中国生态农业学报(中英文)

Effects of plastic film mulching on arable layer soil temperature, moisture and yield of sweet potato

JIANG Yan, SHI Chunyu, WANG Zhenzhen, WANG Cuijuan, LIU Hongjuan

2014, 22(6): 627-634. doi: 10.3724/SP.J.1011.2014.31229

Abstract(1826) PDF(1367)

Abstract:
As a new cultivation technique, plastic film mulching has been increasingly used in sweet potato cultivation. Expert studies have shown that plastic film mulching significantly increased sweet potato yield by improving soil environment conditions. However, few studies have related sweet potato root formation at early growth stage to storage root thickening at late growth stage under different plastic film mulching conditions. Thus this study used the 'Jixu23' sweet potato starch cultivar as the test material in three mulching treatments to study the effects of plastic film mulching on soil moisture and temperature and on the formation of tuber roots and yield of sweet potato. The three mulching treatments were no plastic film mulching (CK), transparent plastic film mulching (TF) and black plastic film mulching (BF). The results showed that at the early root differentiation stage of sweet potato (0?20 days after planting), plastic film mulching obviously increased soil temperature by 1.0?6.5 ℃ in the 0?20 cm arable soil layer. The transparent plastic film mulching treatment was 0.6?3.5 ℃ higher than the black plastic film mulching treatment. Meanwhile, plastic film mulching improved relative soil moisture content in 0-20 cm soil layer by 9.97%?18.1%. Also relative soil moisture under the black plastic film mulching treatment was higher than that under the transparent plastic film mulching treatment by 1.2%?5.1%. Despite the differences in the two forms of plastic film mulching, both increased root absorption area and root activity after 10 days of planting. Root activity under black plastic film mulching declined significantly (P < 0.05) after 20 days of planting. After 20 days of planting, plastic film mulching treatments improved the photosynthetic rate of sweet potato. Plastic film mulching increased zeatin riboside (ZR) content in differentiation roots at 20?40 days after planting, black plastic film mulching showed more significant effects (P < 0.05) than transparent plastic film mulching at 20?30 days after planting. Plastic film mulching also improved abscises acid (ABA) content in differentiation roots at 40 days after planting. ABA content was significantly (P < 0.05) higher under black plastic film mulching than under transparent plastic film mulching. At tuber root enlargement stage, plastic film mulching significantly improved initial and mean accumulation rates of dry matter in tuber roots. It also increased the number of storage roots, fresh root weight per plant and harvest yield. Under treatments of transparent film and black plastic film mulching, yield of storage roots of sweet potato increased by 10.38% and 15.91%, respectively. From the above, it was noted that plastic film mulching improved soil temperature and moisture, altered the contents of ZR and ABA to promote root differentiation during the prophase period of sweet potato growth and further promoted the swell of tuber roots during prophase growth. As a result of the above, dry matter distribution occurred earlier and more was allocated to tuber roots. Finally, plastic film mulching increased the yield of sweet potato and black plastic film mulching was better than transparent plastic film mulching.

Spatial distribution regularities of farmland soil quality in subsidence areas of coal filling mining and non-filling mining

XU Liangji, HUANG Can, ZHANG Ruqin, YAN Jiaping, Helmut MEUSER, Lutz MAKOWSKY

2014, 22(6): 635-641. doi: 10.3724/SP.J.1011.2014.31264

Abstract(1356) PDF(820)

Abstract:
Correlation research results showed that underground filling coal mining can effectively alleviate ground surface settlement in coal mining areas. To study whether filling coal mining was effective in protecting surface soils in cultivated lands, especially the ability of effectively maintaining soil fertility, an investigation was conducted in CT101 filling working face and 1013 non-filling working face in Wugou Coal Mine of Northern Anhui Mining Group. The test region and control region were set in the corresponding surfaces above the filling mining working face and non-filling working face. The two regions [both non-filling area (A) and filling mine area (B)] included division A₁ or B₁ in slope base of surface subsidence (point 1 to point 3 ), division A₂ or B₂ in middle subsidence slope (point 4 to point 6 ) and division A₃ or B₃ at top edge of subsidence (point 7 to point 9 ). In accordance with nine sampling points of each regions, each point was separately sampled at three soil depths [0-20 cm (H1), 20-40 cm (H2) and 40-60 cm (H3)] and two parallel samples collected for each depth, totaling 108 samples in the two regions. By this way, the physical properties (including soil bulk density and water content) and nutrients (including organic matter, available nitrogen, available phosphorus and available potassium contents), the height and yield of wheat in the two regions were analyzed. The results showed that nutrients contents of surface soil in the test region were higher than those in the control region. Based on observations during the experimental period, wheat growth in zones B₂ and B₃ was better than that in zones A₂ and A₃ from May to June until harvest. However, this was not the case for wheat height in zone B₁, which was shorter than that in zone A₁ in March. Wheat yield was higher in B zones than that in A zones at harvest. Soil moisture in the test region was higher than that in the control region. The analysis showed that mine filling activity had a stronger ability than non-filling in holding nutrients and water in overlying soils in mining areas. This was critical for the protection of land and the environment. Compared with normal soil background values, however, the overlying soils of mine filling area still exhibited some problems with nutrients contents such as organic matter and available phosphorus. With regards any effect on agriculture field, mine filling areas needed strengthened artificial activities such as addition of fertilizers, strengthening of field management, etc.

