch accumulation in this study. The aim of the study was to explore suitable density for forecasting accumulated starch content for the purpose of building a model for the accurate forecasting of starch accumulation via spectral remote sensing. In this study, "Jing 9549" winter wheat cultivar was cultivated in 2009 and the "Jing 9549", "Le 639" and "Chang 4738" cultivars cultivated in 2010 at planting densities of 3.0×106 plant·hm-2, 4.5×106 plant·hm-2, 6.0×106 plant·hm-2, 7.5×106 plant·hm-2, 9.0×106 plant·hm-2. In the field experiments, canopy spectral, chlorophyll density and starch accumulation of winter wheat were measured in the five different planting densities. The accuracy of the monitoring model with NDVI (1 200 nm, 670 nm) was highest (0.920 6) at 7.50×106 plant·hm-2 wheat planting density. The model was verified with data for the cultivation period of 2009 to 2010. The result showed a strong agreement with a correlation coefficient of 0.954 2. The 7.5×106 plant·hm-2 density was the most reasonable planting density for monitoring starch accumulation in winter wheat. Also the data for the five densities were integrated to construct a multi-density simulation model. The multi-density model accuracy was 0.883 1 and its relative error (RE) was also the lowest (0.905 4). Thus to some extent, the multi-density simulation model was widely applicable and practically significant. The spectral remote sensing monitoring model for observed optimum density and accumulated starch at different wheat planting densities gave the theoretical basis and guidance for large-scale monitoring of wheat quality from space.
2013, 21(4): 448-455.
doi: 10.3724/SP.J.1011.2013.00448
Abstract:
The effects of organic amendments on the nutrient state of severe saline soil and reed growth under wastewater irrigation were investigated in this study. The results obtained were critical for bioremediation of degraded saline-alkali wetlands in coastal regions. Experiments were performed in a severely degraded coastal saline-alkali wetland (with salinity level of 16.7 g·kg-1) in the Binzhou County of Shandong Province, China. The experiments were started in the spring and four treatments were tested - tillage (CK) as the control; tillage + wastewater irrigation (FF), tillage + wastewater irrigation + grass straw application (FFJ) and tillage + wastewater irrigation + sludge application (FFW). For each treatment, soil organic matter increased significantly compared with CK. At the end of October, organic matter contents of FFJ, FFW and FF were 1.34, 1.29 and 1.22 times that of CK. Compared with CK, soil available nitrogen and phosphorus also increased with the order of FFW > FFJ > FF. The salinity of the top soil layer (0~20 cm) decreased in all the treatments, and especially in FFJ and FFW which decreased by 22.6% and 16.3%, respectively, compared with that of CK. At the end of August, reed height under FFW, FFJ and FF were 3.1, 2.7 and 2.2 times that of CK. Total biomass, root mass/crown mass and average leaf area under FFW and FFJ increased significantly (P < 0.05) compared with CK. Reed heights under FF, FFJ and FFW treatments significantly correlated with soil organic matter/available nitrogen with respective correlation coefficients (R2) of 0.897/0.963, 0.999/0.837 and 0.998/0.778. Total biomass under FF, FFJ and FFW treatments significantly correlated with soil organic matter/available nitrogen with respective R2 of 0.863/0.937, 0.971/0.876 and 0.996/0.799. Plant height and biomass significantly correlated with soil organic matter under FFJ and FFW, but only significantly correlated with soil available nitrogen under FF. The results showed that wastewater irrigation provided ample water in severe saline soil systems and organic amendments supplied massive amounts of soil nutrient. This relieved water and nutrient stress in severe saline soil and promoted reed growth, which combined effect was beneficial to the restoration of severe saline soils. No significant differences were found between soils amended with grass straw and those with sludge. This study showed that combined treatment of wastewater irrigation and organic amendment sufficiently reduced soil salinity in severe saline soils. Furthermore, the combined treatment of wastewater irrigation and organic amendments improved soil nutrient (organic matter and available nitrogen and phosphorus) content and soil microbial biomass (respiration intensity). The above-noted improvements were ultimately reflected in the improvements in reed plants - reed height, biomass and allocation, etc.
The effects of organic amendments on the nutrient state of severe saline soil and reed growth under wastewater irrigation were investigated in this study. The results obtained were critical for bioremediation of degraded saline-alkali wetlands in coastal regions. Experiments were performed in a severely degraded coastal saline-alkali wetland (with salinity level of 16.7 g·kg-1) in the Binzhou County of Shandong Province, China. The experiments were started in the spring and four treatments were tested - tillage (CK) as the control; tillage + wastewater irrigation (FF), tillage + wastewater irrigation + grass straw application (FFJ) and tillage + wastewater irrigation + sludge application (FFW). For each treatment, soil organic matter increased significantly compared with CK. At the end of October, organic matter contents of FFJ, FFW and FF were 1.34, 1.29 and 1.22 times that of CK. Compared with CK, soil available nitrogen and phosphorus also increased with the order of FFW > FFJ > FF. The salinity of the top soil layer (0~20 cm) decreased in all the treatments, and especially in FFJ and FFW which decreased by 22.6% and 16.3%, respectively, compared with that of CK. At the end of August, reed height under FFW, FFJ and FF were 3.1, 2.7 and 2.2 times that of CK. Total biomass, root mass/crown mass and average leaf area under FFW and FFJ increased significantly (P < 0.05) compared with CK. Reed heights under FF, FFJ and FFW treatments significantly correlated with soil organic matter/available nitrogen with respective correlation coefficients (R2) of 0.897/0.963, 0.999/0.837 and 0.998/0.778. Total biomass under FF, FFJ and FFW treatments significantly correlated with soil organic matter/available nitrogen with respective R2 of 0.863/0.937, 0.971/0.876 and 0.996/0.799. Plant height and biomass significantly correlated with soil organic matter under FFJ and FFW, but only significantly correlated with soil available nitrogen under FF. The results showed that wastewater irrigation provided ample water in severe saline soil systems and organic amendments supplied massive amounts of soil nutrient. This relieved water and nutrient stress in severe saline soil and promoted reed growth, which combined effect was beneficial to the restoration of severe saline soils. No significant differences were found between soils amended with grass straw and those with sludge. This study showed that combined treatment of wastewater irrigation and organic amendment sufficiently reduced soil salinity in severe saline soils. Furthermore, the combined treatment of wastewater irrigation and organic amendments improved soil nutrient (organic matter and available nitrogen and phosphorus) content and soil microbial biomass (respiration intensity). The above-noted improvements were ultimately reflected in the improvements in reed plants - reed height, biomass and allocation, etc.
