中国生态农业学报(中英文)

Nutrition characteristics in root surface and rhizosphere soils of direct-seeding rice in rice-duck eco-farming system

SHEN Jian-Kai, HUANG Huang, FU Zhi-Qiang, ZHANG Yang-Zhu, LONG Pan, GAO Wen-Juan, CHEN Can, LIAO Xiao-Lan, HU Ying, XIE Wei, ZHENG Hua-Bin, ZHANG Ya

2010, 18(6): 1151-1156. doi: 10.3724/SP.J.1011.2010.01151

Abstract(2250) PDF(1643)

Abstract:
Soil organic carbon, N, P, K contents and pH in root surface and rhizosphere soils of early season rice in rice-duck eco-farming system and mono-cropping rice system were investigated in a field plot experiment. The results show that the soil pH in root surface and rhizosphere of rice in rice-duck eco-farming system is increased by 4.41%, 0.85% and total N is decreased by 0.11 g·kg^-1, 0.11 g·kg^-1 compared with those in mono-cropping rice system, respectively, while changes in total P and total K contents are not statistically significant. Available N, available K in rice root surface soil in rice-duck eco-farming system are 30.80 mg·kg^-1, 17.93 mg·kg^-1 higher and available P is 8.66 mg·kg^-1 lower than those in mono-cropping rice system, however, available N and available K in rhizospere soil are 15.13 mg·kg^-1, 7.61 mg·kg^-1 lower and available P is 9.66 mg·kg^-1 higher than those in mono-cropping rice system. Compared with the mono-cropping rice system, in rice-duck eco-farming system, active organic carbon and high-active organic carbon in root surface soil are increased by 2.17 g·kg^-1 and 0.56 g·kg^-1 respectively, total organic carbon is deceased by 0.99 g·kg^-1, and total organic carbon, active organic carbon and mid-active organic carbon in rhizosphere soil are decreased by 2.39 g·kg^-1, 2.64 g·kg^-1 and 0.72 g·kg^-1, respectively. It is illustrated that in rice-duck eco-farming system, available K and active organic carbon are accumulated in root surface soil, and available P is accumulated in rhizosphere soil. Hence, soil nutrient status in root surface and rhizosphere in rice-duck eco-farming ecosystem are significantly improved, which probably have a good effect on nutrient absorption of rice.

Factors affecting soil nitrogen supply in tobacco fields in Southwest Hubei

ZHAO Shu-Jun, YUAN Jia-Fu, ZHANG Xin-Ran, XU Xiang-Yu, XIONG You-Sheng, QIN Xing-Cheng

2010, 18(6): 1157-1162. doi: 10.3724/SP.J.1011.2010.01157

Abstract(1781) PDF(1124)

Abstract:
In order to understand the effects of fertilization, planting and climate on soil N supply, field trials were conducted in Jiaoyuan Town, Xuan’en County with high frequent sampling of the field trial plots. Zero-tobacco planting and zero-fertilization were used as the control (CK) in the experiment. In the trials, rainfall and air temperature came from Enshi Meteorological Agency. Results show that soil alkali-hydrolysis N content increases with increasing air temperature, but decreases with increasing rainfall; generally lagging behind rainfall by 5~10 days. For a period of about 45 days, soil alkali-hydrolysis N content significantly increases under fertilization with no plastic film cover. Under combined organic and chemical fertilization, soil alkali-hydrolysis N supply improves in mid- to late-growth stages of tobacco. This is therefore an effective way of regulating N supply during later growth stage of tobacco. The order of significance of the factors affecting soil alkali-hydrolysis N content is planting > fertilization > climate. Cultivation factors such as crop absorption, film mulching are the main factors affecting soil alkali-hydrolysis N content.

Interactive influence of nitrogen and phosphorus application rate on wheat yield in North Henan, China

ZHANG Huan-Jun, YU Hong-Yan, XIANG Jian, DING Wei-Xin

2010, 18(6): 1163-1169. doi: 10.3724/SP.J.1011.2010.01163

Abstract(1948) PDF(1330)

Abstract:
A pot experiment was conducted to evaluate the interactive effects of nitrogen and phosphorus fertilizer application rates on wheat yield via measuring agronomic and physiologic indicators such as root activity (RA), acid phosphatase activity (APA) and nitrate reductase activity (NRA). Six treatments [200 kg(N)·hm^-2+100 kg(P₂O₅)·hm^-2, 200 kg(N)·hm^-2+160 kg(P₂O₅)·hm^-2, 220 kg(N)·hm^-2+100 kg(P₂O₅)·hm^-2, 220 kg(N)·hm^-2+160 kg(P₂O₅)·hm^-2, 240 kg(N)·hm^-2+100 kg(P₂O₅)·hm^-2 and 240 kg(N)·hm^-2+160 kg(P₂O₅)·hm^-2] were used in the study. The highest wheat yield occurs under the combination application of 220 kg(N)·hm^-2, 160 kg(P₂O₅)·hm^-2. Wheat yield is significantly correlated with RA, APA and NRA, and is in turn strongly related with wheat cumulative N and P. RA, APA and NRA increase with increasing application rate of phosphorus and nitrogen, but continue to increase until the application rate of nitrogen reaches 220 kg·hm^-2 before declining. This indicates that over-application of nitrogen fertilizer might reduce RA, APA and NRA, which in turn reduce the absorption rate of N and P and thereby decreasing wheat yield.

Effects of water and nitrogen interaction on photosynthetic characteristics and yield of cucumber in greenhouse

LI Yin-Kun, WU Xue-Ping, WU Hui-Jun, WU Qi-Fu, ZHANG Yan-Cai, WANG Li-Ying, LI Ruo-Nan, CAI Dian-Xiong, WANG Xiao-Bin

2010, 18(6): 1170-1175. doi: 10.3724/SP.J.1011.2010.01170

Abstract(1493) PDF(1125)

Abstract:
Potosynthetic rate, transpiration rate and water use efficiency at different growth stages and yield of cucumber under different water and nitrogen levels were studied in solar greenhouse to investigate the effects of water and nitrogen interaction on cucumber photosynthetic characteristics and production. The relationship between photosynthetic rate and cucumber yield were analyzed too. The results show that photosynthetic rate and transpiration rate reach the highest in full fruit stage, while water use efficiency in primary fruit stages. Under conventional irrigation, photosynthetic rate and transpiration rate increase with increasing nitrogen rate, and reach the highest under 7 470 m³·hm^-2 irrigation quantity and 1 200 kg·hm^-2 nitrogen rate (W₁N₁₂₀₀), but are not significantly different from those under W₂N₆₀₀ (irrigation quantity 5 190 m³·hm^-2, nitrogen rate 600 kg·hm^-2). Water use efficiency reaches the highest under W₂N₆₀₀, which is 1.08 and 1.24 times of those under W₁N₁₂₀₀ and CK respectively. Water and nitrogen interaction significantly affect cucumber yield and yield components. The optimal treatment is W₂N₆₀₀ with 30% reduction in water and 50% reduction in nitrogen compared with conventional treatment. It yields the highest, 17.06×104 kg·hm^-2. Photosynthetic rate presents a conic relationship with yield, fruit number per plant and average fruit weight respectively, in which the best fitting equation is at the full fruit stage.

