中国生态农业学报(中英文)

Effects of irrigation method and straw mulch-nitrogen management pattern on straw decomposition characteristics and nitrogen utilization of hybrid rice

YAN Fengjun, SUN Yongjian, MA Jun, XU Hui, LI Yue, DAI Zou, YANG Zhiyuan, JIANG Mingjin, SUN Yuanyuan

2016, 24(11): 1435-1444. doi: 10.13930/j.cnki.cjea.160279

Abstract(1081) PDF(912)

Abstract:
Irrigation methods have both direct effect and remote effect (through straw decomposition and nitrogen release especially when integrated with nitrogen management) on rice growth. A field experiment was conducted to evaluate the effect of irrigation methods and optimal straw mulch-nitrogen management pattern on root growth, nitrogen accumulation at main growth stages and grain yield of hybrid rice. Also straw decomposition and nitrogen release mechanisms were probed to clarify the effects of the interaction of straw decomposition and nitrogen release on rice growth. The results showed that flooding irrigation (W₀) and alternate wetting and drying irrigation (W₁) methods generally coordinated aboveground growth with underground growth, promoted nitrogen accumulation and increased grain yield compared with drought farming (W₂).However, the water productivity in W₂ treatment was the highest among all treatments, ollowed by W₁. For wheat and rape straw decomposition and nitrogen release, the peak values occurred 30 days after transplanting (30 DAT). However, the degree of decomposition and nitrogen release were influenced by both irrigation methods and straw types. The rape straw under W₂ treatment had larger degree of decomposition, while wheat straw under W₁ led to more nitrogen release. For straw mulch-nitrogen management patterns, wheat straw combined with optimal nitrogen management (S₁N₁) under W₀ and W₁ treatments efficiently coordinated the growth, promoted nitrogen absorption and eventually increased grain yield. However,rape straw combined with optimal nitrogen management (S₂N₁) had a slight inhibitory effect on the whole growth. Under drought irrigation, S1N1 and S2N1 had positive and remarkable effects on growth. Correlation coefficients showed that the effect of the degree of straw decomposition on the 30DAT was significantly negatively correlated with yield and nitrogen accumulation (r=-0.27^*to -0.29^*). Also the effect of the degree of nitrogen release at heading and ripening stages was strongly positively correlated with yield and nitrogen absorption (r=0.31^*to -0.59^**). Also the effects of the degrees of straw decomposition and nitrogen release on root and shoot growth was strong, especially for the heading stage (r=-0.27^*to -0.42^**). The results suggested that it was important for high grain yield and high efficiency of rice production to coordinate the straw decomposition and nitrogen release at different growth stages of rice, especially at 30 days after transplanting.

Effects of plastic film mulching and conventional irrigation on water consumption characteristics and yield of winter wheat

SONG Wenpin, HUANG Jing, CHEN Xiaoli, WANG Lichun, SUN Weituo, WANG Zhimin, XUE Xuzhang, GUO Wenzhong, LI Youli, CHEN Fei

2016, 24(11): 1445-1455. doi: 10.13930/j.cnki.cjea.160377

Abstract(883) PDF(732)

Abstract:
Plastic mulching technology is widely used for agricultural production to limit crop evapotranspiration. In order to clarify the potential of plastic mulching on agricultural productivity and to explore the effect of maximum water-saving on the growth and yield of winter wheat in arid/semi-arid regions, a field experiment was conducted at the National Experiment Station of Precision Agriculture in Changping, Beijing (N40°10′33.26″, E116°23′37.07″). The experiment consisted of four treatments — T1 (plastic film mulching with no irrigation), T2 (wintering watering with no film mulching), T3 (wintering and jointing watering with no film mulching), and T4 (wintering, jointing and flowering watering with no film mulching). Compared with conventional film mulching, T1 treatment was covered with 1 cm soil layer over plastic film surface. Water consumption characteristics and yield were determined using the weighting lysimeter over the whole growth stage and sampling method. Also concurrently, the 200 cm depth soil moisture content was measured (using Diviner 2000) every day for the period from April to May. The results showed that T1 efficiently utilized soil moisture. There was a cubic function between cumulative evapotranspiration and the number of days after sowing for the four treatments, with determination correlation coefficient R² > 0.99. The heading stage had the maximum theoretical and actual values of soil-crop coefficient (Kc) under T1 and T4. For T2 and T3, Kc had a quadratic function with the number of days after sowing during jointing stage, with a determination correlation coefficient R² > 0.70 (that for T2 was 0.69). Water consumption was significantly lower under T1 than under others treatments during sowingjointing period. However, during jointingmaturity period, T1 and T2 were not statistically different in terms of water consumption, but had lower value than T3 and T4 (P < 0.05). During bootingflowering period and floweringmaturity period, water consumption under T1 was higher, respectively, by 3.1 mm and 21.43 mm than that of T2, but not statistically different (P > 0.05). However, this increased water consumption at the 50–100 cm soil depth at late growth stage. The peak evapotranspiration under T1 was higher than that of T2, but both lower than those of T3 and T4. The time of peak evapotranspiration under T1 (215 d after sowing) came later than those of T2, T3 and T4 (194 d after sowing). The time of Kc-max of T1 was consistent with that of T4 (214 d after sowing), but occurred later than that of T2 (200 d after sowing) and T3 (199 d after sowing). Compared with T2 and T3, T1 enhanced flag leaf water potential and delayed leaf-senescence, with soil surface (0–5 cm layer) temperature improving by 0.5 ℃. This temperature increase was not statistically significant (P > 0.05) and contributed minimally to soil evaporation. In terms of yield, yield components and water use efficiency, grain number per spike and the 1000-grain weight of T1 were higher than those of T2 and T3, which were in turn lower than those of T4; but were not statistically different (P > 0.05). The yield of T1 was not statistically different from that of T2 and T3, but significantly lower than that of T4 (P < 0.05) and with 22.6% increase in water use efficiency (P < 0.05). It suggested that plastic film mulching could widely replace wintering and jointing water application by limiting soil evaporation at the early growth stage in semi-humid regions with sufficient soil water content before sowing. The water saved was used for the late growth stage, which thereby reduced the amount of water consumption and increased water use efficiency of winter wheat. Irrespectively, this form of water-saving was not at the expense of crop yield.

