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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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2016 Vol. 24, No. 9
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2016, 24(9): 1151-1160.
doi: 10.13930/j.cnki.cjea.160406
Abstract:
Cold-waterlogged (CW) paddy fields are the main low-yield paddy fields in South China. CW paddy fields have attracted close attention as they belong to common derelict lands with huge potential for crop productivity and good ecological conditions. CW paddy fields are the products of the complex interaction of climate, topography, hydrology and anthropogenic activity. Influenced by years of surface water and groundwater dip, soil physicochemical and biological properties of CW paddy fields have shown huge variations in the degree of coldness, rottenness, toxicity and infertility. CW paddy fields have low-temperature waters, soils and immersed bulk density, excessive reducing substances and soil organic carbon, but also low active organic carbon, microflora and available nutrients or unbalanced nutrients. Soil quality of CW paddy fields can be diagnosed and assessed by gley horizons, soil reducing substances and groundwater levels. This study summarized the integrated management and utilization of CW paddy fields, including engineering, agronomic and biological measures. This included open ditch and hidden drainage tubes, suitable rice varieties, paddy-upland crop rotation, ridge cultivation, balanced fertilization, soil conditioning, etc. In addition to traditional rice cultivation, it was an effective measure to comprehensively improve production capacity by adapting local conditions to the utilization of CW paddy fields. Finally, there was clear need to put future research emphasis on the administration and utilization of CW paddy fields based on sustainable agricultural development. This include 1) studying the differences in soil structure and the composition of organic matter under different gleyic states and the alternation of drying and wetting; 2) Strengthening research on methane emission characteristics under long-term gleyic state in CW paddy fields; 3) Strengthening research on ecological processes of anaerobic microbes and production enzymes and regulating and improving CW paddy fields using micro-organisms; 4) There was also need to strengthen technological integration and policy support based on different ecological types and production conditions in CW paddy fields.
Cold-waterlogged (CW) paddy fields are the main low-yield paddy fields in South China. CW paddy fields have attracted close attention as they belong to common derelict lands with huge potential for crop productivity and good ecological conditions. CW paddy fields are the products of the complex interaction of climate, topography, hydrology and anthropogenic activity. Influenced by years of surface water and groundwater dip, soil physicochemical and biological properties of CW paddy fields have shown huge variations in the degree of coldness, rottenness, toxicity and infertility. CW paddy fields have low-temperature waters, soils and immersed bulk density, excessive reducing substances and soil organic carbon, but also low active organic carbon, microflora and available nutrients or unbalanced nutrients. Soil quality of CW paddy fields can be diagnosed and assessed by gley horizons, soil reducing substances and groundwater levels. This study summarized the integrated management and utilization of CW paddy fields, including engineering, agronomic and biological measures. This included open ditch and hidden drainage tubes, suitable rice varieties, paddy-upland crop rotation, ridge cultivation, balanced fertilization, soil conditioning, etc. In addition to traditional rice cultivation, it was an effective measure to comprehensively improve production capacity by adapting local conditions to the utilization of CW paddy fields. Finally, there was clear need to put future research emphasis on the administration and utilization of CW paddy fields based on sustainable agricultural development. This include 1) studying the differences in soil structure and the composition of organic matter under different gleyic states and the alternation of drying and wetting; 2) Strengthening research on methane emission characteristics under long-term gleyic state in CW paddy fields; 3) Strengthening research on ecological processes of anaerobic microbes and production enzymes and regulating and improving CW paddy fields using micro-organisms; 4) There was also need to strengthen technological integration and policy support based on different ecological types and production conditions in CW paddy fields.
2016, 24(9): 1161-1168.
doi: 10.13930/j.cnki.cjea.151204
Abstract:
Anhui Province, which was once poor and frequency hit by disasters, now produces 35 billion kg grains yearly through hard work for the past 60 years. This is 5.5 times of 6.39 billion kg grain produced in the early period of new China. Grain production in the province has increased greatly. The province has become one of the five largest grain export provinces in China and is being projected to export 40 billion kg grain by 2020. This will play an important role in food security and agricultural development in China. But in Anhui Province, construction of water conservancy is weak, with agriculture in more areas dependent on rainfed. Medium and low-yield fields account for about 60% of arable land in the province. The development of agricultural mechanization is slow, agricultural management is extensive, crop yield per unit area land is lower. Thus the endowed natural resources have failed to benefit agricultural production in the region. Anhui Province is a main area transformed from medium and low-yield fields to high-yield ones in future in China. This paper suggested a development strategy for food security and modern agriculture in Anhui Province to meet the agricultural transformation. Guided by overall policy of green development and enhancing quality, yield and benefit of agriculture, the regional governance should push for the improvement of medium and low-yield fields in lime concretion black soils area. Especially in the north of Huai River, this measure was in favor of developing more ‘Ton-Grain’ counties or cities in Huai River Basin. At regional scale, the emphases should be on grain products of rice-wheat cultivation region along Yangzi River and Huai River, and wheat-maize cultivation regions in the north of Huai River; as well as agricultural modernization in main functional areas of grain deep processing. There was also the need to expand economic forestry and fruits in hilly regions and characteristic fish breeding and poultry raising along Yangzi Rive and Huai River. The green ecology industry development in mountain areas in the south and west of Anhui also should be accelerated. In terms of agricultural infrastructure, the construction of water conservancy in farmlands should be highlighted and the investment in medium and large agricultural mechanization stressed. The province needed to establish disaster prevention and mitigation system to guarantee green agriculture development and enhance the quality and yield of agricultural production. In terms of crop production restructuring, sustainable rice production was required, high-yielding wheat and maize production should be promoted with oil plant (rape and soybean) production rational development. In term of optimization of crop variety layout, in Huainan area, the proper crop layout was reduction of indica rice, increase of japonica rice, and stabilization of rape plantation. Along Huaihe River and Huaibei area, it was more rational to reduce general winter wheat and increase good quality wheat plantation, and to replace middle and late maturity maize varieties with middle and early maturity ones. In conclusion, the developmental way of modern agriculture for food security in Anhui Province was high-efficient utilization of heat and water resources, less investment, rapid improvement of larger areas of low-medium-yield fields, and extension of green-high-efficient agricultural product industry chain.
Anhui Province, which was once poor and frequency hit by disasters, now produces 35 billion kg grains yearly through hard work for the past 60 years. This is 5.5 times of 6.39 billion kg grain produced in the early period of new China. Grain production in the province has increased greatly. The province has become one of the five largest grain export provinces in China and is being projected to export 40 billion kg grain by 2020. This will play an important role in food security and agricultural development in China. But in Anhui Province, construction of water conservancy is weak, with agriculture in more areas dependent on rainfed. Medium and low-yield fields account for about 60% of arable land in the province. The development of agricultural mechanization is slow, agricultural management is extensive, crop yield per unit area land is lower. Thus the endowed natural resources have failed to benefit agricultural production in the region. Anhui Province is a main area transformed from medium and low-yield fields to high-yield ones in future in China. This paper suggested a development strategy for food security and modern agriculture in Anhui Province to meet the agricultural transformation. Guided by overall policy of green development and enhancing quality, yield and benefit of agriculture, the regional governance should push for the improvement of medium and low-yield fields in lime concretion black soils area. Especially in the north of Huai River, this measure was in favor of developing more ‘Ton-Grain’ counties or cities in Huai River Basin. At regional scale, the emphases should be on grain products of rice-wheat cultivation region along Yangzi River and Huai River, and wheat-maize cultivation regions in the north of Huai River; as well as agricultural modernization in main functional areas of grain deep processing. There was also the need to expand economic forestry and fruits in hilly regions and characteristic fish breeding and poultry raising along Yangzi Rive and Huai River. The green ecology industry development in mountain areas in the south and west of Anhui also should be accelerated. In terms of agricultural infrastructure, the construction of water conservancy in farmlands should be highlighted and the investment in medium and large agricultural mechanization stressed. The province needed to establish disaster prevention and mitigation system to guarantee green agriculture development and enhance the quality and yield of agricultural production. In terms of crop production restructuring, sustainable rice production was required, high-yielding wheat and maize production should be promoted with oil plant (rape and soybean) production rational development. In term of optimization of crop variety layout, in Huainan area, the proper crop layout was reduction of indica rice, increase of japonica rice, and stabilization of rape plantation. Along Huaihe River and Huaibei area, it was more rational to reduce general winter wheat and increase good quality wheat plantation, and to replace middle and late maturity maize varieties with middle and early maturity ones. In conclusion, the developmental way of modern agriculture for food security in Anhui Province was high-efficient utilization of heat and water resources, less investment, rapid improvement of larger areas of low-medium-yield fields, and extension of green-high-efficient agricultural product industry chain.