Regrowth responses to cutting of different cultivars of winter wheat

WANG Dandan, TIAN Lihua, SHEN Yuying, LIU Yuanbo

2014, 22(6): 642-647. doi: 10.3724/SP.J.1011.2014.40123

Abstract(1240) PDF(862)

Abstract:
Source-sink distribution response to cutting of common mid-maturity ('Ningmai5' and 'Longyu4') and late-maturity ('Xifeng27' and 'Longyu1') winter wheat cultivars in Longdong region was analyzed in this study. Leaf area index (LAI) at early regrowth stage, dry matter distribution pattern at anthesis and maturity stages of cut wheat with 2 cm stubble and uncut (the control) wheat were analyzed. The results showed that LAI and photosynthetic products of different cut wheat cultivars were different. Compared with the uncut treatment, cut treatment significantly decreased LAI of 'Ningmai5' and 'Lingyu4' mid-maturity cultivars respectively by 27% and 17%, decreased LAI of 'Xifeng27' late-maturity cultivar by 6%, increased LAI of 'Longyu1' late-maturity cultivar by 7%. Aboveground biomass of cut 'Ningmai5' and 'Lingyu4' mid-maturity cultivars decreased respectively by 18% and 11% while that of cut 'Longyu1' late-maturity cultivar increased by 13% at anthesis stage over the uncut ones. Compared with the uncut treatment, the trend of the belowground biomass of the 4 cultivars under cut treatment pointed downwards with the decreasing trend of late-maturity cultivar higher than that of mid-maturity cultivar. However, belowground biomass of late maturity cultivar gradually increased at maturity stage with a significant increase of 26% in 'Longyu1' wheat cultivar. While carbohydrate content of all the parts of mid- and late-maturity cultivars decreased, that of 'Longyu1' late-maturity cultivar increased by 2%?12%. These suggested enhanced distribution of carbohydrate and dry matter to leaf and spike along with redistribution ability and source-sink coordination, which laid the basis for high grain output. Compared with other cultivars, 'Longyu1' late-maturity cultivar was more suitable for forage utilization at tillering stage and harvestable grain at maturity.

Effects of crop rotation and soybean cultivar on rhizobial genomic diversity in root nodules

WANG Hao, ZHAO Shuangjin, WANG Shaodong, CHEN Wenxin

2014, 22(6): 648-654. doi: 10.3724/SP.J.1011.2014.40073

Abstract(1655) PDF(1134)

Abstract:
Soil and soybean cultivar are the main factors that influence genetic diversity of rhizobia. In this study, we isolated a total of 149 fast-growing and 49 slow-growing nodule bacteria strains from four soybean cultivars grown in soils with two different crop rotations by plant trapping method. We used amplified 16S rDNA restriction analysis (ARDRA), restriction fragment length polymorphism (RFLP) analysis of 16S-23S intergenic spacer (IGS) gene and nod C gene to investigate the effects of crop rotation and soybean cultivar on genomic diversity of rhizobia. ARDRA showed two rDNA types. Type Ⅰ covered all fast-growing strains belonged to Sinorhizobium, while type Ⅱ contained all slow-growing strains belonged to Bradyrhizobium. Three patterns constituted IGS-RFLP-IGS pattern Ⅰ identical to B. liaoningense of slow-growing strains, IGS pattern Ⅱ and IGS pattern Ⅲ similar to two reference strains of S. fredii of fast-growing strains. Based on the results for 16S-23S IGS ARDRA and RFLP, slow-growing strains were identified as B. liaoningense and fast-growing strains identified as S. fredii. Percent average of S. fredii in soils with winter wheat as fore-rotating crop (95.18%) was much higher than that in soils with maize as fore-rotating crop (53.78%), and this varied in relation to different soybean cultivars. In both soil types, 'Jidou 12' showed the highest affinity for S. fredii. Correlation analysis between IGS genotypes of 198 strains and host soybean cultivars showed that 'Wuxing 1' cultivar was most correlated to IGS type Ⅰ (Bradyrhizobium), 'Williams' and 'Jidou 17' cultivars most correlated to IGS type Ⅱ (Sinorhizobium) and 'Jidou 12' cultivar most correlated to IGS type Ⅲ (Sinorhizobium). Results for C-RFLP node showed that crop rotation and soybean cultivar did not affect the nodulation genotype of strains. The results from this study revealed some interactions among rhizobia, crop rotation and soybean cultivar. The effect of crop rotation on rhizobium species was greater than that of soybean cultivar. Soybean cultivar showed some selectivity for rhizobium genotype.