Effects of soil straw return and nitrogen on spring maize yield, greenhouse gas emission and soil enzyme activity in black soils

LYU Yanjie, YU Haiyan, YAO Fanyun, CAO Yujun, WEI Wenwen, WANG Lichun, WANG Yongjun

2016, 24(11): 1456-1463. doi: 10.13930/j.cnki.cjea.160405

Abstract(1106) PDF(862)

Abstract:
Northeast China spring maize production area is among the main maize cultivation regions in China. Due to located in high latitude region and singling cropping system, spring maize fields in black soil region of Northeast China is less reported as for researches on farmland greenhouse effects. It is therefore important to explore the effects of straw return to soil and nitrogen application on maize grain yield and greenhouse gas emissions in the area. In this study, a two-factor straw return (no straw return and straw return) and three-factor nitrogen (N) application (N: 120 kg·hm^-2, 240 kg·hm^-2 and 300 kg·hm^-2) field experiment was conducted in a randomized block design. Total emissions of CO₂, N₂O and CH₄, global warming potential of CO₂-eq and greenhouse gas emissions intensity (GHGI), soil catalase and urease activities were determined in the experiment. The results showed that the highest yield was observed in straw return with medium N dose (240 kg·hm^-2) treatment, which was not significantly different from that of the highest N dose (300 kg·hm^-2) with no straw return treatment (P > 0.05). With increasing N dose, CO₂, N₂O and CH4 emissions, global warming potential of CO₂-eq, and GHGI significantly increased under no straw return conditions. On the other hand, N application with straw return only enhanced CO₂ and N₂O emissions, while soil CH4 carbon sink increased (P < 0.05), and greenhouse gas emissions and intensities (CO₂-eq and GHGI) did not increase remarkably (P > 0.05). Under no straw return conditions, N application reduced soil catalase activity and enhanced soil urease activity with increasing N application. However, straw return improved the decreasing range of soil catalase activity, and weakened the increasing range in soil urease activity caused by increased N application. Therefore, straw return with N application enhanced grain yield, with the highest yield under medium N application treatment (N: 240 kg·hm^-2). Medium N application with straw return limited greenhouse effects compared with no straw return in the experiment. The results were valuable for the recommendation of N application rates in spring maize cultivation in black soil regions.

Effect of plowing depth on soil physical characteristics and spatial distribution of root system of flue-cured tobacco

TONG Wenjie, DENG Xiaopeng, XU Zhaoli, MA Erdeng, JIN Yan, LI Junying

2016, 24(11): 1464-1472. doi: 10.13930/j.cnki.cjea.160555

Abstract(1059) PDF(821)

Abstract:
In order to explore the effects of plowing depth on yield and output of tobacco (Nicotiana tabacum L.) leaf, a field experiment was conducted, and soil physical characteristics and water content, spatial distribution of flue-cured tobacco root system as well as yield of tobacco were investigated. A flue-cured tobacco variety of ‘K326’ was planted with plowing depths of 20 cm (GS20, conventional tillage depth, CK), 30 cm (GS30) and 40 cm (GS40) in 2015 growing season, respectively. Leaf area and soil water content of 060 cm were measured after 30 days (rosette stage), 45 days (early vigorous growing stage), 60 days (later vigorous growing stage) and 75 days (early maturing stage) of transplant. Soil bulk density, total porosity, capillary porosity and non-capillary porosity after 54 day of transplant (vigorous growing stage) were investigated. Special distribution of root fresh weight after 65 days of transplant (squaring stage) was investigated too. The results showed that deep plowing had positive effect on soil structure, soil water storage, spatial distribution of flue-cured tobacco root system finally enhanced the yield and output. The deep plowing significantly decreased soil bulk density, increased soil total porosity, and capillary porosity at 2040 cm subsurface soil layer. Compared to CK (G20), GS30 and GS40 decreased soil bulk density by 8.4% and 9.4%, increased soil total porosity by 15.6% and 13.1%, and increased soil capillary porosity by 25.8% and 24.8%, respectively. The deep plowing with depths of 30 cm and 40 cm significantly increased soil moisture content at 020 cm surface soil layer at rosette stage and at 2040 cm subsurface soil layer at vigorous growing and maturing stages compared to those under GS20. Furthermore, the deep plowing not only significantly increased flue-cured tobacco root weight but also promoted the root content and proportion in deep soil. Root fresh biomass weight under GS30 and GS40 was 31.2% and 89.2% higher than that under GS20, respectively. Root depth index under GS30 and GS40 was 7.6% and 4.5% higher than that under GS20, respectively. In addition, tobacco leaf yield increased by 7.0% and 27.3%, average price increased by 1.8% and 6.2%, the ratio of the first-class tobacco increased by 10.4% and 24.4%, and the output value increased by 9.0% and 35.1% under GS30 and GS40 than those under GS20, respectively. There was significant difference between GS40 and GS20. The results showed that the improved soil physical characteristics, e.g., bulk density, total porosity and capillary porosity under deep plowing could increase soil moisture content at plough layer which benefited tobacco seedling growth, and lead to an optimization of the horizontal and vertical distribution of tobacco root system. A strong root system under deep plowing directly strengthened the growth of over-ground part of tobacco. Finally the yield and output value of tobacco leaf were increased.

