中国生态农业学报(中英文)

Migration and transformation of fertilizer nitrogen in a simulated black soil column

ZHANG Chao, CHE Yu-Ping, LI Zhong-Pei

2010, 18(4): 683-688. doi: 10.3724/SP.J.1011.2010.00683

Abstract(1607) PDF(1541)

Abstract:
Urea and ammonium sulfate fertilizer applied with three times application rate of conventional fertilization were used to simulate the migration and transformation characteristics of fertilizer nitrogen with simulated black soil columns. The results show that N migration and transformation vary with fertilizer type. NH₄⁺-N or NO₃^--N concentration is not significantly different across different soil layers under CK (zero fertilization). Whereas NH₄⁺-N and NO₃^--N respectively increase by 100.8~3 408.1 mg·kg^-1 and 113.4~388.0 mg·kg^-1 under urea treatment, 126.7~4 671.1 mg·kg^-1 and 51.4~63.3 mg·kg^-1 under ammonium treatment compared with CK for the 0~50 mm surface layer. The concentration changes most significantly in the first 14 days after fertilization. Under ammonium sulfate treatment, the average contents of NH₄⁺-N and NO₃^--N in different soil layers are respectively 2.54~1 423.7 mg·kg^-1 higher and 4.38~335.1 mg·kg^-1 lower than under urea treatment. Nitrification rate of urea in different soil layers for the whole incubation period is 0.79~9.12 times that for ammonium sulfate. This suggests that migration and transformation of nitrogen mainly occur in the 0~50 mm soil layer, and that nitrogen transformation rate of urea is higher than that of ammonium sulfate.

Vertical distribution and storage of soil organic carbon under long-term fertilization

HU Cheng, QIAO Yan, LI Shuang-Lai, CHEN Yun-Feng, LIU Guo-Ji

2010, 18(4): 689-692. doi: 10.3724/SP.J.1011.2010.00689

Abstract(2173) PDF(1503)

Abstract:
To determine the effect of different fertilization schemes on soil organic carbon content and storage, long-term fertilization experiment were carried out in Nanhu Experimental Station, Hubei Academy of Agricultural Sciences. With the exception of single application of nitrogen or manure, soil organic carbon content and storage in the 0~20 cm soil layer increase under fertilization compared to the control. Soil organic carbon content and storage in the 0~20 cm and 0~100 cm soil layers increase under combined application of chemical fertilizer and manure compared to the control and single application of chemical fertilizer or manure. Soil organic carbon content is less affected and storage is lower with single chemical fertilizer or single manure application in all the soil layers. However, soil organic carbon content and storage in the 0~20 cm and 20~40 cm soil layers are higher under combined application of chemical fertilizer and manure. Except for the control and combined application of chemical fertilizer and excessive manure, significant positive correlations (P<0.05) are noted between soil total nitrogen and organic carbon content under other fertilization schemes. In conclusion, combined applications of chemical fertilizer and manure should be advocated to enhance agricultural soil organic carbon storage.

Effect of cultivation pattern and nitrogen application rate on soil fertility and nitrate accumulation under maize-wheat rotation system

ZHANG Hong, ZHOU Jian-Bin, WANG Chun-Yang, DONG Fang, LI Feng-Juan

2010, 18(4): 693-697. doi: 10.3724/SP.J.1011.2010.00693

Abstract(1657) PDF(1139)

Abstract:
A field experiment was conducted in Guanzhong of Shaanxi Province to study the effects of long-term cultivation patters and fertilization on organic matter, total soil nitrogen, and the quantity and distribution of nitrate N in soil profile under maize-wheat rotation system. The results indicate that the order of effect of the different cultivation patterns on soil organic matter and total nitrogen contents is: straw mulching > furrow planting > conventional cultivation > water-saving cultivation. Straw mulching has the most significant effect on soil organic matter and total nitrogen contents. Nitrogen application significantly influences soil organic matter and total nitrogen. After 6 years of maize-wheat rotation cropping, the order of residual nitrate N in the 0~200 cm soil profile under different cultivation patterns is: furrow planting > water-saving cultivation > straw mulching > conventional cultivation. There are significant differences in nitrate N accumulation among furrow planting, water-saving cultivation and the conventional cultivation. Nitrate N accumulation in the 0~200 cm soil profile increases with longer cultivation periods and increasing nitrogen application rates. Accumulated nitrate N under 240 kg(N)·hm^{-2 (N240) treatment is significantly higher than that under 120 kg(N)·hm^{-2 (N120) treatment. The pattern of nitrate N distribution across the soil profiles differs with differing nitrogen application rate. Under N240 treatment, nitrate N content below the 120 cm soil depth increases with soil depth.}}

Effect of fertilization in immature loess subsoil on productivity and rhizospheric soil nutrient and biological activity of cereal crops

YANG Zhen-Ping, BAI Zhi-Ming, ZHANG Xiang-Yu, MIAO Guo-Yuan

2010, 18(4): 698-705. doi: 10.3724/SP.J.1011.2010.00698

Abstract(1798) PDF(1287)

Abstract:
An experiment was conducted to study the effect of immature loess subsoil fertilization in current year on productivity and rhizospheric soil nutrient and biological activity of cereal crops. The results show that fertilization promotes crop root growth and productivity. A strong root-soil system in turn promotes the multiplication of microbes, enzyme activity, and increases soil nutrient. Aging of immature loess subsoil should adopt measures of both utility and maintenance, with emphasis on soil biological conditions. The study indicates that sorghum and maize could be planted as the pioneer crops to improve immature subsoil conditions. Sorghum owns strong and deep root system, and great biomass. Although the root weight, maximum root length, and number of adventitious root are not as high as those of sorghum, microbe amount and enzyme activity in rhizospheric soil of maize are high enough. Compared with sorghum and maize, broomcorn is not suitable for the improvement of immature subsoil due to its weak root system and low biological activity in rhizospheric soil. Immature losses subsoil is sensitive to fertilization. Since fertilization of immature loess subsoil is achievable with high annual yields, it serves as a significant aging factor of immature subsoil. Aging of immature loess subsoil is both an input and transformation process of matter and energy among plants, soils, microorganisms, including fertilization, crop production, resolving and mineralization of soil microbes, and catalysis of soil enzymes.

Effect of the number of years of vegetable cultivation on soil phosphorus sorption-desorption characteristics

GAO Xiu-Mei, WANG Ji-Dong, ZHANG Yong-Chun, ZHAO Geng-Mao, LIU Zhao-Pu, XU Xian-Ju, NING Yun-Wang, HU Yong-Hong

2010, 18(4): 706-710. doi: 10.3724/SP.J.1011.2010.00706

Abstract(1675) PDF(1396)

Abstract:
An experiment involving 3~5, 15~20 and 25~30 years continuous vegetable cultivation was carried out to determine fixation and release mechanisms of soil phosphorus in cultivated yellow brown soils. Based on the results, phosphorus isothermal adsorption and adsorption-desorption curves are respectively described by Langmuir equation and quadratic equation. With increasing years of cultivation, the maximum phosphorus adsorption (Q_m) and maximum buffer capacity (MBC) of surface soil decrease significantly. However, degree of phosphorus saturation (DPS) and phosphorus desorption rate increase. Phosphorus desorption rates in 15~20- and 25~30-year cultivated vegetable soils are significantly higher than that in the 3~5-year cultivated vegetable soils. Correlation analysis for the main factors affecting soil phosphorous adsorption-desorption (e.g., MBC, DPS, etc.) reveals that soil amorphous Fe-Al content significantly affects soil phosphorus adsorption-desorption.

