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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2014 Vol. 22, No. 4
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2014, 22(4): 375-385.
doi: 10.3724/SP.J.1011.2014.31095
Abstract:
Various biotic and abiotic environmental stresses threaten the productivity of crops. With the development of molecular biology, crop stress research has changed to focus on the regulation mechanisms of stress tolerance at molecular scale, the field today known as ecogenomics. Ecogenomics ecologically integrated the various disciplines of genomic approaches. Here, we reviewed some recent progresses in ecogenomic researches on crop response to biotic and abiotic stresses under the three classes of functional genomics, structural genomics and comparative genomics. Not only the methodologies, but also the applications of genomics in crop stress tolerance were summarized. Specifically, high-throughput approaches based on next generation sequencing were scrutinized. ① Functional genomics, as treated in this review, included transcriptomics, epigenomics, proteomics, interactomics, metabolomics and phenomics. We focused on advances in plant response to stress at gene expression level, which belonged to transcriptomics and epigenomics. A series of vital techniques were introduced, including microarray, RNA-seq, serial analysis of gene expression (SAGE), suppression-substractive hybridization (SSH), bisulfite method, chromatin immunoprecipitation-chip (ChIP-Chip) and ChiP-seq. Recent research results were also discussed, including the functions of transcription factors in crop stress tolerance. It showed that expression of a plant stress factor was regulated by the interaction of the factor with other stress factors of the crop. Several plant stress factors acted in the plant hormone signal transduction pathways. This was more evident for ABA pathway and senescence process as a consequence of stress. It seemed that plants required several transcription factors for the same stress response, whereas the same transcription factor could be involved in different stress responses. Epigenetic studies of epigenetic modifications of genetic materials were about the prevention of change in DNA sequences. Among others, it included DNA methylation, histone post-transcriptional modification and small-RNA-mediated signal transduction. Research also showed that it somehow affected genetic imprint of gene expression. ② Structural genomics was mainly about the utilization of quantitative trait loci mapping (QTL) and DNA sequencing techniques to draw plant genetic maps and genomic physical maps. Due to efficient processes of next generation sequencing, whole genome sequencing was possible for many plants. Until now, whole genome sequencing projects had been completed for only more than forty plants, and more projects were underway. ③ Comparative genetics was based on functional genomics and structural genetics with the aim of investigating the differences and correlations of genomic features among different organisms or populations. It explored the functions of plant stress factors in the evolution process and geographical distribution. Meanwhile, it also provided useful feedback on QTL studies and functional genomic studies. Additionally, various useful online databases on genomic and bioinformatic resources for crop stress research were briefly introduced and some listed. Although some bottlenecks still existed in dealing with numerous genomic data, ecogenomics has already hinted on both basic research on crop stress response and applied strategies for crop improvement.
Various biotic and abiotic environmental stresses threaten the productivity of crops. With the development of molecular biology, crop stress research has changed to focus on the regulation mechanisms of stress tolerance at molecular scale, the field today known as ecogenomics. Ecogenomics ecologically integrated the various disciplines of genomic approaches. Here, we reviewed some recent progresses in ecogenomic researches on crop response to biotic and abiotic stresses under the three classes of functional genomics, structural genomics and comparative genomics. Not only the methodologies, but also the applications of genomics in crop stress tolerance were summarized. Specifically, high-throughput approaches based on next generation sequencing were scrutinized. ① Functional genomics, as treated in this review, included transcriptomics, epigenomics, proteomics, interactomics, metabolomics and phenomics. We focused on advances in plant response to stress at gene expression level, which belonged to transcriptomics and epigenomics. A series of vital techniques were introduced, including microarray, RNA-seq, serial analysis of gene expression (SAGE), suppression-substractive hybridization (SSH), bisulfite method, chromatin immunoprecipitation-chip (ChIP-Chip) and ChiP-seq. Recent research results were also discussed, including the functions of transcription factors in crop stress tolerance. It showed that expression of a plant stress factor was regulated by the interaction of the factor with other stress factors of the crop. Several plant stress factors acted in the plant hormone signal transduction pathways. This was more evident for ABA pathway and senescence process as a consequence of stress. It seemed that plants required several transcription factors for the same stress response, whereas the same transcription factor could be involved in different stress responses. Epigenetic studies of epigenetic modifications of genetic materials were about the prevention of change in DNA sequences. Among others, it included DNA methylation, histone post-transcriptional modification and small-RNA-mediated signal transduction. Research also showed that it somehow affected genetic imprint of gene expression. ② Structural genomics was mainly about the utilization of quantitative trait loci mapping (QTL) and DNA sequencing techniques to draw plant genetic maps and genomic physical maps. Due to efficient processes of next generation sequencing, whole genome sequencing was possible for many plants. Until now, whole genome sequencing projects had been completed for only more than forty plants, and more projects were underway. ③ Comparative genetics was based on functional genomics and structural genetics with the aim of investigating the differences and correlations of genomic features among different organisms or populations. It explored the functions of plant stress factors in the evolution process and geographical distribution. Meanwhile, it also provided useful feedback on QTL studies and functional genomic studies. Additionally, various useful online databases on genomic and bioinformatic resources for crop stress research were briefly introduced and some listed. Although some bottlenecks still existed in dealing with numerous genomic data, ecogenomics has already hinted on both basic research on crop stress response and applied strategies for crop improvement.
2014, 22(4): 386-393.
doi: 10.3724/SP.J.1011.2014.31063
Abstract:
Most studies on straw decomposition in soil have been conducted with straw additions in the range of 0 100 g of straw per kilogram of soil. Actually, straw could be unevenly incorporated into soil resulting in very high local straw addition amounts, higher than 100 g per kilogram of soil under field conditions. There have been contradictory research results about straw decomposition in soil with straw addition of less than 100 g per kilogram of soil. In this study, the effects of straw addition amounts on organic carbon decomposition, composition and liability of yellow fluvo-aquic soils and lime concretion black soils were studied to develop a theoretical basis for straw decomposition in soils, and improvements in soil carbon cycle and soil fertility for high-harvest cultivation. After one year of indoor soil incubation with straw addition amounts of 0 400 g per kilogram of soil at (35±1) ℃ and 80% 95% field water capacity, the decomposition rates and humification coefficients of soil organic matter, soil C/N ratio, active soil organic carbon (AOC), inactive organic carbon (IOC), total organic carbon (TOC), AOC/TOC ratio and carbon lability (soil AOC/IOC ratio, L%) were determined. The results showed that humification coefficients of total soil organic matter were 20% 35%. With increasing straw dose, humification coefficient decreased while organic matter decomposition rate, AOC, IOC, TOC and L increased. These variables were significantly (P < 0.01) and positively correlated with straw addition amount. Also while a significant (P < 0.01) and positive correlation was noted between AOC and TOC, the correlation between the humification coefficient and L was significant (P < 0.01) but negative. The contents of clay particles smaller than 0.002 mm in yellow fluvo-aquic soils and lime concretion black soils were 33% and 41%, respectively. Straw was more likely to break down in yellow fluvo-aquic soils than in lime concretion black soils. Higher clay content in lime concretion black soils highly favored soil carbon storage. After one year of indoor incubation, soil AOC/TOC ratio and L in yellow fluvo-aquic soils were on average 7.6 and 12.3 percentage points higher than those in lime concre-tion black soils, respectively. Humification coefficient and soil C/N ratio in lime concretion black soils were on average 3.2 and 2.3 percentage points higher than those in yellow fluvo-aquic soils, respectively. In conclusion, the higher the soil carbon lability, the more beneficial was to increasing decomposition rate and reducing humification coefficient of soil organic matter. Then the higher the soil clay content, the lower the decomposition rate and the higher the humificatin coefficient of soil organic matter. This was in accordance with the results of previous studies conducted with straw addition amount less than 100 g per kilogram of soil. There was the need for further studies under field conditions under different soil types and different straw addition amounts.