Effects of winter cover crops on physiological and biochemical properties and growth of double cropping rice in South China

TANG Hai-Ming, TANG Wen-Guang, XIAO Xiao-Ping, LUO Zun-Chang, YANG Guang-Li, ZHANG Fan

2010, 18(6): 1176-1182. doi: 10.3724/SP.J.1011.2010.01176

Abstract(1835) PDF(1260)

Abstract:
The effects of four different winter cover crops, rygrass (Lolium multiflorum L.), Chinese mild vetch (Astragalus sinicus L.), rape (Brassica napus L.) and potato (Solanum tuberosum L.), on physiological and biochemical properties and growth of double cropping rice in South China were studied in a located experiment from 2004 to 2009. The results show that chlorophyll content, activities of SOD, POD and CAT in leaves of double cropping rice increase under four winter cover crops compared with CK (fallow of paddy field in winter) during growing season. MDA content decreases except at seedling and tillering stages of early rice. Four winter cover crops increase early rice effective tillers number by 18.08×104·hm^-2, 21.25×104·hm^-2, 12.75×104·hm^-2, 17.26×104·hm^-2; seed setting rate by 4.98%, 8.50%, 13.62%, 6.99%; 1000-grain weight by 0.24 g, 0.10 g, 0.14 g, 0.43 g; yield by 324.44 kg·hm^-2, 381.17 kg·hm^-2, 91.04 kg·hm^-2, 303.46 kg·hm^-2, respectively. They increase late rice effective tillers number by 9.81×104·hm^-2, 11.48×104·hm^-2, 5.06×104·hm^-2, 14.91×104·hm^-2; seed setting rate by 6.29%, 8.81%, 15.11%, 8.50%; 1000-grain weight by 0.93 g, 0.88 g, 0.10 g, 0.90 g; yield by 302.28 kg·hm^-2, 316.03 kg·hm^-2, 110.13 kg·hm^-2, 468.17 kg·hm^-2, respectively. The results indicate that the winter cover crops in double cropping rice paddy field may increase antioxidases activities, promote growth and development, and ultimately improve yield and yield components of rice.

Effects of planting density on sucrose metabolism and activities of enzymes related to starch synthesis in maize hybrids with different plant types

QIN Hong-Ni, CAI Yi-Lin, SUN Hai-Yan, WANG Jiu-Guang, WANG Guo-Qiang, LIU Zhi-Zhai

2010, 18(6): 1183-1188. doi: 10.3724/SP.J.1011.2010.01183

Abstract(2909) PDF(1849)

Abstract:
Loosely type maize “Changyu 13”, semi-compact maize “Dongdan 60” and compact maize “Zhengdan 958” were planted in three planting densities (2 600 plant·667 m^-2, 3 200 plant·667 m^-2, 3 800 plant·667 m^-2) to explore effects of planting density on sucrose metabolism and activities of enzymes related to starch synthesis in different plant types of maize hybrids. The results show significant effects of planting density on sucrose content and activities of sucrose phosphate synthase and sucrose synthase in functional leaves with most beneficial effect of low planting density. Planting density presents less influence on activities of ADP glucose pyrophosphorylase and UDP glucose pyrophosphorylase in maize grains. It is illustrated that loosly type maize “Changyu 13” and compact maize “Zhengdan 958” are source-limiting hybrids, semi-compact maize “Dongdan 60” is pool-limiting hybrid. Effects of planting density on different types of maize are different. They are strongest on loosely type maize “Changyu 13”, weakest on impact maize “Zhengdan 958”.

Effects of different forms of soil disinfection on soil physical properties and cucumber growth

LI Ying-Mei, CAO Hong-Mei, XU Fu-Li, REN Wu-Ting, LIU Jian-Li, ZHANG Shu-Lian, ZHANG Feng, CHEN Zhi-Jie

2010, 18(6): 1189-1193. doi: 10.3724/SP.J.1011.2010.01189

Abstract(1878) PDF(1343)

Abstract:
Experiments were conducted to study the effects of three soil disinfection methods (ridge and furrow soil solarization with plastic film mulch, calcium cyanamid with stalk, dazomet fumigation) on soil physical properties and the growth of cucumber in greenhouse conditions. The results show that ridge and furrow solarization with plastic film mulch has no visible effect on soil physical properties. While the content of coarse silt decreases by 9.5% compared to CK, the contents of two diameter of sands (0.1~0.5 mm, 0.5~1.0 mm) increase by 39.4%, 117.7% respectively compared to CK. No significant changes are noted in the remaining components. The content of clay in soil treated with calcium cyanamid and stalk increases by 163%, the contents two diameter of fine silts (0.001~0.005 mm, 0.005~0.01 mm) increase by 52.1%, 116.8% respectively compared to CK. Clay content of soil treated by dazomet fumigation decreases by 65.8%, the contents of two diameter of fine silt in soil decrease by 33.0%, 32.2% respectively compared to CK. Different soil disinfection treatments exert different inhibitions on soil aggregation. Calcium cyanamid with stalk treatment is most effective, followed by dazomet fumigation treatment. Ridge and furrow soil solarzation with plastic film mulch is least effective. The three soil disinfection treatments increase average plant height, leaf number, chlorophyll content and yield of cucumber. Ridge and furrow soil solarization with plastic film mulch not only significantly increases the biological indices of cucumber, but also promotes cucumber yield.

Effects of rhizosphere ventilation on growth and root activity of potted maize

GUO Chao, NIU Wen-Quan

2010, 18(6): 1194-1198. doi: 10.3724/SP.J.1011.2010.01194

Abstract(1664) PDF(1567)

Abstract:
To aim at the problems of limited and defective aeration environment of potted crops, we conducted an experiment with three ventilation treatments (T1: ventilating root zone every three days; T2: ventilating root zone every five days; CK: no ventilation) to investigate the effects of different rhizosphere aeration environments on growth and root activity of potted maize. The results show that T1 and T2 treatments improve plant height, leaf area, chlorophyll content, dry matter accumulation of aboveground and underground parts of potted maize. T1, T2 treatments increase root-shoot ratio (RSR) and root activity (RA) compared with CK. RSR, RA of T1 and T2 are 1.27, 1.18 times, and 1.26, 1.54 times of those of CK in elongation stage. In heading stage, they are 1.18 and 1.09 times, 1.22 and 1.40 times. Rhizosphere ventilation also promotes absorption of nutrient of soil. The results mean that rhizosphere ventilation enhances root activity and increases crops growth.

Effects of continuous deficit irrigation and partial root-zone irrigation on root growth of young apple tree

LIU Xian-Zhao, LIU De-Lin

2010, 18(6): 1199-1205. doi: 10.3724/SP.J.1011.2010.01199

Abstract(1901) PDF(1210)

Abstract:
A study was conducted to evaluate the effects of different irrigation patterns on root growth in 2-year-old apple trees (Malus pumila Mill. cv. Changfu No. 2). In the traditional pot experiments, the 2-year-old apple trees were subjected to conventional irrigation (CI; i.e., irrigation amount is 100% evaporation, measured with 120 mm diameter pans, on both sides of the root system), continuous deficit irrigation (CDI; i.e., irrigation amount is 50% CI on both sides of the root system), and partial root-zone irrigation (PRI; i.e., irrigation amount is 50% CI alternatively on one side of the root system) in Experimental Orchard of Fruit Research Institute, Yantai Academy of Agricultural Sciences in May to October of 2007. The results show that root length under PRI treatment is longer than that under CI treatment. Apple root length is shortest under CDI treatment. PRI treatment significantly promotes growth of absorbing roots with diameters less than 2 mm without obvious increase in total root dry weight. Curves of root biomass accumulation in young apple trees follow a typical sigmoid curve, corresponding to the three irrigation treatments. It is noted that high apple root growth rate and maximum root weight coincide with extremely high root vitality under PRI treatment. This is attributed to the good soil aeration, resulting from suitable soil moisture conditions. Compared with PRI, slower root growth rate and lower root vitality are observed under CI treatment due to beyond suitable soil water content. This coincides with lower root biomass, ranging between the other two treatments. Both root activity and root weight are the lowest under CDI treatment, probably due to persistent dry soils. For the three irrigation treatments, root-shoot ratios decline with increasing treatment time. Root-shoot ratio is highest under PRI treatment and lowest under CI treatment. PRI is most beneficial to root growth in young apple trees under 50% reduction in water supply.