2016, 24(9): 1169-1176.
doi: 10.13930/j.cnki.cjea.160289
Abstract:
Optimization of spatial structure in intercropping system is important for increasing crop yield and improving resource utilization efficiency. However, the theoretical basis for improving nitrogen fixation functions of legume and nitrogen utilization efficiency by optimizing the spatial structure of intercropping system has not been well investigated. Thus the synergistic effect of legume/cereal intercropping system on nitrogen nutrient utilization and regulation potential of legume plants was investigated in a field experiment on pea/maize intercropping system in the Hexi Corridor. The experiment consisted of monoculture pea, monoculture maize and pea/maize intercropping systems. In intercropping system, three intercropping spacings between pea and maize were set, which were 15 cm, 30 cm and 45 cm, with unchanged pea row spacing and changed maize row spacing; two nitrogen application rates were also set for intercropped maize, 0 kghm-2 and 260 kghm-2. The aim of the experiment was to determine the effect of spatial structure of pea/maize intercropping system on alleviation of “nitrogen inhibition” (N inhibition) on pea nodulation caused by N fertilization. The results of the study also provided a much better understanding of the optimization of the spatial structure of legume/cereal intercropping system, and the improvement of N use efficiency. The results for 2013–2014 showed that pea/maize intercropping significantly increased nodule number and weight of pea, compared with single-cropping pea system. Increase in nodule number varied from 0 to 500%, with the largest nodule number and weight appearing under intercropped spacing of 30 cm. N inhibitory effects (Ca) calculated by using nodule number and weight were all positive. Under N application, the effect on alleviating “N inhibition” under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. With N application, Ca calculated from nodule number reached 78.70% and 161.21% in both 2013 and 2014 growing seasons, and Ca calculated from nodule weight reached 154.87% and 406.52% without N fertilization. The ratio of nutrient competition of pea plants (CRpm) was greater than 1, which suggested that the capacity of interspecific competition of pea was higher than maize. Intercropping system significantly improved N use efficiency and N use efficiency under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. N use efficiency under spacing of 30 cm was average 21.90% and 21.88% higher than that of 15 cm and 45 cm respectively in 2013 and 2014 growing seasons. The optimization of spatial structure in intercropping increased nodule number and weight of pea plants, alleviated “N inhibitory effect”, regulated N uptake effect and enhanced N use efficiency of pea/maize intercropping system. The results of this study were critical for developing N-saving intercropping systems, enriching the theory of N use efficiency and improving the contribution of N fixation of legume to legume/cereal intercropping systems.
Optimization of spatial structure in intercropping system is important for increasing crop yield and improving resource utilization efficiency. However, the theoretical basis for improving nitrogen fixation functions of legume and nitrogen utilization efficiency by optimizing the spatial structure of intercropping system has not been well investigated. Thus the synergistic effect of legume/cereal intercropping system on nitrogen nutrient utilization and regulation potential of legume plants was investigated in a field experiment on pea/maize intercropping system in the Hexi Corridor. The experiment consisted of monoculture pea, monoculture maize and pea/maize intercropping systems. In intercropping system, three intercropping spacings between pea and maize were set, which were 15 cm, 30 cm and 45 cm, with unchanged pea row spacing and changed maize row spacing; two nitrogen application rates were also set for intercropped maize, 0 kghm-2 and 260 kghm-2. The aim of the experiment was to determine the effect of spatial structure of pea/maize intercropping system on alleviation of “nitrogen inhibition” (N inhibition) on pea nodulation caused by N fertilization. The results of the study also provided a much better understanding of the optimization of the spatial structure of legume/cereal intercropping system, and the improvement of N use efficiency. The results for 2013–2014 showed that pea/maize intercropping significantly increased nodule number and weight of pea, compared with single-cropping pea system. Increase in nodule number varied from 0 to 500%, with the largest nodule number and weight appearing under intercropped spacing of 30 cm. N inhibitory effects (Ca) calculated by using nodule number and weight were all positive. Under N application, the effect on alleviating “N inhibition” under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. With N application, Ca calculated from nodule number reached 78.70% and 161.21% in both 2013 and 2014 growing seasons, and Ca calculated from nodule weight reached 154.87% and 406.52% without N fertilization. The ratio of nutrient competition of pea plants (CRpm) was greater than 1, which suggested that the capacity of interspecific competition of pea was higher than maize. Intercropping system significantly improved N use efficiency and N use efficiency under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. N use efficiency under spacing of 30 cm was average 21.90% and 21.88% higher than that of 15 cm and 45 cm respectively in 2013 and 2014 growing seasons. The optimization of spatial structure in intercropping increased nodule number and weight of pea plants, alleviated “N inhibitory effect”, regulated N uptake effect and enhanced N use efficiency of pea/maize intercropping system. The results of this study were critical for developing N-saving intercropping systems, enriching the theory of N use efficiency and improving the contribution of N fixation of legume to legume/cereal intercropping systems.
ZHANG Yuanshuai,
FENG Wei,
ZHANG Haiyan,
QI Shuangli,
HENG Yarong,
GUO Binbin,
LI Xiao,
WANG Yonghua,
GUO Tiancai
2016, 24(9): 1177-1184.
doi: 10.13930/j.cnki.cjea.160207
Abstract:
During the later stage of wheat development, low-light stress caused by cloudy and rainy weather conditions severely influences wheat yield in some wheat (Triticum aestivum L.) production areas in North China. In crop production, in order to get high yield, too much nitrogen fertilizer application has resulted in waste of resources and pollution of the environment. Several studies on the effects of shading or nitrogen application rate on wheat growth have been reported, but little studies have been on the interactive influence of shading and nitrogen rate on photosynthetic characteristics and chlorophyll fluorescence of wheat. Thus, a field experiment was conducted to determine the effects of shading and nitrogen application rate on photosynthetic characteristics of flag leaves and yield of winter wheat during jointing and maturity stages. Wheat plants were planted under diffident treatments including two light levels [S0 (no shading) and S1 (50% full radiation from jointing to mature stages, produced by black sun-shade net of 50% light transmittance)] and three N fertilizer rates [N0 (0 kghm-2), N1 (120 kghm-2) and N2 (240 kghm-2)]. The chlorophyll content, net photosynthetic rate (Pn) and chlorophyll fluorescence parameters of wheat at flower stage (April 23), middle (May 11) and later (May 20) grain-filling stages were investigated, and yield and its components were determined. The results indicated that shading significantly increased chlorophyll content, PSⅡ fluorescence photochemical quenching coefficient (qP) and actual photochemical quantum yield (ΦPSⅡ) of flag leaves of wheat. It, however, significantly decreased chlorophyll a/b ratio and fluorescence of non-photochemical quenching coefficient (qN). Thus shading treatment increased photochemical efficiency and reduced heat dissipation of flag leaves, which was helpful for better utilization of light energy. Due to energy shortage, Pn under S1 was lower than that under S0 at the period from flowering stage to mid-grain-filling stage. Because of higher chlorophyll content and efficiency of light energy conversion in S1, Pn was higher than that under S0 at late-grain filling stage. With increase in N application rate, Pn, chlorophyll content, qP and ΦPSⅡ increased significantly, which enhanced the full use of light energy and improved photosynthetic rate. Shading significantly decreased spike number, kernel number per spike and 1000-grain weight, which severely negated the increase in production due to nitrogen fertilizer application. The comprehensive effect of shading and nitrogen significantly influenced chlorophyll content, kernel number per spike and grain yield, but had no significant effect on other indicators. In conclusion, more nitrogen application alleviated the adverse effects of weak light stress on photosynthesis. Compared with the control (N0), Pn for nitrogen treatments (N1 and N2) increased by 11.5%27.4%, especially, N2 (240 kghm-2) treatment having the best effect among all treatments. At diffident nitrogen levels, although shading treatment improved light energy utilization of wheat, it significantly reduced plant photosynthesis and yield components, and finally led to significant reduction of yield.
During the later stage of wheat development, low-light stress caused by cloudy and rainy weather conditions severely influences wheat yield in some wheat (Triticum aestivum L.) production areas in North China. In crop production, in order to get high yield, too much nitrogen fertilizer application has resulted in waste of resources and pollution of the environment. Several studies on the effects of shading or nitrogen application rate on wheat growth have been reported, but little studies have been on the interactive influence of shading and nitrogen rate on photosynthetic characteristics and chlorophyll fluorescence of wheat. Thus, a field experiment was conducted to determine the effects of shading and nitrogen application rate on photosynthetic characteristics of flag leaves and yield of winter wheat during jointing and maturity stages. Wheat plants were planted under diffident treatments including two light levels [S0 (no shading) and S1 (50% full radiation from jointing to mature stages, produced by black sun-shade net of 50% light transmittance)] and three N fertilizer rates [N0 (0 kghm-2), N1 (120 kghm-2) and N2 (240 kghm-2)]. The chlorophyll content, net photosynthetic rate (Pn) and chlorophyll fluorescence parameters of wheat at flower stage (April 23), middle (May 11) and later (May 20) grain-filling stages were investigated, and yield and its components were determined. The results indicated that shading significantly increased chlorophyll content, PSⅡ fluorescence photochemical quenching coefficient (qP) and actual photochemical quantum yield (ΦPSⅡ) of flag leaves of wheat. It, however, significantly decreased chlorophyll a/b ratio and fluorescence of non-photochemical quenching coefficient (qN). Thus shading treatment increased photochemical efficiency and reduced heat dissipation of flag leaves, which was helpful for better utilization of light energy. Due to energy shortage, Pn under S1 was lower than that under S0 at the period from flowering stage to mid-grain-filling stage. Because of higher chlorophyll content and efficiency of light energy conversion in S1, Pn was higher than that under S0 at late-grain filling stage. With increase in N application rate, Pn, chlorophyll content, qP and ΦPSⅡ increased significantly, which enhanced the full use of light energy and improved photosynthetic rate. Shading significantly decreased spike number, kernel number per spike and 1000-grain weight, which severely negated the increase in production due to nitrogen fertilizer application. The comprehensive effect of shading and nitrogen significantly influenced chlorophyll content, kernel number per spike and grain yield, but had no significant effect on other indicators. In conclusion, more nitrogen application alleviated the adverse effects of weak light stress on photosynthesis. Compared with the control (N0), Pn for nitrogen treatments (N1 and N2) increased by 11.5%27.4%, especially, N2 (240 kghm-2) treatment having the best effect among all treatments. At diffident nitrogen levels, although shading treatment improved light energy utilization of wheat, it significantly reduced plant photosynthesis and yield components, and finally led to significant reduction of yield.