Most studies on straw decomposition in soil have been conducted with straw additions in the range of 0 100 g of straw per kilogram of soil. Actually, straw could be unevenly incorporated into soil resulting in very high local straw addition amounts, higher than 100 g per kilogram of soil under field conditions. There have been contradictory research results about straw decomposition in soil with straw addition of less than 100 g per kilogram of soil. In this study, the effects of straw addition amounts on organic carbon decomposition, composition and liability of yellow fluvo-aquic soils and lime concretion black soils were studied to develop a theoretical basis for straw decomposition in soils, and improvements in soil carbon cycle and soil fertility for high-harvest cultivation. After one year of indoor soil incubation with straw addition amounts of 0 400 g per kilogram of soil at (35±1) ℃ and 80% 95% field water capacity, the decomposition rates and humification coefficients of soil organic matter, soil C/N ratio, active soil organic carbon (AOC), inactive organic carbon (IOC), total organic carbon (TOC), AOC/TOC ratio and carbon lability (soil AOC/IOC ratio, L%) were determined. The results showed that humification coefficients of total soil organic matter were 20% 35%. With increasing straw dose, humification coefficient decreased while organic matter decomposition rate, AOC, IOC, TOC and L increased. These variables were significantly (P < 0.01) and positively correlated with straw addition amount. Also while a significant (P < 0.01) and positive correlation was noted between AOC and TOC, the correlation between the humification coefficient and L was significant (P < 0.01) but negative. The contents of clay particles smaller than 0.002 mm in yellow fluvo-aquic soils and lime concretion black soils were 33% and 41%, respectively. Straw was more likely to break down in yellow fluvo-aquic soils than in lime concretion black soils. Higher clay content in lime concretion black soils highly favored soil carbon storage. After one year of indoor incubation, soil AOC/TOC ratio and L in yellow fluvo-aquic soils were on average 7.6 and 12.3 percentage points higher than those in lime concre-tion black soils, respectively. Humification coefficient and soil C/N ratio in lime concretion black soils were on average 3.2 and 2.3 percentage points higher than those in yellow fluvo-aquic soils, respectively. In conclusion, the higher the soil carbon lability, the more beneficial was to increasing decomposition rate and reducing humification coefficient of soil organic matter. Then the higher the soil clay content, the lower the decomposition rate and the higher the humificatin coefficient of soil organic matter. This was in accordance with the results of previous studies conducted with straw addition amount less than 100 g per kilogram of soil. There was the need for further studies under field conditions under different soil types and different straw addition amounts.
2014, 22(4): 394-400.
doi: 10.3724/SP.J.1011.2014.31036
Abstract:
Phosphorus is a restricted element as it causes eutrophication of especially still water systems. Due to the excessive application of phosphate fertilizers in recent years, farmlands have become the major source of phosphorus which causes water eutrophication. To determine optimal phosphorus applications in paddy fields, a field lysimeter experiment was conducted under different treatments of organic fertilizer (OT), mixed fertilizer (MT) and chemical fertilizer (CT). Phosphorus loss and migration characteristics in the fields under different treatments, and treatments effects on yield and phosphorus utilization ratio of paddy rice were analyzed. Results showed that runoff loads of phosphorus under CT, MT, and OT were 0.56 kg(P)·hm-2, 1.13 kg(P)·hm-2 and 4.19 kg(P)·hm-2, respectively. Also leaching loads of phosphorus under CT, MT and OT were 0.42 kg(P)·hm-2, 0.44 kg(P)·hm-2 and 0.45 kg(P)·hm-2, respectively. Phosphorus loss in paddy fields was mainly through runoff, accounting for 56.86%?90.38% of total phosphorus loss. Runoff of phosphorus was mainly driven by fertilizer dose and rainfall intensity, and the loss through the first runoff accounted for about 50% of phosphorus loss. Phosphorus leach was not influenced by phosphorus dose, and over 80% of phosphorus loss occurred in the first 30 days after fertilizer application. Soluble phosphorus was the main form of phosphorus in surface water, seepage water and runoff water. While it was possible for MT and OT to ensure sufficient phosphorus supply in soils, CT decreased Olsen-P and organic matter in soils. Yields of paddy rice under the three treatments were significantly higher than that under the control, among which MT had the highest yield (6 728.84 kg·hm-2). Phosphorus fertilizer use efficiencies under CT and MT were significantly higher than that under OT. In conclusion, MT was better fertilzation pattern for phosphorus loss control, soil nutrient utilization and paddy rice yield in eco-agricultural systems in China.
Phosphorus is a restricted element as it causes eutrophication of especially still water systems. Due to the excessive application of phosphate fertilizers in recent years, farmlands have become the major source of phosphorus which causes water eutrophication. To determine optimal phosphorus applications in paddy fields, a field lysimeter experiment was conducted under different treatments of organic fertilizer (OT), mixed fertilizer (MT) and chemical fertilizer (CT). Phosphorus loss and migration characteristics in the fields under different treatments, and treatments effects on yield and phosphorus utilization ratio of paddy rice were analyzed. Results showed that runoff loads of phosphorus under CT, MT, and OT were 0.56 kg(P)·hm-2, 1.13 kg(P)·hm-2 and 4.19 kg(P)·hm-2, respectively. Also leaching loads of phosphorus under CT, MT and OT were 0.42 kg(P)·hm-2, 0.44 kg(P)·hm-2 and 0.45 kg(P)·hm-2, respectively. Phosphorus loss in paddy fields was mainly through runoff, accounting for 56.86%?90.38% of total phosphorus loss. Runoff of phosphorus was mainly driven by fertilizer dose and rainfall intensity, and the loss through the first runoff accounted for about 50% of phosphorus loss. Phosphorus leach was not influenced by phosphorus dose, and over 80% of phosphorus loss occurred in the first 30 days after fertilizer application. Soluble phosphorus was the main form of phosphorus in surface water, seepage water and runoff water. While it was possible for MT and OT to ensure sufficient phosphorus supply in soils, CT decreased Olsen-P and organic matter in soils. Yields of paddy rice under the three treatments were significantly higher than that under the control, among which MT had the highest yield (6 728.84 kg·hm-2). Phosphorus fertilizer use efficiencies under CT and MT were significantly higher than that under OT. In conclusion, MT was better fertilzation pattern for phosphorus loss control, soil nutrient utilization and paddy rice yield in eco-agricultural systems in China.
2014, 22(4): 401-407.
doi: 10.3724/SP.J.1011.2014.31023
Abstract:
Soil fumigants have been comprehensively used to control nematodes, weeds, soil-borne pathogens and insects in high value (cash) crop plantations. Though ideal pesticides are toxic only to target organisms, fumigants are a class of pesticides with broad biocidal ability thus affecting many non-target soil organisms, including nitrifying and denitrifying bacteria. It may results in changed soil nitrification and denitrification. The aim of this study was to explore the proper application measures of fumigants by quantifying the effects of different soil fumigants on soil nitrification and denitrification in laboratory and field conditions. To investigate the effects of different soil fumigants on soil nitrogen transformation processes of nitrification and denitrification, chemical analysis and degeneration gradient gel electrophoresis technique (DGGE) were used. Soils fumigated with metham-sodium, dazomet, methyl bromide and sulfuryl fluoride for a period of 100 d were sampled and the effects of fumigation on soil nitrification and denitrification activities determined along with the community structures of amoA nitrification bacteria and nirS denitrifying bacteria. The results showed that compared with the control, no significant differences existed in nitrification activity of soils fumigated with metham-sodium, dazomet, sulfuryl fluoride. However, nitrification activity of soils fumigated with methyl bromide decreased by 13.19%, which was significant (P < 0.05) compared with the control. No significant differences existed among the four fumigants in terms of observed soil nitrification activity. There was also no significant difference in soil denitrification activity among the four fumigants and the control. Diversity index and evenness index of amoA nitrifying bacteria community of soil fumigated with methyl bromide were significantly lower than those of soils fumigated with the other three fumigants and the control. Richness index was not significantly different among all the treatments. The three indexes were not significantly different among soils treated with metham-sodium, dazomet, sulfuryl fluoride and the control. Diversity index, evenness index and richness index of nirS denitrifying bacteria community were significantly different among the four fumigants, but not significantly different from those of the control. The research results showed that the inhibition effect of methyl bromide on soil nitrification activity was achieved through the inhibition of the diversity of amoA nitrifying bacteria community. The other three fumigants had no significant effect on soil nitrification activity. Denitrification activity of soils was not significantly affected by the four fumigants.
