中国生态农业学报(中英文)

2009, 17(5): . doi: 10.3724/SP.J.1011.2009.00000

Abstract(1148) PDF(81)

Abstract:

Effect of Free Air CO₂ Enrichment (FACE) on phenolic acid metabolism

CAO Ji-Ling, ZHU Jian-Guo, MA Hong-Liang, ZHU Chun-Wu, YAN Jian, ZENG Qing, KOU Tai-Ji, XIE XU-Bin

2009, 17(5): 837-841. doi: 10.3724/SP.J.1011.2009.00837

Abstract(1751) PDF(1331)

Abstract:
Effect of elevated pCO₂ on phenolic acid metabolism in the leaves of winter wheat under low N (150 kg·hm^-2) and normal N (250 kg·hm^-2) levels was determined via FACE. The results show different impacts of elevated pCO₂ on the contents of salicylic acid, p-Hydroxybenzoic acid, cinamic acid, ferulic acid and vanillic acid, as well as phenylalnine ammonialyase (PAL) activity in winter wheat leaves under low N and normal N levels. At 1ow N level, salicylic acid, p-Hydroxybenzoic acid, cinamic acid, ferulic acid and vanillic acid are respectively significantly enhanced by 33.7%, 119.6%, 26.7%, 39.9% and 28.6% due to 30.9% increase in phenylalnine ammonialyase activity under elevated pCO₂. This, however, does not change significantly under normal N level. Hence the influence of elevated pCO₂ on phenolic acid metabolism in winter wheat leaf depends on N supply. It is highly important to determine appropriate fertilization rate in elevated CO₂ conditions. Furthermore, total phenol content shows the same variation trend as that of salicylic acid, p-Hydroxybenzoic acid, cinamic acid, ferulic acid and vanillic acid; and 79.6%~151.4% total phenol variation is caused by these acids changes. It then suggests that total phenol content increase in winter wheat leaf is partly accounted for enhanced phenolic acid metabolism under elevated pCO₂. Under low N level, the rise in atmospheric CO₂ may indirectly affect wheat-weed relationship by changing phenolic acid metabolism.

Effects of weed suppression by different allelopathic rice varieties under dry-raising condition

SUN Xiao-Xia, WANG Hai-Bin, LIN Hui-Feng, HE Hai-Bin, LU Jin-Chi, ZENG Cong-Ming, XIONG Jun, LIN Wen-Xiong

2009, 17(5): 842-846. doi: 10.3724/SP.J.1011.2009.00842

Abstract(2050) PDF(1407)

Abstract:
Under dry-raising condition in the paddy fields, an experiment was conducted to determine the differences in weed suppression ability between allelopathic rice “PI312777” and its counterpart “Lemont”. The results show much higher inhibitory effect of “PI312777” than “Lemont” seedlings on weeds under the 2 soil water conditions. The absolute value of weed suppression index for “PI312777” is more than 0.5, and the reverse is the case for “Lemont”. Further analysis suggests that dry stress increases weed suppression ability of the two rice varieties, and the degree of increase for allelopathic rice “PI312777” is higher than its counterpart “Lemont”. With regard to weed biomass, weed suppression effect of “PI312777” can be described as allelopathic inhibitory, which is enhanced by moderate dry stress. Rice has different obstruction ability for different weed species. Allelopathic rice “PI312777” has greater control ability for broadleaf weeds in summer rice fields, and for barnyard grass (Echinochloa crusgalli) under water deficiency stress.

Comparison of impacts of invasive weed, Ambrosia artemisiifolia, and native weed, Digitaria chinensis, on soil enzyme activity and fertility

LI Hui-Na, LIU Wan-Xue, WAN Fang-Hao, CAO Yuan-Yin

2009, 17(5): 847-850. doi: 10.3724/SP.J.1011.2009.00847

Abstract(1876) PDF(1424)

Abstract:
The soil enzyme activity and soil fertility in the invasive ragweed (Ambrosia artemisiifolia) and native weed (Digitaria chinensis) growing-plots were analyzed and compared by the same experimental garden methods. The results show that compared to non-vegetation and native-weed, the invasive ragweed significantly increases soil nutrient availability, especially, available K content in the invasive ragweed plots is 3.6 and 1.3 times of those in the non-vegetation and native weed plots, respectively. Compared to non-vegetation and native weed plots, the invasive ragweed plot has significantly higher activity of soil enzymes. In a conclusion, the invasive ragweed (A. artemisiifolia), has a more strong capacity to improve soil available fertility and activity of soil enzyme than the native weed (D. chinensis), which benefits its competition with native species.

Impact of invasion of exotic plant Alternanthera philoxeroides on interspecies association and stability of native plant community

GUO Lian-Jin, WANG Tao

2009, 17(5): 851-856. doi: 10.3724/SP.J.1011.2009.00851

Abstract(2067) PDF(1295)

Abstract:
Alternanthera philoxeroides is an exotic species in China affecting the biodiversity, composition, structure and stability of native communities. The interspecific association of 12 main species and stability of native plant communities invaded by A. philoxeroides were analyzed via variance ratio (VR), chi-square (χ²) correction test, Jaccard index and improved Godron M’s measure in Shangrao City. The study shows that the native communities non-invaded by A. philoxeroides exhibits positive associations on the whole. There are a number of species pairs with positive associations, and some positive associations are very significant. However, species pairs with negative association appear in native plant communities invaded by A. philoxeroides. The number of species pairs with positive associations reduces sharply compared with the un-invaded communities, and the community exhibits negative association on the whole. Competition among species increases in invaded native communities reducing the stability of certain disadvantaged species due to weak competitiveness. Based on the results of interspecific associations, all species with close relations in local communities invaded by A. philoxeroides disparts into two distinct ecological groups with certain interconnection. Invasion of A. philoxeroides decreases the stability of native community and the number of certain species gradually decreases or are even completely replaced. It is observed that rapid A. philoxeroides invasion induces significant negative effect on native species. Controlling measure and invasive mechanism of A. philoxeroides should be strengthened.

Effect of ecologically-based weed management strategies on weed community and diversity in hilly tea plantations

XIANG Zuo-Xiang, SHAN Wu-Xiong, HE Qiu-Hong, XIAO Run-Lin, XU Hua-Qin, CHEN Pei, CHENG Xiao

2009, 17(5): 857-861. doi: 10.3724/SP.J.1011.2009.00857

Abstract(1776) PDF(1316)

Abstract:
Ecologically controlling weeds does not only reduce consumption of soil water and nutrient, but also avoid or reduce application of chemical herbicides. Two ecologically-based weed management strategies based on pre-evaluation and competition of niche, straw mulching and white clover intercropping, were conducted in hilly tea plantations in 2005 and 2006, with clean tillage as the CK. Characteristics of weed community, including weed abundance, dominance, evenness, biomass and mean height were investigated via multi-sampling in small plot and the effects of two ecologically-based weed management strategies were compared with the clean tillage. About 16 families and 31 species of weeds are identified in the study. In April, the dominant weed species are those growing slowing with low biomass and lower than 30 cm. In July and September, the abundance (Pi) of malignant weed in CK respectively reaches 0.788 and 0.759, while that in straw mulching treatment is respectively 0.256 and 0.420, and a lower malignant weed occurrence frequency is found in white clover intercropping treatment with Pi<0.050. Weed richness, species diversity and evenness under straw mulching treatment are all higher than those under CK, though the dominant concentration index is lower than that of CK in spring, summer and autumn. Total number, biomass in spring, summer and autumn, and mean weed height in summer and autumn under white clover intercropping treatment are lower than those under the control. The two ecologically-based treatments have a favorable effect on weed control than the clean tillage. It therefore implies that white clover intercropping and straw mulching are effective ecological weed control measures.

