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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. 2
Display Method:
2014, 22(2): 127-135.
doi: 10.3724/SP.J.1011.2014.30538
Abstract:
While soil fertility is basic for continuous agricultural development, fertilization remains the primary mode of high soil fertility in agriculture. Moreover, fertilization could compensate soil nutrient deficit arising from repeated harvest of farm produce or crop castoff such as straw. The most important task of current agricultural modernization is the effective improvement of soil fertility. Thus not only it is critical to preserve higher soil fertility, but also to increase yield and quality of crop products and to effectively control agricultural non-point source pollution. Achieving this requires all stakeholders to maintain a sound agricultural eco-environment. This paper summarized research progress on relating fertilization measures with soil fertility improvement. The review explained the relational mechanisms of fertilization measures and soil basic physicochemical properties, enzyme activity and fertility index in terms of soil microbial/animal systems. The review also highlighted the direction of further studies on the relation between fertilization measures and soil fertility improvement. Such studies included the relations between fine/high-efficiency input of organic fertilizer and soil fertility, soil fertility index and soil fauna, long-term fertilization and agro-biological processes, fertilization and agricultural non-point source pollution, etc. The review offered scientific insight into future studies on soil fertility improvement and maintenance of farm ecological environment through sound fertilization measures.
While soil fertility is basic for continuous agricultural development, fertilization remains the primary mode of high soil fertility in agriculture. Moreover, fertilization could compensate soil nutrient deficit arising from repeated harvest of farm produce or crop castoff such as straw. The most important task of current agricultural modernization is the effective improvement of soil fertility. Thus not only it is critical to preserve higher soil fertility, but also to increase yield and quality of crop products and to effectively control agricultural non-point source pollution. Achieving this requires all stakeholders to maintain a sound agricultural eco-environment. This paper summarized research progress on relating fertilization measures with soil fertility improvement. The review explained the relational mechanisms of fertilization measures and soil basic physicochemical properties, enzyme activity and fertility index in terms of soil microbial/animal systems. The review also highlighted the direction of further studies on the relation between fertilization measures and soil fertility improvement. Such studies included the relations between fine/high-efficiency input of organic fertilizer and soil fertility, soil fertility index and soil fauna, long-term fertilization and agro-biological processes, fertilization and agricultural non-point source pollution, etc. The review offered scientific insight into future studies on soil fertility improvement and maintenance of farm ecological environment through sound fertilization measures.
2014, 22(2): 136-142.
doi: 10.3724/SP.J.1011.2014.30589
Abstract:
In order to obtain the higher crop yield, the more fertilizers were applied to the soil. At the same time, unreasonable field management measures cause massive nitrate nitrogen accumulation in soil, which leads to a risk to the ground water due to N leaching. Collocation planting of different types of crops is one of the effective cultivation strategies to increase crops yield and improve utilization of photo-thermal resources, and simultaneously reduce soil nitrate nitrogen loss through enhancing soil nutrient use efficiency. Collocation planting patterns of different types of crops (such as facility vegetables and catch crops, grain crops and economic crops, grain crops and grain crops, grain crops and outdoor vegetables, vegetables and vegetables) were introduced in this paper. And, the effects of different collocation planting patterns on soil N utilization, reduction of accumulation and leachate of soil nitrate nitrogen were discussed too. The mechanisms were explained from the characteristics of different crops. Finally, some research prospects in the future were put forward on the planting patterns. It was suggested that studies on root system of collocation planted crops was the breakthrough point.
In order to obtain the higher crop yield, the more fertilizers were applied to the soil. At the same time, unreasonable field management measures cause massive nitrate nitrogen accumulation in soil, which leads to a risk to the ground water due to N leaching. Collocation planting of different types of crops is one of the effective cultivation strategies to increase crops yield and improve utilization of photo-thermal resources, and simultaneously reduce soil nitrate nitrogen loss through enhancing soil nutrient use efficiency. Collocation planting patterns of different types of crops (such as facility vegetables and catch crops, grain crops and economic crops, grain crops and grain crops, grain crops and outdoor vegetables, vegetables and vegetables) were introduced in this paper. And, the effects of different collocation planting patterns on soil N utilization, reduction of accumulation and leachate of soil nitrate nitrogen were discussed too. The mechanisms were explained from the characteristics of different crops. Finally, some research prospects in the future were put forward on the planting patterns. It was suggested that studies on root system of collocation planted crops was the breakthrough point.
WANG Chongli,
HAN Guiqi,
XU Weihong,
YANG Yun,
XIONG Shijuan,
XIE Wenwen,
ZHANG Jinzhong,
WANG Zhengyin,
XIE Deti
2014, 22(2): 143-150.
doi: 10.3724/SP.J.1011.2014.30947
Abstract:
Laboratory diffusion simulation experiment was conducted to investigate the characteristics of soil ammonia volatilization under the application of large particle urea (PUR), special compound fertilizer (LCCF), special slow-release compound fertilizer (LSRF), with no fertilization as the control. The pot experiment was meantime carried out to investigate yield, and uptake and utilization of nitrogen (N), phosphorus (P) and potassium (K) of 'Gailiangzaofeng' and 'Yujiao5' peppers under the application of LSRF, LCCF, common compound fertilizer (OCCF) and commercially non-coated slow-release compound fertilizer (MSRF). Changes in soil organic matter content and soil enzyme activity were also analyzed. The results showed that the order of the soil ammonia volatilization rate in the first 28 days of laboratory diffusion simulation experiment was as follows: PUR > LCCF > LSRF > no fertilizer (CK). Then soil ammonia volatilization rate of LSRF after 28 days of the experiment was higher than those of PUR and LCCF. Cumulative soil ammonia volatilization from PUR, LSRF and LCCF at 70 days were 71.87 mg·kg-1, 54.29 mg·kg-1 and 63.49 mg·kg-1 respectively under laboratory diffusion simulation experiment. Cumulative ammonia volatilization from LSRF respectively dropped by 24.5% and 11.7% compared with PUR and LCCF under the same dose of N fertilizer. For the pot experiment, yield of 'Yujiao5' and 'Gailiangzaofeng' under LSRF respectively increased by 64.7% and 33.8% compared with OCCF, While the content of soil organic matter and activities of urease, invertase and catalase increased, plant uptake and utilization of N, P and K were enhanced under LSRF treatment. Apparent N fertilizer utilization rates of 'Yujiao5' and 'Gailiangzaofeng' respectively increased by 62.5% and 123.1% compared with that of OCCF. Apparent P and K fertilizer utilization rates of 'Gailiangzaofeng' under LSRF treatment respectively enhanced by 14.0 times and 28.7% compared with OCCF. Also apparent P and K fertilizer utilization rates of 'Yujiao5' under LSRF treatment respectively increased by 3.2 times and 120.9% compared with OCCF treatment.
Laboratory diffusion simulation experiment was conducted to investigate the characteristics of soil ammonia volatilization under the application of large particle urea (PUR), special compound fertilizer (LCCF), special slow-release compound fertilizer (LSRF), with no fertilization as the control. The pot experiment was meantime carried out to investigate yield, and uptake and utilization of nitrogen (N), phosphorus (P) and potassium (K) of 'Gailiangzaofeng' and 'Yujiao5' peppers under the application of LSRF, LCCF, common compound fertilizer (OCCF) and commercially non-coated slow-release compound fertilizer (MSRF). Changes in soil organic matter content and soil enzyme activity were also analyzed. The results showed that the order of the soil ammonia volatilization rate in the first 28 days of laboratory diffusion simulation experiment was as follows: PUR > LCCF > LSRF > no fertilizer (CK). Then soil ammonia volatilization rate of LSRF after 28 days of the experiment was higher than those of PUR and LCCF. Cumulative soil ammonia volatilization from PUR, LSRF and LCCF at 70 days were 71.87 mg·kg-1, 54.29 mg·kg-1 and 63.49 mg·kg-1 respectively under laboratory diffusion simulation experiment. Cumulative ammonia volatilization from LSRF respectively dropped by 24.5% and 11.7% compared with PUR and LCCF under the same dose of N fertilizer. For the pot experiment, yield of 'Yujiao5' and 'Gailiangzaofeng' under LSRF respectively increased by 64.7% and 33.8% compared with OCCF, While the content of soil organic matter and activities of urease, invertase and catalase increased, plant uptake and utilization of N, P and K were enhanced under LSRF treatment. Apparent N fertilizer utilization rates of 'Yujiao5' and 'Gailiangzaofeng' respectively increased by 62.5% and 123.1% compared with that of OCCF. Apparent P and K fertilizer utilization rates of 'Gailiangzaofeng' under LSRF treatment respectively enhanced by 14.0 times and 28.7% compared with OCCF. Also apparent P and K fertilizer utilization rates of 'Yujiao5' under LSRF treatment respectively increased by 3.2 times and 120.9% compared with OCCF treatment.