Soil fumigants have been comprehensively used to control nematodes, weeds, soil-borne pathogens and insects in high value (cash) crop plantations. Though ideal pesticides are toxic only to target organisms, fumigants are a class of pesticides with broad biocidal ability thus affecting many non-target soil organisms, including nitrifying and denitrifying bacteria. It may results in changed soil nitrification and denitrification. The aim of this study was to explore the proper application measures of fumigants by quantifying the effects of different soil fumigants on soil nitrification and denitrification in laboratory and field conditions. To investigate the effects of different soil fumigants on soil nitrogen transformation processes of nitrification and denitrification, chemical analysis and degeneration gradient gel electrophoresis technique (DGGE) were used. Soils fumigated with metham-sodium, dazomet, methyl bromide and sulfuryl fluoride for a period of 100 d were sampled and the effects of fumigation on soil nitrification and denitrification activities determined along with the community structures of amoA nitrification bacteria and nirS denitrifying bacteria. The results showed that compared with the control, no significant differences existed in nitrification activity of soils fumigated with metham-sodium, dazomet, sulfuryl fluoride. However, nitrification activity of soils fumigated with methyl bromide decreased by 13.19%, which was significant (P < 0.05) compared with the control. No significant differences existed among the four fumigants in terms of observed soil nitrification activity. There was also no significant difference in soil denitrification activity among the four fumigants and the control. Diversity index and evenness index of amoA nitrifying bacteria community of soil fumigated with methyl bromide were significantly lower than those of soils fumigated with the other three fumigants and the control. Richness index was not significantly different among all the treatments. The three indexes were not significantly different among soils treated with metham-sodium, dazomet, sulfuryl fluoride and the control. Diversity index, evenness index and richness index of nirS denitrifying bacteria community were significantly different among the four fumigants, but not significantly different from those of the control. The research results showed that the inhibition effect of methyl bromide on soil nitrification activity was achieved through the inhibition of the diversity of amoA nitrifying bacteria community. The other three fumigants had no significant effect on soil nitrification activity. Denitrification activity of soils was not significantly affected by the four fumigants.
2014, 22(4): 408-413.
doi: 10.3724/SP.J.1011.2014.31093
Abstract:
Alternate wetting and drying technique at late growth stage of rice has been widely used in high-yield cultivation techniques to increase water use efficiency, improve soil aeration and enhance root growth in paddy fields. The aim of alternate wetting and drying technique was to coordinate and balance soil water and soil oxygen, making the technique typically different from traditional rice cultivation techniques. To further enhance production under high-yield cultivation techniques like alternate wetting and drying technique, change in soil oxygen and soil water contents were investigated in a paddy field in Sanya, Hainan Province. A field experiment was carried out with alternate wetting and drying treatments at the late growth stage (February to April) of rice in 2013. The aim of the experiment was to develop a novel strategy for further research on physiological mechanism of rice with alternate wetting and drying technique. Soil oxygen content, soil water content and soil temperature at 5 cm soil depth in the studied paddy filed were synchronously monitored from 8:00 to 17:59 every day from heading to maturity stage of rice. While the soil was saturated with water under alternate wetting and drying, soil oxygen was almost impossibly detected by Firesting O2. While soil water content at the 5 cm soil depth decreased gradually as soil slowly dried up, soil oxygen content increased. On the 19th, 24th and 29th day of post-anthesis, soil water content decreased to 25.4%, 25.1% and 24.7% while soil oxygen content increased to 17.5%, 17.4% and 17.4%, respectively. During flowering, grain-filling and maturity stages of rice, daily soil oxygen content initially decreased and then increased later in the day, with the lowest value generally appearing at 14:00 15:00. Soil water content fluctuated but gradually decreased during the day. Soil temperature increased initially and then decreased later in the day, with peak value generally appearing at 15:00 16:00. When soil temperature was the highest during 8:00 17:59, soil water content was lower while soil oxygen content increased. At flowering, grain-filling and maturity stages, a significantly negative correlation was noted between soil oxygen content and soil water content. Although soil water content was negatively influenced by soil temperature, the correlation between soil oxygen content and soil temperature was insignificant. Under alternate wetting and drying cultivation, a reciprocal relationship existed between soil oxygen content and water content in paddy fields during late growth stages of rice. Thus through moderate alternate dry-wet management measure, soil water and soil oxygen balance in root-zone soil layer was adjusted to some extent.
Alternate wetting and drying technique at late growth stage of rice has been widely used in high-yield cultivation techniques to increase water use efficiency, improve soil aeration and enhance root growth in paddy fields. The aim of alternate wetting and drying technique was to coordinate and balance soil water and soil oxygen, making the technique typically different from traditional rice cultivation techniques. To further enhance production under high-yield cultivation techniques like alternate wetting and drying technique, change in soil oxygen and soil water contents were investigated in a paddy field in Sanya, Hainan Province. A field experiment was carried out with alternate wetting and drying treatments at the late growth stage (February to April) of rice in 2013. The aim of the experiment was to develop a novel strategy for further research on physiological mechanism of rice with alternate wetting and drying technique. Soil oxygen content, soil water content and soil temperature at 5 cm soil depth in the studied paddy filed were synchronously monitored from 8:00 to 17:59 every day from heading to maturity stage of rice. While the soil was saturated with water under alternate wetting and drying, soil oxygen was almost impossibly detected by Firesting O2. While soil water content at the 5 cm soil depth decreased gradually as soil slowly dried up, soil oxygen content increased. On the 19th, 24th and 29th day of post-anthesis, soil water content decreased to 25.4%, 25.1% and 24.7% while soil oxygen content increased to 17.5%, 17.4% and 17.4%, respectively. During flowering, grain-filling and maturity stages of rice, daily soil oxygen content initially decreased and then increased later in the day, with the lowest value generally appearing at 14:00 15:00. Soil water content fluctuated but gradually decreased during the day. Soil temperature increased initially and then decreased later in the day, with peak value generally appearing at 15:00 16:00. When soil temperature was the highest during 8:00 17:59, soil water content was lower while soil oxygen content increased. At flowering, grain-filling and maturity stages, a significantly negative correlation was noted between soil oxygen content and soil water content. Although soil water content was negatively influenced by soil temperature, the correlation between soil oxygen content and soil temperature was insignificant. Under alternate wetting and drying cultivation, a reciprocal relationship existed between soil oxygen content and water content in paddy fields during late growth stages of rice. Thus through moderate alternate dry-wet management measure, soil water and soil oxygen balance in root-zone soil layer was adjusted to some extent.
2014, 22(4): 414-421.
doi: 10.3724/SP.J.1011.2014.31037
Abstract:
To deeply understand the effects of combined intercropping and straw mulching practices on crop yield improvement, a 2-factor filed experiment was carried out at the Red Soil Experimental Station of Jiangxi Agricultural University in Nanchang City, Jiangxi Province, China. The experimental design consisted of eight treatments (i.e., 2 × 4) with two planting patterns [maize monoculture (M), maize/soybean intercropping (I)] and four straw mulch levels [0 (S0), 4 000 kg·hm-2 (S1), 8 000 kg·hm-2 (S2) and 12 000 kg·hm-2 (S3)]. The study mainly investigated maize leaf traits, leaf physiological characteristics, photosynthetic characteristics and yield to learn the effects of different straw mulching levels and intercropping patterns on various maize traits. The results showed that mulching and intercropping increased maize leaf length, leaf width and green leaf area per plant. The difference between mulching treatments (S2 and S3 treatments) and non-mulching treatment (S0) was significant at P < 0.05. Moreover, the effects of straw mulching on the studied maize traits were more significant than those of intercropping. While maize leaf water content was little influenced by intercropping, it was significantly influenced by straw mulching. Intercropping and mulching increased leaf nitrogen content. Compared with S0 treatment, S3 treatment increased leaf nitrogen content by 25.6% and 56.6% under M treatment, and 30.0% and 42.9% under I treatment respectively at grain filling and maturity stages. The difference between S3 and S0 treatments was significant. Mulching and intercropping increased chlorophyll content in maize leaves and the effects of straw mulching were greater than those of intercropping. However, the effects of mulching decreased with increasing levels of straw mulching. Both mulching and intercropping enhanced photosynthetic characteristics of maize ear leaf. Compared with M treatment, I treatment respectively increased photosynthetic rate, stomatal conductance and transpiration rate by 13.1%, 42.3% and 39.3% at grain filling stage and 46.8%, 31.2% and 24.5% at maturity stage under S0 treatment. Concurrently, intercropping respectively reduced intercellular CO-2 concentration by 20.8% and 18.4% at grain filling and maturity stages of maize. The difference between monoculture and intercropping under S0 treatment was significant at P < 0.05. While maize yield was obviously influenced by both mulching and intercropping, the effect of straw mulching was greater than that of intercropping. The findings demonstrated that straw mulching and intercropping were critical for improving maize leaf traits, physiological characteristics and yield. However, the effect of straw mulching decreased with increasing levels of straw mulching, and the effect of intercropping was less obvious than that of straw mulching.