Effect of drought stress simulated with PEG-6000 on root system in rice seedling

MA Ting-Chen, YU Rong-Rong, CHEN Rong-Jun, ZENG Han-Lai, ZHANG Duan-Pin

2010, 18(6): 1206-1211. doi: 10.3724/SP.J.1011.2010.01206

Abstract(2374) PDF(2890)

Abstract:
The rice seedlings of two different drought-resistant rice varieties, “Xiangfengzao119” (drought tolerant) and “Aihua No. 5 (drought sensitive), were treated with different concentrations of PEG-6000 (0 g·L^-1, 50 g·L^-1, 125 g·L^-1, 200 g·L^-1), and the morphological and physiological indexes such as root volume, maximum root length, lateral root length, adventitious root length, total root length, root quantity, root POD activity and relative permeability, were determined. The results show inhibiting effect of severe drought (200 g·L-1 PEG-6000) on roots morphological indexes except for root quantity of two rice varieties with more significant effects on drought sensitive variety. The rice roots morphological indexes increase with PEG-6000 treatment time, and make differences among different PEG-6000 concentrations after 3~4 d for treatment. Root POD activity and relative permeability increase with increasing PEG-6000 concentration and treatment time. Drought tolerant variety presents faster increment in POD activity and lower relative permeability than drought sensitive variety. Seedling root system of drought tolerant variety grows well with thicker, longer and stronger roots compared with that of sensitive variety. The results suggest root quantity and relative permeability should not be as indexes of drought tolerance selection.

Ecological effects of continuous potato cropping on soil water

ZHANG Qing-Xia, SONG Nai-Ping, WANG Lei, CHEN Lin

2010, 18(6): 1212-1217. doi: 10.3724/SP.J.1011.2010.01212

Abstract(1530) PDF(1050)

Abstract:
This paper presents a field experiment of continuous potato cropping for 1 year, 3 years, 6 years and 10 years with the aim of investigating biological characteristics of potato and dynamic variations in soil water. The experimental results indicate that with increasing year of continuous cropping, potato height, leaf area and net photosynthetic rate decrease. Pre- and post flowering is the water requirement peak of potato. Seasonal variation trends of soil water at different soil layers under different cropping durations are similar, but significantly differ among different cropping year treatments. For different cropping year treatments soils are dry in 40~60 cm soil layer during potato flowering stage, and with increasing year of continuous cropping, soil desiccation is aggravated. Under 6 and 10 years of continuous cropping, soil water content is 11.63% and 10.54% in 50 cm soil layer, gradually developing from light to medium desiccation. For 3 or more years of continuous potato cultivation, WUE decreases drastically. Rainfall in the hilly regions of South Ningxia, where soil layer is usually deep, complements soil water in the upper soil layers. However, deep soil water compensation is hardly realized under potato continuous cropping for more than 3 years. For more 3 years continuous potato cropping, negative ecological and environmental consequences of soil water shortage occur in study area.

Effects of cultivation regimes on weed community structures in newly reclaimed sandy farmlands

YANG Rong, SU Yong-Zhong

2010, 18(6): 1218-1222. doi: DOI:10.3724/SP.J.1011.year_id].01218

Abstract(1608) PDF(1136)

Abstract:
The varieties, quantities, coverage rates and heights of farmland weeds were surveyed and species diversity and richness analyzed in a newly reclaimed sandy farmland located in the margin oasis of the middle reaches of Heihe River Basin, Northwest China. The aim of the study was to evaluate the effects of cultivation regimes on weed community structure characteristics in the basin. A total of 16 weed species from 10 families were identified and recorded. The most common species of weed communities in newly reclaimed sandy farmlands are Chenopodium album, Eleusine indica, Setaria viridis and Amaranthus retroflexus. Weed community compositions are largely influenced by cultivation regimes. Weed species richness, Shannon-Wiener index and Simpson index are lower in conventional cultivation regimes (film mulching, autumn plowing and continuous maize planting). Those could, however, be improved under straw mulching, zero-autumn plowing and maize-soybean rotation treatments. Compared with film mulching, E. indica has a higher dominance ratio while C. album and A. retroflexus have lower dominance ration under straw mulching treatments. Compared with autumn plowing, S. viridis, A. reteroflexus, Silene conoidea and C. glaucum have a higher dominance ratio whereas E. indica has a lower dominance ratio under zero-autumn plowing treatments. Also compared with continuous maize planting, S. conoidea exhibits a higher dominance ratio under maize-soybean rotation regimes. There exist random rare weed species distribution in the field, which are not significantly effected by cultivation regimes. Results further show that weed species is few and weed communities composition is single in a newly reclaimed sandy farmland, and cultivation regimes obviously influence weed species diversity and community structure in reclaimed sandy farmlands. It is recommended to conduct additional research for a non-subjective interpretation of the effects of cultivation regimes on weed growth in order to guide weed control in newly reclaimed sandy farmlands.

Leaf δ13C of plants in different vegetation succession stages on karst hillslope of Northwest Guangxi, China

TAN Wei, CHEN Hong-Song, WANG Ke-Lin, NIE Yun-Peng, DENG Peng-Yan

2010, 18(6): 1223-1227. doi: DOI:10.3724/SP.J.1011.year_id].01223

Abstract(1777) PDF(1620)

Abstract:
Leaf δ¹³C of nine dominant plant species in grass-shrub stage, shrub stage and forest stage on karst hillslope of Northwest Guangxi was measured to learn leaf δ¹³C seasonal changes and variation among different vegetation succession stages. The results show that plant leaf δ¹³C of three vegetation succession stages have no significant difference in wet season (July, 2009), while it is significantly higher in shrub stage than that in forest stage (P<0.05), and a little higher than that in grass-shrub stage (P>0.05) in dry season (Nov., 2009). Meantime, plant leaf δ¹³C in grass-shrub stage is similar to that in forest stage in dry season. In consideration of life forms, leaf δ¹³C of trees is not significantly different in three vegetation succession stages, however that of shrubs and grasses is higher in shrub stage than in forest stage (P=0.063, 0.074) in dry season. Plant leaf δ¹³C of shrub stage is higher in dry season than in wet season (P<0.05). Not significant difference is observed in plant leaf δ¹³C of grass-shrub and forest stages between dry and wet seasons. Tree leaf δ¹³C in three succession stages are not significantly different in dry and wet seasons. Those of shrubs in grass-shrub stage and grasses in shrub stage are significantly higher in dry season than those in wet season. This indicates that seasonal change in rainfall greatly influences water use efficiency of plants in shrub stage than in other vegetation succession stages, which mainly results from rainfall effect on leaf δ¹³C of shrubs and grasses.