2016, 24(9): 1185-1195.
doi: 10.13930/j.cnki.cjea.151380
Abstract:
Biochar is a carbon-rich solid product resulting from biomass heated in the absence of oxygen. Biochar application is deemed to have the potential for greenhouse gas mitigation. Dryland farming areas in Northwest China contribute tremendously to greenhouse gas emission. However, little studies have been conducted in the region involving the application of biochar to improve carbon sink and reduce carbon emission, and the optimal biochar application has remained uncertain. The aim of this study was to determine the effects of biochar on methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions in the semi-arid regions. Observation was done for the whole growth period of spring wheat and the treatments consisted of six different biochar rates — CK (0 t.hm-2), T1 (10 t.hm-2), T2 (20 t.hm-2), T3 (30 t.hm-2), T4 (40 t.hm-2) and T5 (50 t.hm-2) based on Randomized Complete Block design with three replications. The carbon dioxide analyzer and static chamber-gas chromatographic techniques were used to continuously measure and analyze the greenhouse gases fluxes. Soil moisture and temperature were measured simultaneously with gas measurement. The results showed that dry spring field during whole growth period under different biochar treatments were the sources for CH4, N2O and CO2. The trend of different biochar application rates in the average emission flux of CH4 was CK (0.005 7 mg·m-2·h-1) > T1 (0.004 7 mg·m-2·h-1) > T2 (0.003 6 mg·m-2·h-1) > T3 (0.003 3 mg·m-2·h-1) > T4 (0.002 7 mg·m-2·h-1) > T5 (0.000 4 mg·m-2·h-1). Similar trend of average emission flux of N2O were CK (0.230 5 mg·m-2·h-1) > T5 (0.151 3 mg·m-2·h-1) > T1 (0.144 1 mg·m-2·h-1) > T2 (0.135 3 mg·m-2·h-1) > T4 (0.125 0 mg·m-2·h-1) > T3 (0.098 9 mg·m-2·h-1). The average emission fluxes of CO2 were 0.449 2 μmol·m-2·s-1 (CK), 0.447 0 μmol·m-2·s-1 (T1), 0.430 3 μmol·m-2·s-1 (T2), 0.391 4 μmol·m-2·s-1 (T3), 0.408 0 μmol·m-2·s-1 (T4) and 0.416 4 μmol·m-2·s-1 (T5), respectively. The mean emission flux of CH4 reduced with increasing biochar application level. The results also showed that the mean emissions fluxes of N2O and CO2 significantly increased when biochar input exceeded 30 t·hm-2. Soil temperature and moisture were affected by biochar application. Both soil temperatures at 515 cm depth and soil moistures at 510 cm soil depth in biochar input exceeded 30 t·hm-2 treatments were significantly different from that of those in the other treatments. The ranges of soil temperature and soil moisture for different soil layers under the CK treatment were highest among all treatments. The application of biochar reduced the variation range of soil temperature and soil moisture at different soil layers. CH4 flux was significantly negatively correlated with soil temperature, while significantly positively correlated with soil moisture at 510 cm soil depth. The N2O and CO2 fluxes were negatively correlated with soil temperature at 1015 cm soil depth, however, they were significantly positively correlated with soil temperature at 2025 cm soil depth. In addition, soil temperature at 1520 cm soil depth also had significant positive correlation with average N2O flux. Moreover, soil moisture at 05 cm soil depth had significant negative correlation with average CH4, N2O and CO2 fluxes. It is concluded that during the crop growth period, reasonable application of biochar could mitigate greenhouse gas emission in dry farmlands in the study area.
Biochar is a carbon-rich solid product resulting from biomass heated in the absence of oxygen. Biochar application is deemed to have the potential for greenhouse gas mitigation. Dryland farming areas in Northwest China contribute tremendously to greenhouse gas emission. However, little studies have been conducted in the region involving the application of biochar to improve carbon sink and reduce carbon emission, and the optimal biochar application has remained uncertain. The aim of this study was to determine the effects of biochar on methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions in the semi-arid regions. Observation was done for the whole growth period of spring wheat and the treatments consisted of six different biochar rates — CK (0 t.hm-2), T1 (10 t.hm-2), T2 (20 t.hm-2), T3 (30 t.hm-2), T4 (40 t.hm-2) and T5 (50 t.hm-2) based on Randomized Complete Block design with three replications. The carbon dioxide analyzer and static chamber-gas chromatographic techniques were used to continuously measure and analyze the greenhouse gases fluxes. Soil moisture and temperature were measured simultaneously with gas measurement. The results showed that dry spring field during whole growth period under different biochar treatments were the sources for CH4, N2O and CO2. The trend of different biochar application rates in the average emission flux of CH4 was CK (0.005 7 mg·m-2·h-1) > T1 (0.004 7 mg·m-2·h-1) > T2 (0.003 6 mg·m-2·h-1) > T3 (0.003 3 mg·m-2·h-1) > T4 (0.002 7 mg·m-2·h-1) > T5 (0.000 4 mg·m-2·h-1). Similar trend of average emission flux of N2O were CK (0.230 5 mg·m-2·h-1) > T5 (0.151 3 mg·m-2·h-1) > T1 (0.144 1 mg·m-2·h-1) > T2 (0.135 3 mg·m-2·h-1) > T4 (0.125 0 mg·m-2·h-1) > T3 (0.098 9 mg·m-2·h-1). The average emission fluxes of CO2 were 0.449 2 μmol·m-2·s-1 (CK), 0.447 0 μmol·m-2·s-1 (T1), 0.430 3 μmol·m-2·s-1 (T2), 0.391 4 μmol·m-2·s-1 (T3), 0.408 0 μmol·m-2·s-1 (T4) and 0.416 4 μmol·m-2·s-1 (T5), respectively. The mean emission flux of CH4 reduced with increasing biochar application level. The results also showed that the mean emissions fluxes of N2O and CO2 significantly increased when biochar input exceeded 30 t·hm-2. Soil temperature and moisture were affected by biochar application. Both soil temperatures at 515 cm depth and soil moistures at 510 cm soil depth in biochar input exceeded 30 t·hm-2 treatments were significantly different from that of those in the other treatments. The ranges of soil temperature and soil moisture for different soil layers under the CK treatment were highest among all treatments. The application of biochar reduced the variation range of soil temperature and soil moisture at different soil layers. CH4 flux was significantly negatively correlated with soil temperature, while significantly positively correlated with soil moisture at 510 cm soil depth. The N2O and CO2 fluxes were negatively correlated with soil temperature at 1015 cm soil depth, however, they were significantly positively correlated with soil temperature at 2025 cm soil depth. In addition, soil temperature at 1520 cm soil depth also had significant positive correlation with average N2O flux. Moreover, soil moisture at 05 cm soil depth had significant negative correlation with average CH4, N2O and CO2 fluxes. It is concluded that during the crop growth period, reasonable application of biochar could mitigate greenhouse gas emission in dry farmlands in the study area.