Response of photosynthetic characteristics and disease resistance of watermelon to companion with wheat

XU Weihui, WU Fengzhi, WANG Zhigang, SUN Guoyan, XU Honghong

2014, 22(6): 655-660. doi: 10.3724/SP.J.1011.2014.40136

Abstract(1582) PDF(794)

Abstract:
Watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] is an important fruit that is commonly eaten all over the world. However, studies have shown that continuous cropping of watermelon on the same field could lead to serious problems, including poor plant growth, reduced production and low disease resistance called soil sickness. It has also been noted that intercropping or rotating watermelon with wheat, a process known as companion wheat, could reduce soil sickness disease. To further explore companion wheat 'D₁₂₅' effect on the growth of watermelon, pot experiments were conducted to investigate the response of photosynthetic characteristics and disease resistance in watermelon to companion with wheat 'D₁₂₅'. The two treatments were monoculture watermelon (the control) and watermelon in companion with wheat. The tested soil was planted with watermelon for three consecutive years. The results showed that photosynthetic rate, stomatal conductance and intercellular CO₂concentration of watermelon in companion with wheat were significantly higher than those of monoculture watermelon by 32.2%, 28.5% and 7.8%, respectively. Chlorophyll (chl a + chl b, chl a, and chl a/b) contents of watermelon in companion with wheat were also significantly higher than those in monoculture watermelon on the 40th day after transplanting by 7.5%, 8.4% and 3.2%, respectively. Similar results were obtained on the 60th day after transplanting for photosynthetic rate, stomatal conductance, intercellular CO₂ concentration and chlorophyll (chl a + chl b, chl a, and chl a/b) contents of watermelon in companion with wheat, all of which were significantly higher than those in monoculture watermelon by 52.9%, 116.7%, 33.8%, 5.8%, 7.1% and 4.9%, respectively. No significant differences in Fo, Fυ, Fυ/Fm, ФPSⅡ and qP were noted between the two cropping systems. Powdery mildew disease index of watermelon leaf decreased by 6.3% in companion cropping system, compared with monoculture watermelon on the 40^th day after transplanting watermelon. Also compared with monoculture cropping, MDA content and PAL activity of watermelon leaf in companion cropping system decreased by 44.43% and 8.68%, respectively. The activities of SOD and PPO in watermelon leaf increased by 17.3% and 84.5%, respectively. On the 60^th day after transplanting watermelon, PAL activity of watermelon in companion with wheat was higher than that in monoculture watermelon. No significant differences were noted in MDA content and SOD and PPO activities between the two cropping systems. The results of the study suggested that watermelon had a positive response to wheat 'D₁₂₅' as a companion crop. The companion of watermelon with wheat 'D₁₂₅' was also beneficial for improving photosynthetic characters, increasing disease resistance of watermelon under continuous cropping system.

Determining antifungal spectrum and mechanism of Trichoderma longibrachiatum in vitro

ZHANG Jin, ZHANG Shuwu, XU Bingliang, GU Lijun, XUE Yingyu

2014, 22(6): 661-667. doi: 10.3724/SP.J.1011.2014.31183

Abstract(2460) PDF(5167)

Abstract:
To clarify the antifungal spectrum of Trichoderma longibrachiatum and the probable mechanism of T. longibrachiatum against plant pathogens, confrontational incubation and microscopic observation were used to determine the antifungal spectrum, and to explore the probable mechanism of T. longibrachiatum against twelve kinds of plant pathogens in vitro. The results of confrontational incubation experiment showed that T. longibrachiatum had the greatest magnitude of inhibition against the plant pathogens of Valsa ceratosperma and Rhizoctonia solani in vitro. The inhibitory rates of T. longibrachiatum against the plant pathogens of V. ceratosperma and R. solani were 86.4% and 72.5% respectively. It was further noted that T. longibrachiatum colony covered the whole colony of V. ceratosperma and the edge of R. solani colony, produced large numbers of spores on in whole colony of V. ceratosperma and the edge of R. solani colony 3 d after inoculation. Also the antagonism coefficient of T. longibrachiatum against V. ceratosperma and R. solani plant pathogens were ranked as Ⅰ and Ⅱ, respectively. However, the inhibitory effect of T. longibrachiatum on Bipolaris triticicola plant pathogens was weak, and the inhibitory rate was 27.5%. Meanwhile the antagonism coefficient of T. longibrachiatum against B. triticicola was grade Ⅲ. Analysis of antifungal mechanism of T. longibrachiatum showed that T. longibrachiatum produced inhibition zone, competed for nutrition and spaced with plant pathogens, and showed mycoparasitic behavior against plant pathogens when in contact with each other. Then, T. longibrachiatum mycelia covered the colonies of plant pathogens, grew on the surface and occupied the space of plant pathogens after contact with twelve pathogens. Plant pathogens mycelia appeared twisted after contact with T. longibrachiatum, and twisted part were so obviously constricted that protoplast of pathogen hyphae cell and mycelia eventually spilt and ruptured. T. longibrachiatum strains had different inhibitory effect on the growth of twelve kinds of plant pathogens which determined the probable mechanism of T. longibrachiatum against plant pathogens.