Effect of incorporation of Astragalus sinicus on microbe and enzyme dynamics in tobacco cultivated soils

XIAO Nen-Qun, ZHANG Hong-Xia, CHENG Zhuang, ZHANG Yang-Zhu, TAN Zhou-Jin, TONG Qiao-Zhen, LIU Xiang-Dan

2010, 18(4): 711-715. doi: 10.3724/SP.J.1011.2010.00711

Abstract(1397) PDF(1202)

Abstract:
The organic fertilizer A. sinicus has a strong nitrogen fixing ability. The effect of returning A. sinicus to tobacco culti-vated soils on microbial population, activity and enzyme activity was investigated with the aim of enhancing sustainable agro-devel-opment. The treatments were set at 15 000 kg·hm^-2, 22 500 kg·hm^-2, 30 000kg·hm^-2 A. sinicus, as well as NPK-reduced 22 500kg·hm^-2 A. sinicus, in which NPK amount in A. sinicus was reduced from fertilizer, with non A. sinicus treatment as the control. The results show that aerobic bacteria population rapidly increases in the early growth stage of tobacco, followed by a sluggish increase in the middle stages, with the various population trend in the late growth stages under different treatments. During the early tobacco growth stage, soil aerobic bacteria population is increased under NPK-reduced 22 500 kg·hm^-2 A. sinicus treatment compared to the CK. Actinomycete population slowly decreases in the early growth stage, minimally increases in the middle stage and then decreases in the late stage of growth under different treatments. Actinomycete population in soils with A. sinicus is higher than in the CK at the early growth stage, and is lower under NPK-reduced 22 500 kg·hm^-2 A. sinicus treatment during the whole growth stage. Fungi population increases rapidly in the early and middle growth stages, and decreases afterwards. A little A. sinicus stimulates fungus growth. Soil microbial activity decreases in the early stages, stabilizes in the middle stages, and gradually increases, reaching its peak in the late growth stages. Microbial activity is significantly higher in soil with A. sinicus than in CK soil in tobacco mature stage. It increases with increasing A. sinicus amount, but decreases in soils with NPK-reduced 22 500 kg·hm^-2 A. sinicus. Cellulase activity increases before blossom stage and decreases afterwards. Cellulase activity in soils with A. sinicus is higher than in soils without A. sinicus in later growth stage. Initially, urease activity sharply declines, then increases slightly, but again sharply increases during the late stage. Protease activity decreases in the early stage, and increases slightly in the late stage of growth. Protease activity increases with increasing A. sinicus in the soil. Alterations in soil catalase activity are not severe in the entire tobacco growth season. Based on the analysis and evaluation of the quantity and activity of soil microbes, the optimal application rate of A. sinicus is 22 500 kg·hm^-2.

Effect of organic fertilizer application pattern on vegetable yield, soil chemical property and micro-organism

YANG Bao-Mei, LI Guo-Liang, YAO Li-Xian, ZHOU Chang-Min, HE Zhao-Huan

2010, 18(4): 716-723. doi: 10.3724/SP.J.1011.2010.00716

Abstract(1973) PDF(1336)

Abstract:
Field trials on six successive crops of Brassica parachinensis (BP) were conducted to investigate the influence of organic fertilizer application pattern on the BP yield, and soil chemical property and micro-organism under intensive vegetables cultivation in Guangzhou. The organic fertilizer application patterns include application of inorganic fertilizer (CK), combined application of inorganic and organic fertilizers (BM), combined application of inorganic fertilizer and humic acid (HA), combined application of inorganic fertilizer and sprinkled Bacillus sp. (BSP), combined application of inorganic fertilizer, humic acid and sprinkledBacillus sp. (HA+BSP), combined application of inorganic fertilizer, decomposed chicken manure and sprinkled Bacillus sp. (CM+BSP), and combined application of inorganic fertilizer and Bacillus sp. retted chicken manure (BSPCM). The results show significant variations in mean yields among different crops. Among all the treatments in six crops, CM+BSP treatment yields the highest BP, followed by BSPCM treatment (both of which are significantly higher than the CK). BM, CM+BSP and BSPCM treatments can increase soil pH reducing the risk for soil acidification of intensive vegetable land. The number of soil bacteria, fungi and total micro-organisms under CM+BSP increases with increasing of cropping times, which is significantly higher than those under the initial soil and other treatments. Next in a similar trend is BSPCM treatment. The number of soil bacteria, fungi and total micro-organisms decreases under CK compared with initial soil condition. Hence for continuous vegetable cultivation, in different combinations with chicken manure, inorganic fertilizer plus sprinkled Bacillus sp. increases yield and soil fertility, activates soil biological properties, and reduces risks of continuous vegetables cropping obstacle. This method could therefore be used to realize sustainable development of intensive vegetable production in Guangzhou.

Spatial variability of soil texture in tobacco field

JIANG Hou-Long, WANG Xin-Zhong, LIU Guo-Shun, YANG Xia-Meng, ZHANG Rui-Na, XUE Qing-Mei, LI Yan-Tao

2010, 18(4): 724-729. doi: 10.3724/SP.J.1011.2010.00724

Abstract(1897) PDF(1679)

Abstract:
To understand the distribution mode of soil texture for enhanced precision fertilization in tobacco fields, spatial variability of soil texture in Pingdingshan tobacco field was analyzed via geostatistics method on Geographic Information System (GIS) platform. The spatial distributions of clay, sand and silt were then quantitatively built by ordinary Kriging — a linear unbiased interpolation method. The results show that soil granules have relatively large auto-correlation lengths, and with spatial heterogeneity scales of 609 m, 657 m and 429 m respectively for clay, sand and silt. About 80% of spatial variability of clay and sand is caused by structural factors. Directional semi-variogram analysis indicates that clay and sand have a relatively high spatial auto-correlation. Further analysis shows that while clay and sand are highly anisotropic, silt is feebly anisotropic. Our experiment demonstrates that the relatively strong spatial correlation and spatial variability of the soil texture may be the major factor responsible for spatial variations in soil properties, especially initial distributions of soil texture. It is therefore suggested that spatial variations in soil texture should be incorporated in fertilization scheme designs.

Fractal dimension of particle size distribution and its affecting factors in oasis farmland soils in southern marginal zones of Tarim Basin

GUI Dong-Wei, LEI Jia-Qiang, ZENG Fan-Jiang, MU Gui-Jin, YANG Fa-Xiang, SU Yong-Liang, PAN Yan-Fang

2010, 18(4): 730-735. doi: 10.3724/SP.J.1011.2010.00730

Abstract(1693) PDF(1323)

Abstract:
This paper presents a case study emphasizing the variations in particle size distribution (PSD) characteristics and its influencing factors in Cele Oasis farmland soils in the southern rim of Tarim Basin, Xinjiang, China. The results show significant difference in fractal dimensions (D) of farmland soils in the oasis. D is generally low and varies within 2.11~2.27 range. There exists a significant positive correlation between D and volume content of soil particles <50 μm on the one hand, and between D and soil organic matter content on the other. Whereas the duration of farmland cultivation importantly influences soil PSD, no consistent relation exists between locational distribution of farmland and soil PSD. These results suggest that long-term and appropriate tillage management of farmlands could have such beneficial effects as conserving and improving soil PSD.