2016, 24(9): 1196-1205.
doi: 10.13930/j.cnki.cjea.151325
Abstract:
Soil drought notably influences fruit quality, yield and water use efficiency of wine grape. It is therefore important to clarify the effect of drought stress at different growth stages on soil water precision management and water-saving irrigation schedules in wine grape fields. To explore this effect, an experiment was carried out in 2014 at Weilong vineyard in Qingyuan Town in Liangzhou District, which belongs to Wuwei City in Hexi Corridor. The study evaluated the effects of drought stress caused by regulated deficit irrigation at different growth stages on water consumption and fruit quality of vine grape. In the experiment, 12 treatments were set up, 10 of which were moderate soil water stress (relative soil water content maintained at 60%–65% field capacity) and severe soil water stress (relative soil water content maintained at 50%–55% field capacity), respectively, at germination, vine growth period, florescence period, berry enlargement and coloring maturity periods with other growth stage under normal water condition (relative soil water content maintained at 70%–75% field capacity). Meanwhile, a full irrigation (relative soil water content maintained at 80%–85% field capacity) during berry enlargement period was also carried out and the normal water supply (relative soil water content maintained at 70%–75% field capacity) during the whole growth period was as the control. The results showed that the variation trend in soil water content within the 0100 cm soil layer were similar in different treatments, i.e., the soil water increased with increasing soil depth. The effects of drought stress controlled with regulated deficit irrigation was weakened with increased soil depth, and the soil layer of 4060 cm was with largest soil water reduction compared with CK. Soil water content along profile was lowest at berry enlargement period for all the treatments. The timely change trend of water consumption rate of wine rape was similar for different treatments. The minimum and maximum daily water consumption rates of wine grape occurred respectively during germination period (0.130.33 mm·d-1) and berry enlargement period (2.30–4.09 mm·d-1). Maximum yield and water use efficiency appeared under moderate water stress at grape germination period, which were 15 228 kg·hm-2 and 3.62 kg·m-3, respectively. This was followed by grape enlargement period full irrigation treatment (7 128 kg·hm-2 and 2.26 kg·m-3), while minimum rate was under severe soil water stress at grape enlargement period. Anthocyanins, total reducing sugar, tannin and total phenol contents in wine grape under severe soil water stress at coloring maturity stage were respectively 2.7% and 6.56%, 17.91% and 23.23% higher than that of under the full irrigation treatment, and titratable acid content effectively was restrained (P < 0.05). There was no significant difference (P > 0.05) in wine grape quality between the control and other treatments. In terms of integrated yield, water productivity efficiency and fruit quality, the optimum irrigation pattern of wine grape was moderate soil water stress at coloring maturity (relative soil water content maintained at 60%–65% field capacity) in combination with normal water supply (relative soil water content maintained at 70%–75% field capacity) during the other growth periods. Therefore, reasonable regulated deficit irrigation significantly improved water productivity efficiency of wine grape. This was not only water-saving, but high in water use efficiency and beneficial for grape quality improvement which was important for vine grape cultivation in Hexi Corridor.
Soil drought notably influences fruit quality, yield and water use efficiency of wine grape. It is therefore important to clarify the effect of drought stress at different growth stages on soil water precision management and water-saving irrigation schedules in wine grape fields. To explore this effect, an experiment was carried out in 2014 at Weilong vineyard in Qingyuan Town in Liangzhou District, which belongs to Wuwei City in Hexi Corridor. The study evaluated the effects of drought stress caused by regulated deficit irrigation at different growth stages on water consumption and fruit quality of vine grape. In the experiment, 12 treatments were set up, 10 of which were moderate soil water stress (relative soil water content maintained at 60%–65% field capacity) and severe soil water stress (relative soil water content maintained at 50%–55% field capacity), respectively, at germination, vine growth period, florescence period, berry enlargement and coloring maturity periods with other growth stage under normal water condition (relative soil water content maintained at 70%–75% field capacity). Meanwhile, a full irrigation (relative soil water content maintained at 80%–85% field capacity) during berry enlargement period was also carried out and the normal water supply (relative soil water content maintained at 70%–75% field capacity) during the whole growth period was as the control. The results showed that the variation trend in soil water content within the 0100 cm soil layer were similar in different treatments, i.e., the soil water increased with increasing soil depth. The effects of drought stress controlled with regulated deficit irrigation was weakened with increased soil depth, and the soil layer of 4060 cm was with largest soil water reduction compared with CK. Soil water content along profile was lowest at berry enlargement period for all the treatments. The timely change trend of water consumption rate of wine rape was similar for different treatments. The minimum and maximum daily water consumption rates of wine grape occurred respectively during germination period (0.130.33 mm·d-1) and berry enlargement period (2.30–4.09 mm·d-1). Maximum yield and water use efficiency appeared under moderate water stress at grape germination period, which were 15 228 kg·hm-2 and 3.62 kg·m-3, respectively. This was followed by grape enlargement period full irrigation treatment (7 128 kg·hm-2 and 2.26 kg·m-3), while minimum rate was under severe soil water stress at grape enlargement period. Anthocyanins, total reducing sugar, tannin and total phenol contents in wine grape under severe soil water stress at coloring maturity stage were respectively 2.7% and 6.56%, 17.91% and 23.23% higher than that of under the full irrigation treatment, and titratable acid content effectively was restrained (P < 0.05). There was no significant difference (P > 0.05) in wine grape quality between the control and other treatments. In terms of integrated yield, water productivity efficiency and fruit quality, the optimum irrigation pattern of wine grape was moderate soil water stress at coloring maturity (relative soil water content maintained at 60%–65% field capacity) in combination with normal water supply (relative soil water content maintained at 70%–75% field capacity) during the other growth periods. Therefore, reasonable regulated deficit irrigation significantly improved water productivity efficiency of wine grape. This was not only water-saving, but high in water use efficiency and beneficial for grape quality improvement which was important for vine grape cultivation in Hexi Corridor.
2016, 24(9): 1206-1213.
doi: 10.13930/j.cnki.cjea.160237
Abstract:
Heavy metal pollution has been being the subject of attention because it endangers food security and agro-ecological environment. Raising ducks in paddy fields is a Chinese traditional agriculture mode of integrated planting and breeding in paddy fields in subtropical regions. Neither chemical pesticides nor herbicides are applied throughout the growing season in the mutual rice-duck ecosystem and surface water is maintained about 10 cm depth during the period of raising ducks. Field experiments on Cd transformation, migration and cycling in mutual rice-duck ecosystems were conducted in 2014–2015 in double cropping rice regions in Hunan Province and a conventional rice field used as the control. The aim of the experiment was to explore heavy metal pollution risk of products of rice-duck mutual ecosystem, and provide references for adjustment and improvement of management strategies of fertilizer and feed, optimization of food chain, input-output structure rationalization and Cd pollution control of the rice-duck mutualism. In 2014, 17-day-old ducks were introduced into the paddy field (at a holding capacity of 675 ducks per hectare) 23 days after early rice seedling transplanting; in 2015, 20-day-old ducks were introduced into the paddy field (at a holding capacity of 675 ducks per hectare) 21 days after early rice seedling transplanting. The ducks were retrieved at the end of heading stage of early rice in the experiments in both years. Input-Output Analysis method was used to analyze heavy metal Cd cycling in the mutual rice-duck ecosystem using collected data in field experiments. Input included materials embodied in fertilizers, feed, seedling, duckling and irrigation, while output covered seed and duck in the rice-duck mutualism. The return materials consisted of feces, rice straw, rice root, weeds and insects. The results showed that Cd input in the mutual rice-duck ecosystem decreased in the order of fertilizer > feed > rice seedling > duckling. Fertilizer Cd input was mainly from phosphate fertilizer, duck Cd input was mainly from duck feed, and matured duck feed Cd input was greater than duckling feed Cd input. Cd cycling inner the ecosystem was from duck feces, weeds and insects transforming to rice straws and roots. In the mutual rice-duck ecosystem, heavy metal Cd was amplified along food chain transformation. The migration process of duck feces Cd input was higher than that of duck feed Cd input. For both rice-duck mutual ecosystem and conventional rice system, the order Cd contents of rice organs was root > straw > seed. Compared with conventional rice cultivation, rice-duck mutualism did not increase Cd content and accumulation in rice plants. Cd output of paddy soil under rice-duck mutualism and conventional rice cultivation was not significantly different (P > 0.05). For rice-duck mutual ecosystem, the contents of Cd in brown rice and duck were 0.033 mg·kg-1 and 0.008 mg·kg-1, respectively, lower than the limit standard of food Cd content. In the short-term, mutual rice-duck ecosystems provided a safe and non Cd contaminated mode of agricultural production.
Heavy metal pollution has been being the subject of attention because it endangers food security and agro-ecological environment. Raising ducks in paddy fields is a Chinese traditional agriculture mode of integrated planting and breeding in paddy fields in subtropical regions. Neither chemical pesticides nor herbicides are applied throughout the growing season in the mutual rice-duck ecosystem and surface water is maintained about 10 cm depth during the period of raising ducks. Field experiments on Cd transformation, migration and cycling in mutual rice-duck ecosystems were conducted in 2014–2015 in double cropping rice regions in Hunan Province and a conventional rice field used as the control. The aim of the experiment was to explore heavy metal pollution risk of products of rice-duck mutual ecosystem, and provide references for adjustment and improvement of management strategies of fertilizer and feed, optimization of food chain, input-output structure rationalization and Cd pollution control of the rice-duck mutualism. In 2014, 17-day-old ducks were introduced into the paddy field (at a holding capacity of 675 ducks per hectare) 23 days after early rice seedling transplanting; in 2015, 20-day-old ducks were introduced into the paddy field (at a holding capacity of 675 ducks per hectare) 21 days after early rice seedling transplanting. The ducks were retrieved at the end of heading stage of early rice in the experiments in both years. Input-Output Analysis method was used to analyze heavy metal Cd cycling in the mutual rice-duck ecosystem using collected data in field experiments. Input included materials embodied in fertilizers, feed, seedling, duckling and irrigation, while output covered seed and duck in the rice-duck mutualism. The return materials consisted of feces, rice straw, rice root, weeds and insects. The results showed that Cd input in the mutual rice-duck ecosystem decreased in the order of fertilizer > feed > rice seedling > duckling. Fertilizer Cd input was mainly from phosphate fertilizer, duck Cd input was mainly from duck feed, and matured duck feed Cd input was greater than duckling feed Cd input. Cd cycling inner the ecosystem was from duck feces, weeds and insects transforming to rice straws and roots. In the mutual rice-duck ecosystem, heavy metal Cd was amplified along food chain transformation. The migration process of duck feces Cd input was higher than that of duck feed Cd input. For both rice-duck mutual ecosystem and conventional rice system, the order Cd contents of rice organs was root > straw > seed. Compared with conventional rice cultivation, rice-duck mutualism did not increase Cd content and accumulation in rice plants. Cd output of paddy soil under rice-duck mutualism and conventional rice cultivation was not significantly different (P > 0.05). For rice-duck mutual ecosystem, the contents of Cd in brown rice and duck were 0.033 mg·kg-1 and 0.008 mg·kg-1, respectively, lower than the limit standard of food Cd content. In the short-term, mutual rice-duck ecosystems provided a safe and non Cd contaminated mode of agricultural production.