The combined effect of irrigation and potassium fertilization on the physiological characteristics and yield of peanut

ZHANG Peng, ZHANG Yulong, CHI Daocai, ZOU Hongtao, GAO Na, QU Jing, YU Na

2016, 24(11): 1473-1481. doi: 10.13930/j.cnki.cjea.160482

Abstract(859) PDF(695)

Abstract:
This study clarified the combined effects of different levels of water and potassium supply on physiological characteristics and reproductive growth of peanut. To that end, a pot experiment was conducted to investigate the differences in leaf enzyme activities at late podding stage and reproductive growth. It was a random block design experiment with two factors and four levels for each factor — W₁: 35% field capacity; W₂: 50% field capacity; W₃: 65% field capacity ; W₄: 80% field capacity; K₀: 0 g(K₂O)·kg^-1(soil); K₁: 0.15 g(K₂O)·kg^-1(soil); K₂: 0.30 g(K₂O)·kg^-1(soil); K₃: 0.45 g(K₂O)·kg^-1(soil). The tested peanut cultivar was ‘Huayu 25’. The results showed that irrigation had an extremely significant (P < 0.01) effect on relative water content (RWC) and chlorophyll content of peanut leaves. Also leaf water had an obvious dilution effect on chlorophyll content. Thus, the RWC increased significantly (P < 0.01), while chlorophyll content decreased significantly (P < 0.01) with increasing irrigation amount. Moreover, interaction of water and potassium had an extremely positive effect on the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) (P < 0.05 or P < 0.01). The three enzymes had different responses to different adverse conditions. SOD activity increased obviously under deficient potassium (K₀) or high potassium (K₃) conditions. Also POD increased significantly (P < 0.01) under water stress (W1) or K₃, while CAT increased significantly (P < 0.05) in W₁ or K₀ conditions. With increasing soil water content, CAT activity decreased rapidly to match with the dynamics in chlorophyll content, which two processes had an extremely significant positive correlation (P < 0.01). These evidences indicated that CAT was a key element in reducing the degradation of chlorophyll and lengthening the functional period of peanut leaf at late podding stage. The effects of potassium fertilizer and irrigation on total flowering were significant or extremely significant. The application of potassium fertilizer significantly delayed the beginning of flowering, but reduced irrigation amount advanced termination of florescence. Under K₂ condition, fertile flower number and flower fertility rate of all the water treatments were relatively high. Under W₃ condition, potassium fertilizer had an enhancing-effect on single seed weight, which was also occurred under W₂ condition. The significant increase in single pod number and in dual kernel fruit rate enhanced the yield-increase effect of soil moisture. For all the treatments, W₃ and K₂ had the shortest florescence (25 days), the highest rate of fertile flowers (51%) and seed kernel yield in this experiment.

Effect of single-seed sowing on growth, physiology and yield of summer peanut

ZHANG Jialei, GUO Feng, MENG Jingjing, YANG Sha, GENG Yun, WANG Lili, ZHANG Nan, LI Xinguo, WAN Shubo

2016, 24(11): 1482-1490. doi: 10.13930/j.cnki.cjea.160522

Abstract(1063) PDF(925)

Abstract:
Summer-sowing peanut has developed rapidly with a planting model of peanut-wheat relay cropping. However, studies on individual development and population structure of summer-sowed peanut were inadequate. To supplement this deficiency, a field experiment was conducted in 2014 and 2015, to study the differences in plant development, leaf physiological characteristics and yield components between single-seed (SS) and double-seed (DS) sowed summer peanut. The previous crop was wheat, which was harvested on June 15. The peanut cultivar ‘HY22’ was sowed on ridges and mulched with plastic film on June 20. The ridge was 50 cm with a furrow spacing of 30 cm. Plant spacing was 10 cm for SS, 20 cm for DS, and the plant density was same for both treatments, 2.5 × 10⁵ plant·hm². The results showed that main stem height and lateral branch length of SS treatment were higher than those of DS treatment at the early growth stage, however they became lower than those of DS at the late growth stage. The numbers of both node and leaf in main stem, leaf area index and especially branch numbers of SS were all higher than those of DS during the whole growth period. The activities of SOD, POD and CAT, chlorophyll content and photosynthetic rate increased, while MDA content reduced at pod-filling stage and maturation stage in SS treatment. Although no significant differences was observed on above leaf physiological indexes between SS and DS treatments at pod-filling stage, but the differences was remarkable at maturity stage. Pod yield of SS increased significantly compared with DS treatment due to a significant increase in full pod number per plant. And it positively related to both pod weight per plant and photosynthetic rate. This implied that it was positively correlated with economic coefficients, leaf number per main stem, leaf area index and chlorophyll content.