2014, 22(2): 151-158.
doi: 10.3724/SP.J.1011.2014.30779
Abstract:
Nitrogen (N) is a critical factor influencing yield and quality of triticale. To analyze the effects of N accumulation and distribution on N use efficiency (NUE) at different growth stages (tillering, jointing and heading) of triticale, a pot experiment with three N fertilization rates [0 (zero-N), 0.033 g(N)·kg-1 (low-N) and 0.066 g(N)·kg-1 (normal-N)] and three triticale varieties [two high NUE ('Clxt82', 'PI429186') and one low NUE ('Clxt74')] was carried out. The distribution of N in plant organs, and contents of different N forms were analyzed at various growth stages. The results showed that high NUE triticale varieties were advantages in low N conditions. The differences in biomass between high and low NUE varieties gradually decreased with increasing N fertilization rates at heading stage. Above-ground biomass of 'Clxt82' was respectively 1.55 times, 1.19 times and 1.06 times that of 'Clxt74' under zero-N, low-N and normal-N treatments. Similarly, above-ground biomass of 'PI429186' was respectively 1.79 times, 1.35 times and 1.30 times that of 'Clxt74' under zero-N, low-N and normal-N treatments. N accumulation increased significantly with increasing N fertilization rates at different growth stages. Under low-N and normal-N treatments, N accumulation in both high NUE varieties was significantly higher than that in low NUE variety at tillering and jointing stages. However, no significant difference was noted between the varieties at heading stage. Allocation ratio of N in plant leaves and ears decreased with increasing N fertilization rates and the reverse was the case for plant stems. At tillering and jointing stages, N allocation ratios of stems of high NUE varieties were less than that of low NUE variety, and for leaves it was reverse. At heading stage, N allocation ratio of ears of high NUE varieties was higher than in low NUE varieties and the reverse was the case for leaves. Contents of different forms of N increased with increasing N fertilization rates at various growth stages. At jointing stage, assimilable N (AN) contents in 'Clxt82' and 'PI429186' leaves were respectively 1.31 times and 1.76 times that in 'Clxt74' under zero-N treatment, and 1.12 times and 1.35 times under low-N treatment. Then structural N (SN) contents were respectively 86.12% and 64.01%, and 80.82% and 71.51% that of 'Clxt74'. At heading stage, AN content in 'Clxt82' and 'PI429186' leaves were respectively 1.01 times and 1.11 times that of 'Clxt74' under zero-N treatment, and 1.04 times and 1.13 times under low-N treatment. Also SN content were respectively 74.99% and 63.08%, and 75.78% and 62.84% that of 'Clxt74'. However, functional N (FN) content was not significantly different for the varieties at various growth stages. High NUE varieties maintained N utilization and N cycle by reducing SN content and increasing AN content.
Nitrogen (N) is a critical factor influencing yield and quality of triticale. To analyze the effects of N accumulation and distribution on N use efficiency (NUE) at different growth stages (tillering, jointing and heading) of triticale, a pot experiment with three N fertilization rates [0 (zero-N), 0.033 g(N)·kg-1 (low-N) and 0.066 g(N)·kg-1 (normal-N)] and three triticale varieties [two high NUE ('Clxt82', 'PI429186') and one low NUE ('Clxt74')] was carried out. The distribution of N in plant organs, and contents of different N forms were analyzed at various growth stages. The results showed that high NUE triticale varieties were advantages in low N conditions. The differences in biomass between high and low NUE varieties gradually decreased with increasing N fertilization rates at heading stage. Above-ground biomass of 'Clxt82' was respectively 1.55 times, 1.19 times and 1.06 times that of 'Clxt74' under zero-N, low-N and normal-N treatments. Similarly, above-ground biomass of 'PI429186' was respectively 1.79 times, 1.35 times and 1.30 times that of 'Clxt74' under zero-N, low-N and normal-N treatments. N accumulation increased significantly with increasing N fertilization rates at different growth stages. Under low-N and normal-N treatments, N accumulation in both high NUE varieties was significantly higher than that in low NUE variety at tillering and jointing stages. However, no significant difference was noted between the varieties at heading stage. Allocation ratio of N in plant leaves and ears decreased with increasing N fertilization rates and the reverse was the case for plant stems. At tillering and jointing stages, N allocation ratios of stems of high NUE varieties were less than that of low NUE variety, and for leaves it was reverse. At heading stage, N allocation ratio of ears of high NUE varieties was higher than in low NUE varieties and the reverse was the case for leaves. Contents of different forms of N increased with increasing N fertilization rates at various growth stages. At jointing stage, assimilable N (AN) contents in 'Clxt82' and 'PI429186' leaves were respectively 1.31 times and 1.76 times that in 'Clxt74' under zero-N treatment, and 1.12 times and 1.35 times under low-N treatment. Then structural N (SN) contents were respectively 86.12% and 64.01%, and 80.82% and 71.51% that of 'Clxt74'. At heading stage, AN content in 'Clxt82' and 'PI429186' leaves were respectively 1.01 times and 1.11 times that of 'Clxt74' under zero-N treatment, and 1.04 times and 1.13 times under low-N treatment. Also SN content were respectively 74.99% and 63.08%, and 75.78% and 62.84% that of 'Clxt74'. However, functional N (FN) content was not significantly different for the varieties at various growth stages. High NUE varieties maintained N utilization and N cycle by reducing SN content and increasing AN content.
MA Taotao,
YAN Dongdong,
MAO Liangang,
WANG Qiuxia,
LI Yuan,
OU-YANG Canbin,
GUO Meixia,
CAO Aocheng
2014, 22(2): 159-164.
doi: 10.3724/SP.J.1011.2014.30784
Abstract:
In a laboratory incubation under constant temperature and aerated conditions, the effects of 4 fumigants - chloropicrin (Pic), 1,3-dichloropropene (1,3-D), methyl disulfide (DMDS) and metham-sodium (MS) - on soil dissolved organic nitrogen (DON) transformation and microbial biomass under vegetable greenhouse conditions in Beijing area were investigated. The results revealed that DON concentration increased significantly after fumigant treatment. In 0 day after fumigation (DAF), cumulative DON under Pic, MS, DMDS and 1,3-D treatments were 47.55 mg·kg-1, 42.15 mg·kg -1, 40.34 mg·kg-1 and 32.02 mg·kg-1, respectively. This represented a corresponding increase of 58.67%, 40.65%, 34.61% and 6.87% compared with 29.97 mg·kg-1 of untreated soils. In the 14 84 DAF, the content of DON in Pic, DMDS and MS groups increased. A significant difference was noted in DON content in different groups. Fumigation also strongly increased the proportion of dissolved amino acid (DAA) in DON, which was important in the transformation process of soil N. DAA content increased greatly after fumigation, compared with CK, and peaked in 7 DAF. The highest DAA content (12.87 mg·kg-1) was found under Pic treatment, while the lowest (5.74 mg·kg-1) under CK. After fumigation, the content of soil microorganisms decreased sharply. Pic exhibited the strongest killing effect. Soil microbial biomass carbon and soil microbial biomass nitrogen contents decreased by 69.39% and 70.95%, respectively, under Pic treatment, followed by DMDS and MS treatments. Then 1,3-D had the least effect on microorganisms. While nitrification was inhibited for at least 2 weeks after treatment with Pic, 1,3-D and MS; it was inhibited for at least 1 week after DMDC treatment. Nitrification and mineralization gradually recovered under long-term incubation.
In a laboratory incubation under constant temperature and aerated conditions, the effects of 4 fumigants - chloropicrin (Pic), 1,3-dichloropropene (1,3-D), methyl disulfide (DMDS) and metham-sodium (MS) - on soil dissolved organic nitrogen (DON) transformation and microbial biomass under vegetable greenhouse conditions in Beijing area were investigated. The results revealed that DON concentration increased significantly after fumigant treatment. In 0 day after fumigation (DAF), cumulative DON under Pic, MS, DMDS and 1,3-D treatments were 47.55 mg·kg-1, 42.15 mg·kg -1, 40.34 mg·kg-1 and 32.02 mg·kg-1, respectively. This represented a corresponding increase of 58.67%, 40.65%, 34.61% and 6.87% compared with 29.97 mg·kg-1 of untreated soils. In the 14 84 DAF, the content of DON in Pic, DMDS and MS groups increased. A significant difference was noted in DON content in different groups. Fumigation also strongly increased the proportion of dissolved amino acid (DAA) in DON, which was important in the transformation process of soil N. DAA content increased greatly after fumigation, compared with CK, and peaked in 7 DAF. The highest DAA content (12.87 mg·kg-1) was found under Pic treatment, while the lowest (5.74 mg·kg-1) under CK. After fumigation, the content of soil microorganisms decreased sharply. Pic exhibited the strongest killing effect. Soil microbial biomass carbon and soil microbial biomass nitrogen contents decreased by 69.39% and 70.95%, respectively, under Pic treatment, followed by DMDS and MS treatments. Then 1,3-D had the least effect on microorganisms. While nitrification was inhibited for at least 2 weeks after treatment with Pic, 1,3-D and MS; it was inhibited for at least 1 week after DMDC treatment. Nitrification and mineralization gradually recovered under long-term incubation.