Effect of temperature on development and fecundity of pyridaben resistant and susceptible populations of Tetranychus truncates Ehara (Acari: Tetranychidae)

SONG Liwen, SHEN Huimin

2014, 22(6): 668-674. doi: 10.3724/SP.J.1011.2014.40142

Abstract(1377) PDF(915)

Abstract:
In order to verify the effect of temperature on the development, fecundity and biological fitness of pyridaben resistant and susceptible populations of Tetranychus truncates Ehara, the development, average life span and female egg production along with biotic fitness (calculated by using the net reproductive rate ) of two T. truncatus populations were determined at six different temperatures (16 ℃, 20 ℃, 24 ℃, 28 ℃, 32 ℃ and 36 ℃) and 16 h illumination, 60% ± 5% relative humidity. The results showed that the two T. truncatus populations completed generation development within the investigated temperature ranges and the entire developmental duration and average life-span duration shortened as temperature increased. The entire developmental duration of pyridaben resistant and susceptible populations of T. truncatus respectively were shortened by 20.0 d and 18.7 d within a temperature range of 16?36 ℃. Compared with susceptible population of T. truncatus, the resistant population had shorter developmental duration of every life stage, average life span and reproduction under low and thermophilic temperature range of 16?28 ℃. Apart from egg production (average of 17.15 eggs and 16.64 eggs for per resistant and susceptible female T. truncatus), the developmental duration, average life span and spawning period of resistant population of T. truncatus were longer than those of susceptible population of T. truncatus at a high temperature of 36 ℃. Using life parameter of net reproductive rate (R0) to determine biological fitness of the two T. truncatus populations, it was noted that biological fitness of the resistant population was less than 1 (one) in the temperature range of 16-28 ℃, while fitness of resistant population was greater than 1 (Rf =1.18, 1.19) at high temperature 32 ℃, 36 ℃. It implied that biological fitness of resistant population was significantly higher than that of susceptible population of T. truncatus at high temperature, but indifferent at low and thermophilic temperature ranges. The above results showed that the suitability of T. truncatus to high temperature increased after selection with pyridaben and the survival rate and fecundity of resistant population was obviously greater than that of susceptible population of T. truncatus at high temperature.

Detoxification enzymes activities in two color morphs of pea aphid (Acyrthosiphon pisum) treated with different sub-lethal concentrations of avermectin

WANG Xiaoqiang, LIU Changzhong

2014, 22(6): 675-681. doi: 10.3724/SP.J.1011.2014.40093

Abstract(1227) PDF(962)

Abstract:
Pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: aphidiae), is an important agricultural pest for a wide range of leguminous crops with a very strong reproductive capacity. Pea aphid is a well-studied species in terms of color polymorphism, which occurs as two distinct (red and green) color morphs. It has been proposed that the occurrence of this color polymorphism was a response to environmental factors (in particular pesticides) which increase the adapting ability of A. pisum to changed environment. The resistance of pea becomes weak or disappeared as pea exposed to red color morphs, indicating biological type characters of A. pisums. To learn pesticides effects on different color morphs of A. pisum, the specific activities of acetylcholinesterase (AChE), glutathione S-transferase (GSTs) and mixed function oxidase (MFO) of red and green morphs of A. pisum treated with different sub-lethal concentrations of avermectin were studied in this paper. The results showed that the specific activities of AChE, GSTs and MFO of red and green morphs of A. pisum treated with different concentrations (LC₂₀, LC₁₀ and LC₅) of avermectin were higher than those of the control after 24 h. Also the specific activities of GSTs and MFO improved with increasing sub-lethal dosage. However, the specific activity of AChE of red and green morphs ofA. pisum reached maximum values of 13.93 nmol·min^-l·mg^-l(pro) and 53.93 nmol·min^-l·mg^-l(pro), respectively, under LC₁₀. The specific activity of AChE of green morph of A. pisum was higher than of red morph, and GSTs showed the reverse trend. However, no significant trends were noted in specific activity of MFO between red and green morphs of A. pisum treated with different concentrations. The specific activities of AChE, GSTs and MFO of red and green morphs of A. pisum treated with LC₂₀, LC₁₀ and LC₅ of avermectin decreased or increased with time. Specially, the specific activity of GSTs of green morph of A. pisum treated with different concentrations of avermectin reached the maximum values [which were 49.84 nmol·min^-l·mg^-l(pro) for CK, 48.87 nmol·min^-l·mg^-l(pro) for LC₅, 42.74 nmol·min ^-l·mg ^-l(pro) for LC₁₀ and 45.35 nmol·min ^-l·mg ^-l(pro) for LC₂₀] at 0 h and were significantly higher than those of the rest of the other time scales. In summary, the change in specific activities of AChE, GSTs and MFO of red and green morphs of A. pisum had obvious links with treated concentrations and time.