Evolution characteristics of population quality during genetic improvement in early season indica rice cultivars

YUAN Jiang, WANG Dan-Ying, XU Chun-Mei, ZHANG Xiu-Fu

2010, 18(6): 1228-1232. doi: 10.3724/SP.J.1011.2010.01228

Abstract(1702) PDF(1036)

Abstract:
Sixteen cultivars released during 1934~2006 and ever since widely planted in South China were classified into four rice types under conventional cultivation conditions according to evolution stages. The types include tall cultivar (TC), dwarf cultivar (DC), dwarf and resistant cultivar (DRC), and good-quality and super rice cultivar (QSC). A total of eight crop population quality indices were investigated in this study. The results indicate that photosynthetic ability and accumulated dry matter of rice population in post anthesis are reinforced with the evolution of early season indica rice cultivars. Total spikelet number at full heading stage increases, effective leaf area and spikelet-bleeding intensity slightly decrease, effective leaf area and ear-bearing tiller change slightly and single stem and sheath weight initially decreases but subsequently increases. To further improve population quality of early season indica rice it is important to enhance root activity facilitating absorption of water and mineral nutrients by root and root materials transformation to grains. Increasing effective leaf area rate, photosynthetic products in post-anthesis and total spikelet number are also the most effective ways of improving early season indica rice cultivars. This increases grain-to-leaf ratio and enhances coordinated source-sink balance.

Characteristics of production and quality of peanut in Huang-Huai-Hai region

GUO Hong-Hai, YANG Li-Ping, LI Xin-Hua, YANG Ping, WAN Shu-Bo

2010, 18(6): 1233-1238. doi: 10.3724/SP.J.1011.2010.01233

Abstract(1709) PDF(1504)

Abstract:
In order to guide the regional division of peanut production in Huang-Huai-Hai region, and efficiently utilize the agricultural resources, and provide the theoretical basis for improving peanut quality, the characteristics of production and quality of peanut in Huang-Huai-Hai region were studied based on GIS technology and mathematical statistics. The results show that peanut cultivation technology is advanced in the region producing higher unit yield. Peanut export is developed and processing industry is forming. Therefore, the region occupies a decisive position in peanut production in China, as an important pillar for stabilizing vegetable oil market. Influenced by ecological conditions, the mainly planted cultivar type in the region is virginia type, whose protein content is medium for edible cultivars, and fat content is higher for oil cultivars, with relatively low oleic acid/linoleic acid (O/L) ratio. Overproof contents of aflatoxin, daminozide and heavy metals in peanut are the main obstacles of peanut export in the region. The spatial distribution of protein content characterizes higher in the east, south and hilly area, lower in the west, north, and plain area. The fat content is higher in the north and hilly area, lower in the south and plain area, while O/L ratio presents increasing tendency from west to east and from north to south. The climate and soil fertility of the region are the domination factors affecting peanut fat and protein contents, and O/L value ratio and their spatial distribution of the peanut.

Screening sweet sorghum varieties of salt tolerance and correlation analysis among salt tolerance indices in sprout stage

WANG Xiu-Ling, CHENG Xu, LI Gui-Ying

2010, 18(6): 1239-1244. doi: DOI:10.3724/SP.J.1011.year_id].01239

Abstract(3346) PDF(2376)

Abstract:
Thirty-nine sweet sorghum varieties were screened for salinity tolerance under 0 and 200 mmol·L^-1 NaCl. Effects of salinity stress of three NaCl concentrations of 70 mmol·L^-1, 140 mmol·L^-1, 210 mmol·L^-1 on morphological parameters and their salt toxicity rates of ten selected varieties were investigated with water as the control. Finally, comprehensive evaluation on salt tolerance of sweet sorghum varieties was conducted by using Subordinate Function Value method. The results show that “Rio” and “Theis” are most salinity tolerant and “BJK236”, “Mer-72-2” are most salinity sensitive among thirty-nine sweet sorghum varieties. Germination rate, germination index, germination energy, vigor index, bud length, root length, bud fresh weight, root fresh weight of sweet sorghum varieties under salt stress are significantly different (P<0.05) from those under control. Moreover, with increase of salt concentrations, salt toxicity rates of above eight indicators are enhanced, which are significantly correlated with salt concentration (P<0.01). The correlation coefficients of toxicity rates of germination rate, germination energy, germination index, vigor index to salt concentration increase from significant correlation (P<0.05) to highly significant correlation (P<0.01) with increasing salt concentration. Comprehensive evaluation indicates the salt-tolerance order of ten sweet sorghum varieties as: “Theis”>“Tian132”>“BJK19”> “BJK156”> “Cowley”>“Jitian3”>“Wray”>“Keller”>“Dale”>“Jitian2”.

Comparisons of anatomical structure, component and photosynthetic capacity of leaves at different apple canopy positions

GAO Zhao-Quan, FENG She-Zhang, LI Tian-Hong, ZHANG Xian-Chuan

2010, 18(6): 1245-1250. doi: 10.3724/SP.J.1011.2010.01245

Abstract(1891) PDF(1312)

Abstract:
The work studied the differences in anatomical structure, component and photosynthetic capacity of leaves at different canopy positions of apple (Malus domestica Borkh. cv. ‘Fuji’) trees. Response of photosynthetic rate (P_n) of apple leaves to microclimatic factors was simulated by C₃ photosynthetic mechanism models. And the stomatal conductance was developed by using semi-mechanistic stomatal models. The results indicate that leaf thickness in the middle and upper canopy increases by 31.8% and 37.0% respectively compared to that in the lower canopy. Palisade thickness also increases by 44.8% and 62.7% respectively. Chlorophyll content in the middle and upper canopy increases by 18.0% and 20.6%, soluble sugar increases by 25.2% and 38.8% and proline increases by 11.7% and 29.0% respectively. Difference in photosynthetic capacity of leaves in different canopy position is similar to that in anatomical structure, component of leaves. Fluctuation in P_n of apple leaves is mainly caused by changes of photosynthetically active radiation, and highly sensitive to variations in carbon dioxide (CO₂) concentration at the leaf surface. From upper to lower canopy, daily P_n decreases by 67% (from 400 mmol·m^-2·d^-1 to 130 mmol·m^-2·d^-1 ) on clear-sky days and by 87% (from 170 mmol·m^-2·d^-1 to 22 mmol·m^-2·d^-1) on cloudy days. Maximal photosynthetic rate also decreases by an average of 67%.

Effect of low temperature stress and INA bacteria on parameters of photosynthesis and chlorophyll fluorescence in loquat leaf

ZHENG Guo-Hua, PAN Dong-Ming, NIU Xian-Qian, FANG Shu-Min

2010, 18(6): 1251-1255. doi: 10.3724/SP.J.1011.2010.01251

Abstract(1797) PDF(1156)

Abstract:
Freezing injury is a major factor that influences and restricts loquat’s production and development. In this experiment, the effects of INA (ice nucleation active) bacteria inoculation on photosynthetic and chlorophyll fluorescence parameters of the leaves of “Zaozhong No.6” loquat under low temperatures were investigated. The results show that INA bacteria significantly reduces Pn, Fm, Fv, Fv/Fo, Fv/Fm and water use efficiency under low temperature. This indicates that INA increases degradation of photosynthetic apparatus, which in turn limits photosynthetic activities under low temperatures. INA bacteria inoculation under -3 ℃ more significantly and earlier influences Pn, Fm, Fo, Fv, Fv/Fo and Fv/Fm than under -1 ℃. This implies that the lower the temperature, the greater and the earlier the damage caused by INA bacteria to photosynthetic system. Furthermore, it is noted that Tr is not associated with the presence of INA bacteria.