2014, 22(2): 165-170.
doi: 10.3724/SP.J.1011.2014.30803
Abstract:
Beauveria bassiana is a common entomopathogenic fungus with a global distribution. Isolates of B. bassiana can antagonize a variety of soil and plant pathogens. At present, studies have focused on B. bassiana insecticidal mechanism and symbiosis with plants. In order to investigate the ecological safety of B. bassiana and its environmental behavior in paddy systems, we conducted a potted trial to evaluate the effects of different concentrations of B. bassiana spore suspensions and chemical pesticide (acephate) on the redox state of rice and the intensity of biochemical processes related to soil nitrogen circulation. B. bassiana were expressed with the egfp gene (green fluorescent protein gene) through transformation with a vector, and real-time polymerase chain reaction (PCR) was used to detect B. bassiana in rice grains. To accomplish this, B. bassiana specific DNA primers (eGPF-F1/ eGFP-R1) were designed after the green fluorescent protein sequence marked B. bassiana. Amplification of B. bassiana DNA yielded a single 289 bp-long product using the eGPF-F1/eGFP-R1 primers. The detection limit was 10 fg·μL-1 of B. bassiana genomic DNA. The pot experiments consisted of seven treatments - CK (blank control group), CS (Chilo. suppressalis larvae), B1 (B. bassiana at 7.5×104 spores·mL-1 + CS), B10 (7.5×105 spores·mL-1 + CS), B100 (7.5×106 spores·mL-1 + CS), B1000 (7.5×107 spores·mL-1 + CS) and AE (acephate + CS). The results showed that B. bassiana stimulated the ammonification and nitrification of soils with maximum increases of 12.4% and 36.8%, respectively. Low concentration of B. bassiana facilitated denitrification, while high concentration inhibited denitrification. On the 10th day after treatment, acephate decreased ammonification, nitrification and denitrification rates by 18.6%, 45.3% and 27.5%, respectively. After inoculation with C. suppressalis and acephate application, ratios of AsA︰DHA and GSH︰GSSG reduced with decreasing antioxidant capacity. In contrast, B. bassiana treatment increased AsA︰DHA and GSH︰GSSG ratios. Changes in H2O2 content showed that C. suppressalis and acephate induced peroxidation, while B. bassiana reduced peroxidation intensity induced by C. suppressalis. Finally, B. Bassiana was not found in grains after RT-qPCR analysis. Overall, it was concluded that compared with chemical pesticide (acephate), B. bassiana was an effective and environment-friendly microbial pesticide.
Beauveria bassiana is a common entomopathogenic fungus with a global distribution. Isolates of B. bassiana can antagonize a variety of soil and plant pathogens. At present, studies have focused on B. bassiana insecticidal mechanism and symbiosis with plants. In order to investigate the ecological safety of B. bassiana and its environmental behavior in paddy systems, we conducted a potted trial to evaluate the effects of different concentrations of B. bassiana spore suspensions and chemical pesticide (acephate) on the redox state of rice and the intensity of biochemical processes related to soil nitrogen circulation. B. bassiana were expressed with the egfp gene (green fluorescent protein gene) through transformation with a vector, and real-time polymerase chain reaction (PCR) was used to detect B. bassiana in rice grains. To accomplish this, B. bassiana specific DNA primers (eGPF-F1/ eGFP-R1) were designed after the green fluorescent protein sequence marked B. bassiana. Amplification of B. bassiana DNA yielded a single 289 bp-long product using the eGPF-F1/eGFP-R1 primers. The detection limit was 10 fg·μL-1 of B. bassiana genomic DNA. The pot experiments consisted of seven treatments - CK (blank control group), CS (Chilo. suppressalis larvae), B1 (B. bassiana at 7.5×104 spores·mL-1 + CS), B10 (7.5×105 spores·mL-1 + CS), B100 (7.5×106 spores·mL-1 + CS), B1000 (7.5×107 spores·mL-1 + CS) and AE (acephate + CS). The results showed that B. bassiana stimulated the ammonification and nitrification of soils with maximum increases of 12.4% and 36.8%, respectively. Low concentration of B. bassiana facilitated denitrification, while high concentration inhibited denitrification. On the 10th day after treatment, acephate decreased ammonification, nitrification and denitrification rates by 18.6%, 45.3% and 27.5%, respectively. After inoculation with C. suppressalis and acephate application, ratios of AsA︰DHA and GSH︰GSSG reduced with decreasing antioxidant capacity. In contrast, B. bassiana treatment increased AsA︰DHA and GSH︰GSSG ratios. Changes in H2O2 content showed that C. suppressalis and acephate induced peroxidation, while B. bassiana reduced peroxidation intensity induced by C. suppressalis. Finally, B. Bassiana was not found in grains after RT-qPCR analysis. Overall, it was concluded that compared with chemical pesticide (acephate), B. bassiana was an effective and environment-friendly microbial pesticide.
2014, 22(2): 171-176.
doi: 10.3724/SP.J.1011.2014.30916
Abstract:
Biomass ash is a kind of plant straw residuum produced by combustion of straw at 800 ℃. Biomass ash contains lots of nutrients, including phosphorus (P), calcium (Ca), magnesium (Mg) and especially potassium (K). In biomass ash, K mainly occurs as K2SO4, KCl and K2SO3. In recent years, biomass ash has been used to produce potassium-based fertilizers. However, less work has been done on the principles and mechanisms of biomass ash K+ release. In the new production system and method proposed to produce potassium fertilizers from biomass ash, pH is critical for K+ release. This paper used four types of biomass ash (cornstalk, rice straw, sawn wood and chaff) with different pH of 4, 7 and 9 adjusted by ammonium acetate (NH4Ac) to extract available K by the method of penetration exchange. This study discussed the cumulative quantity and rate of release of K+, and analyzed K+ release dynamics of four types of biomass ash using three kinetic models. The results indicated that K+ release attained equilibrium in 20 80 min with a total capacity of K+ release significantly different for different pH. Total K+ release capacity was 14.77 255.17 cmol·kg-1 at pH of 4, 4.83 106.71 cmol·kg-1 at pH of 7 and 12.11 224.33 cmol·kg-1 at pH of 9. Total K+ release capacity under each pH condition showed that rice straw released the most K+, followed by cornstalk and sawn wood, while chaff released the least K+. Correlation analysis suggested that total K content of biomass ash was critical for the time and total capacity of K+ release. The correlation coefficient of released K+ amount and total K content was 0.991 0.997. A significant difference was noted in K+ release rate among biomass ash types. These implied that the greater content of K contain the more amount of K+ release. This indicated that equilibrium time and quantity of released K+ varied with pH and total K content of exchange solution. Under the three pH conditions, released K+ amounts (Q) of rice straw and cornstalk were in the order of Q4 > Q9 > Q7, while those of sawn wood and chaff were Q9 > Q4 > Q7. The order of total K+ release capacity of biomass ash was QRice straw > QSawn wood > QChaff > QCornstalks under the three pH conditions. Before equilibrium time, K+ release velocity (v) was logarithmically related with time (lnt) during each reaction stage. For the same biomass ash, the optimal kinetic mode of K+ release changed with pH condition. The best models at pH of 4, 7 and 9 were Elovich Equation (EE), Dual Constant Equation (DCE) and EE, respectively. Under the same pH condition, the model that best described K+ release process was the EE and DCE, while the Parabolic Diffusion (PD) was the most inappropriate model.
Biomass ash is a kind of plant straw residuum produced by combustion of straw at 800 ℃. Biomass ash contains lots of nutrients, including phosphorus (P), calcium (Ca), magnesium (Mg) and especially potassium (K). In biomass ash, K mainly occurs as K2SO4, KCl and K2SO3. In recent years, biomass ash has been used to produce potassium-based fertilizers. However, less work has been done on the principles and mechanisms of biomass ash K+ release. In the new production system and method proposed to produce potassium fertilizers from biomass ash, pH is critical for K+ release. This paper used four types of biomass ash (cornstalk, rice straw, sawn wood and chaff) with different pH of 4, 7 and 9 adjusted by ammonium acetate (NH4Ac) to extract available K by the method of penetration exchange. This study discussed the cumulative quantity and rate of release of K+, and analyzed K+ release dynamics of four types of biomass ash using three kinetic models. The results indicated that K+ release attained equilibrium in 20 80 min with a total capacity of K+ release significantly different for different pH. Total K+ release capacity was 14.77 255.17 cmol·kg-1 at pH of 4, 4.83 106.71 cmol·kg-1 at pH of 7 and 12.11 224.33 cmol·kg-1 at pH of 9. Total K+ release capacity under each pH condition showed that rice straw released the most K+, followed by cornstalk and sawn wood, while chaff released the least K+. Correlation analysis suggested that total K content of biomass ash was critical for the time and total capacity of K+ release. The correlation coefficient of released K+ amount and total K content was 0.991 0.997. A significant difference was noted in K+ release rate among biomass ash types. These implied that the greater content of K contain the more amount of K+ release. This indicated that equilibrium time and quantity of released K+ varied with pH and total K content of exchange solution. Under the three pH conditions, released K+ amounts (Q) of rice straw and cornstalk were in the order of Q4 > Q9 > Q7, while those of sawn wood and chaff were Q9 > Q4 > Q7. The order of total K+ release capacity of biomass ash was QRice straw > QSawn wood > QChaff > QCornstalks under the three pH conditions. Before equilibrium time, K+ release velocity (v) was logarithmically related with time (lnt) during each reaction stage. For the same biomass ash, the optimal kinetic mode of K+ release changed with pH condition. The best models at pH of 4, 7 and 9 were Elovich Equation (EE), Dual Constant Equation (DCE) and EE, respectively. Under the same pH condition, the model that best described K+ release process was the EE and DCE, while the Parabolic Diffusion (PD) was the most inappropriate model.