Security of water-ecology and food under replacement of winter wheat-summer maize rotation with spring maize mono-cropping in Hebei Lowland Plains

YAN Peng, CHEN Yuanquan, ZHANG Xuepeng, TAO Zhiqiang, YANG Xiaolei, SUI Peng

2016, 24(11): 1491-1499. doi: 10.13930/j.cnki.cjea.160347

Abstract(1176) PDF(793)

Abstract:
Hebei Lowland Plains, one of the main grain producing areas in China, has an acute water shortage. To ensure sustainable development in the plains, strategies are needed to manage the water shortage and obtain high crop yield in the region. In terms of water-saving and high-yield farming systems for the region, spring maize mono-cropping has shown to be a promising alternative to the traditional winter wheat-summer maize double-cropping system. A comprehensive comparison between the effects of the winter wheat-summer maize rotation and the spring maize mono-cropping on water ecological security and food security in the study area under different yield levels has not yet been tested. Thus, field experiments were conducted at Wuqiao Experiment Station of China Agricultural University in the Hebei Lowland Plains in 2011–2014 to determine the feasibility of replacing traditional high irrigation costs of the winter wheat-summer maize double-cropping rotation system with the spring maize mono-cropping system. The three treatments implemented in the experiment included a winter wheat and summer maize double-cropping rotation (WS), a rain-fed spring maize mono-cropping system (SMRF) and a fully-irrigated spring maize mono-cropping system (SMSW) — in which treatment WS was used as the control (CK). Four main factors were evaluated — actual annual evapotranspiration (ETa), productivity, water use efficiency (WUE), economic benefit and economic water use efficiency (EWUE) — that influenced the performance of the three treatments. Results showed that average annual ETa was highest under WS, followed by SMSW and SMRF. Average annual ETa under SMSW and SMRF decreased by 48.4% and 54.2%, respectively, compared with WS. Under WS cropping system, precipitation accounted for only 32.9% of total water consumption by winter wheat during the three-year experimentation period, while irrigation and soil water were the two main water sources of winter wheat. Adversely, precipitation accounted for 91.9% and 94.9% of total water consumption under SMSW and SMRF systems. Average annual productivity under SMSW and SMRF systems decreased respectively by 24.4% and 45.8%, compared with WS rotation system. In addition, economic benefits were highest under WS, although those under SMSW and WS were very close, with SMSW only 5.2% lower than WS on average. SMRF economic benefits were 36.8% lower than that of WS. However, WUE and EWUE under WS were lower than those under SMSW and SMRF. While WUE increased by 24.8% and 0.3%, EWUE increased by 56.7% and 17.5% respectively under SMSW and SMRF compared with those of WS. Although WS had higher annual grain yield and economic benefits, this was driven primarily by the unsustainable use of intensive irrigation. In comparison to WS, food security under SMSW system reached 75.7% with 46.7% groundwater irrigation. With advancements in spring maize production technology, there was the potential to increase the productivity of spring maize. Compared to the double-cropping system, the spring maize mono-cropping system was a water-saving, high-yielding and efficient alternative cropping system. To balance water resources and food security in the Hebei Lowland Plains, China’s “new normal” conditions with the “Three Increases” (increases in grain production, storage and import) has shifted the ideal cropping system from the winter wheat-summer maize rotation system to a more sustainable spring maize mono-cropping system.

Response of soil physical properties to alfalfa growth years in the Western Loess Plateau

LUO Zhuzhu, NIU Yining, LI Lingling, CAI Liqun, ZHANG Renzhi, XIE Junhong

2016, 24(11): 1500-1507. doi: 10.13930/j.cnki.cjea.160191

Abstract(1003) PDF(726)