2013, 21(4): 456-464.
doi: 10.3724/SP.J.1011.2013.00456
Abstract:
Groundwater quality has been related to drinking water safety and human health, and groundwater pollution directly affecting hydro-ecological environment. High phosphorus in the drinking water has been noted to reduce calcium and vitamin D absorption in humans, which has the potential negative effects on the health of the elderly. In this study, 27 water samples were collected from the groundwater system in the Dezhou Region located in the lower reaches of the Yellow River where many residents use groundwater for drinking. Site electrical conductivity (EC) and pH were determined in situ. The samples were analyzed for concentrations of total phosphorus (TP), orthophosphate (P-ortho), dissolved total phosphorus (TDP) and dissolved orthophosphate (P-D-ortho) in groundwater using UV spectrophotometer as described in the methods for Water and Wastewater Monitoring and Analysis of China and Environmental Protection Agency (EPA) of the United States. The sources and spatial distribution of phosphorus were interpreted using the spatial statistical analysis method. Results showed that the concentration ranges of TP, P-ortho, TDP and P-D-ortho were 0~1.49 mg·L-1, 0~0.11 mg·L-1, 0.04~0.69 mg·L-1 and 0~0.06 mg·L-1, respectively. EC and the concentrations of TP, P-ortho, TDP and P-D-ortho showed large spatial variations. There was high groundwater EC (770~ 5 530 μS·cm-1) in the study area, which obviously increased from the upstream to the downstream of the river. The spatial distributions of TP and TDP gradually decreased from upstream to downstream. Although high-value areas of P-ortho were noted, P-D-ortho distribution did not significantly change. Dominant factors that influenced phosphorus concentrations in groundwater included phosphorus infiltration in surface water and human activity. Groundwater samples in the study area were collected at a depth of less than 50 m. The shallow aquifer was the Yellow River alluvial sands which mainly comprised of silt, fine sand and medium sand of 10~25 m thickness. The river was the main source of recharge to the groundwater system. Hence surface water phosphorus easily leaked into the underlying groundwater in the geological formations. This was especially the case for groundwater systems in the vicinity of the river. Human activity included point source pollution (from improperly handled industrial wastes, domestic sewages) and non-point source pollution (from pesticides and agricultural fertilization). The maximum concentration of TDP in Dezhou Region was 0.69 mg·L-1 with an average of 0.20 mg·L-1. The overproof rates of TDP were respectively 7.41%, 62.96% and 40.74% based on the drinking water standards of the European Community (0.5 mg·L-1) and Class II (0.02 mg·L 1-1) and Class III (0.1 mg·L-1-1) of the Surface Water Environment Quality Standard of China (GB 3838-2002). This study provided the needed scientific basis for evaluating the impact of groundwater phosphorus pollution on human health and hydro-ecological environment.
Groundwater quality has been related to drinking water safety and human health, and groundwater pollution directly affecting hydro-ecological environment. High phosphorus in the drinking water has been noted to reduce calcium and vitamin D absorption in humans, which has the potential negative effects on the health of the elderly. In this study, 27 water samples were collected from the groundwater system in the Dezhou Region located in the lower reaches of the Yellow River where many residents use groundwater for drinking. Site electrical conductivity (EC) and pH were determined in situ. The samples were analyzed for concentrations of total phosphorus (TP), orthophosphate (P-ortho), dissolved total phosphorus (TDP) and dissolved orthophosphate (P-D-ortho) in groundwater using UV spectrophotometer as described in the methods for Water and Wastewater Monitoring and Analysis of China and Environmental Protection Agency (EPA) of the United States. The sources and spatial distribution of phosphorus were interpreted using the spatial statistical analysis method. Results showed that the concentration ranges of TP, P-ortho, TDP and P-D-ortho were 0~1.49 mg·L-1, 0~0.11 mg·L-1, 0.04~0.69 mg·L-1 and 0~0.06 mg·L-1, respectively. EC and the concentrations of TP, P-ortho, TDP and P-D-ortho showed large spatial variations. There was high groundwater EC (770~ 5 530 μS·cm-1) in the study area, which obviously increased from the upstream to the downstream of the river. The spatial distributions of TP and TDP gradually decreased from upstream to downstream. Although high-value areas of P-ortho were noted, P-D-ortho distribution did not significantly change. Dominant factors that influenced phosphorus concentrations in groundwater included phosphorus infiltration in surface water and human activity. Groundwater samples in the study area were collected at a depth of less than 50 m. The shallow aquifer was the Yellow River alluvial sands which mainly comprised of silt, fine sand and medium sand of 10~25 m thickness. The river was the main source of recharge to the groundwater system. Hence surface water phosphorus easily leaked into the underlying groundwater in the geological formations. This was especially the case for groundwater systems in the vicinity of the river. Human activity included point source pollution (from improperly handled industrial wastes, domestic sewages) and non-point source pollution (from pesticides and agricultural fertilization). The maximum concentration of TDP in Dezhou Region was 0.69 mg·L-1 with an average of 0.20 mg·L-1. The overproof rates of TDP were respectively 7.41%, 62.96% and 40.74% based on the drinking water standards of the European Community (0.5 mg·L-1) and Class II (0.02 mg·L 1
2013, 21(4): 465-473.