Soil basal respiration response to grass vegetation restoration and its’affecting factors in the Loess Hilly-Gully Region

HUANG Yi-Mei, AN Shao-Shan, LIU Lian-Jie, XUE Hong

2009, 17(5): 862-869. doi: 10.3724/SP.J.1011.2009.00862

Abstract(1538) PDF(2138)

Abstract:
Soil respiration response to different stages of vegetation restoration was determined via closed system measurements of carbon dioxide and selected factors affecting the correctitude and sensitivity of soil respiration. Eight different soil samples under different vegetation restoration stages were separately collected at 0~20 cm and 20~40 cm soil depth in spring and summer and both fresh and air-dried samples analyzed. The results show that the period of vegetation restoration significantly influences soil basal respiration (SBR), which logarithmically increases with vegetation recovery time. Measurements of equivalent daily respiration (EDR) and cumulative respiration (CR) show that respirations in 73- and 78-year recovery sites are highest, while those in farmland and 3-year recovery sites are lowest. SBR is distinctly different for the spring and summer samples. SBR of spring samples better reflect soil basal microbial activity. Air-dried soils can be used for measuring SBR after pre-incubation, more stably reflecting difference among soils. 1 or 3-day EDR mean data can better reflect soil quality. CR more directly and clearly reflects microbial activities of different soil types than EDR. There is a positive correlation between SBR and soil organic carbon and nitrogen content.

Phosphorus accumulation characteristics and loss risk in vegetable garden soils of Shanxi Province

LI Ting-Liang, XIE Ying-He, TIAN Dong-Fang, HAN Xu, FENG Guo-Liang, LU Wei, JIA Lan, REN Miao-Miao

2009, 17(5): 870-873. doi: 10.3724/SP.J.1011.2009.00870

Abstract(1646) PDF(1281)

Abstract:
Risk of soil phosphorus loss was analyzed through phosphorus saturation degree (DPS), Mehlich3-P, Olsen-P and water-soluble phosphorus (Pw) accumulation to understand the status of soil phosphorus accumulation and loss as influenced by vegetable, soil type in different regions of Shanxi Province. Based on the results, total phosphorus, Pw, Olsen-P and Mehlich3-P of soil accumulate significantly, occurring in far greater amounts than crop need in Shanxi. Pw content increases with increased DPS, Olsen-P and Mehlich3-P content in surface garden soils. Furthermore, significant correlations (P<0.01) between Mehlich3-P and Olsen-P, Pw and Olsen-P, Pw and Mehlich3-P are found with respective correlation coefficients of 0.976 6, 0.923 2 and 0.962 0. Pw content increases rapidly when DPS is above 46.64%, Olsen-P above 81.88 mg·kg-1 and Mehlich3-P above 164.59 mg·kg-1. The critical loss indexes of the garden soils in Shanxi are therefore isolated as 46.64% for DPS, 81.88 mg·kg-1 for Olsen-P, 164.59 mg·kg-1 for Mehlich3-P and 8.05 mg·kg-1 for Pw. This study provides an important theoretical basis for phosphorus nutrient and environmental risk management of vegetable soils in Shanxi Province.

Seasonal dynamics of soil respiration and carbon budget of maize (Zea mays L.) farmland ecosystem

HAN Guang-Xuan, ZHOU Guang-Sheng, XU Zhen-Zhu

2009, 17(5): 874-879. doi: 10.3724/SP.J.1011.2009.00874

Abstract(1569) PDF(1460)

Abstract:
In this investigation, we continually measured the soil respiration in a maize farmland ecosystem from late April to late September 2005. Soil heterotrophic respiration is indirectly evaluated by established linear regression relations between soil respiration rates and dry root weights. Soil respiration fluctuates greatly during the growing season of 2005. The mean soil respiration rate is 3.16 μmol (CO₂)·m^-2·s^-1; with a maximum of 4.77 μmol (CO₂)·m^-2·s^-1 on July 28 and a minimum of 1.31 μmol (CO₂)·m^-2·s^-1 on May 4. The proportions of soil heterotrophic respiration to soil respiration are 45.5%, with a range of 36.4%~56.9%. Assuming that all sequestered C in the grains and straws is not removed from the fields by harvest, net carbon budget of the maize ecosystem is -1 127.0 g (C)·m^-2, with a range of carbon exchange rate of 0.52~ -18.05 g(C)·m^-2·d^-1. Maize ecosystems serve as a minor source of C in early grow stages of maize, and a C-sink from 36 days after planting lasting until harvest.

Distribution and relationship of soil nitrogen and flue-cured tobacco nicotine content in Enshi tobacco fields

XU Zi-Cheng, GUO Yan, SHAO Hui-Fang, BI Qing-Wen, WANG Jian, WANG Hai-Ming, LI Gen

2009, 17(5): 880-884. doi: 10.3724/SP.J.1011.2009.00880

Abstract(1583) PDF(1232)

Abstract:
Field survey and laboratory analysis were conducted to determine the distribution and relationship of soil nitrogen and flue-cured tobacco nicotine content in representative locations in Xuan’en and Xianfeng of Enshi tobacco cultivation areas. The results show a suitable total nitrogen content and a markedly higher available soil nitrogen content in Enshi tobacco cultivation areas. Based on soil nitrogen content, 129 soil samples are divided into three groups of high, medium and low nitrogen content via cluster analysis. Samples with low nitrogen content account for 60.47% of the 129 soil samples. Flue-cured tobacco nicotine content ranges from 8.18 g·kg^-1 to 42.25 g·kg^-1, with a mean and variation coefficient of 22.80 g·kg^-1 and 36.42% respectively. Samples with nicotine content in the range of 15 g·kg-1 to 35 g·kg^-1 account for 66.94% of the total. Significant differences exist in nicotine content of flue-cured tobacco from different cultivars, gradings and altitudes. Flue-cured tobacco nicotine content occurs in the following trend of “K326” > “Yunyan85” > “Yunyan87” for cultivars; B2F > C3F > X2F for grades; and low altitude > medium altitude > high altitude for altitudes. A regression relationship exists between flue-cured tobacco nicotine and soil nitrogen content. However, F-test shows that the relationship is insignificant at 5% confidence level.