Abstract:
As one of the poorest regions in China, the lLoess Plateau has the severe erosion across large areas, which has limited agricultural development beyond subsistence farming. The traditionally cereal-dominant agricultural system driven by extensive tillage and cultivation on slopes has contributed significantly to erosion on the plateau. Alfalfa (Medicago sativa) was introduced in China and has since been cultivated for over 2 000 years now. It is one of the important perennial legumes cultivated on the Loess Plateau which increases livestock production, reduces soil erosion in the annual crop rotation system and improves soil fertility through alfalfa-based pasture crop rotation on slopes and annual cropping in upland plains. In a field experiment conducted in Dingxi City, Gansu Province (a typical semiarid area of the Western Loess Plateau), different growth periods of alfalfa were investigated in relation to soil physical properties. The study also discussed the optimum growth years of alfalfa in the Loess Plateau in the cCentral Gansu Province. Soil samples were taken from the 050 cm soil layers in alfalfa field plots with different growth years (3 years, 10 years and 12 years) and in potato fields. Measurements of soil bulk density, soil aggregate stability, saturated hydraulic conductivity, total organic carbon (TOC) and readily oxidized organic carbon (ROOC) were then recorded. The results showed that soil bulk density was significantly lower and total porosity significantly higher in potato fields than in alfalfa fields for topsoil, but not significantly different for deep soil layers. The content of > 0.25 mm water-stable macro-aggregates, mean weight diameter (MWD) and geometric mean diameter (GMD) of soil aggregates in alfalfa fields increased with alfalfa growth years, and were significantly higher than those in cropland fields for the 030 cm soil depth. Then the percentage aggregate destruction (PAD) of soils in alfalfa fields was significant lower than that in potato fields, which decreased with increasing alfalfa growth years. TOC and ROOC improved growth conditions in alfalfa fields for a certain period of growth. The proportion of ROOC onto TOC wasere 44%–57% and 52%–68% in alfalfa fields and in potato fields, respectively. This indicated that alfalfa fields improved soil organic carbon (SOC) content and as well decreased percent ROOC of to TOC. SOC was significantly higher in alfalfa fields than in potato fields, where it initially increased and then decreased with increasing alfalfa growth period. Therefore alfalfa cultivation on the plateau was significantly beneficial under rainfed cultivationrainfed farming system, including the enhancement of soil structure, changes in SOC fraction, and soil permeability. It was, therefore concluded that the optimum growth period of alfalfa in the semi-arid areas of the Loess Plateau was 10 years. It was recommended to develop alfalfa-cereal rotation system after 10 years of alfalfa growth in order to increase crop production, reduce soil erosion and enhance the sustainability of the agricultural system.

Response of morphological structure and photosynthetic parameters to water deficit in four flue-cured tobacco cultivar seedlings

CHEN Zheng, XU Jiayang, FAN Yikuan, HUANG Wuxing, WANG Peiwen, WEN Xinyi, XU Zicheng

2016, 24(11): 1508-1520. doi: 10.13930/j.cnki.cjea.160504

Abstract(948) PDF(608)

Abstract:
Drought is one of the many environmental factors which affect the growth and development of plants in many regions of the world due to climate change. The effect of moderate drought stress on seedling biomass, root morphology, stomatal characteristics, chloroplast ultra-structure and photosynthetic parameters of four flue-cured tobacco cultivars (Y6, Y10, Y12 and ZY100) were investigated in a hydroponic experiment with polyethylene glycol (PEG-6000) simulating moderate drought stress to evaluate drought tolerance of different flue-cured tobacco varieties. The results showed that the roots and leaves of different cultivars of tobacoo under moderate drought stress had different physiological responses. (1) A close relationship was noted between root growth and water supply in this study. The moderate drought stress stimulated root growth of flue-cured tobacco seedling, while it inhibited shoot growth. Root to shoot ratio of the 4 flue-cured tobacco cultivars significantly increased under drought stress conditions compared with that of control. Root biomass, total root length, root surface area and root volume of Y6 and Y12 significantly increased while root average diameter decreased. Then roots of Y10 and ZY100 were sensitive to moderate drought stress where root morphology index increased little or even decreased. Although the average diameter of the 4 flue-cured cultivars seedlings decreased significantly, root surface area of Y10 increased significantly. (2) Drought stress significantly decreased stomatal density while increasing both stomatal length and width of Y6, Y12 and Y10. There was a significant difference in stomatal density of ZY100 seedlings between the control group and the drought stress group. However, no significant difference was observed in stomatal width of the four flue-cured tobacco cultivars seedlings. Total pore area per leaf area of ZY100 significantly increased under drought stress. (3) Chloroplast ultra-structure of Y6 and Y12 was slightly changed under drought stress and the change was more obvious in Y10 and ZY100 cultivars. The shape of chloroplast in mesophyll cells changed and separated from cell wall, which destroyed chloroplast integrity. The average length, length-width ratio and area index of chloroplast decreased significantly for ZY100 seedlings under drought stress. (4) Net photosynthetic rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s) of the 4 cultivars seedlings declined, while intercellular CO₂ concentration (C_i) increased significantly in response to drought stress. This indicated that the decline in photosynthesis was as a result of the absence of stomatal restriction under moderate drought stress. The differences between drought group and control group were significant for Y10 and ZY100 seedlings. (5) Under drought stress, the chlorophyll contents of Y6 and Y12 increased significantly, while that of Y10 and Z100 increased slightly or even decreased. The comprehensive analysis showed that Y6 and Y12 were drought resistant cultivars, and Y10 and ZY100 were drought sensitive cultivars. Drought resistance ability of the 4 flue-cured tobacco cultivars was in the order of Y6 > Y12 > Y10 > ZY100 at seedling stage.