Effects of antioxidative levels on iron deficiency tolerance and iron accumulation in wheat (Triticum aestivum L.) seedlings

YU Yang, ZHANG Yu-Xiu, YIN Heng-Xia, LI Xia

2010, 18(6): 1256-1260. doi: 10.3724/SP.J.1011.2010.01256

Abstract(1849) PDF(1862)

Abstract:
In this study, we choose wheat cultivars “Shi 4185” and “Cang 6001” as materials to examine effects of antioxidative levels on iron deficiency tolerance and iron accumulation in wheat (Triticum aestivum L.) seedlings. The results show that iron deficiency markedly increases reactive oxygen species (ROS) level in roots, thereby induces oxidative damage in roots of wheat seedlings and reduces the chlorophyll content in leaves. Compared to “Shi 4185”, “Cang 6001” seedlings have lower ROS level, higher chlorophyll content, more lateral roots and higher leaves iron accumulation, as well as higher SOD, CAT and APX activities as exposed to iron deficiency. Supplementation of antioxidants such as ascorbic acid (AsA) and N-acetyl-L-cysteine (NAC) increases Fe content in wheat seedlings, suggesting higher antioxidative level improves Fe absorption and accumulation in wheat seedlings. This study has positive significance for further understanding the physiological mechanisms of wheat in response to iron deficiency stress and screening wheat cultivars for high iron deficiency tolerance and iron accumulation.

Release ways of α-solanine in Solanum melomgena L. plant

LI Zhi-Wen, ZHOU Bao-Li, LIU Xiang, ZHANG Ping

2010, 18(6): 1261-1266. doi: 10.3724/SP.J.1011.2010.01261

Abstract(1290) PDF(1134)

Abstract:
α-solanine release ways, root exudation, remnant decomposition, rainwater elution and seed germination, in eggplants were simulated and the released content determined via HPLC. Results show the α-solanine in eggplants can be released through root exudation, remnant decomposition and seed germination. Remnant decomposition and seed germination are the main paths for releasing α-solanine. Only a small fraction of α-solanine is released through root exudation. Rainwater elution hardly enhances eggplant releasing α-solanine into the environment. α-Solanine content released through root exudation is different in different eggplant growth stages. From seedling alabastrum to maturity stage of third eggplant is the main period of α-solanine release through root exudation. α-Solanine content in soils around eggplant roots significantly increase from the first to the second fruit stage. The order of released α-solanine amount from different organs of remnant body is leaf>root>stem. With the time of remnant decomposition, α-solanine content in soils significantly increases. The amount of α-solanine released via seed germination is closely related to seed germination. Hence α-Solanine inhibits eggplant seed germination. The results also show that α-solanine amount released by “Liaoqie No. 7” and “Chaojiuyeqie” (purple eggplants) is higher than that released by “Tongza No. 2” and “Xi’anluqie” (green eggplant).

Allelopathic effects of salicylic acid on activities of antioxidant enzymes of different allelopathic Chinese fir clones

CAO Guang-Qiu, YANG Mei, LIN Si-Zu, HUANG Yan-Hua

2010, 18(6): 1267-1271. doi: 10.3724/SP.J.1011.2010.01267

Abstract(1888) PDF(1437)

Abstract:
Autotoxicity is one of the main reasons for land degradation and productivity decline in continuous-planting Chinese fir plantations, and salicylic acid (SA) is one of the Chinese fir autotoxins. In this study, the autotoxins-tolerant clone (No. 01) and autotoxins-sensitive clone (No. 02) of Chinese fir were used as the materials in the stress experiment. The allelopathic effects of SA on antioxidant enzymes of the two Chinese fir clones were analyzed to provide the biological strategies to solve the continuous-planting obstacle in pure Chinese fir forest. The results show that all SA levels promote SOD activity of two clones leaves at 10 d and 20 d, but inhibit it at 30 d. The differences of SA allelopathic effects on SOD activity between two clones become obvious from 20 d after stress. Improving effect of SA at the 20th day on No. 01 is more significant, and inhibiting effect at the 30th day is less significant than those on No. 02. All SA levels promote POD and AsA-POD activities of two clones leaves throughout the whole stress period. Stimulatory effect of SA on POD activity of No. 01 clone is greater than that of No. 02 clone at 10th and 20th days of stress. AsA-POD activity of No. 01 increases rapidly after SA stress and keeps higher after long time stress than that of No. 02. PPO activity of No. 01 clone is increased by all SA levels during the stress period, while that of No. 02 clone is decreased, then increased, and decreased finally with stress time.

Effect of ecological management on arthropod community structure and diversity in hilly tea plantation

PANG Dong-Hui, XIAO Run-Lin, HOU Bo-Hua, SHAN Wu-Xiong, CHEN Pei

2010, 18(6): 1272-1276. doi: 10.3724/SP.J.1011.2010.01272

Abstract(1951) PDF(1325)

Abstract:
The experiment was conducted in the tea plantations of Yuanbaoshan Tea Company, Rongshui County, Guangxi to study ecological management of tea plantation on arthropod community structure and diversity. The results show that arthropod community composition increases by 15 families and 84 species under ecological management, compared with conventional tea plantation management. Individual amounts of pest population decrease by 55.9% and natural enemies increase by 188.4%. Tea plantation species richness, Shannon-Wiener index and Pielou index are significantly higher under ecological management than those under conventional management. However, Simpson index and Gowe index are significantly lower under ecological management compared with those under conventional management. The mode of ecological management could improve and restore arthropod community diversity in tea plantations. This mode is readily available for the realization of effective ecological control of tea pests

Diversity of arthropod community in the canopy of genetically modified herbicide-tolerant rice (Oryza sativa L.)

JIANG Xian-Bin, XIAO Guo-Ying

2010, 18(6): 1277-1283. doi: 10.3724/SP.J.1011.2010.01277

Abstract(1846) PDF(1352)

Abstract:
Genetically modified herbicide-tolerant (GMHT) rice may have impacts on arthropods in paddy fields. To detect the potential effects of GMHT rice on arthropods, the structure and feature of canopy arthropod community in fields of GMHT rice “Bar68-1” were compared with those of non-GM control “D68”. The families with high relative abundance of sub-communities of arthropod in GMHT rice field and non-GM rice field are similar, while the families with low relative abundance are different. There is no significant difference between GMHT rice and non-GM rice in the diversity indices, which are species abundance, Shannon-Wiener diversity index, Pielou index, Simpson index, of arthropod communities (P>0.05), with the exception of Simpson index (D) in sub-community of natural enemy in no-pesticide treatment in 2007. Difference in dynamics of most indexes, accounting for 95.3% of all calculated indexes, of arthropod community between GMHT rice field and non-GM rice field are not significant in mid-tillering, late tillering, full heading stage and milk stage of rice. The results suggest that GMHT rice “Bar68-1” does not significantly affect the composition and diversity of arthropod community in canopy.

Effects of mixed-grass feed from hyper-alkali-saline grasslands on daily intake, average daily gain, digestion and slaughter characteristics of sheep

WANG Cong, LIU Qiang, DONG Kuan-Hu, ZHAO Xiang, LIU Sheng-Qiang, HE Ting-Ting, LIU Zhuang-Yu

2010, 18(6): 1284-1288. doi: 10.3724/SP.J.1011.2010.01284

Abstract(2005) PDF(1246)

Abstract:
Twenty-four first filial generations (F1) sire growing-fattening sheep cross-breeds (Chinese Inner Mongolian Fine-wool and German Mutton Merino) averaging 3.0 months old and 23.1±0.62 kg body weight (BW) were arranged into four random groups. Sheep in the control group were fed concentrate supplement and silage maize, whereas sheep in treatments Ⅰ, Ⅱ and Ⅲ were fed concentrate supplement and silage maize, of which 1/3, 2/3 and 3/3 were substituted with grass-mixtures of Elymus dahuricus Turcz, Puccinellia distans (L.) Parl and Astragalus adsurgens Pall cultivated in hyper-alkali-saline grasslands. The feed intake, average daily gain, feed digestibility and slaughter performance of sheep in different groups were investigated. The results show no significant effect of mixed-grass feed on average daily gain (P>0.05). Feed intake in treatment Ⅲ is higher than that in the control (P<0.05). Feed conversion rate in treatmentsⅡand Ⅲ is higher than that in the control (P<0.05). Digestion of dry weight, organic matter, ether extract, neutral detergent fiber and acid detergent fiber linearly decreases with increasing mixed-grass feed proportion (P<0.05). Digestible nitrogen, retained nitrogen and retained-to-digestible nitrogen ratio also linearly decrease with increasing mixed-grass feed proportion (P<0.05). Percents of dressing and meat in treatments Ⅰ and Ⅱ are higher than those in treatment Ⅲ and the control (P<0.05). Meat-to-bone ratio in treatmentsⅠand Ⅱ are higher than those in the control (P<0.05). Eye muscle area in the treatments is significantly higher than that in the control. The above results indicate that though different levels of mixed-grass feed have no effect on average daily gain, they decreases feed digestibility and nitrogen utilization in sheep. Percents of dressing and meat, meat-to-bone ratio and eye muscle area improve when sheep are fed with mixtures of silage corn and mixed-grass feed.