To deeply understand the effects of combined intercropping and straw mulching practices on crop yield improvement, a 2-factor filed experiment was carried out at the Red Soil Experimental Station of Jiangxi Agricultural University in Nanchang City, Jiangxi Province, China. The experimental design consisted of eight treatments (i.e., 2 × 4) with two planting patterns [maize monoculture (M), maize/soybean intercropping (I)] and four straw mulch levels [0 (S0), 4 000 kg·hm-2 (S1), 8 000 kg·hm-2 (S2) and 12 000 kg·hm-2 (S3)]. The study mainly investigated maize leaf traits, leaf physiological characteristics, photosynthetic characteristics and yield to learn the effects of different straw mulching levels and intercropping patterns on various maize traits. The results showed that mulching and intercropping increased maize leaf length, leaf width and green leaf area per plant. The difference between mulching treatments (S2 and S3 treatments) and non-mulching treatment (S0) was significant at P < 0.05. Moreover, the effects of straw mulching on the studied maize traits were more significant than those of intercropping. While maize leaf water content was little influenced by intercropping, it was significantly influenced by straw mulching. Intercropping and mulching increased leaf nitrogen content. Compared with S0 treatment, S3 treatment increased leaf nitrogen content by 25.6% and 56.6% under M treatment, and 30.0% and 42.9% under I treatment respectively at grain filling and maturity stages. The difference between S3 and S0 treatments was significant. Mulching and intercropping increased chlorophyll content in maize leaves and the effects of straw mulching were greater than those of intercropping. However, the effects of mulching decreased with increasing levels of straw mulching. Both mulching and intercropping enhanced photosynthetic characteristics of maize ear leaf. Compared with M treatment, I treatment respectively increased photosynthetic rate, stomatal conductance and transpiration rate by 13.1%, 42.3% and 39.3% at grain filling stage and 46.8%, 31.2% and 24.5% at maturity stage under S0 treatment. Concurrently, intercropping respectively reduced intercellular CO-2 concentration by 20.8% and 18.4% at grain filling and maturity stages of maize. The difference between monoculture and intercropping under S0 treatment was significant at P < 0.05. While maize yield was obviously influenced by both mulching and intercropping, the effect of straw mulching was greater than that of intercropping. The findings demonstrated that straw mulching and intercropping were critical for improving maize leaf traits, physiological characteristics and yield. However, the effect of straw mulching decreased with increasing levels of straw mulching, and the effect of intercropping was less obvious than that of straw mulching.
2014, 22(4): 422-429.
doi: 10.3724/SP.J.1011.2014.31083
Abstract:
Elevated atmospheric carbon dioxide (CO2) concentration increases plant photosynthesis while elevated tropospheric ozone (O3) concentration could have the opposite effect. The interactive effects of the two gaseous processes have remained largely unclear. By using a new sola-illuminated gas fumigation platform, an Indica hybrid rice cultivar 'Shanyou 63' was exposed to these gases in four gas treatments. The treatments included the control (real time ambient CO2/O3 condition), elevated CO2 ([CO2]) (200 μmol·mol-1 above ambient CO2), elevated O3 ([O3]) (60% higher than ambient value) and combined elevated CO2+O3 ([CO2+O3]). Photosynthesis of rice grown in the chambers was determined at jointing stage, heading stage and filling stage, respectively. Over the growing season, the target achievement ratios of CO2 and O3 concentrations were 1.04, 1.00, respectively. Compared with the control, [CO2] increased net photosynthetic rate (Pn) of rice by 15%, 11% and 28% at jointing, heading and grain-filling stages, respectively. However, [O3] decreased Pn by 32%, 32% and 88% at the respective growth stages. Compared with the control, leaf Pn was not altered by the [CO2+O3] treatment at jointing and heading stages, but was 48% lower during grain-filling stage. [CO2] significantly decreased stomatal conductance (Gs) and transpiration rate (Tr) at jointing and heading stages, but the two variables remained unaffected at grain-filling stage. The magnitude of O3 effect on Gs and Tr was larger than that of CO2, with the highest effect of O3 detected during grain filling. The effects of [CO2+O3] treatment on Gs and Tr were generally smaller than those of individual [O3] treatment. Compared with the control, intercellular CO2 concentration (Ci) in rice substantially increased with [CO2] or [CO2+O3] treatment while limited response of Ci was observed in individual [O3] treatments. Leaf water use efficiency (WUE) increased with [CO2] treatment, while reverse trend was noted under [O3], especially during filling stage. [CO2+O3] increased leaf WUE by about 15% at jointing and heading stages, while the reverse trend was noted in the late season, due mainly to cumulative O3 damage. The above findings suggested that the projected rise of atmospheric CO2 level increased the photosynthetic capacity, while the elevated tropospheric O3 concentration decreased it at a progressive severity over the growing season. The concurrent increases in CO2 and O3 ameliorated the severity of deleterious effects of O3 on leaf photosynthesis of 'Shanyou 63'.
Elevated atmospheric carbon dioxide (CO2) concentration increases plant photosynthesis while elevated tropospheric ozone (O3) concentration could have the opposite effect. The interactive effects of the two gaseous processes have remained largely unclear. By using a new sola-illuminated gas fumigation platform, an Indica hybrid rice cultivar 'Shanyou 63' was exposed to these gases in four gas treatments. The treatments included the control (real time ambient CO2/O3 condition), elevated CO2 ([CO2]) (200 μmol·mol-1 above ambient CO2), elevated O3 ([O3]) (60% higher than ambient value) and combined elevated CO2+O3 ([CO2+O3]). Photosynthesis of rice grown in the chambers was determined at jointing stage, heading stage and filling stage, respectively. Over the growing season, the target achievement ratios of CO2 and O3 concentrations were 1.04, 1.00, respectively. Compared with the control, [CO2] increased net photosynthetic rate (Pn) of rice by 15%, 11% and 28% at jointing, heading and grain-filling stages, respectively. However, [O3] decreased Pn by 32%, 32% and 88% at the respective growth stages. Compared with the control, leaf Pn was not altered by the [CO2+O3] treatment at jointing and heading stages, but was 48% lower during grain-filling stage. [CO2] significantly decreased stomatal conductance (Gs) and transpiration rate (Tr) at jointing and heading stages, but the two variables remained unaffected at grain-filling stage. The magnitude of O3 effect on Gs and Tr was larger than that of CO2, with the highest effect of O3 detected during grain filling. The effects of [CO2+O3] treatment on Gs and Tr were generally smaller than those of individual [O3] treatment. Compared with the control, intercellular CO2 concentration (Ci) in rice substantially increased with [CO2] or [CO2+O3] treatment while limited response of Ci was observed in individual [O3] treatments. Leaf water use efficiency (WUE) increased with [CO2] treatment, while reverse trend was noted under [O3], especially during filling stage. [CO2+O3] increased leaf WUE by about 15% at jointing and heading stages, while the reverse trend was noted in the late season, due mainly to cumulative O3 damage. The above findings suggested that the projected rise of atmospheric CO2 level increased the photosynthetic capacity, while the elevated tropospheric O3 concentration decreased it at a progressive severity over the growing season. The concurrent increases in CO2 and O3 ameliorated the severity of deleterious effects of O3 on leaf photosynthesis of 'Shanyou 63'.
2014, 22(4): 430-438.
doi: 10.3724/SP.J.1011.2014.31000
Abstract:
As the main indicator for global change, ongoing climate warming has had significant impact on human life, including agricultural production for human consumption. Crop phonology and yield response to climate change has been critical in the study of the impacts of climate change on agricultural production. This study used data from four typical agro-meteorological experiment stations in the North China Plain (NCP) to study the sensitivity of the response of winter wheat phenology and yield to climate change in the last three decades. The data included detailed observation dates of winter wheat phenology and yield in the NCP study area for the period of 1980 2009. The experiment stations are located in Tangshan of Hebei Province, Huimin of Shandong Province, Shangqiu and Zhumadian of Henan Province. The results showed that while sowing date of winter wheat delayed, heading and maturity dates advanced in the last three decades. The advance or delay of winter wheat phenology induced corresponding changes in the durations of the different growth stages of the crop. The duration from emergence to heading, which was a sensitive vegetative growth stage (VGP), shortened in all the four investigated stations. By contrast, the duration from heading to maturity, which was a critical reproductive growth stage (RGP), prolonged in all the stations. Correlation analysis showed that temperature and radiation were the main climatic factors controlling winter wheat cultivation in the study area. However, winter wheat yield response to meteorological factors differed with different growth stages. With the exception of Zhumadian Station, the temperature increase positively influenced winter wheat yield for the growth stage period from emergence to heading. However, temperature rise negatively influenced winter wheat yield for the growth stage period from heading to maturity. Winter wheat yield was positively correlated with radiation, implying that the decline in radiation in the study area in the last three decades had a negative effect on winter wheat production. Our findings suggested that the sensitivity of the response of winter wheat growth and yield to climate change in the NCP was increasing. The response mechanisms of crop growth and productivity to climate change needed appropriate consideration in order to improve the prediction of the impacts of climate change and to develop requisite adaptation measures to enhance future crop productivity.