Effect of different fertilization systems on soil phosphorus fertility and crop yield

YU Wan-Tai, JIANG Zi-Shao, MA Qiang, ZHOU Hua

2009, 17(5): 885-889. doi: 10.3724/SP.J.1011.2009.00885

Abstract(2644) PDF(1953)

Abstract:
The effect of different fertilization systems on crop yield and soil phosphorous fertility was investigated in an 18-year field experiment in aquic-brown soils. The results indicate that crop yield significantly increases while the yield fluctuation decreased in treatments with phosphorous fertilizer compared to the control. In treatments without phosphorous fertilizer, there is a deficit in P budget and total and available P content decreases significantly. A strong linear correlation exists between P budget and available P fluctuation in treatments without phosphorous. In treatments with phosphorous, total P content increases significantly (from 0.02 to 0.04 g·kg^-1), while available P content also increases significantly (especially in the latter stages of the trial). N fertilizer application significantly increases maize grain yield, while P and K fertilizers have insignificant effect on maize yield increase. Conversely, while mean soybean yield is unaffected by N fertilizer application, P and K fertilizers affect mean soybean yield significantly.

Physiological characteristics of grain filling in high quality winter wheat under different fertilizer application dose and plant density

LIU Jian-Hua, NIU Jun-Yi, YAN Zhi-Li

2009, 17(5): 890-894. doi: 10.3724/SP.J.1011.2009.00890

Abstract(1810) PDF(1211)

Abstract:
Multi-factor Randomized Complete Block Design was set up to study the effects of different fertilization and plant density on the characteristics of grain filling and flag leaf photosynthesis during filling stage of high quality winter wheat “Longjian301”. Variance analysis on the two factors of fertilizer application dose and plant density was conducted. The results indicate that fertilizer amount and plant density influence wheat grain filling process. Moderate fertilization and high plant density are most favorable to wheat grain filling. Grain yield of 4 188.09 kg·hm^-2 is highest under high fertilization and plant density. The level of fertilization and plant density influences photosynthetic parameters in winter wheat, with the degree of effect varying with parameter and treatment. High plant density and medium fertilization are conducive for improved leaf photosynthetic rate. On the other hand, high plant density and fertilization are conducive for improved leaf transpiration rate, while high level of fertilization is conducive for improved leaf stomatal conductance. The interactive effect of fertilizer dose and plant density on grain filling, yield and photosynthetic characteristics is significant and positive. Determination of appropriate degree of fertilization and plant density for improved grain yield production should be based on the characteristics of the variety of cultivated winter wheat.

Nitrogen fixation ability of azotobacter and its effect on growth of spring wheat

LU Bing-Lin, WANG Wen-Li, LI Juan, GUO Tian-Wen

2009, 17(5): 895-899. doi: 10.3724/SP.J.1011.2009.00895

Abstract(2107) PDF(1440)

Abstract:
In order to select high nitrogen-fixing azotobacter strains, nitrogenase activity of 13 strains separated in the rhizosphere in Gansu non-leguminous crop fields were measured by acetylene reduction method. Also the fertilization effect of the strains on spring wheat was investigated via pot experiment. The results show some degree of promotion effects of 13 azotobacter strains on spring wheat grain yield, biomass and the yield components. N6, N10, N13, N14, N27 and N42 strains presenting relative stronger promoting effects on spring wheat yield have application prospects as the bacteria strains of microbial fertilizer. N13 strain significantly increases spring wheat yield. The grain yield, biomass, panicle weight, panicle grain number, 1000-grain weight, plant height and panicle length with N13 respectively increase by 66.04%, 54.19%, 47.65%, 37.91%, 20.42%, 5.16% and 21.89% compared to the treatment with similar fertilizer amount. Its nitrogen-fixing amount in spring wheat soil is 212.55 mg per pot, and nitrogenase activity is significantly higher than other strains, reaching 139.79 nmol (C₂H₄)·h^-1·mL^-1.

Effect of humate compound fertilizer on physiological characteristics and yield of wheat under irrigated and rain-fed conditions

LIANG Tai-Bo, WANG Zhen-Lin, LIU Juan, CHEN Xiao-Guang, SHI Chun-Yu

2009, 17(5): 900-904. doi: 10.3724/SP.J.1011.2009.00900

Abstract(1628) PDF(1411)

Abstract:
The effects of humate compound fertilizer on physiological characteristics and yield of wheat were studied in an experiment under irrigated and rain-fed conditions. The results show that humate compound fertilizer significantly increases root fresh weight and vigor of wheat both in the 0~20 cm and 20~40 cm soil layers, promoting root growth in these layers. Humate compound fertilizer increases wheat flag leaf f PSⅡ and ETR at late filling stage, especially under rain-fed condition. Wheat flag leaf SOD activity increases while MDA content decreases under the application of humate compound fertilizer, resulting in increased active oxygen scavenging ability of wheat. Compared with inorganic fertilizer treatment, spike number and kernel number as well as wheat yield are increased by humate compound fertilizer application. Yield increases by 10.26% under rain-fed condition, which is higher than the 7.77% increase under irrigated condition. This indicates that the application of humate compound fertilizer under rain-fed condition leads to improvements in the physiological characteristics and yield of wheat.

Effect of supplemental irrigation on nitrogen translation and high-yield wheat yield in drylands

HUANG Ling-Feng, LIU Yi-Guo, LIN Qi, LI Jing-Tao

2009, 17(5): 905-908. doi: 10.3724/SP.J.1011.2009.00905

Abstract(1805) PDF(1314)

Abstract:
The effects of different supplemental irrigation schemes on nitrogen translation and high-yield wheat yield in the drylands of Qingdao were investigated via field experiments. The results reveal that increasing supplemental irrigation negatively influences grain protein content, while grain protein content is highest under CK (dry land treatment). Grain protein accumulation under CK is lower than those under treatments with only one or two irrigations, however, obviously higher than those with four or five irrigations. Appropriate supplemental irrigation enhances grain yield and nitrogen utilization efficiency, while nitrogen transfer rates and amounts reduce under excessive irrigation. There is an insignificant yield difference between W4 (a three-time irrigation treatment at wintering, jointing and filling stages) and W3 (a two-time irrigation treatment at jointing and filling stages). With increasing frequency and volume of irrigation, wheat yield, 1000-grain weight and per-spike grain decrease accordingly. Based on yield, water use efficiency and grain protein accumulation under W2 at 120 mm irrigation at jointing and filling stages are optimum.