Decomposition regularity of organic materials in Sanjiang Plain region

KUANG En-Jun, CHI Feng-Qin, SU Qing-Rui, ZHANG Jiu-Ming, GAO Zhong-Chao

2010, 18(4): 736-741. doi: 10.3724/SP.J.1011.2010.00736

Abstract(1763) PDF(1575)

Abstract:
Net bag method was used to determine the decomposition characteristics of soybean and maize stalks under two approaches of returning crop residues into soils. The results show that after 150 days of composting, residual rates of maize and soybean stalks are between 33.7%~61.1% under the two treatments. The order of decomposition rate of the stalks is: soil-covered treatment > open-air treatment, soil-covered maize stalk > soil-covered soybean stalk. Decomposition regularities of soybean and maize stalks in open-air are almost the same. As for the cell structure, with the time of treatments, tissues become blurred and loose, parenchyma and vascular bundles break-down, and intracellular matters disappear in maize stalk. However, there is no significant change in tissue structures of soybean stalk. Organic carbon decomposition rates of different organic materials are respectively 39.9%~48.9% and 49.6%~65.8% under open-air and soil-covered treatments. Stalk decomposition rates under soil-covered treatments are higher than open-air treatments. Decomposition rates of total N and K are respectively 51.1%~67.7% and 74.6%~91.7%. For maize, the decomposition rates of total P are respectively 49.4% and 56.7% higher than soybean under open-air and soil-covered treatments. With regard to material returned to the soil, maize stalk is superior to soybean stalk.

Effect of N supply and wheat/faba bean intercropping on N uptake and accumulation of wheat

ZHAO Ping, ZHENG Yi, TANG Li, LU Yao, XIAO Jing-Xiu, DONG Yan

2010, 18(4): 742-747. doi: 10.3724/SP.J.1011.2010.00742

Abstract(1494) PDF(1169)

Abstract:
Field experiment was conducted to investigate the effects of 4 nitrogen application rates (0, 90 kg·hm^-2, 180 kg·hm^-2 and 270 kg·hm^-2) and intercropping on N content, N accumulation and N uptake rate of wheat plant in wheat/faba bean intercropping system. The results show that intercropping can significantly increase the contents of N in wheat plants during growth stages. In comparison with monocropping, N contents of wheat plant in intercropping are increased by 20.0%, 21.9%, 21.4% and 17.1% in tillering, elongating, heading and maturing stages, respectively. The contents of N in leaves, stems, and panicles of wheat in intercropping are significantly higher than those of monocropping in heading and maturing stages. Intercropping can significantly increase N accumulation and N uptake rate of wheat plant compared with monocropping. N accumulation in plants of wheat increases by 15.5%~30.4% in intercropping during growth stages. N accumulation and N content of wheat plant are increased with increasing of nitrogen supply in both monocropping and intercropping, but impacts of N supply on N content, N accumulation and N uptake rate of wheat plant are stronger in monocropping comparison with intercropping. Intercropping advantages reduce with increasing of N application rate. N uptake rate of monocropped wheat plant increases, and that of intercropped wheat plant increases and then decreases with increasing of nitrogen application rates. The findings indicate that both N supply and intercropping can promote N uptake and accumulation of wheat. N supply influences intercropping advantages in wheat/faba bean intercropping, and a rational N supply is important for crop intercropping.

Diagnosis of nitrogen nutrition in winter wheat (Triticum aestivum) via SPAD-502 and GreenSeeker

HU Hao, BAI You-Lu, YANG Li-Ping, LU Yan-Li, WANG Lei, WANG He, WANG Zhi-Yong

2010, 18(4): 748-752. doi: 10.3724/SP.J.1011.2010.00748

Abstract(1954) PDF(1433)

Abstract:
Leaf SPAD and canopy NDVI of winter wheat under different nitrogen treatments were analyzed using GreenSeeker and SPAD-502 with the aim of building a quick, timely and accurate method for diagnosing nitrogen nutrition. The results show significant positive correlations among leaf SPAD, canopy NDVI and chlorophyll content. Correlation coefficients for leaf SPAD and leaf N and chlorophyll content are significant, except during heading and reviving stages. Correlations for canopy NDVI with leaf N and chlorophyll content at jointing and milking stages are similar to that for leaf SPAD. While SPAD can be used to evaluate chlorophyll content, NDVI can be used to assess nitrogen content. The recommended period for diagnosing nitrogen status is jointing stage. Using SPAD and NDVI, a linear regression model is developed for assessing yield of winter wheat.

Cluster root production and P utilization of macadamia seedling under different P treatments

YUE Hai, LI Guo-Hua, CHEN Li-Lan, KONG Guang-Hong, LIANG Guo-Ping

2010, 18(4): 753-757. doi: 10.3724/SP.J.1011.2010.00753

Abstract(2140) PDF(1634)

Abstract:
Cluster root production of macadamia seedling and its P utilization under six P treatments were evaluated in this study. For plants grown in 0.2~3.2 mol·L^-1 P, the amount of cluster root, plant dry biomass and dry biomass ratio of cluster root to root system exhibit a downward trend. For the plants in 0.2~1.6 mol·L^-1 P, acid phosphatase activity (APA) of non-cluster root exhibit an increasing trend ― a direct reverse of cluster root plants. Average APA of cluster root is 72.86% higher than that of non-cluster root. Also leaf P concentration is higher than roots and stems. Root, stem and leaf P concentration in 0.2 mol·L^-1 P is much higher than in other treatments. Compared with treatment without P, P supply at 0.2~0.4 mol·L^-1 inhibits non-cluster root APA, enhances production of cluster roots, plant dry biomass, dry biomass ratio of cluster root to root system, and cluster root APA. It also increases root, stem and leaf P concentration, subsequently improving P concentration of plants. In 0~1.6 mol·L^-1 P, there are significant or very significant positive correlations between cluster root production and plant dry biomass, biomass ratio of cluster root to root system, and P concentrations of stem, root and plant. The significance of positive correlations between cluster root production and APA, and leaf P concentration exceeds 90%.

Effect of water and nitrogen on photosynthetic characteristics and growth of Rauvolfia vomitoria

HE Zheng-Shan, CAI Zhi-Quan, CAI Chuan-Tao

2010, 18(4): 758-764. doi: 10.3724/SP.J.1011.2010.00758

Abstract(1406) PDF(1385)

Abstract:
A field experiment was conducted in Xishuangbanna during the dry season to study photosynthetic and growth characteristics of 2-year-old Rauvolfia vomitoria Afzel. under different water and nitrogen treatments. A well-watered condition and a water-stress condition for the water treatments, along with zero N, low N (1.25 g·plant^-1) and high N (3.75 g·plant^-1) treatments were used in the study. The results show that leaf relative water content (LRWC), maximum net photosynthetic rate (Pn), stomatal conductance (gs), specific leaf area (SLA), stem mass fraction (SMF) and relative growth rates of height (RGRH), basal diameter (RGRD) and biomass (RGRB) under water-stress condition are lower than those under the well-watered condition. Low N treatment significantly eases water stress induced depression in Pn, RGRH, RGRD and RGRB, and increases transpiration rate (E), root mass fraction (RMF). This significantly enhances root yield (Y_R) compared with zero N and water stress treatment. High N treatment increases drought sensitivity, aggravating photosynthetic and growth depressions of R. vomitoria. The interaction between N rate and drought significantly affects LRWC, Pn, instantaneous water use efficiency (WUEi), SLA, and RMF. This implies that different N rates have different effects under different water conditions. It is concluded that low nitrogen fertilization rate during dry season in Xishuangbanna maximizes root yield of R. vomitoria.