doi: 10.3724/SP.J.1011.2013.00465
Abstract:
Fertilization, an important resource of plant nutrient, has been found to affect the development and reproduction of herbivores and their ability to damage plants. The influences of amino acid foliar fertilizer, phytonutrient and branched-chain amino acids on the growth and nutritional status of tomato and then on the development, survival and reproduction of Bemisia tabaci were studied in the laboratory under condition of (25±1) ℃; L∶D = 14 h∶10 h; and 70%~80% RH. Nymph size and fecundity of B. tabaci were also observed and the potential of amino acid foliar fertilizer application in practice was discussed. Compared with the control, amino acid foliar fertilizer significantly promoted tomato growth which was evident in increased plant height, leaf stentering and leaf area. Phytonutrient also promoted plant growth but to a lesser degree than amino acid fertilizer. Except for nitrogen and sugar, minerals and nutrient contents in tomato leaves varied with fertilizers treatments. The concentrations of phosphorus, protein and free amino acid in tomato leaves were positively correlated with several tomato growth parameters, including plant height, leaf stentering, and leaf area. Negative correlation was observed between potassium and these parameters. Chlorophyll and water contents in tomato leaves showed minimal differences among treatments. The developmental duration of B. tabaci was longest on tomatoes treated with amino acid foliar fertilizer (22.95 d), followed by those treated with phytonutrient (22.83 d), and was shortest on control treatments (21.78 d). B. tabaci survival rate changed little under different foliar fertilizers applications. The body size of B. tabaci 1st instar nymph was larger on tomatoes treated with branched-chain amino acids than on others, especially the control. As nymph developed, however, the 4th instar B. tabaci grew largest on tomatoes treated with amino acid foliar fertilizer. The smallest nymph was also observed on the control group. The longevity of B. tabaci female adults was longest on tomatoes treated with branched-chain amino acids (26.64 d) and shortest on those treated with phytonutrient (16.92 d), and the difference between the two treatments was significant. Fecundity was highest on tomatoes treated with branched-chain amino acids (190.55 eggs), which was significantly higher than the lowest value (119.91 eggs) on the control. The highest intrinsic rate of increase (rm) of B. tabaci was on tomatoes treated with phytonutrient (0.474 9). However, it did not significantly increase on tomatoes treated with amino acid foliar fertilizer (0.406 4) compared with the control (0.405 4). Fertilizer possibly improved crop growth and provided nutrition to herbivores. The balance between production increases brought about by fertilization and offset losses caused by insect infestation was a critical field yield factor. In this study, amino acid foliar fertilizer significantly promoted tomato growth, which caused increased B. tabaci feeding and oviposition. It, however, delayed B. tabaci developmental duration and did not necessarily increase the longevity and fecundity of B. tabaci female adults on tomatoes treated with the fertilizer. Amino acid foliar fertilizer did not enhance the intrinsic rate of increase of B. tabaci, namely did not facilitate B. tabaci population growth. This offset the effects of improved nutritional conditions in tomato and B. tabaci interaction.