Evaluation of nitrogen efficiency for selected Shaan A and B maize inbred lines

LI Yanan, LIU Xueyan, SHI Yaqin, LI Yibo, WANG Yahui, CHEN Pengfei, LIU Jianchao, ZHANG Renhe, XU Shutu, XUE Jiquan

2016, 24(11): 1521-1528. doi: 10.13930/j.cnki.cjea.160433

Abstract(1018) PDF(691)

Abstract:
This study was set up to explore the characteristics of nitrogen (N) use efficiency (NUE) of different groups (Shaan A group and Shann B group) of maize inbred lines, and to screen high N-efficient maize inbred lines. A total of 33 maize inbred lines from the Shaan B and Shaan A groups were used along with 4 elite inbred lines (‘zheng58’, ‘chang7-2’, ‘PH6WC’, ‘PH4CV’) as the control. The study analyzed SPAD value, green leaf area, dry matter accumulation as well as N uptake in stem, leaf and grain of maize inbred lines under no nitrogen [N0, 0 kg(N)?hm^-2] and normal N [N180, 180 kg(N)?hm^-2] levels. Based on principal component analysis (PCA), fuzzy membership function (FRF), stepwise regression analysis and the optimal regression equation, evaluation indexes for low N tolerance of maize inbred lines was established. The results indicated that SPAD value, green leaf area, stem dry weight and leaf dry weight at silking and grain N uptake were reliable secondary indicators for comprehensive evaluation of low N resistant ability of maize inbred lines. Using yield as primary index, among 37 maize inbred lines, 15 lines were determined as high yield with high N efficiency, 5 lines as low yields with high N efficiency, 15 lines as low yields with low N efficiency and 2 lines as high yields with low N efficiency. According to the integrated value of low N resistance (D) calculated using the secondary indexes, 37 maize inbred lines were also divided into three types — 15 lines of strongest resistance to low N with D ≥ 0.5, 15 lines of stronger resistance to low N with 0.35 ≤ D < 0.5, and 7 lines of poor resistant to low N with D < 0.35. Comprehensive analysis of two N levels showed that ‘KB215’, ‘KB417’, ‘KA225’, ‘KB081’ and ‘L123098-2’ had higher green area and stem and leaf dry matter at silking stage, greater grain N content and higher yield, and the strongest resistance to low N. Thus strengthening selection process of breeding environment and low N use effectively improved the utilization efficiency of N fertilizer of maize germplasm.

Response of endogenous ABA and GA to cold resistance of Brassica rapa L. and Brassica napus L.

LIU Haiqing, FANG Yuan, WU Junyan, CHEN Qi, SUN Wancang, LIU Zigang, FANG Yan, MI Chao, PU Yuanyuan, ZHAO Yanning, DONG Xiaoyun, ZENG Xiucun, XU Yaozhao

2016, 24(11): 1529-1538. doi: 10.13930/j.cnki.cjea.160421

Abstract(1299) PDF(918)

Abstract:
Cold resistance is critical in winter rapeseed production in northern China. The abscisic acid (ABA) plant hormone, also known as “stress hormone” is an important signal molecule for the regulation of plant cold resistance. Study of possible regulatory mechanisms of endogenous ABA and GA is needed to develop a valuable insight into the mechanism of cold resistance both in winter rapeseed Brassica rapa L. and Brassica napus L. Thus we investigated the regulation of endogenous hormones in cold-resistance using eight winter rapeseed cultivars with different gradients of cold tolerance in a pot experiment. Different winter rapeseed cultivars were cultivated in a growth chamber with temperature conditions of 25 ℃, 10 ℃, 2 ℃ and 5 ℃, respectively. The endogenous ABA, GA and chlorophyll contents were measured. Regression analysis showed a significantly negative linear correlation between temperature and endogenous ABA content, with a regression equation of y = ax + b. With decreasing of temperature, the endogenous ABA content increased slightly at 10 ℃ and then drastically at both 2 ℃ and 5 ℃. There were remarkable differences in ABA content among the temperature treatments and interaction of temperature and crop cultivar. The trend in endogenous GA content was the exact contrast of that of ABA, highlighting the antagonism between the both phytohormones. Temperature had no significant effect on endogenous ABA content for temperatures > 0 ℃ in different winter rapeseed cultivars. However, temperature effect on endogenous ABA content of B. rapa was more significant than that of B. napus, and the cold tolerant cultivar more sensitive at a temperature of 5 ℃. The increase in ABA content contributed to the change in chlorophyll, which initially increased and then decreasing with decreasing temperature, and with an overall declining trend. The response mechanisms between B. rapa and B. napus were different, which resulted in lower chlorophyll content in B. rapa than in B. napus. The leaf wilting date of B. rapa delayed well into wintering stage, with leaf wilting period of strongly cold resistant varieties occurring early to halt root nutrient uptake. Winter rapeseed root stored enough organic matter to increase its cold resistance and defend against low temperature injury. Thus with decreasing temperature, endogenous ABA content of winter rapeseed leaf increased. However, as chlorophyll degraded, B. rapa winter rapeseed leaf withered early, occurring in advance along with high ABA content after low temperature stress. This was the main reason and the stronger characteristic biological performance of B. rapa over B. napus in terms of cold resistance.