Pattern of strip-planting under film mulching of millet-soybean and changes in photosynthesis and moisture

GUO Zhi-Li, SUN Chang-Qing, LU Cheng-Da

2009, 17(5): 909-913. doi: 10.3724/SP.J.1011.2009.00909

Abstract(1537) PDF(1332)

Abstract:
A new strip-planting pattern under plastic mulching of millet and soybean is developed by integration and optimization of alternate strip-planting technique of millet and soybean, spot-planting technique under film mulching of millet and strip-planting technique under film mulching of soybean. The new planting pattern is more advanced because not only photosynthesis, respiration and water utilization of millet and soybean are improved, but the yields are higher as well. Compared with the ordinary models of alternate strip-planting and monocropping millet, leaf photosynthetic rate (Pn) of millet in the new pattern increases by 19.2% and 32.4% respectively. Stomatal conductance of leaves (Cleaf) is higher by 6.3% and 42.2% respectively, while leaf transpiration rate (E) is similar to that in monocropping millet. For soybean, Pn under the new pattern is higher by 5.6% over that under ordinary alternate strip-planting; and by 56.1% over that under monocropping soybean. E increases by 3.1% and 46.1% respectively. Cleaf also increases by 31.3% and 148.9% respectively. Under the new pattern, water use efficiency (WUE) of millet and soybean are markedly enhanced, especially in millet where WUE exceeds 30% increment over the two old planting patterns. Total output is obviously higher than that in monocropping soybean, very close to that for monocropping millet. Yield increases by 17.7% compared with ordinary alternate strip-planting. Total economic benefit respectively increases by 1 413.75 yuan·hm^-2, 2 242.5 yuan·hm^-2 and 1 542.0 yuan·hm^-2 over monocropping millet and monocropping soybean, and alternate strip-planting system.

Influence of planting pattern with rainwater harvesting and row spacing on yield and water use efficiency of wheat

CUI Huan-Hu, WANG Juan-Ling, JING Hua, WANG Yu-Zhi, MA Ai-Ping, ZHANG Hong-Fang

2009, 17(5): 914-918. doi: 10.3724/SP.J.1011.2009.00914

Abstract(1751) PDF(1235)

Abstract:
In order to increase the use efficiency of natural precipitation resource, the effects of planting pattern with rainwater harvesting and row spacing on wheat yield and water use efficiency were analyzed in a random block design experiment in linfen, shanxi Province. The results show that average wheat yield of the planting patterns with 1︰1.5 and 1︰1 proportion of rainfall collection area to planted field area is significantly higher than that of open field cultivation (CK). When row spacings of 1︰1.5 and 1︰1 planting patterns, and open field cultivation are 11.3 cm, 15 cm and 15 cm respectively, yield increase is more significant. plant height, per-plant tiller number and per-plant green leaf number at the jointing stage under planting patterns of 1︰1.5 and 1︰1 are higher than that under open field cultivation. Water use efficiency in 1∶1.5, 1∶1 planting patterns and open field cultivation is 19.8 kg·mm^-1·hm^-2, 17.4 kg·mm^-1·hm^-2 and 14.3 kg·mm^-1·hm^-2 water for different planting patterns with rainwater harvesting at each growth stage are synchronously determined.

Effect of different machine-plucking on autumn tea yield and quality—A case study of the famous Bailumaojian hilly plantation tea

XIAO Run-Lin, WANG Jiu-Rong, TAN Zheng-Chu, SHAN Wu-Xiong, HE Qiu-Hong

2009, 17(5): 919-922. doi: 10.3724/SP.J.1011.2009.00919

Abstract(1805) PDF(1413)

Abstract:
Through a series of 4-year field experiment in hilly tea plantations, the effect of double machine-plucking, heavy machine-plucking, light machine-plucking and no machine-plucking on yield and quality of Bailumaojian tea was examined. The results show that: double and heavy machine-plucking increase bud density and one-leaf and one-bud (fold) yield in autumn. They also remarkably decrease bud weight, length and fitting ratio for processing of Bailumaojian tea. Among the 4 treatments, light machine- plucking has the largest one-leaf and one-bud (fold) yield fitting for processing famous Bailumaojian tea. Chemical analysis shows that leaves of four treatments are all fit for processing famous Bailumaojian tea, while those of no machine-plucking treatment have the best organoleptic quality. The study shows that proper machine-plucking increases yield of Bailumaojian tea in autumn, whereas no or light machine-plucking yields the best quality fresh tea leaf.

Effect of ecological factors on the quality of Ziziphus jujuba Mill. cv.“Dongzao” fruit

ZHANG Zhao-Bin, ZHAO Xue-Chang, SHI Zuo-An, LI Gong-Cun, LI Xian-Li

2009, 17(5): 923-928. doi: 10.3724/SP.J.1011.2009.00923

Abstract(2086) PDF(1816)

Abstract:
Relationships between main climatic factors, soil fertility and quality indexes of Ziziphus jujuba Mill. cv.“Dongzao” fruit in Boxing of Binzhou City and Xintai of Tai'an City were analyzed at different stages of fruit maturity. The results indicate that soil factors have stronger effect on soluble sugar and protein content of Z. jujube cv. “Dongzao” than climatic factors. Application of K and organic fertilizer remarkably enhances soluble sugar and protein content of Z. jujube cv. “Dongzao”. High rainfall, and P and N fertilizer application remarkably enhance titratable acid and free amino acid content, which is contrast to the effect of K fertilizer application. Vitamin C content is controlled by both climatic and soil factors. Available Cu is significantly correlated with vitamin C content. Fruit water content has positive correlation with soil texture and fertility. Excessive rainfall, and high Fe, P and Zn content in soil increase fruit shape index that make fruits long-globoid, which are otherwise ovoid in shape. Furthermore, application of Ca and Mg microelement fertilizer increases the contents of soluble sugar, Vc and soluble protein

Forms and accumulation of iron at rice root tip

ZHANG Yi, LIU Peng, SONG Jin-Min, XU Gen-Di, CAI Miao-Zhen, CUI Jie-Chen

2009, 17(5): 929-932. doi: 10.3724/SP.J.1011.2009.00929

Abstract(1926) PDF(1332)

Abstract:
To explore the forms and accumulation of iron at root tips in rice (Oryza sativa L.) under Fe2+ toxicity stress, iron-tolerant rice variety “9308” was germinated under laboratory conditions and the seedlings were treated with various Fe²⁺ concentrations (0~400 μmol·L^-1). The content and forms of iron at 0~10 mm root tips were measured via Flame Atomic Absorption Spectrometric and sequential extraction. Under 400 μmol·L^-1 Fe²⁺ stress, iron content in 0~2 mm root tip is highest, while that in root border cells increases with increasing Fe²⁺ concentration. The order of contents of various forms of iron in primary root is Fe-Mn oxide combined form > residual form > organometallic compound > exchangeable form> carbonate-bound form. This finding indicates that the 0~2 mm rice root tip is the main acting site of Fe²⁺ toxicity. Most of the irons are tightly bounded in the 0~10 mm root tip. This reduces iron phyto-availability, enabling root border cells to fix up excessive Fe²⁺.