As the main indicator for global change, ongoing climate warming has had significant impact on human life, including agricultural production for human consumption. Crop phonology and yield response to climate change has been critical in the study of the impacts of climate change on agricultural production. This study used data from four typical agro-meteorological experiment stations in the North China Plain (NCP) to study the sensitivity of the response of winter wheat phenology and yield to climate change in the last three decades. The data included detailed observation dates of winter wheat phenology and yield in the NCP study area for the period of 1980 2009. The experiment stations are located in Tangshan of Hebei Province, Huimin of Shandong Province, Shangqiu and Zhumadian of Henan Province. The results showed that while sowing date of winter wheat delayed, heading and maturity dates advanced in the last three decades. The advance or delay of winter wheat phenology induced corresponding changes in the durations of the different growth stages of the crop. The duration from emergence to heading, which was a sensitive vegetative growth stage (VGP), shortened in all the four investigated stations. By contrast, the duration from heading to maturity, which was a critical reproductive growth stage (RGP), prolonged in all the stations. Correlation analysis showed that temperature and radiation were the main climatic factors controlling winter wheat cultivation in the study area. However, winter wheat yield response to meteorological factors differed with different growth stages. With the exception of Zhumadian Station, the temperature increase positively influenced winter wheat yield for the growth stage period from emergence to heading. However, temperature rise negatively influenced winter wheat yield for the growth stage period from heading to maturity. Winter wheat yield was positively correlated with radiation, implying that the decline in radiation in the study area in the last three decades had a negative effect on winter wheat production. Our findings suggested that the sensitivity of the response of winter wheat growth and yield to climate change in the NCP was increasing. The response mechanisms of crop growth and productivity to climate change needed appropriate consideration in order to improve the prediction of the impacts of climate change and to develop requisite adaptation measures to enhance future crop productivity.
2014, 22(4): 439-446.
doi: 10.3724/SP.J.1011.2014.31112
Abstract:
Chinese kale (Brassica alboglabra L.) is a native endemic variety of Brassica vegetables in China. It is highly rich in anti-cancer glucosinolates (GSs). Recent investigations have shown that methionine and tryptophan were the synthetic precursors of aliphatic and indolyl GSs, respectively. Therefore foliage spray with methionine and tryptophan has been thought to be a potential mode for increasing GSs concentrations in Chinese kale. However, the heavy surface wax layers of Chinese kale affect absorption efficiency of the exogenous amino acids. In this study, pot experiments were carried out to investigate foliage spraying effects of methionine and tryptophan with or without surfactant active agent (SAA) on the growth and GSs composition and concentration in bolting stems of Chinese kale. There was no significant difference in growth indexes and GSs compounds of Chinese kale among the treatments. Eleven individual GSs were separated and identified by liquid chromatography-mass spectrometry (LC-MS) in edible bolting stems of Chinese kale in all the treatments, including seven kinds of aliphatic GSs and four kinds of indolyl GSs. Foliage spraying methionine, tryptophan and tryptophan with SAA had no effect on concentrations of total GSs, total aliphatic GSs and total indolyl GSs. Compared with foliage spray of water, total GSs and total aliphatic GSs concentrations increased by 28.5% and 31.9%, respectively, under foliage spray of methionine with SAA. However, there was no significant difference in total indolyl GSs concentrations between the treatments. Compared with foliage spring water, foliage spraying methionine combined with SAA significantly increased especially the concentration of Gluconapin, increasing on the average by 44.3%. Also foliage spraying methionine combined with SAA increased sulfur (S) content in bolting stems of Chinese kale. This in turn decreased nitrogen/sulfur (N/S) ratio, while the changes in S and N/S ratio influenced GSs concentrations in Chinese kale bolting stems. Moreover, the concentrations of individual GSs within a specific GS group (i.e., aliphatic or indolyl) did not change consistently. The above results suggested that methionine absorbed by Chinese kale promoted the synthesis and accumulation of GSs while SAA enhanced the absorption of methionine through Chinese kale leaves covered with heavy layers of wax. However, the action mechanism of these substances needed further studies.
Chinese kale (Brassica alboglabra L.) is a native endemic variety of Brassica vegetables in China. It is highly rich in anti-cancer glucosinolates (GSs). Recent investigations have shown that methionine and tryptophan were the synthetic precursors of aliphatic and indolyl GSs, respectively. Therefore foliage spray with methionine and tryptophan has been thought to be a potential mode for increasing GSs concentrations in Chinese kale. However, the heavy surface wax layers of Chinese kale affect absorption efficiency of the exogenous amino acids. In this study, pot experiments were carried out to investigate foliage spraying effects of methionine and tryptophan with or without surfactant active agent (SAA) on the growth and GSs composition and concentration in bolting stems of Chinese kale. There was no significant difference in growth indexes and GSs compounds of Chinese kale among the treatments. Eleven individual GSs were separated and identified by liquid chromatography-mass spectrometry (LC-MS) in edible bolting stems of Chinese kale in all the treatments, including seven kinds of aliphatic GSs and four kinds of indolyl GSs. Foliage spraying methionine, tryptophan and tryptophan with SAA had no effect on concentrations of total GSs, total aliphatic GSs and total indolyl GSs. Compared with foliage spray of water, total GSs and total aliphatic GSs concentrations increased by 28.5% and 31.9%, respectively, under foliage spray of methionine with SAA. However, there was no significant difference in total indolyl GSs concentrations between the treatments. Compared with foliage spring water, foliage spraying methionine combined with SAA significantly increased especially the concentration of Gluconapin, increasing on the average by 44.3%. Also foliage spraying methionine combined with SAA increased sulfur (S) content in bolting stems of Chinese kale. This in turn decreased nitrogen/sulfur (N/S) ratio, while the changes in S and N/S ratio influenced GSs concentrations in Chinese kale bolting stems. Moreover, the concentrations of individual GSs within a specific GS group (i.e., aliphatic or indolyl) did not change consistently. The above results suggested that methionine absorbed by Chinese kale promoted the synthesis and accumulation of GSs while SAA enhanced the absorption of methionine through Chinese kale leaves covered with heavy layers of wax. However, the action mechanism of these substances needed further studies.
NIU Xinsheng,
WANG Shaolei,
LYU Zhenyu,
SHEN Guangcheng,
HAO Jinmin,
NIU Ling'an,
YANG Hefa,
YAN Yong
2014, 22(4): 447-455.
doi: 10.3724/SP.J.1011.2014.30926
Abstract:
This research investigated Xingyuan, Xiwei and Dongliuzhuang Villages of Quzhou County, Hebei Province, in a case study to confirm the effects of cultivated land fragmentation on farmland shelterbelt network at village level. While Xingyuan and Xiwei Villages have arable land fragmentation, Dongliuzhuang Village has arable land with scale management. The study used field measurements and questionnaire surveys to clarify the main causes of effects of cultivated land fragmentation on farmland shelterbelt network. The results suggested that arable land fragmentation destroyed the structure and configuration of farmland shelterbelts at village scale. The magnitude of grids of forests network increased and the distance between main forest belts was averagely 2.70 times the recommended value for the North China Plain. Trees of the same species were generally used under agricultural land fragmentation management. About 53.8% of the main lines had no woods planted on the northern flank and the number of trees planted on the northern flank of the main line decreased significantly (about 60.8%) compared with the number of trees on the southern flank in Xingyuan and Xiwei Villages. In these villages, the density of trees in the first row from the fields was 0 26 plants per 50 m. Compared with the first row, this decreased by 25.8% (P < 0.05) in the second row from the fields. It further decreased by 47.3% compared with that in Dongliuzhuang Village. The maximum tree density in Dongliuzhuang Village was 23.2 plants per 100 m2, based on the curve of best fit between tree-belt area and tree number. Maximum tree density in Dongliuzhuang Village increased by 56.5% compared with that in Xingyuan and Xiwei Villages. Most farmers were strongly opposed to forest belt construction near fields and favored forest managements they owned. The main reason for the conflict was the huge population and scarce land. Farmland shelter network under arable land fragmentation also significantly suppressed crops near trees. Furthermore, long-term agricultural land fragmentation actually worsened the land management conflicts. Rearrangement of cultivated lands and reasonable designs were fundamental for resolving the above problems. It was also vital not to ignore social education and management of public farmland shelterbelts.