Effects of Enrofloxacin on hydrolytic enzyme activities and biogas production during anaerobic fermentation

ZHANG Min, QIAN Jinqiu, LI Zhongzhou, LIU Qingyu

2016, 24(11): 1539-1546. doi: 10.13930/j.cnki.cjea.160480

Abstract(818) PDF(1537)

Abstract:
Veterinary antibiotics are widely used as feed additives in domestic animal rearing either to improve growth performance or to prevent disease infection. A wide range of antibiotics is excreted unchanged in urine and feces of animals, posing potential human and ecological health risks after entering the environment. This is confirmed by the presence of widespread detectable antibiotic concentrations in surface waters and manure. Antibiotics originating in manure from livestock operations are a concern because they remain bioactive. Anaerobic digestion is one of the most promising biotechnologies for the conversion of diverse organic substrates, ranging from high solid feedstocks (animal manure, food waste and municipal solid waste) to municipal and industrial wastewaters and to energy-rich biogas. Most of the biogas plants in China are run on animal manure to reduce biological oxygen demand and to produce biogas. After ingestion by animals, some of the compounds are excreted along with the manure which may inhibit biogas process when manure is used as substrate in biogas plants. Most studies on antibiotic inhibition under anaerobic fermentation have focused on animal manure as substrate, showing significant anaerobic fermentation inhibition primarily at higher antibiotic concentrations typically found in manure. An experiment was therefore designed to study the effects of Enrofloxacin (ENR) addition to pig manure on hydrolytic enzyme activities and biogas production in anaerobic fermentation processes with pig manure and corn stalks as raw materials. The results showed that pig manure anaerobic fermentation added with 20 mg?kg1, 60 mg?kg1 and 120 mg.kg^-1 ENR inhibited cellulose and urease activities at the initial stage of anaerobic fermentation (P < 0.05). However, the addition of 20 mg.kg^-1 ENR promoted the activities of sucrose, while the addition of 60 mg.kg^-1 and 120 mg.kg^-1 ENR inhibited the activities of sucrase in the first 15 days (P < 0.05). The effects of ENR on cellulase, urease and sucrose activities were not statistically different in the late stage of anaerobic fermentation (P > 0.05). Pig manure-based anaerobic fermentation with 20 mg?kg^-1, 60 mg.kg^-1 and 120 mg.kg^-1 ENR significantly inhibited gas production rate during 511 days and 2131 days (P < 0.05) of anaerobic fermentation. Compared with control (no ENR application), the gas production rate had no obvious changes in 20 mg.kg^-1, 60 mg.kg^-1 and 120 mg.kg^-1 ENR treatments after 31 days of anaerobic fermentation. Furthermore, biogas yield decreased by 7.38%, 12.08% and 15.77%, respectively, in 20 mg.kg^-1, 60 mg.kg^-1 and 120 mg.kg^-1 ENR treatments during anaerobic fermentation for 50 days. It was obvious that ENR influenced hydrolytic enzyme activities, gas production rate and biogas production during anaerobic fermentation. The effects of ENR on different hydrolytic enzyme activities and gas production rate were also different at different stages of anaerobic fermentation. The results provided a reference for harmless disposal of animal manure containing ENR and for improvement of anaerobic fermentation efficiency.

Regional distribution characteristics of cotton fiber quality in main cotton production areas in China

XU Naiyin, LI Jian

2016, 24(11): 1547-1554. doi: 10.13930/j.cnki.cjea.160485

Abstract(862) PDF(886)

Abstract:
The significant regional differences in cotton fiber characteristics have been well recognized in not only traditional main cotton production areas, but also in the corresponding subregions in China. The evaluation of cotton fiber quality characteristics in each cotton production region is obviously benefical for understanding current developing conditions of cotton fiber quality. This can contribute to the intensification of superior cotton production areas and the development of cotton production areas with special fiber qualtiy characteristics. The GGE biplot experimental design was used to explore the interaction pattern between subregional environments of cotton and cotton fiber quality traits in three main cotton production areas (Changjiang River Valley, Huanghe River Valley and Northwest Inland) and their subregions. Data for the study were collected from the national cotton regional trials during the period 2011–2015. The results indicated that: 1) at main cotton production area scale, fiber length and strength in Changjiang River Valley (CRV) performed the best in the three main cotton production areas. Although all of these areas reached the Class II level of national cotton variety registration standard, there were medium performances for micronaire value and spinning consistency index. Fiber length and strength for the Huanghe River Valley (HRV) were better, while micronaire value was higher than desirable. On the other hand, micronaire value and spinning consistency index were best for the Northwest Inland cotton production area. Both fiber length and micronaire value reached Class II level of national cotton variety registration standard, although fiber strength was the lowest in the three main cotton production areas. 2) For subregions within three main cotton production areas, fiber length was the highest in the lower and upper reaches of CRV, slightly poor in the Loess Plateau region and relatively good in other subregions. Strength performed well in the middle and lower reaches of CRV, Huaibei Plain, Nanxiang Basin and the Loess Plateau. It was relatively poor in the upper reaches of CRV and the Northwest Inland regions. Conversely, micronaire value performed ideally in the upper reaches of CRV and the Northwest Inland regions, but not so satisfactory in the subregions of the Loess Plateau, Huaibei Plain, North China Plain and the lower reaches of CRV. 3) For comprehensive fiber quality trait performance, the upper and lower reaches of CRV and the Northwest Inland regions were the most ideal subregions, followed by Huaibei Plain, Nanxiang Basin and the middle reaches of CRV. Then the North China Plain and the Loess Plateau were less satisfactory in terms of comprehensive fiber quality trait performance. This study demonstrated the effectiveness of “environment vs. trait” biplot in evaluating ecological regionalization of cotton fiber quality. It also provided a reference for the prioritization of development of high-quality cotton production areas and raw cotton selection strategy for the textile industry and also set the guidlines for further ecological regionalization of cotton fiber quality in China.