Fertilization, an important resource of plant nutrient, has been found to affect the development and reproduction of herbivores and their ability to damage plants. The influences of amino acid foliar fertilizer, phytonutrient and branched-chain amino acids on the growth and nutritional status of tomato and then on the development, survival and reproduction of Bemisia tabaci were studied in the laboratory under condition of (25±1) ℃; L∶D = 14 h∶10 h; and 70%~80% RH. Nymph size and fecundity of B. tabaci were also observed and the potential of amino acid foliar fertilizer application in practice was discussed. Compared with the control, amino acid foliar fertilizer significantly promoted tomato growth which was evident in increased plant height, leaf stentering and leaf area. Phytonutrient also promoted plant growth but to a lesser degree than amino acid fertilizer. Except for nitrogen and sugar, minerals and nutrient contents in tomato leaves varied with fertilizers treatments. The concentrations of phosphorus, protein and free amino acid in tomato leaves were positively correlated with several tomato growth parameters, including plant height, leaf stentering, and leaf area. Negative correlation was observed between potassium and these parameters. Chlorophyll and water contents in tomato leaves showed minimal differences among treatments. The developmental duration of B. tabaci was longest on tomatoes treated with amino acid foliar fertilizer (22.95 d), followed by those treated with phytonutrient (22.83 d), and was shortest on control treatments (21.78 d). B. tabaci survival rate changed little under different foliar fertilizers applications. The body size of B. tabaci 1st instar nymph was larger on tomatoes treated with branched-chain amino acids than on others, especially the control. As nymph developed, however, the 4th instar B. tabaci grew largest on tomatoes treated with amino acid foliar fertilizer. The smallest nymph was also observed on the control group. The longevity of B. tabaci female adults was longest on tomatoes treated with branched-chain amino acids (26.64 d) and shortest on those treated with phytonutrient (16.92 d), and the difference between the two treatments was significant. Fecundity was highest on tomatoes treated with branched-chain amino acids (190.55 eggs), which was significantly higher than the lowest value (119.91 eggs) on the control. The highest intrinsic rate of increase (rm) of B. tabaci was on tomatoes treated with phytonutrient (0.474 9). However, it did not significantly increase on tomatoes treated with amino acid foliar fertilizer (0.406 4) compared with the control (0.405 4). Fertilizer possibly improved crop growth and provided nutrition to herbivores. The balance between production increases brought about by fertilization and offset losses caused by insect infestation was a critical field yield factor. In this study, amino acid foliar fertilizer significantly promoted tomato growth, which caused increased B. tabaci feeding and oviposition. It, however, delayed B. tabaci developmental duration and did not necessarily increase the longevity and fecundity of B. tabaci female adults on tomatoes treated with the fertilizer. Amino acid foliar fertilizer did not enhance the intrinsic rate of increase of B. tabaci, namely did not facilitate B. tabaci population growth. This offset the effects of improved nutritional conditions in tomato and B. tabaci interaction.
2013, 21(4): 474-479.
doi: 10.3724/SP.J.1011.2013.00474
Abstract:
This study investigated the effects of larval density on the population dynamics of diamondback moth (Plutella xylostella). It analyzed the growth, development and reproduction of P. xylostella of five larval densities (1 larvae·dish-1, 10 larvae·dish-1, 20 larvae·dish-1, 30 larvae·dish-1 and 40 larvae·dish-1) under laboratory conditions of (22±1) ℃, 70%~80% RH and 12L∶12D photoperiod. The results showed that immature duration, survival rate, pupal weight and adult reproduction of P. xylostella were significantly affected by larval density. The time of development of larva and pupa was longest at the density of 10 larvae per dish and significantly prolonged with increasing larval density. Survival rate from larva to pupa was highest at the density of 10 and 20 larvae per dish, which was significantly higher than those at the density of 1 and 40 larvae per dish. Pupal weight was heaviest at the density of one larvae per dish, which significantly dropped with increasing larval density. Abnormalities of moth adults were significantly different at different larval densities. Abnormality was lowest at the density of 10 larvae per dish, which significantly increased with increasing larval density. Total fecundity per female was highest at the density of one larva per dish, which also gradually declined with increasing larval density. Female and male longevities were highest at the densities of 40 and 10 larvae per dish respectively. It significantly shortened when the density was higher or lower. Life table analysis suggested that larval density significantly affected population growth index. It was highest at the density of 10 larvae per dish and dropped for both higher and lower densities. It was therefore concluded that larval density significantly influenced population growth of P. xylostella.
This study investigated the effects of larval density on the population dynamics of diamondback moth (Plutella xylostella). It analyzed the growth, development and reproduction of P. xylostella of five larval densities (1 larvae·dish-1, 10 larvae·dish-1, 20 larvae·dish-1, 30 larvae·dish-1 and 40 larvae·dish-1) under laboratory conditions of (22±1) ℃, 70%~80% RH and 12L∶12D photoperiod. The results showed that immature duration, survival rate, pupal weight and adult reproduction of P. xylostella were significantly affected by larval density. The time of development of larva and pupa was longest at the density of 10 larvae per dish and significantly prolonged with increasing larval density. Survival rate from larva to pupa was highest at the density of 10 and 20 larvae per dish, which was significantly higher than those at the density of 1 and 40 larvae per dish. Pupal weight was heaviest at the density of one larvae per dish, which significantly dropped with increasing larval density. Abnormalities of moth adults were significantly different at different larval densities. Abnormality was lowest at the density of 10 larvae per dish, which significantly increased with increasing larval density. Total fecundity per female was highest at the density of one larva per dish, which also gradually declined with increasing larval density. Female and male longevities were highest at the densities of 40 and 10 larvae per dish respectively. It significantly shortened when the density was higher or lower. Life table analysis suggested that larval density significantly affected population growth index. It was highest at the density of 10 larvae per dish and dropped for both higher and lower densities. It was therefore concluded that larval density significantly influenced population growth of P. xylostella.