Potential grain output and technology approaches in the plain around the Bohai Sea in Shandong Province

WU Lanfang, BAI Linchuan, OUYANG Zhu, WANG Chunjing

2014, 22(6): 682-689. doi: 10.3724/SP.J.1011.2014.31266

Abstract(1172) PDF(1494)

Abstract:
It is a big challenge to promote grain production in China under the background of limited arable lands and increasing grain demand due to an enormous population. In order to provide scientific basis for national policy decision-making on increasing grain production capacity, planning and distributing, potential grain outputs of 30 counties in the area around the Bohai Sea in Shandong Province were estimated by using current data about arable lands, cropping systems and land productivity in recent years. The results show that the potential increase in grain output was likely to reach 4.034 1 × 10⁹ kg, which could be achieved by expanding planting area of grain crops and enhancing grain yield per unit area. There were two approaches to enlarge the area of grain crops. Firstly, about 50% of the current areas of cotton of single cropping per year system change into wheat/corn double cropping system by enriching soil fertility and adopting special varieties. This approach may increase grain production by 2.364 7 × 10⁹ kg. Secondly, some of the current uncultivated lands with severe saline-alkali develop for planting grain crops after taking comprehensive measures to increase grain output to 7.755 5 × 10⁸ kg. Furthermore, the promotion of wheat and corn grain yield under current cultivated farmlands will further increase grain output by 8.938 5 × 10⁸ kg. Counties with greater potential for grain output increase by either expanding planting area or enhancing grain yield are in the Delta area and along the banks of the Yellow River. The main technology approaches include: 1) leaching and discharge of salt ions from saline-alkali soils by intense freshwater watering and drainage, which will as well reduce salt accumulation in surface soils; 2) enriching soil fertility and increasing land productivity by using soil improvement measures such as application of organic manure, utilization of microbial remediation agents and management of crop residues; 3) optimizing farming systems by screening and applying crop cultivars with high salt-tolerance. Furthermore, it was essential to conduct demonstration of standard technologies at farmland scale.

Variation of standard farming system in agro-pastoral transition zones of northern and southern foothills of Yinshan Mountains in recent thirty years

WANG Fangtian, AN Pingli, LIU Yi, LI Sheng, LI Xuemin

2014, 22(6): 690-696. doi: 10.3724/SP.J.1011.2014.30911

Abstract(1331) PDF(1127)

Abstract:
Standard farming system is the basic work for grading farmlands and is also an important factor for evaluating sustainable agricultural development of given regions. Based on peasant household survey data in the recent two years, planting areas of crops and general meteorological data covering 1980?2010, this paper analyzed variations in standard farming system in the transition zones of agricultural and pastoral areas of northern and southern foothills of Yinshan Mountains, and the corresponding reasons from the aspects of climatic and socioeconomic factors. The study mainly focused on changes in planting structure and spatial configurations of the farming systems. The results showed that the proportion of wheat planting area in northern Yinshan Mountains decreased from 40.00% in 1980 to 11.48% in 2010. Concurrently, cereal planting area in the region in 1980?2010 decreased from about 30% to 13% and while original planting area of potato was rare, it expanded to about 47.32% in 2010. Then from 1980 to 1990 in southern Yinshan Mountains, the proportion of land area planted with wheat increased by 21.70% while the planting area of cereal remained the same at about 35%. Whereas few grew potato and corn in the same period from 1980 to 1990, the planting area of triticeae crops steadily decreased. By 2010, the proportion of land area planted with wheat was 8.55% and that of cereal was very small. Meanwhile the proportion of land area planted with corn and potato rapidly increased, with the proportion of land area under corn of 47.79% and that under potato of about 25% in 2010. The current peasant household survey data were consistent with statistics data for the region. Analysis of the driving factors for the changes in the farming system showed obvious trends for environmental aridity, severely affected cereal by drought, low economic benefits and poor wheat sustainability. Thus although the planting area greatly reduced, high economic benefits was the main factor for the increases in the planting areas of potato and corn. In conclusion, cereal crops have been gradually withdrawn from the local standard farming system. At present, potato and corn were advanced in the development of agriculture in the local region and this had gradually become the standard farming systems of the study area.