Effect of fertilization amount and ratio on yield, quality and nutrient absorption of watermelon

ZHANG Yu-Feng, DONG Liang, LIU Zhao-Hui, CHEN Guang-Si, LI Yan, ZHANG Pei-Ping

2010, 18(4): 765-769. doi: 10.3724/SP.J.1011.2010.00765

Abstract(1840) PDF(1614)

Abstract:
The aim of this study was to determine optimum fertilization amount and ratio for sustainable product of watermelon. To that end, field experiments were conducted, and the watermelon yield, quality and nutrient absorption rate under different fertilization treatments were investigated. Results indicate that yield and Vc content of watermelon under DNPK (decreased nitrogen, phosphorus and potassium) treatment respectively increase by 0.77% and 17.18% over TF (traditional fertilization) method. Sugar and nitrate contents under DNPK treatment respectively decrease by 12.56% and 27.94% over TF treatment. Yield, and Vc and sugar content of watermelon under DNPIK (decreased nitrogen, phosphorus and increased potassium) treatment are higher than under either DNP (decreased nitrogen and phosphorus) or DNPK treatment. Nitrate content under DNPIK treatment is lower than that under either DNP or DNPK treatment. N︰P₂O₅︰K₂O ratio in watermelon stem under TF, DNPK, DNP and DNPIK treatments are respectively 1︰0.18︰2.26, 1︰0.22︰2.66, 1︰0.26︰2.75, and 1︰0.19︰2.46. The ratio of N︰P₂O₅︰K₂O in watermelon peel under TF, DNPK, DNP and DNPIK treatments are respectively 1︰0.34︰2.78, 1︰0.34︰2.60, 1︰0.30︰2.37 and1︰0.29︰2.14. Given the above facts, watermelon average fertilization amount could be less by 36% than that of TF, with N︰P₂O₅︰K₂O ratio of 1︰0.41︰1.28, being the best fertilization of watermelon.

Effect of increased nighttime temperature on dry matter production and nutrient absorption in double cropping rice

WEI Jin-Lian, PAN Xiao-Hua

2010, 18(4): 770-774. doi: 10.3724/SP.J.1011.2010.00770

Abstract(1162) PDF(1048)

Abstract:
n experiment was conducted under different glasshouse conditions to determine the effect of nighttime temperature increase (NTI) on dry matter production and nutrient absorption in double cropping rice. No significant effect of NTI on dry matter production in early rice is noted. However, NTI significantly increases dry matter production in late rice. In early rice, NTI enhances dry matter accumulation before panicle differentiation, but decreases it after that. In the case of late rice, dry matter accumulation is enhanced by NTI, except during panicle differentiation to heading. Flag leaf senescence in early rice is accelerated by NTI, but no similar effect is noted in late rice. There is less obvious impact of NTI on total nitrogen accumulation than on P and K accumulation. In early rice, NTI only benefits crop nutrient absorption before panicle differentiation, but after that NTI inhibits nutrient absorption. However, the opposite tendency is observed before and after heading in late rice. The study therefore suggests that the effect of NTI on dry matter production and nutrient absorption is different between early and late rice, and among growth stages.

Suitable evaluation model for winter wheat water deficit in Xinxiang, Henan Province

LIU Zhan-Dong, DUAN Ai-Wang, GAO Yang, LIU Hao

2010, 18(4): 775-781. doi: 10.3724/SP.J.1011.2010.00775

Abstract(1729) PDF(1476)

Abstract:
Crop water deficit determines irrigation amount and schedule. Using data from field experiments during winter wheat seasons in 2005~2006 and 2006~2007, leaf area index model, soil water infiltration model and crop water requirement model were developed. Then using daily meteorological data during winter wheat seasons for 1951~2001 in Xinxiang of Henan Province (with consideration for the effects of evapotranspiration, precipitation and irrigation), effective precipitation utilization was simulated for each winter wheat season via soil water balance. Based on analysis of relationship between precipitation and effective precipitation during winter wheat season, effective precipitation was calculated at different time-scales. Based on the models for simulating winter wheat water requirement and effective precipitation, a suitable winter wheat water deficit evaluation model was isolated for Xinxiang of Henan Province

Water utilization in alternative irrigation under wheat-maize intercropping system in oasis areas

YANG Cai-Hong, CHAI Qiang, HUANG Gao-Bao

2010, 18(4): 782-786. doi: 10.3724/SP.J.1011.2010.00782

Abstract(1276) PDF(1011)

Abstract:
A field experiment was carried out to investigate the effect of alternative irrigation on water consumption, yield and water use efficiency (WUE) under wheat-maize intercropping in the oasis region of Shiyang River Basin, Gansu Province. The results indicate that evaporation for alternative irrigated intercropping system (AI) decreases by 44.0 mm compared to conventional irrigated intercropping system (CI). Water consumption under AI also increases by 15.4 mm while yield and WUE are respectively enhanced by 13.92% and 9.21% compared to CI. All these results show that alternative irrigation is an effective and practicable way to improve yield and WUE of wheat-maize intercropping. Although evaporation and water consumption in alternative irrigated intercropping system increase with increasing irrigation quota, overall WUE actually decreases.

Correlation analysis on selected traits of high-yield wheat

MU Xiao-Qian, MU Mei-Cai, LIU Xin-Cheng

2010, 18(4): 787-791. doi: 10.3724/SP.J.1011.2010.00787

Abstract(1516) PDF(987)

Abstract:
Correlation analysis was conducted among selected traits and yield of wheat from 47 fields with yield range of 7 243~ 10 610 kg·hm^?2 under stabilizing leaf-controlling plant type-increasing ear number (CPCE) management conditions using SPSS. The research task of this study was to determine the enabling and limiting factors of CPCE. Selected traits analyzed in this study include ear number per-unit-area, grain number per ear, grain weight, maximum grain volume, vascular bundle number per panicle and total vascular bundle number. Among three yield components (ear number per-unit-area, grain number per ear and grain weight), only grain weight is positively correlated with yield, suggesting that grain weight is the main determinant of yield under CPCE management. Positive correlation is also noted between grain weight and maximum grain volume. This implies that management measures to increase maximum grain volume can enhance grain yield. The positive correlation between ear number per-unit-area and total vascular bundle number suggests that high ear number per-unit-area ensures smooth flowing. Based on curve fitting, the regression equations for grain weight and maximum grain volume, and also for ear number per-unit-area and total vascular bundle number are respectively given as y = 12.925+0.479x and y =－14.231+2.685lnx.

Effect of plant density and vegetative branch retention on within-plant yield distribution and maturity performance of cotton

DONG He-Zhong, LI Zhen-Huai, LUO Zhen, LU He-Quan, TANG Wei, ZHANG Dong-Mei, LI Wei-Jiang, XIN Cheng-Song

2010, 18(4): 792-798. doi: 10.3724/SP.J.1011.2010.00792

Abstract(1668) PDF(1155)

Abstract:
A multi-site field experiment was conducted in the counties of Linqing, Xiajin and Huimin in Shandong Province to analyze effects of plant density and vegetative branch (VB) retention on within-plant yield distribution, sink/source ratio, and maturity performance of cotton. Economic yields of VB-excised cotton plants are all derived from fruiting branches (FB), while those of VB-retained plants are most from FB (85%), and the rest is from VB (15%). Cotton yield is mainly distributed in the lower and middle FB (72%) and the inner fruit nodes (74%) of FB, whereas less occurs in upper FB (23%) and extra fruit nodes (26%). Plant density and pruning have significant effects on within-plant yield distribution with an insignificant interaction. While yield distribution from inner to extra fruit nodes is mainly affected by plant density, changes in yield distribution from upper to lower FB is mainly attributed to pruning. Greater yield distribution in inner fruit nodes is noted with increasing plant density whereas VB-retention results into a longitudinally dispersing distribution. Branch pruning does not significantly affect maturity performance, but plant density significantly affects maturity performance and sink/source ratio. Light premature senescence with high sink/source ratio, and late maturity with low sink/source ratio are respectively observed under low and high plant densities. Moderate plant density (5.25 plants per m^-2) presents an appropriate sink/source ratio and desired maturity performance.