Main diseases and control effects of organic, integrated and conventional cultivation patterns of greenhouse tomato

YANG He-Fa, FAN Ju-Fang, GE Zhi-Qi, SHEN Guang-Cheng, LU Run-Hai, LI Ji

2009, 17(5): 933-937. doi: 10.3724/SP.J.1011.2009.00933

Abstract(2451) PDF(1708)

Abstract:
A 3-year experiment was conducted under greenhouse conditions with different cultivation patterns (organic, integrated and conventional cultivation) to investigate the kind and epidemic characteristics of tomato main diseases. The results show that the main diseases of tomato under greenhouse are downy mildew, tomato leaf muld, early and late blight. Soil-borne and physiological diseases tend to increase due to low temperatures and high humidity in greenhouses. The incidence of downy mildew increases from year to year. Tomato main diseases under organic cultivation are less severe than those under other patterns in the same year. Control effect of early blight under organic cultivation respectively increases by 22.2%~57.1% and 36.4%~66.7% compared with integrated and conventional cultivation patterns. Those for downy mildew and late blight under organic cultivation respectively increase by 16.4%~54.9% and 37.7%~73.9%, 26.3%~44.3% and 47.5%~55.4% over integrated and conventional cultivation patterns.

Screening and cloning ligninolytic strain and cellulase gene expression

LIN Ling, LIN Zhi-Wei, GUO Wu-Nian, YANG Jing, WANG Shi-Hua

2009, 17(5): 938-943. doi: 10.3724/SP.J.1011.2009.00938

Abstract(1698) PDF(2051)

Abstract:
In order to effectively biodegrade lignin, lignin-degrading bacteria screening and fiber material treatment with cellulase were conducted. Eight strains producing positive reaction were selected by detecting the growth status and enzyme activity of 14 strains on the media with guaiacol, aniline and tannic acid. The strains were re-screened by using the ratio of Klason lignin degradation rate to holocellulose degradation rate (SF index) as indicator. In comparison to Phanerochaete chrysosporium RP78 and P. chrysosporium BKM-F-1767, strains Pleurotus ostreatus Po 10969 and Ganoderma applanatum WP1 were selected because their higher growth rate, enzyme secretion and degradation ability. Meanwhile, cellulase gene (egl2) was cloned, expressed and enzyme activity determined. Reducing-sugar produced by different treatments was determined by soaking the materials with crude enzymes solution. The results show that sugar-reduction ability of the materials is in the order of: Juncao Penniusetum sinese Roxb treated with NaClO_{2>Juncao P. sinese Roxb treated with Po10969>untreated Juncao P. sinese Roxb. Research on white rot fungus is significant for making full use of plant resources, safe degradation of pollutants and fuel ethanol exploration, as well as the sustainable development of eco-agriculture in China.}

Phenylaprapanoid metabolism of sweet potato against Pseudomonas solanacearum

WANG Wei, RUAN Miao-Hong, QIU Yong-Xiang, WANG Wei-Ying, KE Yu-Qin, PAN Ting-Guo

2009, 17(5): 944-948. doi: 10.3724/SP.J.1011.2009.00944

Abstract(1699) PDF(1297)

Abstract:
Pseudomonas solanacearum is a major diseases in sweet potato which leads to substantive yield loss and quality degradation. Changes in phenylaprapanoid metabolism were studied in resistant and susceptible cultivars of sweet potato seedlings after inoculation by leaf-cut. The results indicate that PAL and POD activities in resistant and susceptible cultivars increase after inoculation. However, the rates of increase in PAL and POD activities are directly related with cultivar resistance to pathogens. Lignin and chlorogenic acid contents increase significantly after inoculation of resistant cultivars. Though chlorogenic acid, total phenolics and flavonoids contents largely fluctuate after inoculation, and lignin content decreases in susceptible cultivars. The relative analysis shows that the accumulation of lignin and chlorogenic acid has close correlation with cultivar resistance. Rapidly increase in PAL and POD activity and in the accumulation of lignin and chlorogenic acid after inoculation is the basis for phenylaprapanoid metabolism against P. solanacearum in sweet potato. This can find application in referencing resistant cultivar identification.

Early reactions of Arabidopsis thaliana to phenanthrene polycyclic aromatic hydrocarbon stress

LIU Hong, CUI Bo, YEI Yuan-Bei, TANG Ling, WANG Zong-Hua

2009, 17(5): 949-953. doi: 10.3724/SP.J.1011.2009.00949

Abstract(1846) PDF(1433)

Abstract:
In order to determine early reactions of A. thaliana to polycyclic aromatic hydrocarbon phenanthrene stress, early responses of antioxidases and membrane protection system of A. thaliana were analyzed. Then differential expressions of related genes in mRNA level under phenanthrene stress were determined via Real-Time PCR. The results show higher superoxide dismutase (SOD) and peroxidase (POD) activities compared with non-treated control samples when A. thaliana seedlings are exposed to phenanthrene for 12 h. This may indicate that the plants are activated inand H2O2. Excess H2O2 begins to precipitate when A. thaliana is exposed to phenanthrene for 72 h, but the membrane system shows no obvious injury from lipid peroxidation. While phenanthrene stress prolongs, A. thaliana photosynthesis is completely inhibited, which is indicated by at gene transcriptional level and/or at cellular level. The findings suggest that oxidative stress reaction is an important early response to polycyclic aromatic hydrocarbons (PAHs) stress in plants.

Dissipation and leaching of oxytetracycline and tylosin in typical agricultural fields

PU Jin-Cheng, ZHANG Ming-Kui

2009, 17(5): 954-959. doi: 10.3724/SP.J.1011.2009.00954

Abstract(1919) PDF(1615)

Abstract:
Antibiotics used in livestock production may be present in manure and slurry as parent compounds and/or metabolites. And environments may therefore be exposed to these antibiotics due to the application of animal manure in agricultural lands. In order to understand the environmental fate of two typical antibiotic compounds tylosin (C₄₆H₇₇NO₁₇) and oxytetracycline (C₂₂H₂₄N₂O₉HCl) in agricultural fields, liquid pig slurry was fortified with the antibiotics and then applied on field plots. The leaching, dissipation and surface runoff under field conditions were investigated. The results show that both degradation and leaching behaviors of the antibiotics are related with antibiotic kind and soil property. Vertical migration of the antibiotics is greater in sandy soils than in clay-loam soils. Transfer capacity of tylosin in soils is greater than that of oxytetracycline. Dissipation rate of antibiotics in surface layers is greater in sandy soils than in clay-loam soils at the initial stage, but eventually becomes similar for both soil types. Degradation rate of oxytetracycline in surface soils of both soil types is greater than that of tylosin. It is observed that degradation rates of the antibiotics measured under field conditions are much smaller than those measured under laboratory conditions. This suggests that antibiotics become stable as they enter into the deeper soil layer. Runoff losses of antibiotics mainly occur at the initial stage of manure application. Concentrations of the antibiotics in runoff are greater in sandy soils than in clay-loam soils. Tylosin poses a greater risk of ground surface water contamination.