LIU Bingyang,
ZHANG Xiaoquan,
ZHANG Yunyun,
XU Zhiwen,
PENG Yufu,
YANG Lijun,
ZHANG Guangpu,
YANG Tiezhao
2016, 24(9): 1214-1222.
doi: 10.13930/j.cnki.cjea.160065
Abstract:
It is important to explore correlation between meteorological factors and aroma precursors for cultivation of high aroma flue-cured tobacco varieties. In this study, the contents of main aroma precursors of the high aroma flue-cured tobacco variety ‘Yuyan 11’ and conventional flue-cure tobacco variety ‘Yunyan 87’ at 5 different experimental locations (with different meteorological conditions due to different altitudes and latitudes) were analyzed to determine the effects of meteorological factors on aroma precursors contents of high aroma flue-cured tobacco. The correlations between aroma precursors contents and 6 meteorological factors (average temperature, relative humidity, sunshine duration, rainfall, evaporation and cloudiness) at rooting stage, vigorous growth and mature stage of tobacco, a total of 18 meteorological factors, were also determined using the grey relational degree method. The results indicated that the main aroma precursors contents of ‘Yuyan 11’ at each location was significantly higher than those of ‘Yunyan 87’. The contents of tobacco leaf carotenoids in low latitude locations were lower than those in high latitude locations. Polyphenol content increased gradually with decreasing altitude and increasing sunshine hour at maturity stage. The content of leaf trichome exudates in high latitude locations was higher than that in low-latitude locations, and it was highest in Henan Lushi. The contents of carotenoid in the leaves of ‘Yuyan 11’ and ‘Yunyan 87’ were influenced more by sunshine hour at maturity stage and average temperature at other growth stages. Sunshine duration during the growth period greatly influenced the content of polyphenols. Grey correlation trend for the contents of petroleum ether extracts and leaf trichome exudates with meteorological conditions for ‘Yuyan 11’ and ‘Yunyan 87’ were significantly different. The content of petroleum ether extract of ‘Yuyan 11’ was more influenced by sunshine hour during the growth period, but that of ‘Yunyan 87’ was more influenced by average temperature. The content leaf trichome exudates of ‘Yuyan 11’ was more influenced by sunshine hour at maturity stage and average temperature during vigorous growth stage, but that of ‘Yunyan 87’ was more influenced by average temperature at rooting stage, and by evaporation and average temperature at maturity stage. The effect of sunshine hour at maturity stage and that of average temperature at vigorous growth stage on the quality of high aroma flue-cured tobacco variety ‘Yuyan 11’ should be fully considered when choosing a planting area.
It is important to explore correlation between meteorological factors and aroma precursors for cultivation of high aroma flue-cured tobacco varieties. In this study, the contents of main aroma precursors of the high aroma flue-cured tobacco variety ‘Yuyan 11’ and conventional flue-cure tobacco variety ‘Yunyan 87’ at 5 different experimental locations (with different meteorological conditions due to different altitudes and latitudes) were analyzed to determine the effects of meteorological factors on aroma precursors contents of high aroma flue-cured tobacco. The correlations between aroma precursors contents and 6 meteorological factors (average temperature, relative humidity, sunshine duration, rainfall, evaporation and cloudiness) at rooting stage, vigorous growth and mature stage of tobacco, a total of 18 meteorological factors, were also determined using the grey relational degree method. The results indicated that the main aroma precursors contents of ‘Yuyan 11’ at each location was significantly higher than those of ‘Yunyan 87’. The contents of tobacco leaf carotenoids in low latitude locations were lower than those in high latitude locations. Polyphenol content increased gradually with decreasing altitude and increasing sunshine hour at maturity stage. The content of leaf trichome exudates in high latitude locations was higher than that in low-latitude locations, and it was highest in Henan Lushi. The contents of carotenoid in the leaves of ‘Yuyan 11’ and ‘Yunyan 87’ were influenced more by sunshine hour at maturity stage and average temperature at other growth stages. Sunshine duration during the growth period greatly influenced the content of polyphenols. Grey correlation trend for the contents of petroleum ether extracts and leaf trichome exudates with meteorological conditions for ‘Yuyan 11’ and ‘Yunyan 87’ were significantly different. The content of petroleum ether extract of ‘Yuyan 11’ was more influenced by sunshine hour during the growth period, but that of ‘Yunyan 87’ was more influenced by average temperature. The content leaf trichome exudates of ‘Yuyan 11’ was more influenced by sunshine hour at maturity stage and average temperature during vigorous growth stage, but that of ‘Yunyan 87’ was more influenced by average temperature at rooting stage, and by evaporation and average temperature at maturity stage. The effect of sunshine hour at maturity stage and that of average temperature at vigorous growth stage on the quality of high aroma flue-cured tobacco variety ‘Yuyan 11’ should be fully considered when choosing a planting area.
2016, 24(9): 1223-1230.
doi: 10.13930/j.cnki.cjea.160040
Abstract:
Soil sterilization is often used to explore feedback effects of soil microbes in community successions of competitive exclusion of native plants by invasive plants. In order to choose the most suitable soil sterilization method and to further analyze feedback effects of soil microbes on invasive plant Ageratina adenophora competition with native plants, we compared the differences in biomass between A. adenophora and native plant Rabdosia amethystoides cultured in sterilized soils. The tested soil sterilization methods in the study included dry-heating sterilization, autoclaving sterilization and irradiation sterilization. Non-sterilized soil was the control. In order to mitigate effects of sterilization on soil physico- chemical properties, vermiculite was added to soils sterilized with different methods. The results showed that sterilization by the three methods significantly decreased A. adenophora and R. amethystoides biomass, regardless of vermiculite addition. For the three different sterilization methods, adding vermiculite to soil promoted the growth of A. adenophora and R. amethystoides whereas plant biomass in non-sterilized soils was not affected by vermiculite addition. A. adenophora and R. amethystoides biomass under irradiation sterilization soils plus vermiculite was 30.8% and 66.5% higher than that under dry-heating and autoclaving sterilization soils with vermiculite, respectively. Then R. amethystoides biomass under irradiation sterilization soils plus vermiculite increased by 109.5% and 63.4% compared with that in dry-heating sterilization or autoclaving sterilization soils plus vermiculite, respectively. Plants in gamma irradiated soils had the highest plant biomass among the soils subjected to the three sterilization treatments. Through mixed pot experiment of A. adenophora and R. amethystoides under irradiation sterilization soils plus vermiculite and non-sterilized soils plus vermiculite, we found that soil microbes enhanced the competitive ability of A. adenophora over the native plant R. amethystoides and relative competitive advantage increased by 16%. These results indicated that irradiation sterilization soil plus vermiculite treatment was efficient in pot experiment studies on feedback effects of soil microbes on plants. Soil microbes exerted positive feedback during invading process of invasive plant A. adenophora.
Soil sterilization is often used to explore feedback effects of soil microbes in community successions of competitive exclusion of native plants by invasive plants. In order to choose the most suitable soil sterilization method and to further analyze feedback effects of soil microbes on invasive plant Ageratina adenophora competition with native plants, we compared the differences in biomass between A. adenophora and native plant Rabdosia amethystoides cultured in sterilized soils. The tested soil sterilization methods in the study included dry-heating sterilization, autoclaving sterilization and irradiation sterilization. Non-sterilized soil was the control. In order to mitigate effects of sterilization on soil physico- chemical properties, vermiculite was added to soils sterilized with different methods. The results showed that sterilization by the three methods significantly decreased A. adenophora and R. amethystoides biomass, regardless of vermiculite addition. For the three different sterilization methods, adding vermiculite to soil promoted the growth of A. adenophora and R. amethystoides whereas plant biomass in non-sterilized soils was not affected by vermiculite addition. A. adenophora and R. amethystoides biomass under irradiation sterilization soils plus vermiculite was 30.8% and 66.5% higher than that under dry-heating and autoclaving sterilization soils with vermiculite, respectively. Then R. amethystoides biomass under irradiation sterilization soils plus vermiculite increased by 109.5% and 63.4% compared with that in dry-heating sterilization or autoclaving sterilization soils plus vermiculite, respectively. Plants in gamma irradiated soils had the highest plant biomass among the soils subjected to the three sterilization treatments. Through mixed pot experiment of A. adenophora and R. amethystoides under irradiation sterilization soils plus vermiculite and non-sterilized soils plus vermiculite, we found that soil microbes enhanced the competitive ability of A. adenophora over the native plant R. amethystoides and relative competitive advantage increased by 16%. These results indicated that irradiation sterilization soil plus vermiculite treatment was efficient in pot experiment studies on feedback effects of soil microbes on plants. Soil microbes exerted positive feedback during invading process of invasive plant A. adenophora.