This research investigated Xingyuan, Xiwei and Dongliuzhuang Villages of Quzhou County, Hebei Province, in a case study to confirm the effects of cultivated land fragmentation on farmland shelterbelt network at village level. While Xingyuan and Xiwei Villages have arable land fragmentation, Dongliuzhuang Village has arable land with scale management. The study used field measurements and questionnaire surveys to clarify the main causes of effects of cultivated land fragmentation on farmland shelterbelt network. The results suggested that arable land fragmentation destroyed the structure and configuration of farmland shelterbelts at village scale. The magnitude of grids of forests network increased and the distance between main forest belts was averagely 2.70 times the recommended value for the North China Plain. Trees of the same species were generally used under agricultural land fragmentation management. About 53.8% of the main lines had no woods planted on the northern flank and the number of trees planted on the northern flank of the main line decreased significantly (about 60.8%) compared with the number of trees on the southern flank in Xingyuan and Xiwei Villages. In these villages, the density of trees in the first row from the fields was 0 26 plants per 50 m. Compared with the first row, this decreased by 25.8% (P < 0.05) in the second row from the fields. It further decreased by 47.3% compared with that in Dongliuzhuang Village. The maximum tree density in Dongliuzhuang Village was 23.2 plants per 100 m2, based on the curve of best fit between tree-belt area and tree number. Maximum tree density in Dongliuzhuang Village increased by 56.5% compared with that in Xingyuan and Xiwei Villages. Most farmers were strongly opposed to forest belt construction near fields and favored forest managements they owned. The main reason for the conflict was the huge population and scarce land. Farmland shelter network under arable land fragmentation also significantly suppressed crops near trees. Furthermore, long-term agricultural land fragmentation actually worsened the land management conflicts. Rearrangement of cultivated lands and reasonable designs were fundamental for resolving the above problems. It was also vital not to ignore social education and management of public farmland shelterbelts.
2014, 22(4): 456-463.
doi: 10.3724/SP.J.1011.2014.31109
Abstract:
Herbicide application has attracted increasing global attention as it severely affects the structure and function of ecosystems. In China, the effects of herbicide on soil fauna community structure and diversity have gained considerable attention in recent years. As a form of herbicide, acetochlor could accumulate in some soil ecosystems, thus the wide use of acetochlor could have serious effects on soil ecosystems. Unfortunately, the effects of acetochlor on the structure, biodiversity and vertical distribution of soil biotic communities have remained largely unclear. Acetochlor was applied with three concentrations (10.80 mL·L-1 of high concentration, 3.20 mL·L-1 of middle concentration and 0.54 mL·L-1 of low concentration) and a control (distilled water) in maize field in May, July and September of 2012 in Hulan District of Harbin City, China. And 7 days after acetochlor application every time, soil samples were collected to investigate the composition, biodiversity and vertical distribution of soil meso/micro-fauna. In the study, 15 groups and 4 648 individuals of soil meso-fauna and micro-fauna were captured. The fauna belonged to 2 phyla, 4 classes and 10 orders. Oribiatida and Mesostigmata were dominant groups (69.12%), Onychiuridae, Isotomidae, Paronellidae, Sminthuridae, Prostigmata, Coleoptera and Hymenoptera were common groups (27.59%), and the others were rare groups. The results showed that different concentrations of acetochlor had significant effects on soil fauna community. In terms of the Sorenson and Morisita-Hron indices of soil fauna community, the difference between high and medium concentrations was largest. Also the difference between high concentration treatment and the control was lowest. Then a moderate difference was noted between high and low concentrations. The above results suggested that differences among soil fauna community structures increased with increasing acetochlor concentration. Except for dominance index, all the other diversity indices of CK were significant different at P < 0.05 from those of medium and low concentrations; and signifcant different at P < 0.001 from those of high concentration. The density of soil fauna in 0 5 cm soil layer under different acetochlor concentrations were in the order of CK > low concentration > medium concentration > high concentration in May, July and September. However, the relationships between soil fauna density and acetochlor concentrations in the deeper soil layers were insignificant. The changes in soil fauna diversity became significant with increasing acetochlor concentration. This was largely attributed to fluctuations in soil fauna counts and groups in the 0 5 cm soil layer. The results suggested that the use of high concentration acetochlor not only disturbed soil ecosystem, but was also harmful to soil environmental health. It was critical to have the appropriate concentration of acetochlor in order to limit any harmful effects on soil environmental conditions and soil fauna communities in farmlands.
Herbicide application has attracted increasing global attention as it severely affects the structure and function of ecosystems. In China, the effects of herbicide on soil fauna community structure and diversity have gained considerable attention in recent years. As a form of herbicide, acetochlor could accumulate in some soil ecosystems, thus the wide use of acetochlor could have serious effects on soil ecosystems. Unfortunately, the effects of acetochlor on the structure, biodiversity and vertical distribution of soil biotic communities have remained largely unclear. Acetochlor was applied with three concentrations (10.80 mL·L-1 of high concentration, 3.20 mL·L-1 of middle concentration and 0.54 mL·L-1 of low concentration) and a control (distilled water) in maize field in May, July and September of 2012 in Hulan District of Harbin City, China. And 7 days after acetochlor application every time, soil samples were collected to investigate the composition, biodiversity and vertical distribution of soil meso/micro-fauna. In the study, 15 groups and 4 648 individuals of soil meso-fauna and micro-fauna were captured. The fauna belonged to 2 phyla, 4 classes and 10 orders. Oribiatida and Mesostigmata were dominant groups (69.12%), Onychiuridae, Isotomidae, Paronellidae, Sminthuridae, Prostigmata, Coleoptera and Hymenoptera were common groups (27.59%), and the others were rare groups. The results showed that different concentrations of acetochlor had significant effects on soil fauna community. In terms of the Sorenson and Morisita-Hron indices of soil fauna community, the difference between high and medium concentrations was largest. Also the difference between high concentration treatment and the control was lowest. Then a moderate difference was noted between high and low concentrations. The above results suggested that differences among soil fauna community structures increased with increasing acetochlor concentration. Except for dominance index, all the other diversity indices of CK were significant different at P < 0.05 from those of medium and low concentrations; and signifcant different at P < 0.001 from those of high concentration. The density of soil fauna in 0 5 cm soil layer under different acetochlor concentrations were in the order of CK > low concentration > medium concentration > high concentration in May, July and September. However, the relationships between soil fauna density and acetochlor concentrations in the deeper soil layers were insignificant. The changes in soil fauna diversity became significant with increasing acetochlor concentration. This was largely attributed to fluctuations in soil fauna counts and groups in the 0 5 cm soil layer. The results suggested that the use of high concentration acetochlor not only disturbed soil ecosystem, but was also harmful to soil environmental health. It was critical to have the appropriate concentration of acetochlor in order to limit any harmful effects on soil environmental conditions and soil fauna communities in farmlands.