2014, 22(2): 177-184.
doi: 10.3724/SP.J.1011.2014.30847
Abstract:
Soil salinization is a vital non-biological factor restricting crops yield and quality improvements across the world. The most effective and economic way of exploiting saline soils has been breeding and planting salt-tolerant species. Yet the lack of reliable, inexpensive and convenient screening method has limited progress in salt-tolerant breeding programs. Screening the applicability of different salt-intolerant indexes of cultivar under different salt stresses was critical for providing requisite scientific evidence of breeding salt-tolerant species and molecular marker in selective breeding. In this paper, the applicability of different salinity tolerance indexes of sunflower was screened. This laid the scientific relevance of salinity tolerance breeding and marker-assisted selection. To determine salinity tolerance indexes of sunflower in Hetao Irrigation District, the main local cultivar 'LD 5009' was cropped and observed in fourteen representative fields over a period of two years. The fields included non-saline, mild-saline, saline and severe-saline zones. Twelve indexes, including yield, biomass, plant height, leaf area index, face plate diameter, SOD activity and contents of leaf chlorophyll, proline, Na+ and K+ were analyzed in response to salinity conditions and indexes which reduced with increased soil ECe selected. Nonlinear least squares numerical approximation method was used to establish an S-shaped salinity tolerance function which reflected the relationship between salinity tolerance indexes and soil ECe in different layers. The results indicated that yield, biomass, plant height, leaf area index, disc diameter, and leaf and stem K+ contents decreased with increasing soil salinity. The coefficient of determination of salinity tolerance function between biomass and ECe in the 0-20 cm soil layer was highest. There was no obvious impact of salinity on chlorophyll content. Under salinity conditions, Na+ content gradually increased, while proline content and SOD activity increased followed by a decrease. In conclusion, this study verified the suitability of biomass as a key index of sunflower salinity tolerance analysis in Hetao Irrigation District.
Soil salinization is a vital non-biological factor restricting crops yield and quality improvements across the world. The most effective and economic way of exploiting saline soils has been breeding and planting salt-tolerant species. Yet the lack of reliable, inexpensive and convenient screening method has limited progress in salt-tolerant breeding programs. Screening the applicability of different salt-intolerant indexes of cultivar under different salt stresses was critical for providing requisite scientific evidence of breeding salt-tolerant species and molecular marker in selective breeding. In this paper, the applicability of different salinity tolerance indexes of sunflower was screened. This laid the scientific relevance of salinity tolerance breeding and marker-assisted selection. To determine salinity tolerance indexes of sunflower in Hetao Irrigation District, the main local cultivar 'LD 5009' was cropped and observed in fourteen representative fields over a period of two years. The fields included non-saline, mild-saline, saline and severe-saline zones. Twelve indexes, including yield, biomass, plant height, leaf area index, face plate diameter, SOD activity and contents of leaf chlorophyll, proline, Na+ and K+ were analyzed in response to salinity conditions and indexes which reduced with increased soil ECe selected. Nonlinear least squares numerical approximation method was used to establish an S-shaped salinity tolerance function which reflected the relationship between salinity tolerance indexes and soil ECe in different layers. The results indicated that yield, biomass, plant height, leaf area index, disc diameter, and leaf and stem K+ contents decreased with increasing soil salinity. The coefficient of determination of salinity tolerance function between biomass and ECe in the 0-20 cm soil layer was highest. There was no obvious impact of salinity on chlorophyll content. Under salinity conditions, Na+ content gradually increased, while proline content and SOD activity increased followed by a decrease. In conclusion, this study verified the suitability of biomass as a key index of sunflower salinity tolerance analysis in Hetao Irrigation District.
JI Guisu,
YAN Yonglu,
LYU Peng,
DU Ruiheng,
HOU Dongli,
REN Hanying,
MA Xue,
WANG Xiaokun,
LIU Guoqing,
LI Suying,
HOU Shenglin,
GUO Yanlong,
FU Cuiqing
2014, 22(2): 185-192.
doi: 10.3724/SP.J.1011.2014.30623
Abstract:
Sweet sorghum, which is used to produce alcohol and energy, hardly enters human food chain. This purpose combined with powerful root uptake ability makes sweet sorghum a low-cost, safe and effective plant in removing heavy metals (HMs) from polluted soils. In this study, eight sweet, two forage and one grain sorghum accessions planted in polluted soil were evaluated and compared with those planted in unpolluted soil. Eight HMs were evaluated in different plant organs to characterize HMs uptake ability of different sorghum accessions. The results showed that contents of Hg, Cd, Mn and Zn in sweet sorghum accessions were significantly different in polluted and unpolluted soil. However, the contents of Co, Cr, Pb and Cu were not significantly different. Mn content in sweet sorghum accessions in unpolluted soil was higher than that in polluted soil. Zn content was much higher in leaves and spikes than in stems and roots of plants from unpolluted soil, much different from that of plants from polluted soil. HMs contents varied in different sweet sorghum organs. For instance, there were high contents of Hg, Cd, Co, Cr and Zn in plant root while high contents of Cu, Mn and Pb were in plant spike in polluted soil. Significant differences existed in uptake, transfer and accumulation of HMs both among different accessions and HMs. Forage sorghum 'Wancao 2' had more Cr and Zn in leaves while 'Jinzhong 0823' grain sorghum accession had more heavy metals in stems than other accessions. High HMs enrichment coefficients were existed in the root of sorghum, which ranged from 0.02 (for Pb) to 0.23 (for Cd), and transfer coefficients were 0.21 (for Co) to 3.42 (for Pb). Significant differences existed among accessions in terms of certain HM uptake. Enrichment coefficients of Co, Cr, Cu, Mn, Pb and Zn in root of 'Ximeng' sweet sorghum were high. Also enrichment coefficients of Hg, Cd, Mn, Pb and Zn in stem of 'Jinzhong 0823' grain sorghum were high. The ability of HMs enrichment and transfer was not consistent in sorghum accessions, such as 'Lüneng No.1' sweet sorghum had a high transfer coefficient for several HMs, only Zn had high transfer coefficient in 'Jinzhong 0823' grain sorghum. Thus the result above suggested that the enrichment and transfer of HMs varied with HM types in sweet sorghum. Sweet sorghum first absorbed Zn and then accumulated it in leaves and spikes, and then in stems and roots as Zn content of the plant was high enough. Mn uptake of sweet sorghum competed with other HMs. Hg was seldom transferred to above-ground parts after its uptake by sweet sorghum, while Cu, Mn and Pb mainly accumulated in sweet sorghum spikes. 'Ximeng' sweet sorghum had a rich accumulation of several HMs in roots, while large amounts of various HMs accumulated in stems of 'Jinzhong 0823' grain sorghum accession. There was no specific pattern of HMs uptake in forage and sweet sorghum accessions. Therefore, sorghum plant could be used to remove HMs from polluted soils. This could be more efficiently done by employing accessions with high HM enrichment and transfer ability.
Sweet sorghum, which is used to produce alcohol and energy, hardly enters human food chain. This purpose combined with powerful root uptake ability makes sweet sorghum a low-cost, safe and effective plant in removing heavy metals (HMs) from polluted soils. In this study, eight sweet, two forage and one grain sorghum accessions planted in polluted soil were evaluated and compared with those planted in unpolluted soil. Eight HMs were evaluated in different plant organs to characterize HMs uptake ability of different sorghum accessions. The results showed that contents of Hg, Cd, Mn and Zn in sweet sorghum accessions were significantly different in polluted and unpolluted soil. However, the contents of Co, Cr, Pb and Cu were not significantly different. Mn content in sweet sorghum accessions in unpolluted soil was higher than that in polluted soil. Zn content was much higher in leaves and spikes than in stems and roots of plants from unpolluted soil, much different from that of plants from polluted soil. HMs contents varied in different sweet sorghum organs. For instance, there were high contents of Hg, Cd, Co, Cr and Zn in plant root while high contents of Cu, Mn and Pb were in plant spike in polluted soil. Significant differences existed in uptake, transfer and accumulation of HMs both among different accessions and HMs. Forage sorghum 'Wancao 2' had more Cr and Zn in leaves while 'Jinzhong 0823' grain sorghum accession had more heavy metals in stems than other accessions. High HMs enrichment coefficients were existed in the root of sorghum, which ranged from 0.02 (for Pb) to 0.23 (for Cd), and transfer coefficients were 0.21 (for Co) to 3.42 (for Pb). Significant differences existed among accessions in terms of certain HM uptake. Enrichment coefficients of Co, Cr, Cu, Mn, Pb and Zn in root of 'Ximeng' sweet sorghum were high. Also enrichment coefficients of Hg, Cd, Mn, Pb and Zn in stem of 'Jinzhong 0823' grain sorghum were high. The ability of HMs enrichment and transfer was not consistent in sorghum accessions, such as 'Lüneng No.1' sweet sorghum had a high transfer coefficient for several HMs, only Zn had high transfer coefficient in 'Jinzhong 0823' grain sorghum. Thus the result above suggested that the enrichment and transfer of HMs varied with HM types in sweet sorghum. Sweet sorghum first absorbed Zn and then accumulated it in leaves and spikes, and then in stems and roots as Zn content of the plant was high enough. Mn uptake of sweet sorghum competed with other HMs. Hg was seldom transferred to above-ground parts after its uptake by sweet sorghum, while Cu, Mn and Pb mainly accumulated in sweet sorghum spikes. 'Ximeng' sweet sorghum had a rich accumulation of several HMs in roots, while large amounts of various HMs accumulated in stems of 'Jinzhong 0823' grain sorghum accession. There was no specific pattern of HMs uptake in forage and sweet sorghum accessions. Therefore, sorghum plant could be used to remove HMs from polluted soils. This could be more efficiently done by employing accessions with high HM enrichment and transfer ability.