Environmental fate of released nitrogen from scattered-feeding duck-feces during rainy seasons in the Baiyangdian Lake Region

WANG Hui-Hui, HU Zheng-Yi, WANG Shu-Ping, SHI Peng, SHI Yi-Chao

2010, 18(6): 1289-1294. doi: 10.3724/SP.J.1011.2010.01289

Abstract(1920) PDF(1383)

Abstract:
Scattered-feeding is an important duck breeding mode in the Baiyangdian Lake Rgion (BLR). During breeding, it is always hard to collect duck-feces because of the lack of concentrated breeding. Hence most duck-feces are abandoned on the soil surface. This paper stimulates a plot experiment condition to study the dynamics of released nitrogen from scattered feeding duck-feces and how they are influenced by environmental factors in BLR in rainy season of June to September. Investigation shows that during the reason part of nitrogen in duck-feces losses as NH₃ and NH₃ volatilization lasting for about 45 days at 8.72 kg·hm^-2. The first 7 days are critical for NH₃ volatilization, accounting for 82.7% of the total content. Volatile flux decreases gradually with decreasing temperature, illumination and increasing humidity and becomes insignificantly correlated with the environment factors. The load of total nitrogen loss in runoff is 10.05 kg·hm^-2, with the highest proportion of particle nitrogen in the duck-feces treatment. There is increasing concentration of inorganic nitrogen in dissolved total nitrogen. Total nitrogen loss in leached water is 19.30 kg·hm^-2 in duck-feces treatment, with the highest proportion of nitrate nitrogen. Under natural conditions, nitrogen loss through leaching, volatilization and runoff accounts for about 10% of total nitrogen in duck-feces. Non-mineralized nitrogen in duck-feces on soil surface plus nitrogen remaining in soil accounts for 45.09%. Once soil nitrogen content exceeds the critical value, it threatens water safety in BLR. Hence it is so urgent to adopt effective countermeasures that would eliminate hidden risks in free-range poultry in BLR.

Analysis on current situation of water pollution and pollutant sources in Ningxia Yellow River irrigation region

ZHANG Ai-Ping, YANG Shi-Qi, YI Jun, YANG Zheng-Li

2010, 18(6): 1295-1301. doi: 10.3724/SP.J.1011.2010.01295

Abstract(2310) PDF(1464)

Abstract:
With the control of point source pollution, the agricultural non-point source pollution is becoming the major factor affecting water quality. In Ningxia Yellow River irrigation region, one of China’s important commodity grain production areas, high-input in agriculture exacerbates the local water quality. This article analyzed water quality of the Yellow River flowing over several monitoring sections and of main drainage ditches in Ningxia. The results show that water quality of the Yellow River in Ningxia is mainly affected by agricultural irrigation return flow, industrial wastewater and domestic sewage. The water quality becomes worse after flowing through Ningxia with one class decreasing of comprehensive pollution index illustrating a certain degree of pollution. The main pollutants in Ningxia Yellow River irrigation region are Ar-OH, NH₄⁺-N, COD_Mn and BOD₅, which are decreasing generally from 2002 to 2007 in company with the reducing comprehensive pollution index. Water quality of main drainage ditches of the region is inferior class Ⅴ with 100% overproof monitoring sections. Its main pollutants are NH₄⁺-N, COD_Cr, BOD₅. The analysis on non-point pollution source shows that TN and NH₄⁺-N mainly come from farming, followed by breeding industry and the Yellow River water. Farming and livestock breeding are the main resources of TP. Most COD is from livestock breeding. The large amount of pollutants in farmland irrigation return flow is one of the major factors leading to deterioration of water quality in Ningxia.

Effect of acetochlor application on soil microorganism number and enzymes activities

JING Rui-Yong, WANG Li-Yan, WANG Yan-Jie, TAN Huan-Bo, MU Gui-Qiang, WANG Wei-Dong

2010, 18(6): 1302-1305. doi: 10.3724/SP.J.1011.2010.01302

Abstract(1964) PDF(1216)

Abstract:
An indoor inoculation experiment was conducted to determine acetochlor effect on soil microbe and enzyme activity. The results indicate that numbers of bacteria and actinomycete increase two weeks after applying acetochlor, then inhibited by 30 mg·kg^-1 acetochlor at the 30th day. After that, actinomycete number recovers while bacteria number is still inhibited till the 60th days. Fungi number decreases at 14 days after applying acteochlor, but then recovers at the 30th day and is stimulated at the 60th day. Soil dehydrogenase activity is stimulated two weeks after applying acetochlor, then is inhibited by 30 mg·kg^-1 acetochlor from 45 to 60 days after application. Catalase activity is not sensitive to acetochlor, but invertase and urease are sensitive at the early period of application. Invertase activity is inhibited by 0.3 mg·kg^-1 acetochlor, but stimulated by 3 mg·kg^-1 and 30 mg·kg^-1 acetochlor. Urease activity is inhibited by acetochlor in different application amount.

Effect of TBHQ on avermectin photo-degradation and its synergism on small brown planthopper

XU Guang-Chun, GU Zhong-Yan, XU De-Jin, XU Xiao-Long, FAN Peng

2010, 18(6): 1306-1310. doi: 10.3724/SP.J.1011.2010.01306

Abstract(1389) PDF(1332)

Abstract:
To delay avermectin photo-degradation, the paper studied the effects of different concentrations of antioxidant, terliary butyl hydroqulnon (TBHQ), on avermectin photo-degradation. The toxicity of avermectin and TBHQ mixture on small brown planthopper (SBPH) Laodelphax striatellus (Fallén) was also determined via rice-stem-dipping method. The results indicate that avermectin photo-degradation fits into the equation for first-order chemical reaction kinetics. Photolysis rate of avermectin photo-degradation under sunlight is slower than that under UV light. When TBHQ and avermectin ratio is 1︰1, photolysis rate is lowest for avermectin photo-degradation, and its half-life is 11.81 h. This is 167.19% increase compared with treatment without TBHQ. Laboratory bioassay results demonstrate that the synergistic effect of TBHQ and avermectin mixture on SBPH is significantly strong. After 3 h exposure to sunlight and UV light, the toxicity of avermectin and TBHQ mixture on SBPH increases significantly compared to that without TBHQ. The synergism ratio is 2.00 and 2.63, respectively.

Repellent effect of non-host vegetables and their extracts on Pieris rapae L.