2013, 21(4): 480-486.
doi: 10.3724/SP.J.1011.2013.00480
Abstract:
To screen plant-derived attractants for ecological management of three scarab beetles (Holotrichia oblita, H. parallela and Anomala corpulenta), 10 binary blends (labeled as 1, 2, …, 10, see below) with 5 main volatiles from the leaves of Ricinus communis were selected. Then the electrophysiological activity and attractiveness of the selected R. communis volatiles blends were evaluated by electroantennogram (EAG) and field trapping experiments. The EAG bioassay showed that blends containing green leaf volatile of cis-3-hexen-1-ol usually exhibited strong EAG activities. Blend 1 (cis-3-hexen-1-ol plus dibutyl phthalate) and blend 6 (cis-3-hexen-1-ol plus benzyl alcohol) showed stronger EAG response to both sexes of the three scarab beetle species. Blend 7 (cis-3-hexen-1-ol plus 2-phenylethanol) exhibited a fairly strong EAG activity toward H. oblita sexes. Also blend 8 (cinnamaldehyde plus benzyl alcohol) effectively stimulated response to male A. corpulenta antennae. The preliminary trapping experiment indicated that among the ten candidate binary blends, blends 6, 8 and 1 performed the best regarding the target species at occurrence peak with respectively 110.30, 101.73 and 74.97 catches per trap in 30 days. Most interestingly, the blends also attracted a certain number of A. exoleta. Further mass-trapping experiments conducted in Luoyang and Kaifeng regions were used to compare the attractiveness of the mentioned 3 blends. The results showed that blends 6 and 1 caught significantly more scarab beetles than blend 8. A significantly great number of H. parallela and a few A. corpulenta and Popillia quadriguttata were among the species caught in the trapping experiment conducted in Luoyang. In the Kaifeng trapping experiment, Maladera orientalis was the most abundant species caught, followed by H. parallela and P. quadriguttata. The different natural distributions of the scarab species in different regions possibly explained the differences in trapped species. Altogether, blends 6 and 1 were possibly the two promising ecological control attractants that were generically targeted to several scarab beetle species in the region.
To screen plant-derived attractants for ecological management of three scarab beetles (Holotrichia oblita, H. parallela and Anomala corpulenta), 10 binary blends (labeled as 1, 2, …, 10, see below) with 5 main volatiles from the leaves of Ricinus communis were selected. Then the electrophysiological activity and attractiveness of the selected R. communis volatiles blends were evaluated by electroantennogram (EAG) and field trapping experiments. The EAG bioassay showed that blends containing green leaf volatile of cis-3-hexen-1-ol usually exhibited strong EAG activities. Blend 1 (cis-3-hexen-1-ol plus dibutyl phthalate) and blend 6 (cis-3-hexen-1-ol plus benzyl alcohol) showed stronger EAG response to both sexes of the three scarab beetle species. Blend 7 (cis-3-hexen-1-ol plus 2-phenylethanol) exhibited a fairly strong EAG activity toward H. oblita sexes. Also blend 8 (cinnamaldehyde plus benzyl alcohol) effectively stimulated response to male A. corpulenta antennae. The preliminary trapping experiment indicated that among the ten candidate binary blends, blends 6, 8 and 1 performed the best regarding the target species at occurrence peak with respectively 110.30, 101.73 and 74.97 catches per trap in 30 days. Most interestingly, the blends also attracted a certain number of A. exoleta. Further mass-trapping experiments conducted in Luoyang and Kaifeng regions were used to compare the attractiveness of the mentioned 3 blends. The results showed that blends 6 and 1 caught significantly more scarab beetles than blend 8. A significantly great number of H. parallela and a few A. corpulenta and Popillia quadriguttata were among the species caught in the trapping experiment conducted in Luoyang. In the Kaifeng trapping experiment, Maladera orientalis was the most abundant species caught, followed by H. parallela and P. quadriguttata. The different natural distributions of the scarab species in different regions possibly explained the differences in trapped species. Altogether, blends 6 and 1 were possibly the two promising ecological control attractants that were generically targeted to several scarab beetle species in the region.
2013, 21(4): 487-493.
doi: 10.3724/SP.J.1011.2013.00487
Abstract:
This paper investigated spatial variations in chemical characteristics, hydrochemistry type and sources of major ions in water. It analyzed the composition of chemical ions in surface water of Majia River, Dehuixin River and Yinhuangguanqu of the irrigation districts in the downstream of Yellow River. The study attempted to lay the theoretical guidelines for long-term observation of hydrochemical changes of surface water and groundwater under irrigation from the Yellow River. In addition, the paper provided the scientific basis for evaluating water environment conditions and pollution prevention measures. The results showed that pH and elec-trical conductivity (EC) varied in space. Surface water in the study area was alkaline with pH range of 7.65~9.34. EC of the water samples was in the range of 965~1 530 μs·cm-1. The ranges of concentration of NO3- , SO42- , HCO3- , Cl-, Ca2+, Mg2+, Na+, K+ were respectively 1.32~60.15 mg·L-1, 53.41~781.90 mg·L -1, 143.35~823.50 mg·L-1, 98.00~564.00 mg·L-1, 22.57~265.00 mg·L -1, 29.41~195.50 mg·L-1, 103.20~472.00 mg·L-1 and 0.83~59.05 mg·L -1. The major ions and their average concentrations were as follows: HCO3- (330.45 mg·L -1) > SO42- (308.48 mg·L -1) > Cl- (286.83 mg·L-1) > NO3- (29.60 mg·L-1) and Na+ (236.85 mg·L-1) > Ca2+ (98.15 mg·L-1) > Mg2+ (82.62 mg·L-1) > K+ (9.05 mg·L-1). The hydrochemical type of the surface water was Na+·Ca2+-HCO3-·SO42- . The pH and Cl- of Majia River along with mean Mg2+ concentration were highest in the three rivers. Mean EC, concentrations of NO3- and HCO3- were highest in Dehuixin River. Also mean concentrations of SO42- , Na+, Ca2+ and K+ for Yinhuangguanqu were higher than those for the other two rivers. The Piper diagrams suggested that the hydrochemical types of the surface waters were different for different rivers. Water assessment showed that water in study area was suitable for irrigation. Correlation analysis showed that Ca2+, Mg2+ and Na+ were significantly correlated with SO42 and Cl-. Furthermore, Ca2+ and Mg2+, Na+ and K+, and SO42- and Cl- were significantly correlated. The results suggested inter-related influence or same source water ions in the region which were likely driven by human activity.