Evaluation of the suitability and influencing factors of winter rapeseed planting in Gansu Province

ZHOU Dongmei, ZHANG Renzhi, SUN Wancang, ZHANG Jun, WANG Heling

2014, 22(6): 697-704. doi: 10.3724/SP.J.1011.2014.40153

Abstract(1225) PDF(1287)

Abstract:
Research have shown that under global climate change, the development of winter rapeseed cultivation technology and the introduction of new varieties have significantly changed traditional crop production patterns and structures of winter rapeseed. Winter rapeseed planting regions have extended northwards and the altitudes increased which have in turn increased crop planting area and output in Gansu Province. Through analysis of the adaption of winter rapeseed to climate change using GIS spatial platform and maximum entropy models, this paper provided the basic reference for improving winter rapeseed production layout and restructuring of agricultural construction. The study analyzed the main influencing factors and distribution characteristics of winter rapeseed planting patterns in Gansu Province. It also simulated the adaption of winter rapeseed to climate change and provided reasonable scientific suggestions on the production patterns of winter rapeseed in Gansu Province. The growth regions were divided into four types based on the degree of adaption to climate - unsuitable area, less suitable area, suitable area and optimum area. The results showed that the winter rapeseed planting area accounted for 60% of the total area, which was greater than the actual planting area in Gansu Province. The planting distribution probability of winter rapeseed was 0 0.89 and with significant potential for the development of winter rapeseed cultivation in Gansu Province. The key climatic factors affecting the cultivation, distribution of winter rapeseed production were precipitation during the growth period, negative cumulative temperatures, minimum temperature of the coldest month, average temperature of the coldest month, annual average temperature and extreme low temperature. And their limits were 50?200 mm, ≥?800, ≥?20 ℃, ≥?15 ℃, ≥4 ℃ and ≥-28 ℃.

Evaluation and regionalization of maize vulnerability to drought disaster in Western Jilin Province based on CERES-Maize model

PANG Zeyuan, DONG Shuna, ZHANG Jiquan, TONG Zhijun, LIU Xingpeng, SUN Zhongyi

2014, 22(6): 705-712. doi: 10.3724/SP.J.1011.2014.31268

Abstract(1255) PDF(1217)

Abstract:
Natural disaster risk is the possibility of disaster-related losses depending on hazard, vulnerability, exposure and emergency response and recovery capability. Vulnerability is the indicator measuring the damage extent of hazard-affected body. Vulnerability is not only an important part of risk assessment for loss estimation and disaster, but also the link between hazard-inducing factors and disaster. This study collected meteorological, soil, land use and field management data along with other related information on the research area to evaluate the vulnerability of maize drought disaster based on CERES-Maize model in western Jilin Province. According to the define of vulnerability of natural disaster risk and climate change, the study established the evaluation method of drought vulnerability based on disturbance, sensitivity and adaptive capacity. Data for three typical drought years (2004, 2006 and 2007) in western Jilin Province were used to calculate drought vulnerability using CERES-Maize model. Regression analysis was also conducted for maize yield losses caused by drought and vulnerability index in the three typical drought years for each growth period. The results showed exponential correlations between yield loss and vulnerability, which were significant at α = 0.05 (F test) for different growth stages. This indicated that it was reasonable to evaluate and predict maize vulnerability to drought using the es-tablished model in the region. Correlation coefficients indicated most close relationship between maize yield losses and vulnerability index at tasseling to milk-ripe stage and jointing to tasseling stage, and followed by milk-ripe to maturity stage and seeding to jointing stage. Drought vulnerability indexes of maize were divided into 4 grades and draught vulnerability zone maps of western Jilin Province drawn on GIS platform. The results showed that areas with high drought vulnerability included Baicheng, Taonan and Zhenlai. Low drought vulnerability areas included Songyuan and Fuyu. The established drought vulnerability evaluation model was suitable for evaluating and predicting drought vulnerability of maize at different growth stages and maize yield loss due to drought. The results of this study provided the basis for improving agricultural drought risk and emergency response and recovery capability.