WU Li-Min, LU Wen-Yan, YUAN Guo-Hui, XU Yan-Ling, GUO Xian-Ru, LUO Mei-Hao

2010, 18(6): 1311-1316. doi: 10.3724/SP.J.1011.2010.01311

Abstract(2079) PDF(1340)

Abstract:
To evaluate the control effects of non-host vegetables on imported cabbage butterfly Pieris rapae, bioassays were conducted to investigate the repellent effects of 6 non-host vegetables such as tomato (Lycopersicon esculentum), fennel (Foeniculum vulgare), catnip (Nepeta cataria), lettuce (Lactuca sativa), coriander (Coriandrum sativum) and towel gourd (Luffa cylindrical) on the butterfly in laboratory and field experiments. Indoor bioassay results show that selection response percentage of adult butterfly to cabbage reduces after treated with non-host vegetable extracts. The selection response percentages of mated female butterfly to cabbages treated with catnip, fennel, tomato and lettuce extracts are particularly low, only 3.67%, 4.30%, 5.27% and 8.26% respectively. Egg numbers laid by adult butterflies in cabbage seedlings treated with non-host vegetable extracts significantly reduce as well. Repellent activities of tomato, fennel and catnip extracts are strongest. After one day of treatment, the percentages of no-choice oviposition repellent are 91.04%, 75.54% and 71.67%, and those of choice oviposition repellent are 94.64%, 79.66% and 78.96% respectively. Field test results show that the amount of butterfly eggs in per cabbage plant could drop by 68.80%, 62.62% and 55.09% respectively in intercropping filed of cabbage with tomato, fennel and catnip. Effective repellent distances of the three non-host vegetables are 4 m, 2 m and 2 m respectively. Therefore, imported cabbage butterfly could be repelled by intercropping non-host vegetables or spraying not-host vegetable extracts in the cabbage fields.

Relationship between five major phytophaga pests and their natural predatory enemies in pomegranate field

YU Kun, ZOU Yun-Ding, BI Shou-Dong, ZHAO Peng, ZHAO Xue-Juan, DANG Feng-Hua, YU Xiao-Bei

2010, 18(6): 1317-1323. doi: 10.3724/SP.J.1011.2010.01317

Abstract(1914) PDF(1962)

Abstract:
The purpose of this study was to provide a scientific basis for the comprehensive control of pests in pomegranate fields using natural predatory enemies and chemical measures. Through the systematic investigation of the pests and natural predatory enemies in pomegranate fields, the paper identifies Aphis gossypii, Cnidocampa flavescens, Empoasca flavescens, Thosea sinensis and Cryptothelea minuscula as the major phytophaga pests in the hilly pomegranate fields of Jianghuai Area. The relationship in number, time and space between the major pests and their natural predatory enemies was studied through correlation analysis, ecological niche analysis and spatial pattern aggregation intensity index analysis. The comprehensive results show the order of the main natural predatory enemies of the major phytophaga pests as follows — A. gossypii: Harmonia axyridis, Chrysopa sinica and Theridion octomaculatum; C. flavescens: Clubiona japonicola, Misumenops tricuspidatus and Erigonidium graminicolum; E. flavescens: C. japonicola, Tetragnatha maxillosa and T. octomaculatum; T. sinensis: T. maxillosa, T. octomaculatum and C. japonicola; C. minu-scula: M. tricuspidatus, C. japonicola and H. axyridis. The cumulative average (l) of A. gossypii community excesses 2, this is because of the aggregation nature of the insect. On the other hand, the cumulative averages of communities of C. flavescens, E. flavescens, T. sinensis, C. minuscule, and natural predatory enemies are less than 2. This is mainly due to uncertain environmental factors.

A disease warning-source traceability model based on disaster chain-styled theory for solar greenhouse cucumber downy mildew

LI Ming, SUN Chuan-Heng, QIAN Jian-Ping, JI Zeng-Tao, YANG Xin-Ting

2010, 18(6): 1324-1329. doi: 10.3724/SP.J.1011.2010.01324

Abstract(1595) PDF(1241)

Abstract:
Warning-source traceability provides basis for disease early warning in solar greenhouse vegetables. Using disaster chain-styled theory and plant epidemiological theory, disease warning-source traceability problems and disaster mitigation modes by cutting the disaster chain were systematically analyzed. The disease warning-source traceability model was tested for cucumber downy mildew in solar greenhouse conditions. The model took into account the multi-warning-sources of disease early warning under solar greenhouse conditions and their effects on the interpretation ways of disease early warning. The instance of cucumber downy mildew under solar greenhouse conditions was tracked and analyzed using the disease warning-source traceability model. The study shows that overcast, rainy, snowy and foggy weather conditions are the warning-sources of cucumber downy mildew. The spatial and temporal variability of solar greenhouse environment was detected, and then warning-sources information was determined. The model could provide decision-making support for obviating downy mildew disease situations in solar greenhouse cucumber.

Complexity of soil type in Sangong River Basin of Xinjiang, China

YU Pu-Jia, XU Hai-Liang, ZHANG Qing-Qing, LIU Shi-Wei, ZHOU Cai-Xia, AN Hong-Yan

2010, 18(6): 1330-1334. doi: 10.3724/SP.J.1011.2010.01330

Abstract(1968) PDF(1216)

Abstract:
Based on fractal theory and patch shape index, scale/frequency relations of soil patches in Sangong River Basin were quantitatively analyzed. By combining soil patch area/perimeter fractal dimensions and shape index, soil type spatial distribution complexity in Sangong River Basin were discussed. Results show clear scale/frequency relations and area/perimeter relations of the soil patches in Sangong River Basin. Fractal dimensions of the soil types differ substantially in the basin. The highest fractal dimension is in alluvial soils and the lowest in meadow soloncha soils. There is significant correlation between complexity index and fractal dimension or patch shape index. The complexity index largely reflects the spatial distribution complexity of the soils. The most complex spatial distribution is in the alpine desert soils (K=2.403) and the simplest in semi-fixed aeolian soils (K=1.259).

Analysis on correlation between sugar content and planting conditions of sugarcane using NIR and GIS

DU Jian-Hong, SUN Li-Ya, ZHANG Yong-Kang, Masami UENO, Hidenobu KAWAMITHI

2010, 18(6): 1335-1339. doi: 10.3724/SP.J.1011.2010.01335

Abstract(1875) PDF(1088)

Abstract:
In order to provide the guidline for sugarcane cultivation, the temporal and special variations in sugarcane yield and sugar content, the relationship between planting area environment, soil compositions and sugarcane quality were analyzed. In the study, the sugar content of sugarcane was measured by using Near Infrared Spectrometer (NIR), and a space database containing information of field locations, sugarcane yield, sugar content, P and K contents in sugar juice and soil K content was established with Geographic Information System (GIS). Based on this, distribution maps of yield, contents of sugar, P and K of sugarcane in three cultivation annuals of 2000~2003 were achieved. It is found that sugar content of sugarcane is mainly affected by rainfall and water environment of plantation. The analysis on relationships of sugar content with P and K contents in sugarcane juice and soil K content shows that sugar content is positively correlated with P content of sugarcane juice, but negatively correlated with K content of sugarcane juice and soil.

Diagnosis of N nutrient status of corn using digital image processing technique

ZHANG Li-Zhou, WANG Dian-Wu, ZHANG Yu-Ming, CHENG Yi-Song, LI Hong-Jun, HU Chun-Sheng

2010, 18(6): 1340-1344. doi: 10.3724/SP.J.1011.2010.01340

Abstract(1847) PDF(1230)

Abstract:
Canopy images of summer corn were taken in the 6-leaf and 10-leaf stages in a field experiment with six N application levels. And the relationships between color parameter indexes of corn canopy images and N application level, leaf SPAD, stem sap nitrate concentration, plant total N content and nitrate N content in 0~90 cm soil were determined. The results show that in the 6-leaf stage, color parameter indexes of B/(R+G+B), G/B, R/B, B/L are significantly linearly correlated with N application level, leaf SPAD, stem sap nitrate concentration, plant total N content and nitrate N content in 0~90 cm soil (P<0.01). And B/(R+G+B) presents most significant correlation, and B/L is next to it. In 10-leaf stage, the correlations are not so significant as those in 6-leaf stage. The results suggest that it is feasible to use digital image processing technique to diagnose N nutrient statues of summer corn. The 6-leaf stage is crucial period with B/(R+G+B) as the index for the N nitrogen diagnosis using digital image processing technique.