2016, 24(9): 1231-1238.
doi: 10.13930/j.cnki.cjea.160319
Abstract:
Tropospheric ozone has been assumed to be the most phytotoxic air pollutant, which has created a severe concern for environmental pollution due to its negative impact on crop production. However, high ozone concentration also affects crop quality, which has so far not been treated in sufficient detail. Rice (Oryza sativa L.) is one of the most important food crops in the world, providing a significant proportion of human daily dietary needs. The accurate assessment of the impact of elevated concentration of surface layer ozone on rice quality is critical for reducing uncertainties in predicting future global food security. Using a Free-Air gas Concentration Enrichment (FACE) facility in Xiaoji Town (which is in Jiangdu County, Jiangsu Province, China), we conducted a field experiment to investigate the impacts of ozone stress on rice grain quality, including processing quality, appearance quality, cooking/eating quality and nutritional quality. Two rice cultivars (a conventional japonica cultivar ‘Wujing 15’ and a hybrid japonica cultivar ‘Lingfengyou 18’) were exposed to either ambient or elevated ozone concentration (ca. 21% above ambient values) from tillering to harvest. The results showed that elevated ozone resulted in a small decrease in brown rice percentage, milled rice percentage and head rice percentage, with the effect on milled rice percentage significant at the 0.05 level. Averaged across the two cultivars, elevated ozone concentration increased chalky grain percentage, area of chalkiness and degree of chalkiness by 15.0% (P = 0.10), 42.0% (P < 0.05) and 60.5% (P < 0.05), respectively. On average, elevated ozone concentration decreased gel consistency by 7.1% (P < 0.05), while no significant effect was observed on amylose concentration and gelatinization temperature for both cultivars. Measurements of RVA profile (Rapid Visco Analyser) indicated no significant changes in maximum viscosity, breakdown, cold viscosity, setback, and return due to elevated ozone. Elevated ozone concentration caused a non-significant increase in grain protein concentration for both cultivars. Analysis of variance indicated that in most cases, the effect of cultivar differences was significant. However, the interaction of ozone with cultivar was not detected for the tested traits of grain quality, suggesting that the response to ozone stress was similar for the two rice cultivars. The open-air field experiment suggested that moderate high ozone environment greatly increased grain chalkiness and significantly decreased gel consistency, but had little effect on other quality parameters of both cultivars.
Tropospheric ozone has been assumed to be the most phytotoxic air pollutant, which has created a severe concern for environmental pollution due to its negative impact on crop production. However, high ozone concentration also affects crop quality, which has so far not been treated in sufficient detail. Rice (Oryza sativa L.) is one of the most important food crops in the world, providing a significant proportion of human daily dietary needs. The accurate assessment of the impact of elevated concentration of surface layer ozone on rice quality is critical for reducing uncertainties in predicting future global food security. Using a Free-Air gas Concentration Enrichment (FACE) facility in Xiaoji Town (which is in Jiangdu County, Jiangsu Province, China), we conducted a field experiment to investigate the impacts of ozone stress on rice grain quality, including processing quality, appearance quality, cooking/eating quality and nutritional quality. Two rice cultivars (a conventional japonica cultivar ‘Wujing 15’ and a hybrid japonica cultivar ‘Lingfengyou 18’) were exposed to either ambient or elevated ozone concentration (ca. 21% above ambient values) from tillering to harvest. The results showed that elevated ozone resulted in a small decrease in brown rice percentage, milled rice percentage and head rice percentage, with the effect on milled rice percentage significant at the 0.05 level. Averaged across the two cultivars, elevated ozone concentration increased chalky grain percentage, area of chalkiness and degree of chalkiness by 15.0% (P = 0.10), 42.0% (P < 0.05) and 60.5% (P < 0.05), respectively. On average, elevated ozone concentration decreased gel consistency by 7.1% (P < 0.05), while no significant effect was observed on amylose concentration and gelatinization temperature for both cultivars. Measurements of RVA profile (Rapid Visco Analyser) indicated no significant changes in maximum viscosity, breakdown, cold viscosity, setback, and return due to elevated ozone. Elevated ozone concentration caused a non-significant increase in grain protein concentration for both cultivars. Analysis of variance indicated that in most cases, the effect of cultivar differences was significant. However, the interaction of ozone with cultivar was not detected for the tested traits of grain quality, suggesting that the response to ozone stress was similar for the two rice cultivars. The open-air field experiment suggested that moderate high ozone environment greatly increased grain chalkiness and significantly decreased gel consistency, but had little effect on other quality parameters of both cultivars.
ZHAO Yankun,
WANG Xiutang,
WANG Jing,
FU Xiaoyi,
DONG Zhanghui,
SHI Zhanliang,
GUO Jinkao,
HE Mingqi
2016, 24(9): 1239-1245.
doi: 10.13930/j.cnki.cjea.160056
Abstract:
In order to achieve high and stable yield and offer information for the selection of heat tolerant new varieties of wheat, the yield, 1000-kernel weight and grain-filling rate of 12 wheat varieties collected across the North China Wheat Belt and Huanghuai Wheat Region were studied under normal and heat treatments. The experiment was conducted in 20142015 at Malan Farm in Xinji, Hebei Province. A greenhouse was used as heating facility. Then grain-filling rate was measured for any increase in dry grain weight of different wheat varieties under normal and heated conditions. The yield and 1000-kernel weight were also analyzed after harvest. The results showed that yields of ‘Zhongmai 175’, ’Heng 4399’, ‘Heng 4444’, ‘CA0816’ and ‘Zhongmai 875’ were higher than those of other wheat varieties under both normal and heated conditions. Wheat grain weight was significantly affected by heating during rapid and slow grain-filling stages by reducing grain-filling rate. An evaluation of heat tolerance using the thermal index of yield and 1000-kernel weight showed that ‘Jingdong 8’, ‘CA0816’, ‘CA1062’, ‘Zhongmai 875’, ‘Zhongmai 895’ and ‘Heng 4444’ were heat-tolerant wheat varieties with the thermal index less than 1. Then, the other wheat varieties were heat -sensitive varieties with thermal index greater than or equal to 1. Wheat grain-filling rate, which was affected by high temperatures, differed for wheat varieties at grain-filling stage. Grain-filling rate of heat-tolerant varieties was affected at the last period of grain-filling whereas that of heat-sensitive varieties was affected at the middle period of grain-filling. In conclusion, ‘CA0816’, ‘Zhongmai 875’ and ‘Heng 4444’ wheat varieties showed both good yield and high heat-tolerance. Then ‘Heng 4399’ and ‘Zhongmai 175’ had a general thermal index for 1000-kernel weight whereas the related yield was high under both normal and heat treatments. Also ‘Jingdong 8’ showed a good heat tolerance with slightly lower yield. All the wheat varieties tested were as heat-tolerant wheat varieties for use in wheat breeding. We proposed further evaluation of both yield and thermal index of 1000-kernel weight in heat-tolerant wheat breeding.
In order to achieve high and stable yield and offer information for the selection of heat tolerant new varieties of wheat, the yield, 1000-kernel weight and grain-filling rate of 12 wheat varieties collected across the North China Wheat Belt and Huanghuai Wheat Region were studied under normal and heat treatments. The experiment was conducted in 20142015 at Malan Farm in Xinji, Hebei Province. A greenhouse was used as heating facility. Then grain-filling rate was measured for any increase in dry grain weight of different wheat varieties under normal and heated conditions. The yield and 1000-kernel weight were also analyzed after harvest. The results showed that yields of ‘Zhongmai 175’, ’Heng 4399’, ‘Heng 4444’, ‘CA0816’ and ‘Zhongmai 875’ were higher than those of other wheat varieties under both normal and heated conditions. Wheat grain weight was significantly affected by heating during rapid and slow grain-filling stages by reducing grain-filling rate. An evaluation of heat tolerance using the thermal index of yield and 1000-kernel weight showed that ‘Jingdong 8’, ‘CA0816’, ‘CA1062’, ‘Zhongmai 875’, ‘Zhongmai 895’ and ‘Heng 4444’ were heat-tolerant wheat varieties with the thermal index less than 1. Then, the other wheat varieties were heat -sensitive varieties with thermal index greater than or equal to 1. Wheat grain-filling rate, which was affected by high temperatures, differed for wheat varieties at grain-filling stage. Grain-filling rate of heat-tolerant varieties was affected at the last period of grain-filling whereas that of heat-sensitive varieties was affected at the middle period of grain-filling. In conclusion, ‘CA0816’, ‘Zhongmai 875’ and ‘Heng 4444’ wheat varieties showed both good yield and high heat-tolerance. Then ‘Heng 4399’ and ‘Zhongmai 175’ had a general thermal index for 1000-kernel weight whereas the related yield was high under both normal and heat treatments. Also ‘Jingdong 8’ showed a good heat tolerance with slightly lower yield. All the wheat varieties tested were as heat-tolerant wheat varieties for use in wheat breeding. We proposed further evaluation of both yield and thermal index of 1000-kernel weight in heat-tolerant wheat breeding.