Response of photosynthetic induction to irradiance transition in mulberry leaf

HU Yan-Bo, XU Nan, BAO Zhuo, ZHANG Xiao-Song, SUN Guang-Yu

2010, 18(4): 799-803. doi: 10.3724/SP.J.1011.2010.00799

Abstract(1605) PDF(1795)

Abstract:
Using “Menggusang” mulberry (Morus alba L.) seedling grown under greenhouse conditions in Heilongjiang Province, we analyzed photosynthetic induction responses to irradiance transitions via gas-exchange and chlorophyll fluorescence techniques. Results show that 10 min photosynthetic induction is needed for the photosynthetic rate ( Pn ) of mulberry leaf to reach stable state under the sudden irradiance transition from dark/low irradiance (LI) to high irradiance (HI). A biphasic photosynthetic response is evident — rapid phase (1~2 min) and slow phase (8~10 min). When irradiance is transited from LI to HI, induction of photosynthetic quantum conversion efficiency falls behind the photosynthetic CO₂ assimilation. When irradiance is changed from high to low/dark, Pn faster approaches steady-state compared to the irradiance transfer from low/dark to high. This indicates that induction efficiency of quantum conversion is limited by photosynthetic CO₂ assimilation following increase in irradiance. Induction efficiency of photosynthetic quantum conversion may therefore be regulated by the proportion of open PSⅡ reaction centers.

Relational analysis of spectra and red-edge characteristics of plant leaf and leaf biochemical constituent

LIANG Shou-Zhen, SHI Ping, MA Wan-Dong, XING Qian-Guo, YU Liang-Ju

2010, 18(4): 804-809. doi: 10.3724/SP.J.1011.2010.00804

Abstract(1730) PDF(2640)

Abstract:
Using LOPEX’93 dataset, this paper simulated spectra reflectance, transmittance and absorptance of plant leaves under different biochemical constituents of leaf mesophyll structure parameter, water, chlorophyll, carotenoids and dry matter. The newest PROSPECT5 (leaf optical properties spectra) model was used for relational analysis of spectra and biochemical constituents as detected by vegetation remote sensing, on the basis of which red-edge characteristics were determined. The research task was to establish a model relating biochemical constituents to spectral characteristics via systematic relational analysis. Biochemical constituents of plant leaf should be inverted by the model. The results show that visible range of leaf spectra mainly depend on leaf mesophyll structure parameter and pigment (including chlorophyll and carotenoid). In the infrared range, leaf spectra largely depend on water, leaf mesophyll structure parameter and dry matter. Red-edge position moves towards long-wave with increasing chlorophyll, the so-called red-shift. Red-edge characteristics are not affected by water and carotenoid, and red-edge slope increases with increasing leaf mesophyll structure parameter. These relations are perfectly describable by di-order fitting equations. This lays the basis for solving mesophyll structure parameter issues.

Effect of light and temperature on the germination of three annual plants

LIU You-Jun, JI Yong-Fu, MA Quan-Lin, ZHANG De-Kui, ZHANG Jin-Chun, LIU Hu-Jun, PENG Jin-Feng

2010, 18(4): 810-814. doi: 10.3724/SP.J.1011.2010.00810

Abstract(1607) PDF(1316)

Abstract:
germination experiment on three typical annual plants (Halogeton glomeratus, Corispermum patelliforme and Echinopilon divaricatum) was conducted in the desertifying regions of Minqin under different temperature and light conditions. The objective of the study was to determine the germination characteristics of plant seeds in the desertifying conditions of Minqin. The results show that the three annual plants start to germinate in 1~4 days after sowing and complete germination in 2~12 days under optimum conditions. The optimum germination temperature of H. glomeratus in continuous light is 15 ℃, with a germination percentage of 96.00%±0.00%. For C. patelliforme, the optimum germination temperatures are 20 ℃ and 15 ℃/25 ℃ in continuous dark and 14 h light/10 h dark conditions, with respective germination percentages of 18.00%±2.00%, 28.00%±2.31%. In the case of E. divaricatum, the optimum germination temperatures are 20 ℃ and 15 ℃/25 ℃ under continuous dark and 14 h light/10 h dark conditions, with respective germination percentages of 96.00%±0.00% and 96.00%±2.31%.H. glomeratus and E. divaricatum can germinate under three different light conditions (continuous light, dark and 14 h dark/10 h light). C. patelliforme generally germinates under the continuous dark condition and hardly germinates under other light conditions.

Plant diversity in field margin systems in the hilly regions of northern Henan

MA Shou-Chen, YUAN Dong-Fang, YANG Shen-Jiao, WANG He-Zhou

2010, 18(4): 815-819. doi: 10.3724/SP.J.1011.2010.00815

Abstract(1483) PDF(1039)

Abstract:
Based on field investigation, plant species abundance and indices of evenness, diversity and dominance were analyzed in field margin systems in the hilly regions of northern Henan. The results show that species abundance is highest for shrub-grassland, followed by aqueduct margin, sparse forests, roadsides, orchard border and cropland border. Species abundance is significantly higher for shrub-grassland and lower for cropland border compared to other field margin systems. Evenness index is highest for sparse forests, followed by shrub-grassland, aqueduct margin, roadsides, cropland border and orchard border. Evenness index is significantly higher for sparse forests and lower for orchard border. Diversity and dominance indices are highest for aqueduct margin, followed by sparse forests, shrub-grassland, orchard border, roadsides and then cropland border. Diversity and dominance indices are significantly higher for aqueduct margin and lower for cropland border. There are much more common species among shrub-grassland, roadsides, aqueduct margin, sparse forests and orchard border, with similarity coefficients above 0.7. There are less common species between cropland border and the other field margin systems, with similarity coefficients below 0.7. The lowest similarity coefficient (0.47) is between cropland border and shrub-grassland.

Analysis of energy flux in rice paddy in the Sanjiang Plain

JIA Zhi-Jun, ZHANG Wen, HUANG Yao

2010, 18(4): 820-826. doi: 10.3724/SP.J.1011.2010.00820

Abstract(1513) PDF(1097)

Abstract:
Using eddy covariance data for May to October 2005, 2006 and 2007 collected from rice paddies in the Sanjiang Plain, diurnal and seasonal variations in energy flux, partitioning and balance closure were analyzed. The results show that diurnal varia-tions in net radiation and latent heat flux are uni-peak model. However, a relatively distinct diurnal variation in sensible heat flux isobserved only at the maturity stage of rice. There is no obvious diurnal variation in soil heat flux in the entire growing season. Seasonal variations in net radiation are significant, generally reaching the maximum of 18~20 MJ·m^-2·d^-1 during late June to early July. Seasonal variations in latent heat flux are similar to those in net radiation, with a maximum range of 13~19 MJ·m^-2·d^-1. In contrast, sensible heat flux is smaller and less variable on seasonal scale (-3.90~3.94 MJ·m^-2·d^-1) than latent heat flux. Soil heat flux is not only small, but has a declining trend for May to October, and with a range of -2.67~3.62 MJ·m^-2·d^-1. There is a sig-nificant energy partition in the rice paddies of the Sanjiang Plain, with mean LE/Rn ratio of 0.67 (for May to October). This suggests that most of the energy is latent heat flux, but with a larger LE/Rn ratio at blooming stage than at other growth stages. The seasonalpattern of Hs/Rn ratio is inversely related to LE/Rn ratio, with an average Hs/Rn ratio of 0.10. This implies that the Bowen ratio is smaller for blooming stage and larger for the early and late stages of growth. G/Rn ratio is small, showing a declining trend of 0.14~ -0.08 from May to October. The energy balance closure, evaluated by methods of Ordinary Linear Squares regression and Energy Balance Ratio, is generally small in the study area. Averaged energy imbalance ratio in the paddy fields for May to October isrespectively 22% and 16% for 2005 and 2006. However, energy balance ratio surprisingly hits 1.07 in 2007, showing that the sum of latent and sensible heat fluxes is larger than the available energy