2014, 22(4): 464-472.
doi: 10.3724/SP.J.1011.2014.31093
Abstract:
To find out the management mode conducive to arthropod community structure in Zanthoxylum bungeanum garden, a survey was systematically conducted on the community composition and structure of arthropod under three different management modes (extensive, no-tillage and precision) in 2012 in Zhaotong City of Yunnan Province. Using community character indexes and principal component analysis, the characteristics, seasonal change and stability of arthropod community were studied. About 318 species (belonging to 97 families, 9 orders and 2 classes) were observed in the studied gradens. The main pest species were Tettigoniella viridis, Empoasca flavescens, Aphis gossypii and Nysius ercae. Then the main natural enemy species were Metasyrphus corolla, Melanostoma scalare, Frigates sp. and Perilampus prasinus. The highest richness (21.985 7) and number of herbivorous arthropod sub-community (36.13%) appeared in extensively managed gardens. Diversity index (3.649 1), evenness index (0.694 3) and stability indexes including Ss/Si (0.074 7), Nn/Np (0.557 2), Sd/Sp (0.545 5) and Nd/Np (1.467 8) of arthropod community in Z. bungeanum garden under no-tillage management were higher than those under the other two management modes. For the whole year, Z. bungeanum garden with precision management had higher dominance index (0.193 1) and more volatile index for community characteristics than gardens under the other two modes of management. This could have been induced by significant disturbances under the precision management. The following-role of natural enemies to main pests in gardens under no-tillage management was better than that in gardens under the other modes of management. The highest pest number in Z. bungeanum garden was 81 under no-tillage management mode, lower than that under extensive management (189) and that under precision management (123). Results of principal component analysis showed that the main factor controlling arthropod community change in Z. bungeanum garden was pest number under extensive and precision management modes. Natural enemies in Z. bungeanum garden dominated arthropod community change, showing a better ability to regulate pests. Thus in terms of ecological and economic benefits, no-tillage mode of management was a better method of pest control in Z. bungeanum gardens in Zhaotong, Yunnan Province.
To find out the management mode conducive to arthropod community structure in Zanthoxylum bungeanum garden, a survey was systematically conducted on the community composition and structure of arthropod under three different management modes (extensive, no-tillage and precision) in 2012 in Zhaotong City of Yunnan Province. Using community character indexes and principal component analysis, the characteristics, seasonal change and stability of arthropod community were studied. About 318 species (belonging to 97 families, 9 orders and 2 classes) were observed in the studied gradens. The main pest species were Tettigoniella viridis, Empoasca flavescens, Aphis gossypii and Nysius ercae. Then the main natural enemy species were Metasyrphus corolla, Melanostoma scalare, Frigates sp. and Perilampus prasinus. The highest richness (21.985 7) and number of herbivorous arthropod sub-community (36.13%) appeared in extensively managed gardens. Diversity index (3.649 1), evenness index (0.694 3) and stability indexes including Ss/Si (0.074 7), Nn/Np (0.557 2), Sd/Sp (0.545 5) and Nd/Np (1.467 8) of arthropod community in Z. bungeanum garden under no-tillage management were higher than those under the other two management modes. For the whole year, Z. bungeanum garden with precision management had higher dominance index (0.193 1) and more volatile index for community characteristics than gardens under the other two modes of management. This could have been induced by significant disturbances under the precision management. The following-role of natural enemies to main pests in gardens under no-tillage management was better than that in gardens under the other modes of management. The highest pest number in Z. bungeanum garden was 81 under no-tillage management mode, lower than that under extensive management (189) and that under precision management (123). Results of principal component analysis showed that the main factor controlling arthropod community change in Z. bungeanum garden was pest number under extensive and precision management modes. Natural enemies in Z. bungeanum garden dominated arthropod community change, showing a better ability to regulate pests. Thus in terms of ecological and economic benefits, no-tillage mode of management was a better method of pest control in Z. bungeanum gardens in Zhaotong, Yunnan Province.
2014, 22(4): 473-479.
doi: 10.3724/SP.J.1011.2014.31013
Abstract:
Different forms of nitrogen (N) in nature are important in both crop and animal agro-ecosystems. N is not only a valuable resource in agro-economics, but also the by-product of animal husbandry which could cause eutrophication of water environment via nitrogen overload and global warming via nitrous oxide (N2O) emissions. In animal husbandry, nitrogen is ingested as a valuable resource of protein in feeds and left the system as fertilizer or waste. In large scale pig farming in China, ammonia (NH3) volatilization has been responsible for odd smells in surrounding environments. Recent development of fermentation bed technology (FBT) in large scale pig farming systems has partially addressed concerns relating to reducing NH3 volatilization and N2O emission. It was hypothesized that different compositions of fermentation beds had different effects on NH3 volatilization and N2O emission in this study. To justify the hypothesis, the characteristics of NH3 volatilization and N2O emission of three different fermentation beds [rice husk + sawdust (FD), rice husk + mushroom bran (FJ) and rice husk + vinasse (FW)] available in large quantities in farmlands were investigated. Gas samples were collected by static box method during one production cycle (140 d). The experimental conditions and basic environmental factors (e.g., water content, physical and chemical properties of fermentation bed) were recorded and analyzed. The results showed that NH3 volatilization in the three beds had different patterns. NH3 volatilization peak appeared earliest at the feeding period in FW, followed by FJ and then finally FD. The total amounts of NH3 volatilization in three beds during the experimental period were significantly (P < 0.05) different. Of the three treatments, the largest amount of NH3 volatilization was FW (9.06 kg), followed by FJ (4.83 kg) and then it was lowest in FD (3.82 kg). The three beds were consistent in the patterns of N2O emission and N2O emission peaks were mainly at mid-anaphase of the feeding period. The total amounts of N2O emission were significantly (P < 0.05) different; of which it was highest in FW (2.06 kg), followed by FJ (1.74 kg) and then finally FD (1.50 kg). Material flow analysis showed that N gas (NH3 and N2O) loss accounted for 23% 36% of total N loss. The results revealed that the main path ways of N loss were via nitrogen transformation into NH3 or N2O during the production cycle of pig fermentation beds. This suggested that FJ performed the best in terms of composition.
Different forms of nitrogen (N) in nature are important in both crop and animal agro-ecosystems. N is not only a valuable resource in agro-economics, but also the by-product of animal husbandry which could cause eutrophication of water environment via nitrogen overload and global warming via nitrous oxide (N2O) emissions. In animal husbandry, nitrogen is ingested as a valuable resource of protein in feeds and left the system as fertilizer or waste. In large scale pig farming in China, ammonia (NH3) volatilization has been responsible for odd smells in surrounding environments. Recent development of fermentation bed technology (FBT) in large scale pig farming systems has partially addressed concerns relating to reducing NH3 volatilization and N2O emission. It was hypothesized that different compositions of fermentation beds had different effects on NH3 volatilization and N2O emission in this study. To justify the hypothesis, the characteristics of NH3 volatilization and N2O emission of three different fermentation beds [rice husk + sawdust (FD), rice husk + mushroom bran (FJ) and rice husk + vinasse (FW)] available in large quantities in farmlands were investigated. Gas samples were collected by static box method during one production cycle (140 d). The experimental conditions and basic environmental factors (e.g., water content, physical and chemical properties of fermentation bed) were recorded and analyzed. The results showed that NH3 volatilization in the three beds had different patterns. NH3 volatilization peak appeared earliest at the feeding period in FW, followed by FJ and then finally FD. The total amounts of NH3 volatilization in three beds during the experimental period were significantly (P < 0.05) different. Of the three treatments, the largest amount of NH3 volatilization was FW (9.06 kg), followed by FJ (4.83 kg) and then it was lowest in FD (3.82 kg). The three beds were consistent in the patterns of N2O emission and N2O emission peaks were mainly at mid-anaphase of the feeding period. The total amounts of N2O emission were significantly (P < 0.05) different; of which it was highest in FW (2.06 kg), followed by FJ (1.74 kg) and then finally FD (1.50 kg). Material flow analysis showed that N gas (NH3 and N2O) loss accounted for 23% 36% of total N loss. The results revealed that the main path ways of N loss were via nitrogen transformation into NH3 or N2O during the production cycle of pig fermentation beds. This suggested that FJ performed the best in terms of composition.