Indication and response of soil microbe to acetochlor

GUO Xing-Hua, QIAO Yu-Hui, ZHAO Jing, SUN Zhen-Jun

2009, 17(5): 960-963. doi: 10.3724/SP.J.1011.2009.00960

Abstract(1740) PDF(1369)

Abstract:
An experiment was conducted to determine the effect of acetochlor (a soil pollutant) on soil microbe and soil microbial biomass carbon. Then the potential of soil microbe and microbial biomass carbon as indicators for acetochlor pollution in soil was analyzed. The results show that soil microbe is inhibited by short-term acetochlor application, but it recovers over the long-run due to the acetochlor degradaton. During inhibition, the number of bacteria, actinomycete and microbial biomass carbon content exhibit negative linear correlation with the log of acetochlor concentration. On the 7th day, the correlation between the log of acetochlor concentration and bacteria and actinomycete are expressed in the respective equations as y = -2.97x + 12.36, R² = 0.999 3; and y = -2.13x + 6.67, R² = 0.956 4. For microbial biomass carbon, the correlation equation on 14th day is y = -89.25x + 348.90, R² = 0.995 4; which are all significant. However, the effect of acetochlor on fungi is insignificant and hardly noticeable. Hence soil bacteria, actinomycete number and microbial biomass carbon content can be as good indicators for soil pollution by acetochlor in the short-run.

Physiological response of warm-season turf-grass to high temperature stress

HUANG Jin-Wen, CHEN Dong-Mei, ZHENG Hong-Yan, LUO Juan, LIN Zheng-Chun, LIN Wen-Xion

2009, 17(5): 964-967. doi: 10.3724/SP.J.1011.2009.00964

Abstract(2263) PDF(1624)

Abstract:
An experiment was conducted to determine physiological responses of Zoysia matrella and Z. japonica to high temperature stress. The results show that the contents of soluble sugar and protein, proline, ABA, GA3, IAA and MDA increase in two tested turf-grass species, along with increased SOD, POD and CAT activity under high temperature stress. High temperature stress treatment decreases chlorophyll a (Chla), chlorophyll b (Chlb) and carotenoid (Car) content, and it concurrently induces changes in leaf Chla/Chlb ratio in the two turf-grass species. The contents of the osmotic adjustment substances, ABA, GA3 and IAA are higher in Z. matrella than in Z. japonica. The same is true for SOD and CAT activity in the two turf-grass species when exposed to high temperature treatment. Hence Z. matrella exhibits better heat resistance than Z. japonica under high temperature conditions.

Effect of waterlogging on growth and agronomic trait of different peanut varieties

LIU Deng-Wang, LI Lin, ZOU Dong-Sheng, LIU Fei

2009, 17(5): 968-973. doi: 10.3724/SP.J.1011.y2009.00968

Abstract(1793) PDF(1666)

Abstract:
The growth and agronomic traits of 18 peanut varieties under waterlogging during late vegetative to flowering stage was analyzed. Based on the results, waterlogging decreases plant height, and the number of branches, total pods and full pods. Waterlogging, however promotes pod growth and the ratio of seeds that develop into full pods. Cluster analysis based on agronomic traits is somehow integrated with yield classification after waterlogging (with the 18 varieties classified into 6 types). Some difference exists in waterlogging sensitive varieties, e.g. they do not synchronously change in number and weight of pod and seed. However, the most tolerant varieties (HT type) selectively bred under waterlogging are dwarfed with synchronously increasing number and weight of pod and seed, and promoved ratio of full pod number and ratio of full pod weight. The findings illustrate that waterlogging tolerant eco-breeding is effective. Because more water is demanded in the late vegetative to flowering stage, the impact of waterlogging is limited and even promotes pod and seed development for most waterlogging tolerant varieties so long there is water flow and peanut plants not completely submerged. Therefore, peanut flood impact assessment should focus on flood intensity, growth and development period, and variety tolerance.

Effect of Chinese herbal additive on growth performance and tissue melanin content in Taihe silky fowls

LI Guan-Hong, PAN Ke, QU Ming-Ren, YOU Jin-Ming, YI Zhong-Hua

2009, 17(5): 974-979. doi: 10.3724/SP.J.1011.2009.00974

Abstract(1632) PDF(1210)

Abstract:
The effects of three different Chinese herbal additives on growth performance and content of melanin in tissues of Taihe silky fowls were evaluated to determine the feasibility of improving medicinal values of the fowls. Birds were fed basal diet (control group), basal diet supplemented with 1% Chinese herbal additive Ⅰ with Sesamum indicum L. as main ingredient (treatment group Ⅰ), 1% Chinese herbal additive Ⅱ with Polygonum multiflorum Thunb as main ingredient (treatment group Ⅱ) and 1% Chinese herbal additive Ⅲ with Crinis carbonisatus as main ingredient (treatment groupⅢ), respectively. Results show no significant differences in average daily gain, daily feed intake, and feed to gain ratio (P>0.05) of Taihe silky fowls aged 0~12 weeks among the 4 treatment groups. With the exception of groupⅢ, mortality rate in Chinese herbal additive groups generally tends to decline in comparison with the control group, and diarrhea frequency in all Chinese herbal additive treatment groups is lower than that in the control. The Chinese herbal additive treatment groups have higher melanin content in pectoral muscle, leg muscle and skin than the control as the Taihe silky fowl is 4 weeks old. At 8 and 12 weeks old, content of melanin in Chinese herbal additive treatment groups is generally higher than in the control. However, skin melanin content is slightly lower in treatment group Ⅱ than in the control at 8 weeks old, and at 12 weeks old treatment groups Ⅰ and Ⅱ have lower melanin content in leg muscle than control group does. Three different Chinese herbal additive supplements at 1% total diet do not affect growth performance in general, but increase (by different degrees) tissue melanin content of Taihe silky fowls.

Effect of wall height on air temperature of greenhouse during night

WEN Xiang-Zhen, LIANG Hai-Yan, LI Ya-Ling, GUO Rui-Feng

2009, 17(5): 980-983. doi: 10.3724/SP.J.1011.2009.00980

Abstract(1897) PDF(1606)

Abstract:
The temperature inside model greenhouses with the wall height of 1.26 m, 0.96 m, 0.66 m, 0.36 m was investigated, and some measures were adopted to reduce or exclude the effects of thermal storage of soil and air, in order to study the effects of wall height on night temperature in solar greenhouse. The results show that there is a significant effect of wall height on the night temperature of the greenhouse. The average temperature during night is increased as the wall height increasing. And the relative changing rate of night temperature indicates that the higher the wall, the lower the decreasing rate of night temperature of greenhouse. The night air temperature in the greenhouse with the wall height of 1.26 m is 1.2~1.8 ℃ higher than that with the wall height of 0.36 m. In addition, the average temperature of the greenhouses during night increases about 0.5 ℃ with increasing the ratio of wall surface area to total transparent surface area by 0.1, which suggests that increasing wall height reduces the speed of temperature decreasing and improves the property of heat preservation of the greenhouse.