Influence of SO₂ emission from high sulfur gas fields on growth and yield of rice

YANG Gang, ZHONG Gui-Jiang, WU Jun, DENG Shi-Huai

2010, 18(4): 827-830. doi: 10.3724/SP.J.1011.2010.00827

Abstract(1534) PDF(1323)

Abstract:
The influence of SO₂ from the high sulfur gas field on the growth, yield and quality of rice were studied through sampling of soil and rice in both polluted and non-polluted areas. The results show that SO₂ in the air emitted from the high sulfur gas field, can increase sulfur content in the grain and leaves of rice, and significantly reduce the 1000-grain weight and rice yield. Rice yield decreases by 16.6%~28.2% in polluted areas, compared with the non-polluted areas. Sulfur absorbed by rice vegetative organs and accumulated in the reproductive organs, can significantly debase rice quality by the inhibition of protein, starch and fat formation. Compared with the non-polluted areas, rice protein content in contaminated areas decreases by 8.6%~22.3%, starch content decreases by 27.4%~53.6%, fat content decreases by 45.6%~71.7%, while the ash content is increased by 52.2%~69.4%.

Dynamic change in surface pH and organic acid content in rice seedling root-tip exposed to aluminum stress

PANG Zhen-Wu, XIE Guo-Sheng, GUO Shui, CAI Ke-Tong

2010, 18(4): 831-835. doi: 10.3724/SP.J.1011.2010.00831

Abstract(1212) PDF(1401)

Abstract:
Surface pH and cytoplasm organic acid contents of root-tips of rice seedlings under aluminum stress were monitored via a modified agarose gelling plate technique, with bromocresol purple as pH indicator. While no obvious changes are noted in surface color of rice seedling root-tip under Al stress for 1 h, 3 h and 6 h, significant changes occur under no-Al stress, showing little orange in 1 h and deep orange in 3~6 h. Surface pH of Al-free rice seedling root-tip is time-dependent and strongly alkaline under an initial pH of 4.4 condition. On the contrary, increase in surface pH of rice seedling root-tip is inhibited by Al stress. Under 200 μmol·L-1 Al stress, three out of a total 10 detected organic acids in cell of rice seedling root-tip, show varying, time-dependent dynamics. There is insignificant change in oxalic acid in rice seedling root-tip during the test and a minimal change in citric acid in the initial 3 h of Al stress. However, citric acid rapidly and significantly increases then, reaching the maximum in 12 h (P<0.05) before decreasing by 16.27% in 24 h. Though change in citric acid is small (P>0.05) after 24 h of Al stress, it is still higher than that in 6 h. Malic acid in rice seedling root-tip decreases, but at an insignificant rate in 3 h of Al stress. After 3 h, malic acid decreases significantly, but the decrease ceases to be significant after 6 h of exposure to Al stress.

Antioxidative defense system differences among four plants under combined Pb and Cd stress

GAO Yang1, MAO Liang, ZHOU Pei, ZHANG Chun-Hua, SHI Wan-Jun, CAO Jie-Jun, JIN Zhi-Guo, SHI Wei-Wei

2010, 18(4): 836-842. doi: 10.3724/SP.J.1011.2010.00836

Abstract(1332) PDF(1365)

Abstract:
The hyperaccumulative plants of Solanum nigrum and Brassica juncea, and non-hyperaccumulative plants of maize (Zea?mays) and radish (Raphanus sativus) were used to analyze the antioxidative system response to combined Pb and Cd pollution. The results show that leaf biomass for the hyperaccumulators, S. nigrum and B. junce, significantly decrease under the pollution, against a slight change in root and stem biomass under low Pb and Cd concentration. The biomass of non-hyperaccumulators, maize and radish, significantly decreases with increasing concentration of heavy metals. Hyperaccumulators’superoxide dismutase (SOD) activity increases with increasing concentration of heavy metals in the soil. While peroxidase (POD) activities for the four plants are different, response of non-hyperaccumulators’ POD activities to heavy metal stress is the same and increases with increasing heavy metal concentration. Hyperaccumulators’s malondialdehyde (MDA) content also increases with increasing heavy metal concentration. B. juncea and radish have higher GSH content than the other two plants. For the hyperaccmulators, SOD, MDA, TSTA, GSH and PC are significantly correlated with heavy metal toxicity coefficient. POD and total GSH in maize significantly correlate with heavy metal toxicity coefficient, while TAST and PC in radish significantly correlate with heavy metal toxicity coefficient. The results indicate the detoxification mechanisms are different for plants. Therefore, it is important to further research on hyperaccumulator gene control and enzyme expression for a greater insight into detoxification mechanism.

Spectral space model for diagnosing As stress in mature rice

CAO Shi, LIU Xiang-Nan, CAO Shan

2010, 18(4): 843-846. doi: 10.3724/SP.J.1011.2010.00843

Abstract(1249) PDF(1084)

Abstract:
Sixty leaf samples of mature rice were scanned by ASD field pro3 for optical data and analyzed for As content using atomic absorption spectrometry. A space model for diagnosing As contamination in rice based on 12 hyperspectral potentially sensitive indices of As stress was used in this paper. In the first step, single diagnosis indices (PSNDa, DSWI, SIPI) representing different rice physiological parameters were determined using correlation analysis between hyper-spectral indices and As content, and then two-dimension diagnosis spaces (PSNDa-DSWI, PSNDa-SIPI, DSWI-SIPI) were constructed, of which PSNDa-SIPI representing chlorophyll and cell structure shows a more effective prediction of As contamination in rice. In the second step, another diagnosis space (F1-F2) was built from principal component analysis of the 12 hyperspectral indices, whose accumulative contribution rate was 88%. This was an exact predictor of As pollution in rice; where F1<1.95 and F2>0.75 represents high pollution, 1.95<F1<3.15 and 0.75>F2>0.40 represent medium pollution, and F1>3.15 and F2<0.40 represent low pollution. These diagnosis spaces form a comprehensive diagnosis space model that services for monitoring large-scale As contamination in rice from different levels.

Effects and mechanisms of amendments on remediation of cadmium contaminated acid paddy soils

ZHU Qi-Hong, HUANG Dao-You, LIU Guo-Sheng, ZHU Guang-Xu, ZHU Han-Hua, LIU Sheng-Ping

2010, 18(4): 847-851. doi: 10.3724/SP.J.1011.2010.00847

Abstract(2095) PDF(2185)

Abstract:
A field experiment was conducted to study Cd immobilization in Cd contaminated soils. The study analyzed the remediation effects of lime (L), fused calcium magnesium phosphate (P), sepiolite (S), humic acid (H) and mixed lime amendments (LP, LS and LH) on Cd bioavailability in a Cd contaminated acid paddy soils. The results indicate that amendments significantly change the proportion of Cd forms in contaminated soils. Except for H, the other 3 amendments lower acid extractable fraction of Cd, while increasing oxidation fraction and residual Cd. The 4 amendments reduce the 0.1 mol·L^-1 NaNO₃ and 0.01 mol·L^-1 CaCl₂ extracted Cd by 26%~97%. The order of reduction is LS > S > LP > P > L > LH > H. The content of Cd in the aboveground parts of rice decreases by 6%~49% under amendment application. Amendment increasing soil pH is the main factor influencing soil Cd immobilization. In conclusion therefore, sepiolite could be a suitable amendment of Cd contaminated acid paddy soils. However, humic acid is not so suitable for remediating Cd contaminated acid paddy soils.