2016, 24(9): 1246-1253.
doi: 10.13930/j.cnki.cjea.151319
Abstract:
The oilseed flax yield formation model was developed to predict biomass yield and provide scientific guidance for oilseed flax production, which was an important sub model of oilseed flax development model, APSIM-Oilseed flax. Its’ accuracy was related to the performance of APSIM-Oilseed flax. In the study, the oilseed flax yield formation model was developed for Northwest China using data generated from experiments, and was calibrated and validated under varying fertilizers, seeding methods, planting densities, nitrogen and phosphorus application conditions. The experiments were conducted at Dingxi and Yuzhong of Gansu Province from 2012 to 2015. Calibration was done using data for 2012–2013 and validation with data for 2014–2015. Two methods, yield component factors method and grain pod ratio method, were used to build oilseed flax yield formation model. The oilseed flax yield formation model of yield component factors was based on genetic parameters, such as, number of pods per unit area, grains number per pod, grain weight and water and fertilizer stress factors. The oilseed flax yield formation model of the grain pod ratio was based on grain pod ratio and total dry matter. The results showed that the average RMSE for the model-simulated and field values related to the yield component factors method under different fertilizers, sowing densities in Dingxi was 133.47 kg per hm2. Then it was 195.51 kg per hm2 for the grain pod ratio method. Then R2 values were 0.819 8 and 0.743 9 for the yield component factors and grain pod ratio, respectively. The average RMSE was 140.70 kg per hm2 for the yield component factors method under varying nitrogen and phosphorus levels in Yuzhong and it was 193.22 kg per hm2 for the grain pod ratio method. The R2 values were 0.832 9 and 0.805 8 of yield component factors and grain pod ratio, respectively. The validation results showed that the yield component factors method was better than the grain pod ratio method in simulating oilseed flax yield formation. In view of different varieties of oilseed flax under varying experimental treatments, the yield component factors method simulated oilseed flax yield with high accuracy and versatility using the number of pods per unit area, seeds number per pod and grain weight as genetic parameters.
The oilseed flax yield formation model was developed to predict biomass yield and provide scientific guidance for oilseed flax production, which was an important sub model of oilseed flax development model, APSIM-Oilseed flax. Its’ accuracy was related to the performance of APSIM-Oilseed flax. In the study, the oilseed flax yield formation model was developed for Northwest China using data generated from experiments, and was calibrated and validated under varying fertilizers, seeding methods, planting densities, nitrogen and phosphorus application conditions. The experiments were conducted at Dingxi and Yuzhong of Gansu Province from 2012 to 2015. Calibration was done using data for 2012–2013 and validation with data for 2014–2015. Two methods, yield component factors method and grain pod ratio method, were used to build oilseed flax yield formation model. The oilseed flax yield formation model of yield component factors was based on genetic parameters, such as, number of pods per unit area, grains number per pod, grain weight and water and fertilizer stress factors. The oilseed flax yield formation model of the grain pod ratio was based on grain pod ratio and total dry matter. The results showed that the average RMSE for the model-simulated and field values related to the yield component factors method under different fertilizers, sowing densities in Dingxi was 133.47 kg per hm2. Then it was 195.51 kg per hm2 for the grain pod ratio method. Then R2 values were 0.819 8 and 0.743 9 for the yield component factors and grain pod ratio, respectively. The average RMSE was 140.70 kg per hm2 for the yield component factors method under varying nitrogen and phosphorus levels in Yuzhong and it was 193.22 kg per hm2 for the grain pod ratio method. The R2 values were 0.832 9 and 0.805 8 of yield component factors and grain pod ratio, respectively. The validation results showed that the yield component factors method was better than the grain pod ratio method in simulating oilseed flax yield formation. In view of different varieties of oilseed flax under varying experimental treatments, the yield component factors method simulated oilseed flax yield with high accuracy and versatility using the number of pods per unit area, seeds number per pod and grain weight as genetic parameters.
2016, 24(9): 1254-1264.
doi: 10.13930/j.cnki.cjea.151237
Abstract:
Leaf area index (LAI) is an important agronomic parameter used in evaluating crop growth characteristics. The accurate estimation of LAI based on remote sensing technology is critical for precision agriculture. The current cost-effective unmanned aerial vehicle (UAV) of agricultural remote sensing monitoring system, which was established based on a multi-rotor UAV with a digital camera mounted on its platform, has led to significant achievements in agricultural research. However, there has been little research on retrieving crop LAI based on UAV digital imagery. To demonstrate the feasibility of using UAV digital imagery to estimate winter wheat LAI, we used this cost-effective UAV system to monitor agricultural operation in the study area. Then many UAV digital images (also known as RGB images) used as the study data source recorded at three critical growth stages — booting, anthesis and filling stages of winter wheat. We calculated ten characteristic parameters from the RGB images based on digital imaging conversion principle. Furthermore, we systematically analyzed the relationship between LAI at the three growth stages of the two winter wheat varieties with the four nitrogen levels and characteristic parameters of RGB images. It was indicated that among the ten characteristic parameters, R/(R+G+B) and UAV-based VARIRGB (visible atmospherically resistant index based on UAV RGB image, which was calculated in this paper based on DN in the red, green and blue channels of UAV digital images and the calculation principle of VARI) regularly changed with LAI of winter wheat. The change occurred regularly and simultaneously for the three growth stages. It showed that different nitrogen levels in winter wheat not only influenced LAI, but also influenced some characteristic parameters of digital images. Meanwhile, the study also indicated that R/(R+G+B) and UAV-based VARIRGB were more significantly correlated with LAI under different conditions, including variety, nitrogen level and growth stage among the ten characteristic parameters. Then two comprehensive evaluation of LAI inversion models between LAI and R/(R+G+B) and UAV-based VARIRGB were established. The evaluation demonstrated that UAV-based VARIRGB was the best parameter which optimally retrieved LAI of winter wheat. LAI estimated by the exponential model of UAV-based VARIRGB strongly matched with measured LAI, with R2 = 0.71, RMSE = 0.8 and at 0.01 significance level. Therefore, the results showed that the application of UAV digital imagery in retrieving winter wheat LAI was feasible. The study also enriched the achievements and experience of using cost-effective UAV remote sensing monitoring system in precision agriculture.
Leaf area index (LAI) is an important agronomic parameter used in evaluating crop growth characteristics. The accurate estimation of LAI based on remote sensing technology is critical for precision agriculture. The current cost-effective unmanned aerial vehicle (UAV) of agricultural remote sensing monitoring system, which was established based on a multi-rotor UAV with a digital camera mounted on its platform, has led to significant achievements in agricultural research. However, there has been little research on retrieving crop LAI based on UAV digital imagery. To demonstrate the feasibility of using UAV digital imagery to estimate winter wheat LAI, we used this cost-effective UAV system to monitor agricultural operation in the study area. Then many UAV digital images (also known as RGB images) used as the study data source recorded at three critical growth stages — booting, anthesis and filling stages of winter wheat. We calculated ten characteristic parameters from the RGB images based on digital imaging conversion principle. Furthermore, we systematically analyzed the relationship between LAI at the three growth stages of the two winter wheat varieties with the four nitrogen levels and characteristic parameters of RGB images. It was indicated that among the ten characteristic parameters, R/(R+G+B) and UAV-based VARIRGB (visible atmospherically resistant index based on UAV RGB image, which was calculated in this paper based on DN in the red, green and blue channels of UAV digital images and the calculation principle of VARI) regularly changed with LAI of winter wheat. The change occurred regularly and simultaneously for the three growth stages. It showed that different nitrogen levels in winter wheat not only influenced LAI, but also influenced some characteristic parameters of digital images. Meanwhile, the study also indicated that R/(R+G+B) and UAV-based VARIRGB were more significantly correlated with LAI under different conditions, including variety, nitrogen level and growth stage among the ten characteristic parameters. Then two comprehensive evaluation of LAI inversion models between LAI and R/(R+G+B) and UAV-based VARIRGB were established. The evaluation demonstrated that UAV-based VARIRGB was the best parameter which optimally retrieved LAI of winter wheat. LAI estimated by the exponential model of UAV-based VARIRGB strongly matched with measured LAI, with R2 = 0.71, RMSE = 0.8 and at 0.01 significance level. Therefore, the results showed that the application of UAV digital imagery in retrieving winter wheat LAI was feasible. The study also enriched the achievements and experience of using cost-effective UAV remote sensing monitoring system in precision agriculture.