2014, 22(4): 480-490.
doi: 10.3724/SP.J.1011.2014.30985
Abstract:
With the discharge of industrial wastewater, and application of copper-containing pesticides and fertilizers, copper content in soils has increased steadily. This has had severe effect on yield and quality of Brassica rapa L. Chinensis. However, little has been done in terms of analyzing the molecular biology of copper stress in B. rapa. In this research, copper stress responding genes of B. rapa variety 'Shanghaiqing' were analyzed using the cDNA-AFLP technique. Seedlings were cultivated in solution with 10 mg·L-1 Cu2+ concentration for the cDNA-AFLP analysis. A total of 5 800 transcript-derived fragments (TDFs) were obtained via cDNA-AFLP, with 135 primer pairs. Each primer pair was amplified to 30 60 bands with fragment size of 100 1 000 bp. The TDF expression patterns were divided into four - up-regulation, down-regulation, transient-expression and continuous-expression. A total of 180 differentially-expressed TDFs were identified from a total of 5 800 TDFs, which included 77 up-regulated (42.8%), 61 down-regulated (33.9%) and 42 transient-expressed (23.3%) genes. About 152 TDFs were recovered and sequenced, and 151 reliable sequences obtained. The sequences included 68 up-regulated (45.0%), 50 down-regulated (33.1%) and 33 transient-expressed (21.9%) genes. Also the functions of 151 of the reliable TDF sequences were determined through BLAST search in GenBank database. Out of the 151 TDFs, 112 were homolog genes with known functions, 16 were similar genes with unknown functions and 23 had no sequence homology in GenBank entries. The functions of homologous genes were involved in energy and metabolism, protein synthesis and ion transport, stress response, signal transduction and regulation. Of the 151 reliable TDFs, 4 homologous genes were selected for fluorogenic quantitative reverse-transcription polymerase chain reaction (RT-PCR) analyses. The analysis used actin of B. rapa as internal reference gene. The results showed that cDNA-AFLP was a reliable technique for analyzing expression patterns of genes involved in copper stress response. Genes involved in copper stress response were identified and their expression patterns successfully determined. This study laid the theoretical basis for the analysis of molecular mechanism and cloning of genes related with copper stress in B. rapa.
With the discharge of industrial wastewater, and application of copper-containing pesticides and fertilizers, copper content in soils has increased steadily. This has had severe effect on yield and quality of Brassica rapa L. Chinensis. However, little has been done in terms of analyzing the molecular biology of copper stress in B. rapa. In this research, copper stress responding genes of B. rapa variety 'Shanghaiqing' were analyzed using the cDNA-AFLP technique. Seedlings were cultivated in solution with 10 mg·L-1 Cu2+ concentration for the cDNA-AFLP analysis. A total of 5 800 transcript-derived fragments (TDFs) were obtained via cDNA-AFLP, with 135 primer pairs. Each primer pair was amplified to 30 60 bands with fragment size of 100 1 000 bp. The TDF expression patterns were divided into four - up-regulation, down-regulation, transient-expression and continuous-expression. A total of 180 differentially-expressed TDFs were identified from a total of 5 800 TDFs, which included 77 up-regulated (42.8%), 61 down-regulated (33.9%) and 42 transient-expressed (23.3%) genes. About 152 TDFs were recovered and sequenced, and 151 reliable sequences obtained. The sequences included 68 up-regulated (45.0%), 50 down-regulated (33.1%) and 33 transient-expressed (21.9%) genes. Also the functions of 151 of the reliable TDF sequences were determined through BLAST search in GenBank database. Out of the 151 TDFs, 112 were homolog genes with known functions, 16 were similar genes with unknown functions and 23 had no sequence homology in GenBank entries. The functions of homologous genes were involved in energy and metabolism, protein synthesis and ion transport, stress response, signal transduction and regulation. Of the 151 reliable TDFs, 4 homologous genes were selected for fluorogenic quantitative reverse-transcription polymerase chain reaction (RT-PCR) analyses. The analysis used actin of B. rapa as internal reference gene. The results showed that cDNA-AFLP was a reliable technique for analyzing expression patterns of genes involved in copper stress response. Genes involved in copper stress response were identified and their expression patterns successfully determined. This study laid the theoretical basis for the analysis of molecular mechanism and cloning of genes related with copper stress in B. rapa.
2014, 22(4): 491-495.
doi: 10.3724/SP.J.1011.2014.31127
Abstract:
The amount of vegetable residues produced through plucking, processing, transporting and selling vegetables has been rising sharply with the rapid growth of vegetable industry and commercial vegetable processing. Because of lack of suitable economic processing technology, the reclamation rate of vegetable residues has been low. Large amount of vegetable residues still remained in the fields, on the side of rural roads and in drainage canals. Vegetable residues eventually rot and cause severe pollution of soil, water and the atmosphere. In particular, vegetable residues have endangered green vegetables production areas. In recent years, vegetable residues have been mainly used as feed, organic fertilizer or directly returned to the field as mulch/green mature. However, the cost of such processing has increased significantly, precluding efforts for commercial industrialization. Thus low cost processing of vegetable residues was urgently needed to mitigate loss in the vegetable industry. This study mainly focused on available low cost processes of vegetable residues to prompt their reclamation. Fodder processing lines were designed according to vegetable residue conditions-high water content, easy to rot, large amount. Fodder processing lines included units of cleaning, beating, pressure filtration, water treatment, mixing, granulating and block making. The production parameters of vegetable residue processing were optimized by using the Chinese cabbage, cabbage and celery residues. Single factor method and orthogonal experiment were used to optimize the contents of adjuvant roughage of vegetable residues, which included bentonite, middling powder, rice shell powder and corn gluten meal. The results showed that after cleaning and beating, the diameter of Chinese cabbage, cabbage and celery residue particles were within 10 mm. The convey belt speed of bubble washers of the Chinese cabbage, cabbage and celery residues were 6 7 m·min-1, 7 8 m·min-1, 8 9 m·min -1, respectively. After filtration under 0.05 0.06 MPa diaphragm squeeze pressure for 20 min, water content of vegetable residues dropped to below 35% with monofilament filter cloth for celery and 750B filter cloth for Chinese cabbage and cabbage as filtration materials. The vegetable residues roughage contained 12.5% bentonite, 10.0% middling powder, 15.0% rice shell powder and 3.0% corn gluten meal. Its' average rate of briquetting was 94.67%. The production capacity of processing lines equaled or exceeded 5.0 t·h-1, power consumption was 22.0 kW·h-1·t-1, discharged water of pressure filtration was within the GB8978-1996 requirements. The density of roughage was 920.0 kg·m -3, water content less than 10.0%, firmness 82.0% and uniformity 95.0%. The applications indicated that the vegetable residue pretreatment device had a high degree of automation and simple operation with practical features. It was suitable for vegetable residues resolution by commercial processing and large farmers' markets.
The amount of vegetable residues produced through plucking, processing, transporting and selling vegetables has been rising sharply with the rapid growth of vegetable industry and commercial vegetable processing. Because of lack of suitable economic processing technology, the reclamation rate of vegetable residues has been low. Large amount of vegetable residues still remained in the fields, on the side of rural roads and in drainage canals. Vegetable residues eventually rot and cause severe pollution of soil, water and the atmosphere. In particular, vegetable residues have endangered green vegetables production areas. In recent years, vegetable residues have been mainly used as feed, organic fertilizer or directly returned to the field as mulch/green mature. However, the cost of such processing has increased significantly, precluding efforts for commercial industrialization. Thus low cost processing of vegetable residues was urgently needed to mitigate loss in the vegetable industry. This study mainly focused on available low cost processes of vegetable residues to prompt their reclamation. Fodder processing lines were designed according to vegetable residue conditions-high water content, easy to rot, large amount. Fodder processing lines included units of cleaning, beating, pressure filtration, water treatment, mixing, granulating and block making. The production parameters of vegetable residue processing were optimized by using the Chinese cabbage, cabbage and celery residues. Single factor method and orthogonal experiment were used to optimize the contents of adjuvant roughage of vegetable residues, which included bentonite, middling powder, rice shell powder and corn gluten meal. The results showed that after cleaning and beating, the diameter of Chinese cabbage, cabbage and celery residue particles were within 10 mm. The convey belt speed of bubble washers of the Chinese cabbage, cabbage and celery residues were 6 7 m·min-1, 7 8 m·min-1, 8 9 m·min -1, respectively. After filtration under 0.05 0.06 MPa diaphragm squeeze pressure for 20 min, water content of vegetable residues dropped to below 35% with monofilament filter cloth for celery and 750B filter cloth for Chinese cabbage and cabbage as filtration materials. The vegetable residues roughage contained 12.5% bentonite, 10.0% middling powder, 15.0% rice shell powder and 3.0% corn gluten meal. Its' average rate of briquetting was 94.67%. The production capacity of processing lines equaled or exceeded 5.0 t·h-1, power consumption was 22.0 kW·h-1·t-1, discharged water of pressure filtration was within the GB8978-1996 requirements. The density of roughage was 920.0 kg·m -3, water content less than 10.0%, firmness 82.0% and uniformity 95.0%. The applications indicated that the vegetable residue pretreatment device had a high degree of automation and simple operation with practical features. It was suitable for vegetable residues resolution by commercial processing and large farmers' markets.
2014, 22(4): 496-500.
doi: 10.3724/SP.J.1011.2014.30961
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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