Effect of three bio-fertilizers on degradation of chlorimuron-ethyl residue and rice growth

WANG Yan-Jie, ZUO Yu-Hu, JING Rui-Yong, GAO Ya-Mei, WANG Wei-Dong

2010, 18(4): 852-855. doi: 10.3724/SP.J.1011.2010.00852

Abstract(1166) PDF(1096)

Abstract:
A plot experiment was conducted to investigate the effects of Nongda bio-agent (NBA), Shilu bio-fertilizer (SBF) and Nongda bio-fertilizer (NBF) on chlorimuron-ethyl residue degradation and rice growth under different concentrations of chlorimuron-ethyl. Results show that the three bio-fertilizers degrade 3 μg·kg^-1 and 6 μg·kg^-1 chlorimuron-ethyl residues in soils. Degradation rates of 6 μg·kg^-1 chlorimuron-ethyl by the three bio-fertilizers are respectively 61.5%, 58.3% and 62.7%, which are 17.8%, 14.6% and 19.0% higher than those under natural conditions. Plant height, ear length, seed setting rate and rice yield are significantly influenced by 0.03 μg·kg^-1 chlorimurone-thyl. The symptoms of phytotoxicity deteriorate with increasing chlorimuron-ethyl concentration. The three bio-fertilizers tends to eliminate negative effects on rice yield induced by 0.03 μg·kg^-1 chlorimuron-ethyl. However, though chlorimuron-ethyl phytotoxicity is not effectively degraded by the three bio-fertilizers with increasing application, phytotoxicity is significantly alleviated. Chlorimuron-ethyl bio-degradability by SBF is inferior to that by the other two bio-fertilizers. Application of the three bio-fertilizers guarantees safe production of rice at chlorimuron-ethyl application rate below 0.03 μg·kg^-1.

Effect of enhanced UV-B radiation and inoculated blast isolate (Magnaporthe grisea) on phenylalanine ammonial-yase activity and flavonoid content in seedlings of two rice cultivars

LI Yuan, GAO Xiao-Xiao, GAO Zhao-Hua, HE Yong-Mei, CHEN Jian-Jun, ZU Yan-Qun

2010, 18(4): 856-860. doi: 10.3724/SP.J.1011.2010.00856

Abstract(1898) PDF(1360)

Abstract:
The effects of UV-B radiation and Magnaporthe grisea on the activities of phenylalanine ammonia-lyase and flavonoid contents in seedling leaves of two rice (Oryza sativa L.) cultivars (“Huangkenuo” and “Hexi 41”) were investigated under pot experimental conditions. The two rice cultivars were treated at three UV-B radiation levels (2.5 kJ·m^-2, 5.0 kJ·m^-2 and 7.5 kJ·m^-2) and two blast isolates (Y98-16T and Y99-63C). Changes in the activity of phenylalanine ammonia-lyase and flavonoid content of the rice seedling leaves were then determined. While the phenylalanine ammonia-lyase activities and flavonoid contents of “Huangkenuo” seedling leaves significantly increase under 2.5 kJ·m^-2 and 5.0 kJ·m^-2 UV-B radiation, they significantly decrease under 7.5 kJ·m^-2 UV-B radiation. Leaf flavonoid content of “Hexi 41” significantly increases under enhanced UV-B radiation from 2.5 kJ·m^-2 to 7.5 kJ·m^-2. While “Hexi 41” leaf phenylalanine ammonia-lyase activity significantly increases under 5.0 kJ·m^-2 UV-B radiation, it remains stable under other UV-B treatments. Whereas “Hexi 41” leaf phenylalanine ammonia-lyase activity and flavonoid content significantly increase, “Huangkenuo” leaf phenylalanine ammonia-lyase activity decreases against increasing flavonoid content under Y98-16T inoculation. Both “Huangkenuo” and “Hexi 41” leaf phenylalanine ammonia-lyase activities and flavonoid contents significantly decrease under Y99-63C inoculation. Under enhanced UV-B radiation and inoculated blast isolates, “Huangkenuo” phenylalanine ammonia-lyase activity and flavonoid content decrease, whereas those of “Hexi 41” either remain stable or increase. In general, “Huangkenuo” sensitivity and “Hexi 41” tolerance increase under enhanced UV-B radiation and inoculated blast isolates.

Colonization ability of plant growth promoting Bacillus B96-Ⅱ-gfp labeled with GFP

HAO Bian-Qing, MA Li-Ping, QIAO Xiong-Wu

2010, 18(4): 861-865. doi: 10.3724/SP.J.1011.2010.00861

Abstract(1805) PDF(1899)

Abstract:
Colonization dynamics of plant growth promoting Bacillus B96-Ⅱlabeled with GFP (B96-Ⅱ-gfp) in soils and cucumber plants were investigated via Green Fluorescent Protein Gene Label technique. The results show that B96-Ⅱ-gfp successfully colonizes in soils and cucumber plants. Total B96-Ⅱ-gfp populations are respectively 2.7×10⁴ cfu·g^-1 and 6.6×10⁴ cfu·g^-1 at 180 days after incubation in natural soils and usarium wilt pathogenic soils. B96-Ⅱ-gfp is detectable in the soil even at 360 days after incubation. Spatial colonization test indicates that B96-Ⅱ-gfp can colonize in the surface (0~4 cm), middle layer (4~8 cm) and lower layer (8~12 cm) of soil, and its population density increases with soil depth. Furthermore, B96-Ⅱ-gfp colonizes in different organs of cucumber plants, with a higher population in the interior than at the exterior surface. B96-Ⅱ-gfp population in roots is highest (7.2×10⁴ cfu·g^-1). Whereas B96-Ⅱ-gfp significantly reduces the population of cultured native soil microorganisms (e.g., fungi), it does not significantly influence the population of bacteria and antinomyces. The results further show that B96-Ⅱ-gfp increases the height, fresh weight and dry weight of cucumber plants. B96-Ⅱ-gfp exhibits a certain degree of control on Fusarium wilt. Labeled B96-Ⅱ-gfp is not significantly different from un-labeled B96-Ⅱ in terms of disease control and growth promotion.

Microbial community diversity in tea root zone soils at different elevations

ZHENG Xue-Fang, SU Yuan-Ke, LIU Bo, LAN Jiang-Lin, YANG Shu-Sheng, LIN Ying-Zhi

2010, 18(4): 866-871. doi: 10.3724/SP.J.1011.2010.00866

Abstract(1927) PDF(1543)

Abstract:
Soil samples were collected in tea root zone of Tieguanyin tea gardens at different elevations in Anxi County, Fujian Province. Then phospholipid fatty acids (PLFAs) biomarkers were used to analyze microbial community diversity in the tea root zone soils. Significant differences exist among the 22 PLFAs detected in the soil samples from 525 m, 603 m, 717 m and 834 m elevations. For the purpose of analysis, PLFAs biomarkers are divided into two groups — complete distribution group, which means that a biomarker is well distributed across soil sample; and incomplete distribution group, which means that a biomarker is distributed in a fraction of soil sample. Tea root zone soil at higher elevation exhibits richer PLFAs distribution both in type and amount. The PLFAs biomarkers with the first three maximum concentration are 16:0, 18:3ω6c(6, 9, 12) and 18:0 — respectively indicating bacteria, fungi and hydrogenobacter. Biomarker 16:0 has the richest distribution, followed by 10Me 16:0 (indicating actinomyces) and 18:3ω6c(6,9,12) at different elevations. Cluster analysis reveals that PLFAs in root zone soils at different elevations are categorized into three groups at an euclidean distance of 11.51. PLFAs biomarkers in the group one are completely distributive, but at medium contents at different elevations. PLFAs biomarkers in the group two are completely distributive at a much higher contens at different elevations than those in the group one. Contrary to the group two, PLFAs biomarkers in the group three are much less than in the group two, with an incompletely distributive characteristics. Based on community diversity indices of Shannon-Wiener, Simpson and Pielou, it is concluded that maximum Shannon-Wiener, Simpson and Pielou indices occur in root zone soils at 834 m elevation whereas the minimum in root zone soils at 717 m elevation.