This paper investigated spatial variations in chemical characteristics, hydrochemistry type and sources of major ions in water. It analyzed the composition of chemical ions in surface water of Majia River, Dehuixin River and Yinhuangguanqu of the irrigation districts in the downstream of Yellow River. The study attempted to lay the theoretical guidelines for long-term observation of hydrochemical changes of surface water and groundwater under irrigation from the Yellow River. In addition, the paper provided the scientific basis for evaluating water environment conditions and pollution prevention measures. The results showed that pH and elec-trical conductivity (EC) varied in space. Surface water in the study area was alkaline with pH range of 7.65~9.34. EC of the water samples was in the range of 965~1 530 μs·cm-1. The ranges of concentration of NO3- , SO42- , HCO3- , Cl-, Ca2+, Mg2+, Na+, K+ were respectively 1.32~60.15 mg·L-1, 53.41~781.90 mg·L -1, 143.35~823.50 mg·L-1, 98.00~564.00 mg·L-1, 22.57~265.00 mg·L -1, 29.41~195.50 mg·L-1, 103.20~472.00 mg·L-1 and 0.83~59.05 mg·L -1. The major ions and their average concentrations were as follows: HCO3- (330.45 mg·L -1) > SO42- (308.48 mg·L -1) > Cl- (286.83 mg·L-1) > NO3- (29.60 mg·L-1) and Na+ (236.85 mg·L-1) > Ca2+ (98.15 mg·L-1) > Mg2+ (82.62 mg·L-1) > K+ (9.05 mg·L-1). The hydrochemical type of the surface water was Na+·Ca2+-HCO3-·SO42- . The pH and Cl- of Majia River along with mean Mg2+ concentration were highest in the three rivers. Mean EC, concentrations of NO3- and HCO3- were highest in Dehuixin River. Also mean concentrations of SO42- , Na+, Ca2+ and K+ for Yinhuangguanqu were higher than those for the other two rivers. The Piper diagrams suggested that the hydrochemical types of the surface waters were different for different rivers. Water assessment showed that water in study area was suitable for irrigation. Correlation analysis showed that Ca2+, Mg2+ and Na+ were significantly correlated with SO42 and Cl-. Furthermore, Ca2+ and Mg2+, Na+ and K+, and SO42- and Cl- were significantly correlated. The results suggested inter-related influence or same source water ions in the region which were likely driven by human activity.
2013, 21(4): 494-502.
doi: 10.3724/SP.J.1011.2013.00494
Abstract:
Net primary productivity (NPP) is the total dry organic matter produced by green plants in unit time and area. It is one of the key parameters used in carbon and oxygen cycle research. Not much NPP research has covered the whole of Northwest China and model estimates of NPP have also varied considerably. Photosynthesis is the main mode vegetation generates dry mater and is the core link between natural carbon and oxygen cycles. The synthesis of NPP is accompanied by energy fixing, carbon sinking and oxygen production; which are three indispensable ecological processes for human survival and development. By estimation of NPP based on photosynthetic equation, ecological effects via the synthesis of NPP can be effectively and quantitatively evaluated. This study compared different NPP evaluation models and analyzed (at both temporal and spatial scales) different characteristics of NPP for the period from 2000 to 2009 in Norwest China. The study showed that the Comprehensive model and the Beijing model most closely with the CASA model estimates. Calculated mean NPP for croplands, grasslands and evergreen needle leaf forests were 4.15 t·hm-2, 4.87 t·hm-2 and 7.35 t·hm-2, respectively. Human activity had enhanced vegetation in dry areas not to completely depend on rain. This implied that some differences existed in the estimation of the NPP by statistical models. Estimation results of NPP values by different methods through evaluating dry matter production, carbon fixing and oxygen release functions showed that NPP values increased with time. Also NPP values for grass increased at the fastest rate in the study area, which was 7.91×1011 Yuan in 2009. NPP value recalculated based on county unit showed three spatial-temporal patterns: in the high value area, it first decreased then increased; in low value area, it first increased then decreased; NPP value gradually diversely distributed. The spatial agglomeration tendency of change in NPP showed that the lowest value units rose rapidly, the highest value units rose gradually and the medium units dropped gradually. The asymmetry and deviation from the mean intensified and the agglomeration of high values also strengthened. The rise in NPP was more apparent than the decline, which lead to smaller NPP values difference from the east to the west and higher NPP values difference from the south to the north. The spatial decentralization development of counties favored a better ecological environment, although with local deterioration. For the weak ecological environment in Northwest China, it was necessary to partition NPP into ecological services value estimation and ecological safety evaluation at regional scale. The combination of direct agricultural income and potential ecological assets was more effective for sustainable regional development planning and control.