2014, 22(2): 193-200.
doi: 10.3724/SP.J.1011.2014.30840
Abstract:
Benzo(a)pyrene (B[a]P), one of the most persistent organic pollutants (POPs), accumulates in soil and thereby poses a serious threat to soil environment quality. There have been frequent overestimations of environmental risks of B[a]P due to the over-evaluated toxic effects of available fractions with one-time imposed pollution method. In this paper, we proposed a new multi-time addition method aimed at reliable simulation of the process of B[a]P infiltration into soils. Furthermore, soil available B[a]P contents, accumulated B[a]P in earthworms (Eisenia fetida) and the toxic effects on superoxide dismutase (SOD) and peroxidase (POD) activities in earthworms coelomocytes were investigated by using superimposed multi-time and one-time pollution methods. The results suggested that the contents of available B[a]P and its accumulated amounts in earthworms sharply declined in 1 28 d and then slowly decreased in the following 28 56 d of incubation time under both superimposed multi-time and one-time pollution methods. The rates of decrease of soil available B[a]P were 2.37 μg·kg-1·d-1 and 3.35 μg·kg-1·d-1 in 1 28 d and 0.24 μg·kg-1·d-1 and 0.53 μg·kg-1·d-1 in 28 56 d for the superimposed multi-time and one-time pollution methods, respectively. The accumulated B[a]P in earthworms declined at the rates of 6.94 μg·kg-1·d-1 and 14.84 μg·kg-1·d-1 in 1 28 d, and 0.73 μg·kg-1·d-1 and 1.64 μg·kg-1·d-1 in 28 56 d under the superimposed multi-time and one-time pollution methods, respectively. The highly significant positive correlation (R2 = 0.914 7,P < 0.01) was noted between accumulated amounts of B[a]P in earthworms and Tenax extracted contents of B[a]P from soils. Moreover, SOD and POD activities in earthworms were positive correlated with soil available B[a]P contents, with best-fit regression equations of y = 0.118 6x + 3.595 and y = 0.114x + 17.727 (where y is enzyme activity and x is the available B[a]P content in soil) and correlation coefficients R2 = 0.754 3 and 0.829 6, respectively. Also SOD and POD activities in earthworms were positively correlated with accumulated amounts of B[a]P in earthworms, with best-fit regression equations of y = 0.028 9x + 4.524 8 and y = 0.026 9x + 18.803 (where y is enzyme activity and x is accumulated quantity in earthworm) and correlation coefficients R2 = 0.704 0 and 0.727 1, respectively. Although soil available B[a]P content was significantly (P < 0.05) correlated with enriched B[a]P amount in earthworms under the superimposed multi-time pollution method, the correlation coefficient was lower for superimposed multi-time pollution than for one-time pollution assay. Under superimposed multi-time pollution, soil available B[a]P content and accumulated amounts of B[a]P in earthworms were 17.1% 38.6% (P < 0.05) and 22.6% 46.8% (P < 0.05) lower than those under one-time pollution, respectively. The ranges of SOD and POD activities in earthworm coelomocytes under superimposed multi-time pollution were respectively 49.6% 82.7% and 75.5% 109.6% lower than those under one-time pollution method during the entire incubation time. The results suggested that soil available B[a]P content and its toxicity to earthworms under superimposed multi-time pollution were lower than those under one-time pollution.
Benzo(a)pyrene (B[a]P), one of the most persistent organic pollutants (POPs), accumulates in soil and thereby poses a serious threat to soil environment quality. There have been frequent overestimations of environmental risks of B[a]P due to the over-evaluated toxic effects of available fractions with one-time imposed pollution method. In this paper, we proposed a new multi-time addition method aimed at reliable simulation of the process of B[a]P infiltration into soils. Furthermore, soil available B[a]P contents, accumulated B[a]P in earthworms (Eisenia fetida) and the toxic effects on superoxide dismutase (SOD) and peroxidase (POD) activities in earthworms coelomocytes were investigated by using superimposed multi-time and one-time pollution methods. The results suggested that the contents of available B[a]P and its accumulated amounts in earthworms sharply declined in 1 28 d and then slowly decreased in the following 28 56 d of incubation time under both superimposed multi-time and one-time pollution methods. The rates of decrease of soil available B[a]P were 2.37 μg·kg-1·d-1 and 3.35 μg·kg-1·d-1 in 1 28 d and 0.24 μg·kg-1·d-1 and 0.53 μg·kg-1·d-1 in 28 56 d for the superimposed multi-time and one-time pollution methods, respectively. The accumulated B[a]P in earthworms declined at the rates of 6.94 μg·kg-1·d-1 and 14.84 μg·kg-1·d-1 in 1 28 d, and 0.73 μg·kg-1·d-1 and 1.64 μg·kg-1·d-1 in 28 56 d under the superimposed multi-time and one-time pollution methods, respectively. The highly significant positive correlation (R2 = 0.914 7,P < 0.01) was noted between accumulated amounts of B[a]P in earthworms and Tenax extracted contents of B[a]P from soils. Moreover, SOD and POD activities in earthworms were positive correlated with soil available B[a]P contents, with best-fit regression equations of y = 0.118 6x + 3.595 and y = 0.114x + 17.727 (where y is enzyme activity and x is the available B[a]P content in soil) and correlation coefficients R2 = 0.754 3 and 0.829 6, respectively. Also SOD and POD activities in earthworms were positively correlated with accumulated amounts of B[a]P in earthworms, with best-fit regression equations of y = 0.028 9x + 4.524 8 and y = 0.026 9x + 18.803 (where y is enzyme activity and x is accumulated quantity in earthworm) and correlation coefficients R2 = 0.704 0 and 0.727 1, respectively. Although soil available B[a]P content was significantly (P < 0.05) correlated with enriched B[a]P amount in earthworms under the superimposed multi-time pollution method, the correlation coefficient was lower for superimposed multi-time pollution than for one-time pollution assay. Under superimposed multi-time pollution, soil available B[a]P content and accumulated amounts of B[a]P in earthworms were 17.1% 38.6% (P < 0.05) and 22.6% 46.8% (P < 0.05) lower than those under one-time pollution, respectively. The ranges of SOD and POD activities in earthworm coelomocytes under superimposed multi-time pollution were respectively 49.6% 82.7% and 75.5% 109.6% lower than those under one-time pollution method during the entire incubation time. The results suggested that soil available B[a]P content and its toxicity to earthworms under superimposed multi-time pollution were lower than those under one-time pollution.
2014, 22(2): 201-207.
doi: 10.3724/SP.J.1011.2014.31041
Abstract:
Tobacco bacterial wilt caused by Ralstonia solanacearum is one of the most destructive bacterial diseases of tobacco. As a recurring soil-borne disease, it is controlled mainly by chemical methods that are not only costly and less efficient but also have food safety and environment safety problems. Consequently, biological control methods that use antagonistic strains have gained strength in tobacco bacterial wilt disease research. To find new antagonist bacteria against R. solanacearum, 238 strains were identified and screened for in vitro antibiosis. By placing each strain on cultured pathogen plates with toothpicks 24 strains showed inhibition zones. Among the 24 strains, the width of the inhibition zones of 7 antagonist strains exceeded 10 mm. Then pathogen inhibitive ingredients of the 7 strains were extracted to determine bacteriostatic efficacy. Finally, 3 promising strains (H19, Y6, H34) were obtained. H19 and Y6 were identified as Bacillus amyloliquefaciens and the other strain (coded H34) identified as B. methylotrophicus. The strain classification was based on phylogenetic analysis of 16S rDNA sequence, gyrB sequence and fatty acid composition. Siderophores secreted by microorganisms to take up iron from the environment had an action mode of disease suppression that was solely based on competition with the pathogens for iron. Besides, indole-3-acetic acid (IAA) is a phytohormone known to be involved in root initiation, cell division and cell enlargement. In follow-up experiments, all the three strains showed the ability to produce siderophores and plant growth promotor IAA. However, productions of siderophores and IAA were different, with H19 and Y6 as the highest and lowest producers under improved CAS and Salkowski colorimetric methods. The three strains were further characterized for plant growth promoting traits and disease control effects. Compared with control treatment, the strains significantly improved the growth of tobacco with increases of 19% 24% in the maximum leaf length, 7% 12% in the maximum leaf width, 70% 115% in plant height, 2% 14% in stem diameter, 40% 49% in fresh weight and 32% 42% in dry weight. H19, H34 and Y6 reduced bacterial wilt incidence by 76.57%, 60.98% and 69.83%, respectively in greenhouse experiments. This was slightly lower than using 40% agricultural streptomycin which had disease incidence control efficacy of 78.66%. In conclusion, the research isolated new efficient antagonistic strains against tobacco bacterial wilt. It also proved the mechanism of disease control and plant growth promotion by H19, H34 and Y6. The study further showed that the three strains had great potential for plant growth promotion and biological con-trol under greenhouse conditions, which developed the needed reference for follow-up studies.