Spatial distribution characteristics of arable lands in Taihang Mountain area of Hebei Province

TAN Li-Mei, LI Hong-Jun, LIU Hui-Tao, LIU Hong-Juan, LIU Jin-Tong

2010, 18(4): 872-875. doi: 10.3724/SP.J.1011.2010.00872

Abstract(1721) PDF(1420)

Abstract:
Based on the application of RS and GIS technologies, this paper analyzed spatial distribution characteristics of the arable lands in Taihang Mountain area of Hebei Province. The results show that 80.9% area of the mountain arable land distributes below 500 m elevation, 93.7% area distributes with less than 15° slope gradient and 70.3% area distributes in flats and U-shaped valleys. This indicates that the exploitation of arable land resources in Taihang Mountain area of Hebei Province is reasonable. The research conclusion could be used as the reference on quality assessment and utilization of arable land resources in other areas of Taihang Mountain.

Development of water-saving wheat cultivars to limit water shortagein North China— a case study of Hebei Province

GUO Jin-Kao, SHI Zhan-Liang, HE Ming-Qi, ZHANG Xiang-Qi, ZHANG Ai-Min, JIA Xu

2010, 18(4): 876-879. doi: 10.3724/SP.J.1011.2010.00876

Abstract(1704) PDF(1238)

Abstract:
Water is a critical crop production factor. This paper analyzed the state of water shortage in North China using Hebei Province as a case study. The study expatiates on modern water-saving agriculture and shows that agriculture is a key to water-saving. In North China, water-saving agriculture is determined by reducing water use for wheat production. In addition to engineering water-saving, greater attention should be paid to biological water-saving and agronomic water-saving. High water-use-efficient wheat cultivars combined with water-saving cultivation technology is important in reducing water consumption in wheat production. Consequently, that is most important mode of limiting water shortage in the region. Water-saving cultivation of “Shimai 15” and “Shijiazhuang No. 8” bred by Shijiazhuang Academy of Agricultural Sciences, Hebei Province is used as an example to illustrate the feasibility of breeding of water-saving wheat cultivars, and the potential of water-saving wheat cultivars in water-saving agriculture.

Relational discussion on agricultural productivity and agricultural systems structure

ZHANG Li-Feng

2010, 18(4): 880-883. doi: 10.3724/SP.J.1011.2010.00880

Abstract(1002) PDF(1025)

Abstract:

The progress of research on sugarcane intercropping

LI Zhi-Xian, FENG Yuan-Jiao, YANG Wen-Ting, WANG Jian-Wu

2010, 18(4): 884-888. doi: 10.3724/SP.J.1011.2010.00884

Abstract(1635) PDF(2007)

Abstract:
This paper is a brief view of ongoing advances in sugarcane intercropping research and key future research directions on sugarcane intercropping. Reasonable sugarcane intercropping system enhances crop growth and light interception, ensures simultaneous soil exhaustion and restoration with enhanced soil nutrition, and reduces the incidence of pest and disease. However, there exists limited study on the mechanisms of beneficial ecological effects of sugarcane intercropping. Future research should therefore focus on nutrition uptake, utilization and transfer mechanisms, and the relationships among nutrition transfer and environmental factors under intercropping.

Agro-ecosystem service and its managerial essence

ZHU Wen-Feng, WANG Song-Liang, Claude D CALDWELL

2010, 18(4): 889-896. doi: 10.3724/SP.J.1011.2010.00889

Abstract(2170) PDF(3877)

Abstract:
Agro-ecosystem is the interface between human society and natural ecological system. Its healthy service function has further and actual significance in the sustainability and stability of agricultural systems and human society. In this paper, advances, connotations and contents of agro-ecosystem service are analyzed. Based on existing quantitative assessment indices and methods of agro-ecosystem service, we figure out four obstacles in agro-ecosystem service research — (1) quantification difficult of agro-ecosystem service, (2) outdated agro-ecosystem service research techniques, (3) absence or weakness of mechanisms in agro-ecosystem service research, and (4) ideological constraints to agro-ecosystem service research. Based on the above obstacles, trends of future agro-ecosystem service research are summarized. This is followed by proposing the essence of ago-ecosystem management from aspects of conception, mechanism and technology in order to function the agro-ecosystem service healthily.

Review of atmospheric nitrogen deposition research

XIE Ying-Xin, ZHANG Shu-Li, FENG Wei, ZHAO Xu, GUO Tian-Cai

2010, 18(4): 897-904. doi: 10.3724/SP.J.1011.2010.00897

Abstract(1898) PDF(2992)

Abstract:
Atmospheric N deposition under human influence is an important part of global biogeochemical N cycle. As an important source of plant nutrient and soil acidification, increased N deposition from the atmosphere would greatly impact production and stability of global terrestrial and aquatic ecosystems. This paper reviews recent literatures on atmospheric N deposition and the related ecological effects on soil and water environment, agriculture and forest ecosystems and biodiversity. It summarizes documented measurement methods of atmospheric N deposition. Finally, the prospected and trend of atmospheric N deposition research development in China is advanced.

Impact of climatic change on agricultural production and response strategies in China

LIU Yan-Sui, LIU Yu, GUO Li-Ying

2010, 18(4): 905-910. doi: 10.3724/SP.J.1011.2010.00905

Abstract(3419) PDF(7563)

Abstract:
A number of studies indicate increasing global climate warming especially in recent decades. Climate warming greatly influences global agro-production and food security — the focus of global environmental change. This paper proposes a structural and orientational framework for scientifically addressing climatic change impact on agro-production. Through literature review and comparative studies, the paper systematically summarizes influencing mechanisms and effect of climate warming on such agro-production factors as light, temperature, soil quality and water environment. The impact of climate warming on cultivation regions, cropping systems, crop pests, agro-production capacity, agro-economy and farm management is analyzed. Then, suitable climate-adapted agro-development strategies are put forward for different regions in China. The strategies are carefully selected from a repository of international tested climatic change countermeasures in agriculture at national or district level.

Study on the adaptive farming system in saline soils —A case study in saline area of strand plain in Hebei Province

LIU Xiao-Jing, LI Xiang-Jun, CHEN Li-Na, SUI Pen

2010, 18(4): 911-913. doi: 10.3724/SP.J.1011.2010.00911

Abstract(1658) PDF(1205)

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Complex effect of Cr6+ and acid rain on soybean germination

WEN Ke-Jia, LIU Ting-Ting ZHOU Qing, ZHOU Qing

2010, 18(4): 914-916. doi: 10.3724/SP.J.1011.2010.00914

Abstract(1560) PDF(1456)

Abstract:

2010 Vol. 18, No. 4