Long-term quantitative simulation and evaluation of potential productivity of winter wheat in Mengjin, Luoyang

JIANG Zhi-Wei, WU Xue-Ping, HUA Luo, CAI Dian-Xiong, PANG Huan-Cheng, WU Hui-Jun, JIANG Tao, ZHENG Yan, LI Yin-Kun

2009, 17(5): 984-991. doi: 10.3724/SP.J.1011.2009.00984

Abstract(1764) PDF(1506)

Abstract:
DSSAT crop growth model was used to estimate potential productivity of photo-temperature and photo-temperature-precipitation of winter wheat using weather, soil, crop variety and field trial data in Mengjin, Luoyang. Potential productivity development status as well as the developmental measures of winter wheat was analyzed. From the study, the range of photo- temperature productivity of winter wheat is 7 571~10 965 kg·hm^-2 with a mean of 9 209 kg·hm^-2. This can serve as reference value for maximum yield in irrigated fields. The range of photo-temperature-precipitation productivity is 3 957~7 450 kg·hm^-2 with a mean of 5 510 kg·hm^-2. This accounts for 59.8% photo-temperature productivity, and can serve as reference value for maximum yield in rainfed fields. The average precipitation is 226.29 mm during the development stage of winter wheat, which is less than half of crop water requirement. Average water deficit is 72.5% of the precipitation at winter wheat development stage with an average water content ratio of 66.4%. This indicates that water deficit during growth is the primary obstacle to winter wheat development in Mengjin. As soil type and annual rainfall are different in the region, potential range of water use efficiency changes significantly —12.06~22.94 kg·hm^-2·mm^-1, with a mean of 16.94 kg·hm^-2·mm^-1 for the soil types and 46-year period. In the past eight years, the actual water use efficiency of winter wheat only accounts for 58.5% potential water use efficiency, while the exploitation degree of potential photo-temperature-precipitation productivity is 60.5%. The study shows that winter wheat has a very high water-saving potential in Mengjin. In order to enhance future winter wheat production, it is quite essential that reasonable agricultural water-saving measures are taken and water use efficiency are augmented by increasing use efficiency of precipitation and improving field conditions that enhances soil water storage capacity.

Effect of cropping approach and harvest time on yield and sugar content of sugarcane

SUN Li-Ya, Masami UENO, Masateru NAGATA

2009, 17(5): 992-996. doi: 10.3724/SP.J.1011.2009.0992

Abstract(1581) PDF(1403)

Abstract:
The effects of cropping approaches, including new-planting sugarcane (in summer and spring ) and ratoon sugarcane, and harvest time, on the yield, quality, and generated income of sugarcane were analyzed using 33-year data collected in Japan from 1975 to 2008. The study shows that the order of the cropping approaches in relation to yield is: summer new-planting sugarcane > ratoon sugarcane > spring new-planting sugarcane. The earlier the planting time of new-planting sugarcanes, the higher the yield is. A quadratic functional relationship exists between yield and first crop harvest time of ratoon sugarcane, meaning that early or too late harvest of the first crop does not favor ratoon sugarcane growth. The more the ratoon times, the lower the yield of ratoon sugarcane is. While sugar content of ratoon sugarcane is usually higher than that of new-planting sugarcane, sugar content generally increases with delayed harvest provided that the harvest time is earlier than late March. Based on the above quantitative findings, mathematical prediction models for the yield and sugar content of sugarcane are established taking into account of cropping approach features. Such models are of great significance for China’s sugarcane industry.

Field crop water-yield models and their applications

ZHANG Heng-Jia

2009, 17(5): 997-1001. doi: 10.3724/SP.J.1011.2009.0997

Abstract(1775) PDF(1496)

Abstract:
In this paper, crop water-production functions, namely crop water-yield models, of wheat, maize and cotton were analyzed and intrinsic relations among the different models advanced. Models of water-production function of different crops were fitted based on least-square theory using field experimental data from various irrigation regions, with quadratic model used for the whole growth period and Jensen model for growth stages. Water sensitivity index resulting from the fitting shows a low-high-low trend during the growth period. The results could provide agricultural irrigation practice with vital reliable academic hits to optimize irrigation systems in water deficient regions.

Urban eco-agriculture model and countermeasures for Shanghai metropolis

YU Ju-Sheng, WU Yi-Yun, LUO Qiang

2009, 17(5): 1002-1006. doi: 10.3724/SP.J.1011.2009.01002

Abstract(1966) PDF(1521)

Abstract:
This survey sums up the status-quo of eco-agriculture in Shanghai metropolis using questionnaire and statistical techniques. It proposes six eco-agriculture modes for Shanghai as follows: facility-ecological technology mode, intensive-ecological technology mode, technicalization-ecological technology mode, market-ecological technology mode, industrialization-ecological technology mode and tourism-ecological technology mode. What is more is that the survey identifies the problems in the course of urban eco-agriculture development, and analyzes and reviews the different practiced modes of eco-agriculture in Shanghai. Based on the above, the survey proposes several measures for the development of urban eco-agriculture in Shanghai.

Integrative technology of straw-edible fungi industry and management countermeasure for resource recycling utilization

WENG Bo-Qi, LIAO Jian-Hua, LUO Tao, HUANG Qin-Lou, LEI Jin-Gui, JIANG Zhi-He, CHEN Jun-Chen, WANG Huang-Ping

2009, 17(5): 1007-1011. doi: 10.3724/SP.J.1011.2009.01007

Abstract(1903) PDF(1435)

Abstract:
This article discusses the practical production techniques of rural edible fungi, explores the main technical links and optimized structure of crop straw-edible fungi industry with detailed descriptions of a series of technical measures. On the base of the efficient links and optimized key techniques including straw fermentation through composting, high-yield cultivation technique of Agaricus bisporus, fungi residues recycling utilization technique and environmental monitoring, a new mode of action is established, which is: straw → edible f?ungi → fungi residues → farmland (garden) recycle → resource reuse. Consequently, efficient promotion and prospect of crop straw-edible fungi industry are envisaged.

Analysis of forest reservation modes and development countermeasures

FENG Chang-Hong, HE Kang-Ning, BAI Shi-Hong, LIAN Shi-Qi, ZHANG Xiao-Guang

2009, 17(5): 1012-1016. doi: 10.3724/SP.J.1011.2009.01012

Abstract(1797) PDF(1308)

Abstract:
Forest reservation in mountain areas is an effective and economic way of restoring vegetation and rapid formation of stable community. In Hebei Province environmental construction, full use was made of self-rejuvenating capability of natural environments. This, in combination with artificial measures, results in speedy establishment of high quality forests and improvement of ecological industries of mountain areas. This paper summarizes the successful patterns of forest reservation in Hebei Province. Patterns such as mountain closure, combined aerial planting and mountain closure, combined forest culture and mountain closure, combined existing forest transformation and mountain closure and combined natural forest protection and mountain closure accelerate forest reservation in the province. The benefits and demerits of forest reservation are discussed and countermeasures such as increased investment and policy performance suggested.