Net primary productivity (NPP) is the total dry organic matter produced by green plants in unit time and area. It is one of the key parameters used in carbon and oxygen cycle research. Not much NPP research has covered the whole of Northwest China and model estimates of NPP have also varied considerably. Photosynthesis is the main mode vegetation generates dry mater and is the core link between natural carbon and oxygen cycles. The synthesis of NPP is accompanied by energy fixing, carbon sinking and oxygen production; which are three indispensable ecological processes for human survival and development. By estimation of NPP based on photosynthetic equation, ecological effects via the synthesis of NPP can be effectively and quantitatively evaluated. This study compared different NPP evaluation models and analyzed (at both temporal and spatial scales) different characteristics of NPP for the period from 2000 to 2009 in Norwest China. The study showed that the Comprehensive model and the Beijing model most closely with the CASA model estimates. Calculated mean NPP for croplands, grasslands and evergreen needle leaf forests were 4.15 t·hm-2, 4.87 t·hm-2 and 7.35 t·hm-2, respectively. Human activity had enhanced vegetation in dry areas not to completely depend on rain. This implied that some differences existed in the estimation of the NPP by statistical models. Estimation results of NPP values by different methods through evaluating dry matter production, carbon fixing and oxygen release functions showed that NPP values increased with time. Also NPP values for grass increased at the fastest rate in the study area, which was 7.91×1011 Yuan in 2009. NPP value recalculated based on county unit showed three spatial-temporal patterns: in the high value area, it first decreased then increased; in low value area, it first increased then decreased; NPP value gradually diversely distributed. The spatial agglomeration tendency of change in NPP showed that the lowest value units rose rapidly, the highest value units rose gradually and the medium units dropped gradually. The asymmetry and deviation from the mean intensified and the agglomeration of high values also strengthened. The rise in NPP was more apparent than the decline, which lead to smaller NPP values difference from the east to the west and higher NPP values difference from the south to the north. The spatial decentralization development of counties favored a better ecological environment, although with local deterioration. For the weak ecological environment in Northwest China, it was necessary to partition NPP into ecological services value estimation and ecological safety evaluation at regional scale. The combination of direct agricultural income and potential ecological assets was more effective for sustainable regional development planning and control.
2013, 21(4): 503-510.
doi: 10.3724/SP.J.1011.2013.00503
Abstract:
As a populous nation, improve grain production capacity along with rational use and protection of cultivated land resources has posed a considerable challenge in domestic agriculture and land related research in China. Higher NPP for cultivated lands has suggested the existence of more organic biomass. This has been critical for the final production of food crops in the country. It was therefore likely for research on NPP to provide the basis for resolving food security issues. Functional zoning has been the commonly used method to guarantee sustainable use of land. Presently, however, heavily fragmented research merely described real supply of cultivated lands. A deeper understand on the potential reserves of cultivated lands was needed in this regard. Based on remote sensing observation, it is possible to have statistics of the output of a large number of cultivated lands within a short time. Compared with the yearbook data, remote sensing observation has advantages including timeliness and spatial precision. Remote sensing observations have therefore been strongly supplemental to statistical data. NPP estimated by remote sensing was used as crop biomass in cultivated lands instead of the traditional calculations based statistics data. Cultivated land in the Guanzhong-Tianshui Economic Region (GTER) was zoned by using neural network algorithm model and remote sensing data in 2001-2009 substituting for statistic crop yield data. Then the wavelet neural network was used to predict the NPP in the zoned regions. Three results were eventually attained. 1) From 2002 to 2009, total estimated NPP per year in GTER was 1.6×107 t. It showed large variation patterns between estimated NPP data and statistics grain data for cultivated lands in GTER. This suggested statistical and remote sensing data were not substitutable for one another. As clustering function was unknown, zoning via estimated NPP data reflected a more universal adaptability than via statistical data. 2) The final zonal type relatively corresponsed with common cognitions in the study area. It was important to emphasize counties in central GTER and Weihe River Valley (WRV) in the agriculture development of GTER. It was also important for government to set up precision agriculture and agricultural integration in these zones. 3) The prediction calculation by the wavelet neural network showed higher per unit area NPP as the principal trend in 2010 to 2015. Because of the reflected fluctuation patterns varied considerably for different data, it was important to note the differences in data sources and find the driving factors for the reflection of different pressures in cultivated lands. The discussions on data errors suggested that remote sensing data and statistical data should be compared in the study. As rapidly enhancing total crops biomass increase was difficult in the short term, the most effective way of remitting pressure on croplands was to improve use ratio of crop bio-energy.