Tobacco bacterial wilt caused by Ralstonia solanacearum is one of the most destructive bacterial diseases of tobacco. As a recurring soil-borne disease, it is controlled mainly by chemical methods that are not only costly and less efficient but also have food safety and environment safety problems. Consequently, biological control methods that use antagonistic strains have gained strength in tobacco bacterial wilt disease research. To find new antagonist bacteria against R. solanacearum, 238 strains were identified and screened for in vitro antibiosis. By placing each strain on cultured pathogen plates with toothpicks 24 strains showed inhibition zones. Among the 24 strains, the width of the inhibition zones of 7 antagonist strains exceeded 10 mm. Then pathogen inhibitive ingredients of the 7 strains were extracted to determine bacteriostatic efficacy. Finally, 3 promising strains (H19, Y6, H34) were obtained. H19 and Y6 were identified as Bacillus amyloliquefaciens and the other strain (coded H34) identified as B. methylotrophicus. The strain classification was based on phylogenetic analysis of 16S rDNA sequence, gyrB sequence and fatty acid composition. Siderophores secreted by microorganisms to take up iron from the environment had an action mode of disease suppression that was solely based on competition with the pathogens for iron. Besides, indole-3-acetic acid (IAA) is a phytohormone known to be involved in root initiation, cell division and cell enlargement. In follow-up experiments, all the three strains showed the ability to produce siderophores and plant growth promotor IAA. However, productions of siderophores and IAA were different, with H19 and Y6 as the highest and lowest producers under improved CAS and Salkowski colorimetric methods. The three strains were further characterized for plant growth promoting traits and disease control effects. Compared with control treatment, the strains significantly improved the growth of tobacco with increases of 19% 24% in the maximum leaf length, 7% 12% in the maximum leaf width, 70% 115% in plant height, 2% 14% in stem diameter, 40% 49% in fresh weight and 32% 42% in dry weight. H19, H34 and Y6 reduced bacterial wilt incidence by 76.57%, 60.98% and 69.83%, respectively in greenhouse experiments. This was slightly lower than using 40% agricultural streptomycin which had disease incidence control efficacy of 78.66%. In conclusion, the research isolated new efficient antagonistic strains against tobacco bacterial wilt. It also proved the mechanism of disease control and plant growth promotion by H19, H34 and Y6. The study further showed that the three strains had great potential for plant growth promotion and biological con-trol under greenhouse conditions, which developed the needed reference for follow-up studies.
2014, 22(2): 208-216.
doi: 10.3724/SP.J.1011.2014.30778
Abstract:
To determine the application methods of different antibiotics in relation to the biological characteristics of green pea aphid [Acyrthosiphon piusm (Harris)], we sprayed different antibiotics (chlortetracycline HCl, chloraomycetin, oxytetracycline HCl, penicillin-G K salt and streptomycin sulfate) using different methods. The application methods were spraying antibiotics on aphids and plants, on aphid only, and on plants only. Biological parameters of green pea aphid were obtained, which were the days of development, average weight, weight difference, mean relative growth rate and average fecundity of larvae. The results showed that the order of effect of three application methods on the biological characteristics of green pea aphid was as follows: spraying antibiotics on aphids and plants > spraying antibiotics on plants only > spraying antibiotics on aphids only. The order of effect of five different antibiotics on the biological characteristics of green pea aphid was as follows: oxytetracycline HCl > chlortetracycline HCl > streptomycin sulfate > chloraomycetin > penicillin-GK salt. After sprayed both on aphids and plants, oxytetracycline HCl in five antibiotics most significantly influenced the growth and development of green pea aphids - nymph stage prolonged by 2.25 days, generation time prolonged by 3.70 days, weight dropped by 52.37%, weight difference dropped by 55.84%, mean daily relative growth rate dropped by 53.85% and average fecundity of larvae dropped by 79.07%. While aphid development period under chlortetracycline HCl treatment increased, it decreased under penicillin-GK salt, chloraomycetin and streptomycin sulfate. After treatment with five antibiotic, similar weight losses and aphid fecundity drops were noted. The influence of oxytetracycline HCl on aphid nymph stage, generation period and average body weight growth rate was significantly different from others treatment. Both oxytetracycline HCl and chlortetracycline HCl had a clear effect on the average weight and weight difference of aphids, but with no significant difference between the two. When five antibiotics sprayed on plant surface only, oxytetracycline HCl had the highest effect on the growth and development of green pea aphid. Nymph stage prolonged by 1.63 days, generation time prolonged by 3.38 days, weight dropped by 50.28%, weight difference dropped by 51.49%, mean daily relative growth rate dropped by 41.67% and aphid fecundity dropped by 75.45%. Chlortetracycline HCl had a lower effect than oxytetracycline HCl, which led to a longer development period of aphids. Then penicillin-GK salt, chloraomycetin and streptomycin sulfate shortened aphid development period. When five antibiotics sprayed on aphid only, oxytetracycline HCl still had the highest effect on aphid development - nymph stage prolonged by 0.34 days, weight dropped by 24.32%, mean daily relative growth rate dropped by 26.32% and aphid fecundity dropped by 44.23%. In conclusion, spraying antibiotics on both aphid and plant was the most effective application method and oxytetracycline HCl was the most effective antibiotic for pea aphid. The other antibiotics and application methods had less effect on pea aphid. The three combinations of antibiotics and application methods had obvious effects on green pea aphid growth and development, their action order was as follows: oxytetracycline HCl antibiotic sprayed on aphids and plants > oxytetracycline HCl sprayed on plants > chlortetracycline HCl sprayed on aphids. There was no significant difference among the three. Oxytetracycline HCl sprayed on aphids and plants was significantly different from the others combinations in terms of effect.
To determine the application methods of different antibiotics in relation to the biological characteristics of green pea aphid [Acyrthosiphon piusm (Harris)], we sprayed different antibiotics (chlortetracycline HCl, chloraomycetin, oxytetracycline HCl, penicillin-G K salt and streptomycin sulfate) using different methods. The application methods were spraying antibiotics on aphids and plants, on aphid only, and on plants only. Biological parameters of green pea aphid were obtained, which were the days of development, average weight, weight difference, mean relative growth rate and average fecundity of larvae. The results showed that the order of effect of three application methods on the biological characteristics of green pea aphid was as follows: spraying antibiotics on aphids and plants > spraying antibiotics on plants only > spraying antibiotics on aphids only. The order of effect of five different antibiotics on the biological characteristics of green pea aphid was as follows: oxytetracycline HCl > chlortetracycline HCl > streptomycin sulfate > chloraomycetin > penicillin-GK salt. After sprayed both on aphids and plants, oxytetracycline HCl in five antibiotics most significantly influenced the growth and development of green pea aphids - nymph stage prolonged by 2.25 days, generation time prolonged by 3.70 days, weight dropped by 52.37%, weight difference dropped by 55.84%, mean daily relative growth rate dropped by 53.85% and average fecundity of larvae dropped by 79.07%. While aphid development period under chlortetracycline HCl treatment increased, it decreased under penicillin-GK salt, chloraomycetin and streptomycin sulfate. After treatment with five antibiotic, similar weight losses and aphid fecundity drops were noted. The influence of oxytetracycline HCl on aphid nymph stage, generation period and average body weight growth rate was significantly different from others treatment. Both oxytetracycline HCl and chlortetracycline HCl had a clear effect on the average weight and weight difference of aphids, but with no significant difference between the two. When five antibiotics sprayed on plant surface only, oxytetracycline HCl had the highest effect on the growth and development of green pea aphid. Nymph stage prolonged by 1.63 days, generation time prolonged by 3.38 days, weight dropped by 50.28%, weight difference dropped by 51.49%, mean daily relative growth rate dropped by 41.67% and aphid fecundity dropped by 75.45%. Chlortetracycline HCl had a lower effect than oxytetracycline HCl, which led to a longer development period of aphids. Then penicillin-GK salt, chloraomycetin and streptomycin sulfate shortened aphid development period. When five antibiotics sprayed on aphid only, oxytetracycline HCl still had the highest effect on aphid development - nymph stage prolonged by 0.34 days, weight dropped by 24.32%, mean daily relative growth rate dropped by 26.32% and aphid fecundity dropped by 44.23%. In conclusion, spraying antibiotics on both aphid and plant was the most effective application method and oxytetracycline HCl was the most effective antibiotic for pea aphid. The other antibiotics and application methods had less effect on pea aphid. The three combinations of antibiotics and application methods had obvious effects on green pea aphid growth and development, their action order was as follows: oxytetracycline HCl antibiotic sprayed on aphids and plants > oxytetracycline HCl sprayed on plants > chlortetracycline HCl sprayed on aphids. There was no significant difference among the three. Oxytetracycline HCl sprayed on aphids and plants was significantly different from the others combinations in terms of effect.