Risk analysis of climate variability on food production in Hailun, Northeast China

ZHANG Hai-Ping, CHEN Li-Ding, WANG Xiao-Yan, MA Yan, ZHAO Xin-Feng, YANG Li-Rong

2010, 18(6): 1345-1350. doi: 10.3724/SP.J.1011.2010.01345

Abstract(1392) PDF(1120)

Abstract:
Climate variability is one of the main factors affecting annual changes in crop yield. In this study, a risk analysis method was used to describe the relationship between climate change and crop yield. The results could provide the basis for reducing the risk of food production. Based on available data on yield of soybean and corn in 22 towns of Hailun City for 1978~2007, relative meteorological yield was used as an indicator for the influence degree of climate change on crop yield. Yield reduction probabilities for different crops in each township were calculated using information diffusion method. Furthermore, the risk of crop production affected by climate variability was identified. Using daily rainfall and temperature as aridity index, all years were divided into partially dry, normal and partially wet years. The degree of risk was estimated under different hydrothermal years for each township. Results show that the probability of extremely high-yield years is lower than that of extremely low-yield years. The risk level of production reduction of soybean in north area is lower than that in south area, while the corn shows the contrary spatial tendency. There are spatial differences in risk levels of crop production among the different hydrothermal years. And spatial distribution of soybean production is more relative with rive network than that of corn production.

Developmental level of artificial oasis system in Tarim River Mainstream Area

HAN Chun-Xian, LUO Hui, LI Xia

2010, 18(6): 1351-1356. doi: 10.3724/SP.J.1011.2010.01351

Abstract(2105) PDF(1102)

Abstract:
Population and cultivated lands are the key sub-systems of artificial oasis system in arid areas. Their levels of development reflect the state of artificial oases. The state of the artificial oasis system in Tarim River Mainstream Area (TRMA) largely influences sustainable development of the entire Tarim region. Per-cultivated land production, which composes of food, cotton and other economic crops, was used to estimate land production in the region in this paper. Next, the factors that affect total cultivated land production in TRMA were measured. Food population carrying capacity and cultivated land pressure indices were used to assess the level of development of artificial oasis system in TRMA. Studies show that irrational human activities in the lower reaches of Tarim River heavily influence sustainable development of oasis system in TRMA during 1988~2007. Rapid increases in population and cultivated lands, irrational planting structures, unsafe food problems and mounting pressure on cultivated lands are the determinant factors of oasis systems in TRMA. More attention should therefore be given not only to rational cultivated land utility in the upper and middle reaches of TRMA, but also to population growth and rational development of cultivated land in the lower reaches of TRMA. It is essential to control population and cultivated land growth strictly in the lower reaches of TRMA for the sustainable development of TRMA. And the optimizing pattern of sustainable product is to develop cotton plant mainly and give consideration to crop product on the base of crop safety in TRMA.

Functional orientation of eco-economic regions in the Loess Plateau

ZHANG Qing-Feng, WU Fa-Qi, WANG Li

2010, 18(6): 1357-1365. doi: 10.3724/SP.J.1011.2010.01357

Abstract(1829) PDF(1174)

Abstract:
The concept of functional orientation of eco-economic regions (as defined in previous studies) is re-examined in this study. The dominant resources of economic development in the Loess Plateau were identified, and their distribution and exposition were systematically discussed. Meanwhile, a regional quotient method was used to analyze the comparative dominances in industries and resources of 18 eco-economic regions of the Loess Plaeteau. Furthermore, the study summarized relatively important ecological function regions and their regional distribution patterns. Finally, the study used systematic analysis and comprehensive induction to explain functional orientation of eco-economic regions in the Loess Plateau.

Market failure and loss of ecosystem service value of farmland in the process of farmland conversion —A case study of Jiangsu Province

XU Heng-Zhou

2010, 18(6): 1366-1371. doi: 10.3724/SP.J.1011.2010.01366

Abstract(1816) PDF(1094)

Abstract:
In the process of urbanization, much farmland has been changed into urban construction land, however, the non-market value of farmland is always be neglected. It is necessary to classify and quantify the ecological value of farmland. Taking Jiangsu Province as example, this paper classified the ecosystem service of farmland into four categories such as supplying, regulation, sustaining and culture. The value-appraising method was used to estimate ecosystem service value, loss of ecological value of farmland during process of farmland conversion. The results show that farmland ecosystem service value in Jiangsu Province is 213 859.9 Yuan·hm^-2, and its loss is 3 370 404.85 million Yuan from 1997 to 2004. Difference in environment and economy among different regions causes regional variation of farmland ecosystem service value in Jiangsu Province. The spacial distribution of farmland ecosystem service value characterizes reducing progressively from South Jiangsu to North Jiangsu. Finally, the paper suggests implementing ecological compensation mechanism, reconsidering farmland value, normalizing government behavior and innovation of appraising methods etc to protect farmland and properly estimate farmland ecological value.

Influences of organic fertilizer application on soil biological properties

XUE Feng, YAN Ting-Mei, YANG Lin-Zhang, QIAO Jun

2010, 18(6): 1372-1377. doi: 10.3724/SP.J.1011.2010.01372

Abstract(2236) PDF(2301)

Abstract:
It is necessary to study the influences of fertilizer application on soil since it is an important part of agricultural ecosystem. Soil biological properties such as enzyme activity, microbial biomass, respiration and biodiversity have received increasing attention due to they are much more sensitive to the outside disturbance than physiochemical properties. Contrast to the mineral fertilization, long time application of organic fertilizer can provide proper soil ecological environment for high crop production by improving contents of microbial biomass carbon and nitrogen, activities of soil enzymes and biodiversity and decreasing the metabolic respiratory quotient. Changes of soil biological properties influence the soil quality, agricultural yields and stabilization of ecosystem. This paper reviewed some works in these years about the influences of organic fertilizer application on soil biological characters.

Research advances on community structure and function of denitrifiers

WANG Ying, HU Chun-Sheng

2010, 18(6): 1378-1384. doi: 10.3724/SP.J.1011.2010.01378

Abstract(2105) PDF(3128)

Abstract:
Denitrification is an important part of N-cycling in ecosystem, and is closely associated with nitrate accumulation in groundwater and greenhouse gas emission. Various bacteria, fungi and archaea involved in denitrification play important roles in controlling rate and N₂O︰N₂ ratio of denitrification. Populations of denitrifiers are structured by long-term environmental factors. They respond to temperature, moisture, pH, O₂ content, nutrient availability and vegetation in different ways. Environmental factors indirectly control denitrification rate and enzyme production through affecting denitrifiers. The molecular technology application facilitates the study on denitrifiers in natural environments, and shows new directions for further understanding of correlation between denitrifier population structure and their function. This paper summarized research achievers in denitrifier population, and advanced a framework for future studies about connections between denitrifier population structure and function.

Change of orchard soil pH in the Loess Plateau

YANG Shi-Qi, ZHANG Ai-Ping, YANG Zheng-Li, LIU Guo-Qiang

2010, 18(6): 1385-1387. doi: 10.3724/SP.J.1011.2010.01385

Abstract(1817) PDF(1528)

Abstract:

2010 Vol. 18, No. 6