2016, 24(9): 1265-1274.
doi: 10.13930/j.cnki.cjea.160007
Abstract:
High-standard prime farmlands are high production capacity systems that integrate natural quality of cultivated lands, perfect supporting infrastructures, advanced agricultural techniques and management concepts. However, national investment levels for high-standard prime farmland constructions have remained persistently low. Thus scientifically and reasonably constructing high-standard prime farmlands is critical for present and future sustainability of production. With the construction area of high-standard prime farmland as the studied unit in Zhuozhou County, Hebei Province, the paper adopted the model method, comprehensive multi-factor evaluation method, paired comparison method, and the feasibility and suitability composition matrix method to decide time sequence of high-standard prime farmland. In this article, construction areas were first divided on the basis of prime farmland contiguous condition, eliminating smaller construction areas. Then the construction areas were refined according to the ownership of the divided construction areas. On this basis, the construction areas were used as the basic evaluation units to discuss high-standard prime farmland construction conditions. The established construction feasibility and ecological suitability evaluation index system was used to ultimately determine construction time sequence according to the composition matrix of feasibility and suitability. The results divided Zhuozhou County into 73 high- standard prime farmland construction areas. This included 15 areas of recent construction with total area of 11 241.23 hm2, which mainly distributed in Songlindian Town, Matou Town, Diaowo Town, etc. In these regions, social and economic development levels were higher, location conditions superior with better ecological landscape conditions and higher degree of continuity. About 50 medium-term construction areas with a total area of 27 054.07 hm2 were widely distributed in the northeast of Yihezhuang Township, the southeast of Gaoguanzhuang Town and Douzhuang Town, and most areas was in the west and northwest of the city. Another 8 long-term construction areas with a total area of 875.98 hm2 had a scattered distribution with small average construction areas of only 109.50 hm2. In order to fully complete the number and quality goals of high-standard prime farmland construction, relevant government departments needed to consider areas that were feasible for construction and ecologically suitable, and coupled with early and late funding supports for social and economic development. The implementation of any such projects needed rationally to arrange time sequence and select key regions. This was potential in eliminating the main limiting elements through engineering or technical measures that ensured gradual expansion of suitable construction regions. In addition, policy-making should carefully choice pilot regions with low construction intensity and good ecological suitability. At the same time, it was important to broaden investment channels for successful construction of high-standard prime farmlands.
High-standard prime farmlands are high production capacity systems that integrate natural quality of cultivated lands, perfect supporting infrastructures, advanced agricultural techniques and management concepts. However, national investment levels for high-standard prime farmland constructions have remained persistently low. Thus scientifically and reasonably constructing high-standard prime farmlands is critical for present and future sustainability of production. With the construction area of high-standard prime farmland as the studied unit in Zhuozhou County, Hebei Province, the paper adopted the model method, comprehensive multi-factor evaluation method, paired comparison method, and the feasibility and suitability composition matrix method to decide time sequence of high-standard prime farmland. In this article, construction areas were first divided on the basis of prime farmland contiguous condition, eliminating smaller construction areas. Then the construction areas were refined according to the ownership of the divided construction areas. On this basis, the construction areas were used as the basic evaluation units to discuss high-standard prime farmland construction conditions. The established construction feasibility and ecological suitability evaluation index system was used to ultimately determine construction time sequence according to the composition matrix of feasibility and suitability. The results divided Zhuozhou County into 73 high- standard prime farmland construction areas. This included 15 areas of recent construction with total area of 11 241.23 hm2, which mainly distributed in Songlindian Town, Matou Town, Diaowo Town, etc. In these regions, social and economic development levels were higher, location conditions superior with better ecological landscape conditions and higher degree of continuity. About 50 medium-term construction areas with a total area of 27 054.07 hm2 were widely distributed in the northeast of Yihezhuang Township, the southeast of Gaoguanzhuang Town and Douzhuang Town, and most areas was in the west and northwest of the city. Another 8 long-term construction areas with a total area of 875.98 hm2 had a scattered distribution with small average construction areas of only 109.50 hm2. In order to fully complete the number and quality goals of high-standard prime farmland construction, relevant government departments needed to consider areas that were feasible for construction and ecologically suitable, and coupled with early and late funding supports for social and economic development. The implementation of any such projects needed rationally to arrange time sequence and select key regions. This was potential in eliminating the main limiting elements through engineering or technical measures that ensured gradual expansion of suitable construction regions. In addition, policy-making should carefully choice pilot regions with low construction intensity and good ecological suitability. At the same time, it was important to broaden investment channels for successful construction of high-standard prime farmlands.
2016, 24(9): 1275-1284.
doi: 10.13930/j.cnki.cjea.160023
Abstract:
Urban development and urban agriculture constitutes an integrated system due to the complicated interaction mechanism of functional complementation and promotion. The multi-functionality of agriculture has been increasingly highlighted during urbanization and the gradual integration of urban agriculture into urban economic, social and ecological development and spatial formation. Urban development, encompassing the natural environment, resource endowment, development foundation and comprehensive strength, is significantly different in the eastern, central and western regions of China. Therefore, diversified development models have been tailored for urban agriculture constantly highlighting the related advantages and characteristics in different regions of China. Evaluating the developing rationality and current characteristics of urban agricultural multi-functionality and exploring the related development models suitable for specific regions are helpful in coordinating urban functions, urban agricultural multi-functions and for formulating urban agriculture development strategies based on region-specific conditions. It is necessary to coordinate the development between urban functions and functions produced by urban agriculture for sustainable development of urbanization areas. We quantitatively assessed urban agriculture multifunction from the aspects of production function, economic function, social function and ecological services in 22 cities of China using a four-dimension evaluation model. We classified and proposed ten development models of multifunctional development of urban agriculture based on the assembly of the related four functions using the system clustering method. The research showed that an individual or comprehensive functions provided by urban agriculture presented obvious differences among the eastern, central and western regions of China. This was due to the differentiation of natural environment, and social and economic development of different regions. From cities in the western region of China to cities in the central and eastern regions, urban agriculture multifunction development models shifted gradually from weakly coordinated development to generally coordinated development and then to strongly coordinated development. It shifted gradually from ecological priority development to predominantly social and ecological development model and then to production, social and economic development model. The development level of ecological services of urban agriculture exceeded 0.40 for cities with the model of ecological priority development. Then, the development level of social functions of urban agriculture was more than 0.55 in cities with the model of social priority development. Next, the development level of economic functions of urban agriculture reached 0.80 in cities for which the model was economic priority development. Finally, the development level of production of urban agriculture reached 0.75 in cities for which the model was provisioning priority development. This series of multi-functional urban agricultural development models suggested that multi-dimensional evaluation method actually reflected the development level of urban agriculture multifunction and the related regional differences in China. Furthermore, it not only provided accurate measurements for evaluation of development degree of urban agricultural functions under different urbanization level, but also clearly indicated the development of the internal structure of urban agricultural services and functions in each city and the related development merits and demerits. The research had important implications for the optimization of urban agricultural multifunction, scientific adjustment of urban agriculture structure, and implementation of coordinated policies on the development of urban agriculture multifunction with the development of urban socio-economy.
Urban development and urban agriculture constitutes an integrated system due to the complicated interaction mechanism of functional complementation and promotion. The multi-functionality of agriculture has been increasingly highlighted during urbanization and the gradual integration of urban agriculture into urban economic, social and ecological development and spatial formation. Urban development, encompassing the natural environment, resource endowment, development foundation and comprehensive strength, is significantly different in the eastern, central and western regions of China. Therefore, diversified development models have been tailored for urban agriculture constantly highlighting the related advantages and characteristics in different regions of China. Evaluating the developing rationality and current characteristics of urban agricultural multi-functionality and exploring the related development models suitable for specific regions are helpful in coordinating urban functions, urban agricultural multi-functions and for formulating urban agriculture development strategies based on region-specific conditions. It is necessary to coordinate the development between urban functions and functions produced by urban agriculture for sustainable development of urbanization areas. We quantitatively assessed urban agriculture multifunction from the aspects of production function, economic function, social function and ecological services in 22 cities of China using a four-dimension evaluation model. We classified and proposed ten development models of multifunctional development of urban agriculture based on the assembly of the related four functions using the system clustering method. The research showed that an individual or comprehensive functions provided by urban agriculture presented obvious differences among the eastern, central and western regions of China. This was due to the differentiation of natural environment, and social and economic development of different regions. From cities in the western region of China to cities in the central and eastern regions, urban agriculture multifunction development models shifted gradually from weakly coordinated development to generally coordinated development and then to strongly coordinated development. It shifted gradually from ecological priority development to predominantly social and ecological development model and then to production, social and economic development model. The development level of ecological services of urban agriculture exceeded 0.40 for cities with the model of ecological priority development. Then, the development level of social functions of urban agriculture was more than 0.55 in cities with the model of social priority development. Next, the development level of economic functions of urban agriculture reached 0.80 in cities for which the model was economic priority development. Finally, the development level of production of urban agriculture reached 0.75 in cities for which the model was provisioning priority development. This series of multi-functional urban agricultural development models suggested that multi-dimensional evaluation method actually reflected the development level of urban agriculture multifunction and the related regional differences in China. Furthermore, it not only provided accurate measurements for evaluation of development degree of urban agricultural functions under different urbanization level, but also clearly indicated the development of the internal structure of urban agricultural services and functions in each city and the related development merits and demerits. The research had important implications for the optimization of urban agricultural multifunction, scientific adjustment of urban agriculture structure, and implementation of coordinated policies on the development of urban agriculture multifunction with the development of urban socio-economy.
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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