2014, 22(2): 217-224.
doi: 10.3724/SP.J.1011.2014.30709
Abstract:
Soil texture is a qualitative classification tool used in both the field and laboratory to determine the classes of agricultural soils based on physical texture. Surface soil texture reflects soil physical and chemical properties, which affects not only soil fertility and farming/production performance but also crop quality and yield. Precision agriculture requires reliable data on the variations in field soil properties for effective management decisions. The most common way to do this is to predict the values for un-sampled places using observed samples and represent the variations in maps. The optimal sampling method is importation in the evaluation of spatial variations in soil texture, which is more critical for fertilization or irrigation in precision agriculture. The acquisition of precise soil data which are representative of an entire survey area is critical for irrigation and fertilization in precision agriculture. Here, we compared the ability of three sampling methods used in estimating the precision agriculture practices and predict the spatial distribution of soil texture with the goal of choosing the optimal sampling method. About 289 soil samples were collected from the field at 0 20 cm depth in 16 m grid cells in the Southeast Pengshui County of Chongqing City. The geostatistics method and Geographic Information System (GIS) was used to evaluate the accuracy of the 16 m grid-cell sampling (a total of 253 sampling points), 32 m grid-cell sampling (a total of 115 sampling points) and random sampling (a total of 115 sampling points). The results showed that the largest component of the soil texture was silt and the lowest was sand. While sand and clay exhibited a medium variation, silt showed a low variation. Based on Kolmogorov-Smirnov test, sand, silt and clay were all normally distributed. Results of geostatistics analysis suggested that larger sampling intervals were needed under grid-cell sampling while lower sampling intervals could be used under random sampling of spatial variability of soil texture in the study area. Cross validation showed that the interpolation precision was highest for soil texture components under experimental control (16 m grid-cell sampling). This was followed by 32 m grid-cell sampling, while then random sampling had the lowest interpolation precision. The research indicated that based on the factors considered (including interpolation precision, cost effectiveness and timeliness), random sampling was the optimal method for analyzing soil texture in the study area.
Soil texture is a qualitative classification tool used in both the field and laboratory to determine the classes of agricultural soils based on physical texture. Surface soil texture reflects soil physical and chemical properties, which affects not only soil fertility and farming/production performance but also crop quality and yield. Precision agriculture requires reliable data on the variations in field soil properties for effective management decisions. The most common way to do this is to predict the values for un-sampled places using observed samples and represent the variations in maps. The optimal sampling method is importation in the evaluation of spatial variations in soil texture, which is more critical for fertilization or irrigation in precision agriculture. The acquisition of precise soil data which are representative of an entire survey area is critical for irrigation and fertilization in precision agriculture. Here, we compared the ability of three sampling methods used in estimating the precision agriculture practices and predict the spatial distribution of soil texture with the goal of choosing the optimal sampling method. About 289 soil samples were collected from the field at 0 20 cm depth in 16 m grid cells in the Southeast Pengshui County of Chongqing City. The geostatistics method and Geographic Information System (GIS) was used to evaluate the accuracy of the 16 m grid-cell sampling (a total of 253 sampling points), 32 m grid-cell sampling (a total of 115 sampling points) and random sampling (a total of 115 sampling points). The results showed that the largest component of the soil texture was silt and the lowest was sand. While sand and clay exhibited a medium variation, silt showed a low variation. Based on Kolmogorov-Smirnov test, sand, silt and clay were all normally distributed. Results of geostatistics analysis suggested that larger sampling intervals were needed under grid-cell sampling while lower sampling intervals could be used under random sampling of spatial variability of soil texture in the study area. Cross validation showed that the interpolation precision was highest for soil texture components under experimental control (16 m grid-cell sampling). This was followed by 32 m grid-cell sampling, while then random sampling had the lowest interpolation precision. The research indicated that based on the factors considered (including interpolation precision, cost effectiveness and timeliness), random sampling was the optimal method for analyzing soil texture in the study area.
2014, 22(2): 225-233.
doi: 10.3724/SP.J.1011.2014.30392
Abstract:
Nitrogen dioxide (N2O) is a major greenhouse gas. Investigating N2O emissions from agro-ecosystems of Fujian Province is critical for developing efficient mitigation strategies. Based on agricultural data in Fujian Province, a regional nitrogen cycle model, IAP-N, was adopted to estimate N2O emissions (in nitrogen gauge) from agro-ecosystems in Fujian Province for the period 1991 2010. The results showed that N2O emissions from agro-ecosystems (including direct and indirect farmland emissions, emissions from field-straw burning and animal manure) initially increased from 23 675.3 t·a-1 in 1991 to 32 610.4 t·a-1 in 2006 and then decreased to 30 810.7 t·a-1 in 2010. Average annual N2O emissions were 26 170.7 t·a-1, 29 870.0 t·a-1, 32 085.8 t·a-1 and 31 287.6 t·a-1 during 1991-1995, 1996-2000, 2001-2005, 2006-2010, respectively. The order of N2O emissions from different sources was direct farmland (66.2%) > animal manure (20.7%) > indirect farmland (12.9%) > filed-straw burning (0.2%). Direct N2O emissions from farmland increased from 15 108 t·a-1 in 1991 to 21 547 t·a-1 in 2006 and then decreased to 20 594 t·a-1 in 2010. Average annual direct N2O emissions from farmland were 17 073.0 t·a-1, 19 976.8 t·a-1, 21 183.4 t·a-1 and 20 778.6 t·a-1, respectively. Upland crops such as vegetables, non-vegetables upland and paddy-upland rotation systems were the primary sources, accounting for 83.0% 90.7% of direct N2O emissions from farmlands. N2O emission from animal manure was 5 213.2 6 988.0 t·a-1 in 1991 2010, with no obvious changes. Pigs were the primary source of animal manure, accounting for 57.4% 67.9% of N2O emissions from animal manure. In 2010, N2O emissions from the agro-ecosystems mainly concentrated in Zhangzhou, Nanping, Quanzhou and Ningde Districts, with over 4 000 t·a-1 N2O emissions. These districts led N2O emission rates in the study area, accounting for 61.7% of provincial emission. The results laid the scientific basis for policy decisions on fertilizer efficiency and N2O emission mitigation in the agro-ecosystems in Fujian Province.
Nitrogen dioxide (N2O) is a major greenhouse gas. Investigating N2O emissions from agro-ecosystems of Fujian Province is critical for developing efficient mitigation strategies. Based on agricultural data in Fujian Province, a regional nitrogen cycle model, IAP-N, was adopted to estimate N2O emissions (in nitrogen gauge) from agro-ecosystems in Fujian Province for the period 1991 2010. The results showed that N2O emissions from agro-ecosystems (including direct and indirect farmland emissions, emissions from field-straw burning and animal manure) initially increased from 23 675.3 t·a-1 in 1991 to 32 610.4 t·a-1 in 2006 and then decreased to 30 810.7 t·a-1 in 2010. Average annual N2O emissions were 26 170.7 t·a-1, 29 870.0 t·a-1, 32 085.8 t·a-1 and 31 287.6 t·a-1 during 1991-1995, 1996-2000, 2001-2005, 2006-2010, respectively. The order of N2O emissions from different sources was direct farmland (66.2%) > animal manure (20.7%) > indirect farmland (12.9%) > filed-straw burning (0.2%). Direct N2O emissions from farmland increased from 15 108 t·a-1 in 1991 to 21 547 t·a-1 in 2006 and then decreased to 20 594 t·a-1 in 2010. Average annual direct N2O emissions from farmland were 17 073.0 t·a-1, 19 976.8 t·a-1, 21 183.4 t·a-1 and 20 778.6 t·a-1, respectively. Upland crops such as vegetables, non-vegetables upland and paddy-upland rotation systems were the primary sources, accounting for 83.0% 90.7% of direct N2O emissions from farmlands. N2O emission from animal manure was 5 213.2 6 988.0 t·a-1 in 1991 2010, with no obvious changes. Pigs were the primary source of animal manure, accounting for 57.4% 67.9% of N2O emissions from animal manure. In 2010, N2O emissions from the agro-ecosystems mainly concentrated in Zhangzhou, Nanping, Quanzhou and Ningde Districts, with over 4 000 t·a-1 N2O emissions. These districts led N2O emission rates in the study area, accounting for 61.7% of provincial emission. The results laid the scientific basis for policy decisions on fertilizer efficiency and N2O emission mitigation in the agro-ecosystems in Fujian Province.