Hyper-spectral retrieval of soil nutrient content of various land-cover types in Ebinur Lake Basin

JIANG Yelin, WANG Ranghui, LI Yan, LI Cheng, PENG Qing, WU Xiaoquan

2016, 24(11): 1555-1564. doi: 10.13930/j.cnki.cjea.160547

Abstract(954) PDF(746)

Abstract:
The soil nutrient affects soil quality, vegetation type, crops growth and yield. To rapidly and accurately determine soil nutrient contents, an indoor spectral data (measured by ASD FieldSpec3) of 75 soil samples of Jinghe County of Ebinur Lake Basin were analyzed. Then the collected data were processed at resampling interval of 10 nm to suppress noise. Soil nutrient hyper-spectral forecast models were used to forecasts soil nutrient contents in three transformation conditions. The performance of the models was evaluated based on stepwise multiple linear regression (SMLR) analysis, partial least squares regression (PLSR) analysis and artificial neural network (ANN) analysis and the optimal model determined by comparison. The results showed that the transformation of first-order and second-order differential dramatically enhanced correlation between spectroscopy data and soil nutrient content. Specifically, the first-order differential of soil spectroscopy had a good correction with soil nutrient content. The correlation coefficients for organic matter and total nitrogen were 0.87 and 0.91, respectively. In conclusion, spectral transformation technique increased the sensitivity of high spectral data to soil nutrient change, and it produced far better forecasting results. Although all the three models had good predictive ability, ANN model had the best predictive effect, followed by PLSR model. The ANN model estimation test based on the second-order differential of spectroscopy data with independent datasets from different soil samples respectively produced R² and RMSE values of 0.885 and 0.984 for organic matter and 2.614 and 0.147 for total nitrogen. The prediction effect of total nitrogen was obviously better than that of organic matter. This indicated that the sensitivity of soil hyper-spectral reflectance to the soil total nitrogen content was much better. Overall, the ANN model based on the second-order differential of spectroscopy data rapidly and precisely predicted soil nutrients contents. It was beneficial for monitoring spatial distributions and dynamic changes of soil nutrients in Ebinur Lake Basin.

Land use dynamics in Weibei upland in China*— A case study of Heyang County

LIU Jing, CHEN Tao, CHANG Qingrui, GAO Yimin, LI Fenling

2016, 24(11): 1565-1574. doi: 10.13930/j.cnki.cjea.160510

Abstract(957) PDF(711)

Abstract:
Spatial-temporal evolution of land use and landscape pattern has become a core component of research on land use and cover change. In order to understand the spatial and temporal change characteristics of land use of Weibei upland, Heyang County, we used the geo-informatics TUPU, land use transfer matrix and the Markov model to evaluate quantitative characteristics of changes and spatial transfer of the land use types in this area based on interpretation data form TM image in 1990 and 2000 and SPOT image in 2010. The driving forces of land use change were also analyzed in this research. The results showed obviously hierarchical distribution of land use types. Crop land, mining and construction land and water body were distributed in area of terrain relief under 25 m as well as slope of slope (SOS) less than 3°. During the past 20 years, crop land was the dominant land use type. Grass land and forestry land mainly distributed on middle or high terrain gradient. Forest land and unused land were the dominant land use types on the area of high terrain gradient. From 1990 to 2010, the area of arable land decreased continuously, from 893.13 km² in 1990 to 861.88 km² in 2010, and arable land mainly transformed into grass land, forest land, mining and construction land and water body. Area of orchard increased obviously, from 14.54 km² in 1990 to 35.76 km2 in 2010, mainly transformed from arable land, grass land and forest land. There had 5 land use change TUPU types: the stable type, anaphase type, prophase type, transform type and constant type. Stable type and anaphase type were the dominant types in the study area from 1990 to 2010. The areas of stable type and anaphase type accounted for more than 86% and 7% of total area, respectively. The other land use change TUPUs occupied low proportions of total area. This indicated that land use changes were gently in this area, land use changes mainly occurred during 2000 to 2010. Landform and anthropogenic activities was the main factors driving land use cover change (LUCC). Moreover, the policy guidance and market demand for LUCC also had a greater impact on LUCC. The study provided scientific theoretical basis for the dynamic optimal configurations of land use pattern and the decision support of construction of eco-environment of Heyang County.

Reserch on Mechanisms of Nitrogen and Phosphorus Leaching Loss and Control of Farmland

2016, 24(11): 1575-1576. doi: 10.13930/j.cnki.cjea.160892

Abstract(960) PDF(889)

Abstract:

Research on Migration and Transformation of Heavy metals and Their Safe Thresholds in Farmland System

2016, 24(11): 1577-1578. doi: 10.13930/j.cnki.cjea.160893

Abstract(870) PDF(852)

Abstract:

Research and Development of Moitoring Technology and Supervisory Platform of Agricultural Non-point and Heavy Metal Pollutions

2016, 24(11): 1579-1580. doi: 10.13930/j.cnki.cjea.160894

Abstract(886) PDF(1201)

Abstract: