16 research outputs found
Research and Development of Decision Support System for Regional Agricultural Development Programming
International audienceUnder the guidance of the agricultural system theory, operational research theory and decision-making support system theory, the regional agricultural development decision support system (RADDSS) was developed in this study ,in which different analysis method and models was integrated. By providing data, right models and analysis methods, RADDSS can assist decision-makers and administrators to solve half-structured and unstructured problems, improving level of management on agriculture. The agriculture in Xuchang has been analyzed using the system constructed in this study. The distribution of local agricultural production elements was rather reasonable, indicating that the district was suitable for agriculture development. The insufficient agricultural investment is the main factor that limits yield, and the more investment, the better yield. The level of agricultural modernization in Xuchang for nearly 20 years has been rising gradually, but still at the initial stage. The agricultural sustainable development potential index of Xuchang was 40.2, which was still at a low level. The gross output value of agriculture in Xuchang was predicted to undergo year-on-year growth. Fourteen multiple cropping patterns were designed and chose by RADDSS, and then the Effiency-oriented and grain-oriented program were proposed. The above-mentioned results indicate that the system can be applied to the analysis and decision-making of regional agriculture
Climate Warming and Crop Management: A Comprehensive Analysis of Changes on Distribution of Suitable Areas for Double Rice
Understanding the effect of climate warming and technological progress on crop production systems is crucial for developing climate adaptation strategies. This study presents a methodological framework with which to assess the suitability of the double rice cropping system in Southern China and the effects of crop management and climate warming on its distribution. The results indicate that the isolated effects of climate warming have led to the northward and westward expansions of double rice northern limits over the past six decades and an increase in suitable areas by 4.76 Mha. Under the isolated effect of crop management, the northern limits of the medium- and late-maturity double rice changed significantly due to the increased accumulated temperature required caused by varietal replacement and planting date change, which moved an average of 123 and 134 km southward, respectively. A combined scenario analysis indicated that crop management could offset the effects of climate warming and push the northern limits southward, reducing the overall suitable area by 1.31 Mha. Varietal replacement and other crop management methods should also be appropriately considered in addition to climate warming to develop locally adapted agricultural management strategies
Effect of nitrogen and water deficit type on the yield gap between the potential and attainable wheat yield
Large-Scale and High-Resolution Crop Mapping in China Using Sentinel-2 Satellite Imagery
Large-scale, high-resolution mapping of crop patterns is useful for the assessment of food security and agricultural sustainability but is still limited. This study attempted to establish remote sensing-based crop classification models for specific cropping systems using the decision trees method and monitored the distribution of the major crop species using Sentinel-2 satellites (10 m) in 2017. The results showed that the cropping areas of maize, rice, and soybean on the Northeast China Plain were approximately 12.1, 6.2, and 7.4 million ha, respectively. The cropping areas of winter wheat and summer maize on the North China Plain were 13.4 and 16.9 million ha, respectively. The cropping areas of wheat, rice, and rape on the middle-lower Yangtze River plain were 2.2, 6.4 and 1.3 million ha, respectively. Estimated images agreed well with field survey data (average overall accuracy = 94%) and the national agricultural census data (R2 = 0.78). This indicated the applicability of the Sentinel-2 satellite data for large-scale, high-resolution crop mapping in China. We intend to update the crop mapping datasets annually and hope to guide the adjustment and optimization of the national agricultural structure
Defect Detecting Technology for over 100-meter Shaft
Concrete defect detection of diversion shafts in large hydropower station has a direct impact on the safe operation of the station,endangering the lives of cities and millions of people downstream.However,the research on the detection of the 100-meter-level shafts is still a blank in the world.It is a "blind spots" in detection field.In this paper,a method of integrating multiple mapping sensors based on unmanned airship is proposed to resolve the international problem of data acquisition and disease detection in vertical profile the diversion shafts in hydropower stations; We have designed a brand new device to acquire data and detect the disease of the shafts:a cylindrical unmanned airship adapted to the shafts environment is the floating loading platform,on which multi-sensors such as panoramic CCD camera,3D laser scanner,inertial measurement unit,barometric altimeter,illumination module and control module etc is integrated.Trial implemented inside the No.2,No.3 and No.4 shafts of Nuozhadu hydropower station from May 2017 to July,indicates that the detection device can be well applied for the overhaul of similar vertical profile.The detecting device fills the gap of 100-meter-level shaft detection field and presents a wide application prospect
Impact of Climate Change on the Water Requirements of Oat in Northeast and North China
Crop water requirements are directly affected by climatic variability, especially for crops grown in the areas which are sensitive to climatic change. Based on the SIMETAW model and a long-term meteorological dataset, we evaluated the spatiotemporal variations of climatic change impacts on water requirement of oat in North and Northeast China. The results indicated that effective rainfall showed an increasing trend, while the crop water requirement and irrigation demand presented decreasing trends over the past decades. The water requirement of oat showed significant longitudinal and latitudinal spatial variations, with a downtrend from north to south and uptrend from east to west. Climatic factors have obviously changed in the growth season of oat, with upward trends in the average temperature and precipitation, and downward trends in the average wind speed, sunshine hours, relative humidity, and solar radiation. Declines in solar radiation and wind speed, accompanied with the increase in effective rainfall, have contributed to the reduced crop water requirement over these decades. Given the complex dynamic of climate change, when studying the impact of climate change on crop water requirements, we should not only consider single factors such as temperature or rainfall, we need to analyze the comprehensive effects of various climatic factors
Influence of sputtering power on the structural and morphological properties of semiconducting Mg2Si films
Actin nucleator Spire 1 is a regulator of ectoplasmic specialization in the testis
Abstract Germ cell differentiation during the epithelial cycle of spermatogenesis is accompanied by extensive remodeling at the Sertoli cell–cell and Sertoli cell–spermatid interface to accommodate the transport of preleptotene spermatocytes and developing spermatids across the blood–testis barrier (BTB) and the adluminal compartment of the seminiferous epithelium, respectively. The unique cell junction in the testis is the actin-rich ectoplasmic specialization (ES) designated basal ES at the Sertoli cell–cell interface, and the apical ES at the Sertoli–spermatid interface. Since ES dynamics (i.e., disassembly, reassembly and stabilization) are supported by actin microfilaments, which rapidly converts between their bundled and unbundled/branched configuration to confer plasticity to the ES, it is logical to speculate that actin nucleation proteins play a crucial role to ES dynamics. Herein, we reported findings that Spire 1, an actin nucleator known to polymerize actins into long stretches of linear microfilaments in cells, is an important regulator of ES dynamics. Its knockdown by RNAi in Sertoli cells cultured in vitro was found to impede the Sertoli cell tight junction (TJ)-permeability barrier through changes in the organization of F-actin across Sertoli cell cytosol. Unexpectedly, Spire 1 knockdown also perturbed microtubule (MT) organization in Sertoli cells cultured in vitro. Biochemical studies using cultured Sertoli cells and specific F-actin vs. MT polymerization assays supported the notion that a transient loss of Spire 1 by RNAi disrupted Sertoli cell actin and MT polymerization and bundling activities. These findings in vitro were reproduced in studies in vivo by RNAi using Spire 1-specific siRNA duplexes to transfect testes with Polyplus in vivo-jetPEI as a transfection medium with high transfection efficiency. Spire 1 knockdown in the testis led to gross disruption of F-actin and MT organization across the seminiferous epithelium, thereby impeding the transport of spermatids and phagosomes across the epithelium and perturbing spermatogenesis. In summary, Spire 1 is an ES regulator to support germ cell development during spermatogenesis