2014, 22(2): 234-240.
doi: 10.3724/SP.J.1011.2014.30893
Abstract:
In order to determine the effect of climate on winter wheat yield in the North China Plain, potential wheat productivity (Ymp) was simulated using daily dynamic crop growth model and agro-climate data from the Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences. Yield gap (YG) was calculated as the difference between Ymp and the actual yield under sufficient irrigation (Yh). A correlative stepwise regression analysis was used to determine the relationship between climate factors at different growth stages and YG. The same analysis was used to determine the relationship between climate factors and Yh. Before heading, sunshine hours and temperature factors (mean air temperature, maximum air temperature, minimum air temperature and daily temperature-range) were positively related with YG. After heading, however, both sunshine hours and daily temperature-range tended to be negatively correlated with YG. The results suggested that higher light and temperature increased production potential in the early growth stage. At the late stage, however, sufficient sunshine and large daily temperature-range benefited actual yield by enhancing vigorous growth. For actual yield, sunshine hours and daily temperature-range were positively correlated with Yh at most growth stages. This suggested that high sunshine and daily temperature-range were favored actual yield. While precipitation was negatively correlated to YG for almost the whole growth period, it was not significantly correlated with Yh. This suggested that precipitation influenced yield gap by reducing production potential. Only at the late ripening stage (about ten days before harvest) was precipitation positively correlated with YG and slightly negatively related with Yh. It implied that at late ripening stage, winter wheat yield did not benefit from precipitation.
In order to determine the effect of climate on winter wheat yield in the North China Plain, potential wheat productivity (Ymp) was simulated using daily dynamic crop growth model and agro-climate data from the Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences. Yield gap (YG) was calculated as the difference between Ymp and the actual yield under sufficient irrigation (Yh). A correlative stepwise regression analysis was used to determine the relationship between climate factors at different growth stages and YG. The same analysis was used to determine the relationship between climate factors and Yh. Before heading, sunshine hours and temperature factors (mean air temperature, maximum air temperature, minimum air temperature and daily temperature-range) were positively related with YG. After heading, however, both sunshine hours and daily temperature-range tended to be negatively correlated with YG. The results suggested that higher light and temperature increased production potential in the early growth stage. At the late stage, however, sufficient sunshine and large daily temperature-range benefited actual yield by enhancing vigorous growth. For actual yield, sunshine hours and daily temperature-range were positively correlated with Yh at most growth stages. This suggested that high sunshine and daily temperature-range were favored actual yield. While precipitation was negatively correlated to YG for almost the whole growth period, it was not significantly correlated with Yh. This suggested that precipitation influenced yield gap by reducing production potential. Only at the late ripening stage (about ten days before harvest) was precipitation positively correlated with YG and slightly negatively related with Yh. It implied that at late ripening stage, winter wheat yield did not benefit from precipitation.
2014, 22(2): 241-245.
doi: 10.3724/SP.J.1011.2014.30661
Abstract:
The existing methods of calculating reference crop evapotranspiration (ET0) from meteorological data need various climatic and physical parameters. Net radiation (Rn) is one essential parameter for ET0. However, professional measurement devices of Rn are seldom installed in agro-meteorological stations. To overcome problems in calculating ET0 without Rn data, a genetic algorithm model was used to calibrate recommended values (as and bs) of the FAO56 method, using meteorological data from Nanshaliang Meadow Steppe in the southeastern margin of Hunshandake. Rn and the corresponding ET0 for April to September and October to March were calculated and the pre-calibration solar radiation compared with that of post-calibration. The simulation accuracy of ET0 was analyzed using the estimated residual index method. From comparison of the result using recommended and calibrated values (as and bs), a consistent annual trend was noted for simulated Rn in areas without Rn data. Although Rn obtained from calibrated values was unstable with high fluctuations, the overall accuracy of ET0 improved. The analysis showed that large error immediately before and after precipitation events. Although precipitation factor is not directly included in the Penman-Monteith equation, it certainly influences local humidity and temperature. Apparent, both as and bs were affected by changes in humidity. There was therefore the need to further analyze these parameters in relation to humidity.
The existing methods of calculating reference crop evapotranspiration (ET0) from meteorological data need various climatic and physical parameters. Net radiation (Rn) is one essential parameter for ET0. However, professional measurement devices of Rn are seldom installed in agro-meteorological stations. To overcome problems in calculating ET0 without Rn data, a genetic algorithm model was used to calibrate recommended values (as and bs) of the FAO56 method, using meteorological data from Nanshaliang Meadow Steppe in the southeastern margin of Hunshandake. Rn and the corresponding ET0 for April to September and October to March were calculated and the pre-calibration solar radiation compared with that of post-calibration. The simulation accuracy of ET0 was analyzed using the estimated residual index method. From comparison of the result using recommended and calibrated values (as and bs), a consistent annual trend was noted for simulated Rn in areas without Rn data. Although Rn obtained from calibrated values was unstable with high fluctuations, the overall accuracy of ET0 improved. The analysis showed that large error immediately before and after precipitation events. Although precipitation factor is not directly included in the Penman-Monteith equation, it certainly influences local humidity and temperature. Apparent, both as and bs were affected by changes in humidity. There was therefore the need to further analyze these parameters in relation to humidity.
2014, 22(2): 246-252.
doi: 10.3724/SP.J.1011.2014.21031
Abstract:
There has been a rampant water shortage in the Wei River Basin in recent years, significantly affecting the ecological and economic functions of the river and drastically limiting the socio-economic development of the administrative regions within the basin. Although the respective local/national governments have adopted adjustment strategies of the water use structure, agriculture has remained the biggest water user, accounting for over half of total water use in the basin. Meanwhile, agricultural water use efficiency in the basin has been some 1 kg·m-3, much lower than that in developed countries like Israel and USA. The main reasons for the low agricultural water use efficiency have included low use of advanced technology (e.g., springklers, drop irrigation and mulching), low channel lining rates and high water contamination. In this study, we summarized the current state and trend in agricultural irrigation, calculated the agricultural water-saving potential and then developed a new mode based on current and future crop water requirement. The two main modules of the mode (resource-based water-saving and efficiency-based water-saving) were respectively representative of small-scale and large-scale water analysis. Based on main crops in typical irrigation areas, different water-saving schemes were designed and the water-saving potential of each scheme calculated. The probable water-saving amounts in the nine irrigation districts were analyzed and calculated for different hydrologic years. For instance, in years with water guarantee rates of 25%, 50%, 75% and 95%, agricultural water-saving potentials in Guanzhong Irrigation Area were respectively 30.69 million m3, 111.67 million m3, 117.50 million m3 and 125.21 million m3. Efficiency-based water-saving potential was over 50%, expect for the 25% rate water guarantee condition where it was 42%. Then based on present water-saving technology and planting structure characteristics of the nine irrigation areas, a water-saving mode was put forward which reduced water diversion by 10% and improved agricultural irrigation water use efficiency by 5%. Exploitation of agricultural water-saving potential was the basis for water resources reallocation in the region. This study also laid the base for theoretical and technical support for the development of water-saving irrigated agriculture, planning of water resources reallocation and construction of water-saving society.
There has been a rampant water shortage in the Wei River Basin in recent years, significantly affecting the ecological and economic functions of the river and drastically limiting the socio-economic development of the administrative regions within the basin. Although the respective local/national governments have adopted adjustment strategies of the water use structure, agriculture has remained the biggest water user, accounting for over half of total water use in the basin. Meanwhile, agricultural water use efficiency in the basin has been some 1 kg·m-3, much lower than that in developed countries like Israel and USA. The main reasons for the low agricultural water use efficiency have included low use of advanced technology (e.g., springklers, drop irrigation and mulching), low channel lining rates and high water contamination. In this study, we summarized the current state and trend in agricultural irrigation, calculated the agricultural water-saving potential and then developed a new mode based on current and future crop water requirement. The two main modules of the mode (resource-based water-saving and efficiency-based water-saving) were respectively representative of small-scale and large-scale water analysis. Based on main crops in typical irrigation areas, different water-saving schemes were designed and the water-saving potential of each scheme calculated. The probable water-saving amounts in the nine irrigation districts were analyzed and calculated for different hydrologic years. For instance, in years with water guarantee rates of 25%, 50%, 75% and 95%, agricultural water-saving potentials in Guanzhong Irrigation Area were respectively 30.69 million m3, 111.67 million m3, 117.50 million m3 and 125.21 million m3. Efficiency-based water-saving potential was over 50%, expect for the 25% rate water guarantee condition where it was 42%. Then based on present water-saving technology and planting structure characteristics of the nine irrigation areas, a water-saving mode was put forward which reduced water diversion by 10% and improved agricultural irrigation water use efficiency by 5%. Exploitation of agricultural water-saving potential was the basis for water resources reallocation in the region. This study also laid the base for theoretical and technical support for the development of water-saving irrigated agriculture, planning of water resources reallocation and construction of water-saving society.
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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