Evaluation of land use sustainability in Qinghai Lake area

YU Wen-Zheng, QU Fu-Tian, QI Ying-Xiang, YU Guo-Feng, SHI Jun

2009, 17(5): 1017-1022. doi: 10.3724/SP.J.1011.2009.01017

Abstract(1743) PDF(1271)

Abstract:
Following the principle of practice and syntax, a variety of methods based on the complexity, mechanism and unitarity of ecology, society and economy was used to evaluate sustainable land use in Qinghai Lake area. The evaluation took into account of the land productivity, protective value, stability, economic vitality, and acceptability and security of society. From the view of land productivity, Qinghai Lake area is in start-up phase of sustainable land use with spatial variances among different regions. For the land protective value, developmental stages of sustainable land use evaluated according to different indexes are different. For stability, land use is in the initial stage of sustainability and crop farming stability is lower than that for livestock. Economic vitality of land use in the region is low, indicating unsustainable habitus. Sustainable use of land with regard to acceptability of society is in the start-up phase, while that relating to security is simply non-sustainable. More importantly, this study advances corresponding strategies and countermeasures for sustainable use of land in Qinghai Lake area. It lays further scientific basis for efficient management strategies and methods of sustainable development and utilization of land and related policy-making supports for new countryside construction in minority areas (e.g. pastoral areas).

Eco-economic regionalization of the Loess Plateau

ZHANG Qing-Feng, WU Fa-Qi

2009, 17(5): 1023-1028. doi: 10.3724/SP.J.1011.2009.01023

Abstract(1884) PDF(1518)

Abstract:
This paper discussed the significance of eco-economic regionalization of the Loess Plateau as reported in existing literature. 22 indexes of natural ecological and socio-economic systems were covered, and administrative counties (districts) were considered as complete individual taxons. The Loess Plateau was devided into 4 eco-economic belts — southern warm-temperate semi- humid agroforestry (Ⅰ); central warm-temperate, semi-humid and semi-arid agroforestry & animal husbandry (Ⅱ); northwestern temperate semi-arid agro-stockbreeding (Ⅲ); and northern temperate arid and semi-arid agro-stockbreeding (Ⅳ) eco-economic bands via principal component analysis (PCA) and cluster analysis (CA) on GIS platform. These belts were further divided into 18 eco-economic regions. The discussion emphasizes regionalization and methodological framework for large areas like the Loess Plateau region. Such practice could be specialized supplement in developing appropriate regional eco-economic theory.

Advances in functional gene diversity of microorganism in relation to soil nitrogen cycling

ZHANG Jing, LIN Xian-Gui, YIN Rui

2009, 17(5): 1029-1034. doi: 10.3724/SP.J.1011.2009.01029

Abstract(4385) PDF(7726)

Abstract:
Soil nitrogen cycling is an important part of biogeochemical cycling. Not only does it influence soil productivity and durative development, but also influences global environmental changes. Terrestrial microorganisms play a vital role in soil nitrogen cycling. They participate in important ecological processes such as nitrogen fixation, ammonification, nitrification and denitrification. With the development of molecular biological technology in recent decades, it is possible to study microbial functional community composition, structure and abundance in relation to soil nitrogen cycling from the point of functional gene. In this paper, advances in functional gene diversity in relation to soil nitrogen cycling are reviewed and future areas of improvement identified.

Response of respiration during seed germination to environment

LIU Shuang-Ping, ZHOU Qing

2009, 17(5): 1035-1038. doi: 10.3724/SP.J.1011.2009.01035

Abstract(1928) PDF(2982)

Abstract:
Respiration is necessary for catabolism of storage materials and energy supply in seed germination. It directly affects seed vitality, and furthermore, influences growth after germination. In order to understand the response of respiration metabolism to changes in external and internal environment during seed germination, the paper summarizes recent research findings on cyanide resistant respiration, enzymes, membrane system and hormones, use of material storage, germination activity, genetic protection, etc., and their relation to environmental factors of drought, heat-stress, cold-bite, salinity, UV, heavy metal, organic pollutant and pesticide. The response mechanism of respiration metabolism to post-germination external environment, the influence of external environment on respiration as well as the influence of respiration on seed germination are summarized. Finally, mainstream research, development and direction are proposed. It is pointed out that 5 aspects of this filed of study should be strengthened.

Research progress on soil moisture measurement via ground-penetrating radar

ZHU An-Ning, JI Li-Qing, ZHANG Jia-Bao, XIN Xiu-Li, LIU Jian-Li

2009, 17(5): 1039-1044. doi: 10.3724/SP.J.1011.2009.01039

Abstract(1992) PDF(2455)

Abstract:
Rapidly, accurate and non-destructive determination of the spatial and temporal distribution of soil moisture in farmlands and small-scaled basins is of immense importance in soil science, agronomy, ecological environmental studies and other related fields. As a new geophysical prospecting method, Ground-Penetrating Radar (GPR) is widely used in field studies. This paper analyzes the GPR application in soil moisture monitoring, focuses on the principle and approach of GPR soil water measurement, summarizes the progress of research in this field both at home and abroad, introduces common relationship between soil dielectric constant and soil water content, evaluates various GPR applications methods in farmlands, and advances problems and prospects of GPR with the view of providing a relevant scientific reference source.

A literature review on evaluation of agricultural ecosystem services

YANG Zheng-Yong, YANG Huai-Yu, GUO Zong-Xiang

2009, 17(5): 1045-1050. doi: 10.3724/SP.J.1011.2009.01045

Abstract(2135) PDF(2732)

Abstract:
Agricultural ecosystem services play a key role in the sustainable development of mankind. However, certain values of the services are too often neglected as they are not directly reflected in market transactions. It is therefore important to evaluate these services. The characteristics of previous studies in this field were analyzed from the points of view of research method, content, scale and supporting disciplines. The basic problems of domestic studies were probed into from the context of ecological ecosystem completeness, study perspective, and research method perfection and fullness of content. On this basis, it is pointed out that much important progress has been made in the field of forest and grassland ecosystem and evaluation method. Some breakthroughs are also made in the field of agricultural ecosystem evaluation. However, the values of crop and fishery ecosystem services and non-market evaluation methods of ecosystem services require further studies. The values of forest and grassland ecosystems also need further exploration from the perspectives of value composition and temporal and spacial variation.

Effect of La(Ⅲ) on energy metabolism in germinating soybean seeds under acid rain stress

YU Hui, WANG Hui, ZHOU Qing

2009, 17(5): 1051-1053. doi: 10.3724/SP.J.1011.2009.01051

Abstract(2010) PDF(1573)

Abstract:

2009 Vol. 17, No. 5