As a populous nation, improve grain production capacity along with rational use and protection of cultivated land resources has posed a considerable challenge in domestic agriculture and land related research in China. Higher NPP for cultivated lands has suggested the existence of more organic biomass. This has been critical for the final production of food crops in the country. It was therefore likely for research on NPP to provide the basis for resolving food security issues. Functional zoning has been the commonly used method to guarantee sustainable use of land. Presently, however, heavily fragmented research merely described real supply of cultivated lands. A deeper understand on the potential reserves of cultivated lands was needed in this regard. Based on remote sensing observation, it is possible to have statistics of the output of a large number of cultivated lands within a short time. Compared with the yearbook data, remote sensing observation has advantages including timeliness and spatial precision. Remote sensing observations have therefore been strongly supplemental to statistical data. NPP estimated by remote sensing was used as crop biomass in cultivated lands instead of the traditional calculations based statistics data. Cultivated land in the Guanzhong-Tianshui Economic Region (GTER) was zoned by using neural network algorithm model and remote sensing data in 2001-2009 substituting for statistic crop yield data. Then the wavelet neural network was used to predict the NPP in the zoned regions. Three results were eventually attained. 1) From 2002 to 2009, total estimated NPP per year in GTER was 1.6×107 t. It showed large variation patterns between estimated NPP data and statistics grain data for cultivated lands in GTER. This suggested statistical and remote sensing data were not substitutable for one another. As clustering function was unknown, zoning via estimated NPP data reflected a more universal adaptability than via statistical data. 2) The final zonal type relatively corresponsed with common cognitions in the study area. It was important to emphasize counties in central GTER and Weihe River Valley (WRV) in the agriculture development of GTER. It was also important for government to set up precision agriculture and agricultural integration in these zones. 3) The prediction calculation by the wavelet neural network showed higher per unit area NPP as the principal trend in 2010 to 2015. Because of the reflected fluctuation patterns varied considerably for different data, it was important to note the differences in data sources and find the driving factors for the reflection of different pressures in cultivated lands. The discussions on data errors suggested that remote sensing data and statistical data should be compared in the study. As rapidly enhancing total crops biomass increase was difficult in the short term, the most effective way of remitting pressure on croplands was to improve use ratio of crop bio-energy.
2013, 21(4): 511-518.
doi: 10.3724/SP.J.1011.2013.00511
Abstract:
Leisure agriculture as a product of modern economic development has played a critical role in the development of modern agriculture. Current developments of leisure agriculture in China have been good. Despite the several methods of evaluation of leisure agriculture, this study developed a new method of evaluation of leisure agriculture in Hebei Province. This study was practically significant in promoting the development of leisure agriculture and rural tourism in Hebei Province. Leisure agriculture, a dual agriculture and tourism practice, basically characterized by marketing, science & technology, spectatorship, experience, culture, education, ecology, etc. Leisure agriculture and rural tourism demonstration sites have been typically selected by the Ministry of Agriculture and National Tourism Administration. Data Envelopment Analysis is a linear programming method for assessing the relative effectiveness of a set of conditions. It has often been used in multiple input-output scenarios. Efficiency of the input-output analysis and scale effect analysis were conducted in this study. Using a total of 12 leisure agriculture and rural tourism demonstration sites in Hebei Province for 2011, representative analyses and measures of comprehensive, economic and social benefits along with efficiency and scale benefit analyses were conducted. The results showed that overall efficiency of leisure agriculture in Hebei Province was low, and as such, needed increasing investment to attain rapid development. Six out of 12 leisure agriculture and rural tourism demonstration sites in Hebei Province was effective in comprehensive technology efficiency. As for economic or social benefits, only 2 sites were effective. Three sites were low in efficiency of investment in experience projects and tourism element type. Four sites were excessive in scientific and technological personnel. There was need to change small and fully equipped developmental patterns and to confirm scale development direction, especially for leisure experience projects. The main body of leisure agriculture management needed improving management level and service quality. According to social and economic evaluation, 1 site was deficient in employing population, and 4 sites were deficient in economic benefit. This required that based on park technology, relevant departments and main management body met not only economic benefits of improved leisure agriculture, but also increased social benefits of local employment. With government policy support (e.g., streamline management, public services, etc.), leisure agriculture development was obtainable and applicable to full market forces. This was good for mobilizing enthusiastic social forces and industrial associations for a full market research. That purpose provided decision support for building a good condition for the development of leisure agriculture in China.
Leisure agriculture as a product of modern economic development has played a critical role in the development of modern agriculture. Current developments of leisure agriculture in China have been good. Despite the several methods of evaluation of leisure agriculture, this study developed a new method of evaluation of leisure agriculture in Hebei Province. This study was practically significant in promoting the development of leisure agriculture and rural tourism in Hebei Province. Leisure agriculture, a dual agriculture and tourism practice, basically characterized by marketing, science & technology, spectatorship, experience, culture, education, ecology, etc. Leisure agriculture and rural tourism demonstration sites have been typically selected by the Ministry of Agriculture and National Tourism Administration. Data Envelopment Analysis is a linear programming method for assessing the relative effectiveness of a set of conditions. It has often been used in multiple input-output scenarios. Efficiency of the input-output analysis and scale effect analysis were conducted in this study. Using a total of 12 leisure agriculture and rural tourism demonstration sites in Hebei Province for 2011, representative analyses and measures of comprehensive, economic and social benefits along with efficiency and scale benefit analyses were conducted. The results showed that overall efficiency of leisure agriculture in Hebei Province was low, and as such, needed increasing investment to attain rapid development. Six out of 12 leisure agriculture and rural tourism demonstration sites in Hebei Province was effective in comprehensive technology efficiency. As for economic or social benefits, only 2 sites were effective. Three sites were low in efficiency of investment in experience projects and tourism element type. Four sites were excessive in scientific and technological personnel. There was need to change small and fully equipped developmental patterns and to confirm scale development direction, especially for leisure experience projects. The main body of leisure agriculture management needed improving management level and service quality. According to social and economic evaluation, 1 site was deficient in employing population, and 4 sites were deficient in economic benefit. This required that based on park technology, relevant departments and main management body met not only economic benefits of improved leisure agriculture, but also increased social benefits of local employment. With government policy support (e.g., streamline management, public services, etc.), leisure agriculture development was obtainable and applicable to full market forces. This was good for mobilizing enthusiastic social forces and industrial associations for a full market research. That purpose provided decision support for building a good condition for the development of leisure agriculture in China.
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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