Impact of climate change on the division of jujube planting zones in Xinjiang

ZHANG Shanqing, PU Zongchao, LI Jinglin, LI Xinjian, JI Chunrong, FU Weidong, WANG Mingquan, LI Xiaoju, ZHENG Xinqian

2014, 22(6): 713-721. doi: 10.3724/SP.J.1011.2014.31259

Abstract(1527) PDF(1113)

Abstract:
On the backdrop of climate change, changes in climatic zones of jujube planting in Xinjiang was studied. Of significant importance were adaptation to climate change, full rational use of agro-climatic resources, scientific planting of Xinjiang jujube, development planning and promotion of sustainable/stable development of Xinjiang jujube industry. Using long-term (1961 2012) climate data from 101 meteorological stations in Xinjiang region along with linear regression, cumulative anomaly, t-test and mixed spatial interpolation analyses in ArcGIS environment, the study analyzed the fundamental characteristics of spatio-temporal changes in ≥10 ℃ cumulative temperature, extreme minimum temperature in winter and mean temperature for June July. The impact of climate change on jujube planting zones was studied in relation to climate division index of jujube planting zones. The results showed that spatial distributions of ≥10 ℃ cumulative temperature, extreme minimum temperature and mean temperature for June July obviously varied from place to place in Xinjiang. Generally, these factors were higher in the south than in the north and in the plain/basin than in the mountain regions of jujube planting zones in Xinjiang. On the backdrop of global warming in the last 52 years, ≥10 ℃ cumulative temperature, extreme minimum temperature and mean temperature for June July showed significantly increasing trends by the tendency rate of 62.22 ℃.d.10a^-1, 0.551 ℃.10a^-1 and 0.221 ℃.10a^-1, respectively, and with significant changes in 1997, 1982 and 1994. With this effect, suitable planting areas of jujube increased by 1.2 × 10⁵ km² after 1997, representing 7.3 percentage points increase in total area ratio. The areas with sub-suitability for planting jujube decreased by 4.0 × 10⁴ km², representing 2.4 percentage points decrease in total area ratio. Also areas classified as unsuitable for planting jujube decreased by and 8.0×10⁴ km², representing 4.9 percentage points decrease in total area ratio. While climate change increased the areas suitable for planting jujube, it decreased sub-suitable area and unsuitable areas for planting jujube in Xinjiang. This was critical for enhancing the development of jujube industry in Xinjiang.

Evaluation of ecological footprint of straw resources utilization based on emergy theory: A case study of typical rice-wheat rotation region in Chengdu Plain

HUANG Chun, DENG Liangji, GAO Xuesong, ZHANG Shirong

2014, 22(6): 722-728. doi: 10.3724/SP.J.1011.2014.31236

Abstract(1203) PDF(892)

Abstract:
Using Guanghan City and Dayi County as typical regions of rice-wheat rotation system in Chengdu Plain, emergy and ecological footprint theories were applied in the determination of the utilization status of straw resources based on statistical and survey data in 2011. Firstly, the emergies of different ways of straw utilization were calculated and the values of ecological footprint and capacity per capita then estimated and analyzed using the ecological footprint analysis method. The results showed that the values of per capita ecological footprint of rice and wheat straw resources in Guanghan City were 0.066 1 hm² and 0.034 2 hm² and the per capita ecological surpluses corresponding were 0.017 8 hm² and 0.008 1 hm², respectively. As for different utilization ways, the ecological footprint per capita of rice straws was in the order of fertilizer > raw materials > incineration and other ways > feed > biogas; for wheat straws, it was in the order of fertilizer > incineration and other ways > raw materials > biogas > feed. The values of per capita ecological footprints of rice and wheat straw resources in Dayi County were 0.051 6 hm² and 0.020 9 hm² with corresponding per capita ecological capacities of 0.061 0 hm² and 0.021 7 hm² and per capita ecological surpluses of 0.009 4 hm² and 0.000 8 hm², respectively. As for different utilization ways, the ecological footprint per capita of rice straws was in the order of raw materials > fertilizer > biogas > incineration and other ways > feed; for wheat straws it was in the order of fertilizer > incineration and other ways > raw materials > biogas > feed. The above results indicated that there still existed some room for reutilization of straw resources in Guanghan City and Dayi County. Specifically, if the unused part of the current straw resources were reused fully, it would greatly promote agricultural development which could lead to significant economic, ecological and environmental benefits.

Comparison of different straw cycling modes in farmland ecosystems in Chengdu Plain based on emergy theory

GAO Xuesong, DENG Liangji, ZHANG Shirong

2014, 22(6): 729-736. doi: 10.3724/SP.J.1011.2014.40005

Abstract(1336) PDF(900)

Abstract:
The flow and transformation of energy and circulation of materials can reflect the basic functional processes of agricultural ecosystems. Energy analysis of agricultural ecosystems focuses on the characteristics of energy flow, which converts different resources into standard emergy. Thus energy conversion in intra-ecosystems or inter-systems can be explained and the optimized modes or structures can be chosen. This paper aimed at finding out the most applicable straw utilization mode for local agricultural ecosystems in Chengdu Plain. Chengdu Plain is one of the biggest grain and oil production bases with high straw quantity in China. How to make better use of the straw resources rather than excessive consumption of agro-ecological resources has attracted considerable interest in recent years. In this paper, the theory and method of emergy analysis were used to study different straw cycling modes in "rice-wheat rotation" farmland ecosystems in Chengdu Plain. Through the systematic positioning test and random sampling, emergy inputs and outputs of farm land production modes with different straw cycling ways in Chengdu Plain were investigated. The modes included regular fertilization mode (CF), straw returning mode (CFS) and mushroom residues utilization modes (FRs, in which three modes with different inputs were involved, FR₁, FR₂, FR₃). Results indicated that non-renewable emergy inputs of CF and CFS modes accounted for a large portion in all emergy input. This mainly depended on auxiliary emergy of non-renewable industry, which easily resulted into non-point source pollution. The sequence of total emergy values of different modes was CF > FR₂ > CFS > FR₁ > FR₃. Compared with CF and CFS modes, emergy input-output ratios of FR₁, FR₂ and FR₃ modes were relatively higher. Total emergy output and emergy input-output ratio of FR₂ mode were highest, reaching 2.20×10¹⁶ sej and 2.35, respectively. Mushroom residues utilization modes had high net emergy yield ratio with emergy self-sufficiency ratio above 50%. Emergy loading ratios of CF and CFS modes were relatively high, reaching 1.66 and 1.75, respectively. Emergy loading ratios of all the other modes of mushroom residues utilization were below 1. The sustainable indexes of CF, CFS, FR₁, FR₂ and FR₃ modes were 1.68, 1.42, 6.56, 5.75 and 4.07, respectively. While the CFS mode increased organic emergy input, it decreased net emergy yield ratio. The CFS mode not only had high emergy input and emergy loading ratio, but also under considerable environmental pressure. However, the FRs modes had less chemical fertilizer emergy input, low emergy loading ratio and high net emergy yield ratio. Due to the sustainable features and development potential, the FRs modes were recommended as applicable modes in Chengdu Plain. The FR₂ mode was considered as the most suitable straw utilization production mode.

Remote sensing inversion of soil moisture in Hebei Plain based on ATI and TVDI models

DI Lanjie, WANG Wei, CHENG Hexi, NIU Zining

2014, 22(6): 737-743. doi: 10.3724/SP.J.1011.2014.31115

Abstract(1422) PDF(1474)

Abstract:
Soil moisture, as a strong indicators for soil water content, is a critical element for crop growth in Hebei Plain, one of the main crop production bases in Hebei Province. Scientific monitoring of soil relative moisture in Hebei Plain is vital for sustainable development of agriculture in the province. With respect to research on soil relative moisture monitoring, a series of soil relative moisture inversion models have been established. Inversion models based on thermal inertia and temperature vegetation index have been the most widely used models in recent years. However, the single use of any inversion model has always posed certain limitations in application scope. In terms of the advantages and disadvantages of the above two models, this paper used MODIS data and measured soil relative moisture data to retrieve soil moisture in Hebei Plain by integrating Apparent Thermal Inertia (ATI) model and Temperature Vegetation Dryness Index (TVDI) model. NDVI was employed as the division factor in March, April, May, October and November. TVDI model was used in area with NDVI > 0.2 for each ten days; in the area withNDVI ≤ 0.2, ATI model was used. TVDI model was used alone to retrieve soil relative moisture in June, July, August and September. Because of low vegetation coverage and missing measured soil relative moisture data in January, February and December, ATI model was used to invert soil relative moisture. The models were tested through P value, which was generally less than 0.01 for all the models. The retrieval results showed that soil relative moisture in Hebei Plain had two cycles, which changed from increasing to decreasing in the year. In the first cycle, from December to June of the next year, soil relative moisture increased from December to March and then decreased from March to June, with the maximum value in March. In the second cycle, from June to December, soil relative moisture increased from June to August and then decreased from August to December, with the peak value in August. While the average annual maximum value was in August, the average annual minimum value was in June. The spatial distribution of soil relative moisture was influenced mainly by precipitation, irrigation and land use patterns. During the same period, soil relative moisture in the east Hebei Plain and coastal plain in Cangzhou was relatively higher than that in other regions of the plain. The soil relative moisture in the piedmont plains of Taihang Mountain and Yanshan Mountain was relatively higher in spring. The point-to-point validation of three representative months (May, July, October) showed that the average relative errors of retrieval results were 21.4%, 19.25% and 22.22%, respectively, consistent with what was in the literature. The study showed that soil relative moisture from remote sensing inversion was in good correlation with field-measured data. The average relative error of the union of ATI and TVDI models was less than those from separate ATI and TVDI model.

Effects of straw returning on nitrogen mineralization of manure in solar greenhouse

WU Ailian1, WANG Jinsong, JIAO Xiaoyan, DONG Erwei, WANG Lige, HAN Xiong, CHEN Qing

2014, 22(6): 744-748. doi: 10.3724/SP.J.1011.2014.31097

Abstract(1076) PDF(980)

Abstract:

2014 Vol. 22, No. 6