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Study on the Optimum N Rates Under Spring Cabbage-Maize-Winter Cabbage rotation system

Agricultural Sciences in China 2007年第11期6卷 1322-1329页

作者： HE Chuan-long GUO Xi-sheng WANG Weng-jun WU Ji The Soil and Fertilizer Institute Anhui Academy of Agricultural Sciences Hefei 230031 P.R. China

In this paper, field trials in two soils with different Nmin were conducted to study the effects of mineral N content （Nmin） in soil on the maximum yield N rate （MYNR）, N recovery of cabbage under spring cabbage-maize-winter cabbage rotation system, and the correlation of N fertilization with cabbage yield and quality, and to provide the theoretical basis for N recommendation for high-yield, quality, and safety production of vegetables. The effects of six N rates of 0, 90, 180, 270, 360, and 450 kg ha-1 on the yield, N recovery of spring cabbage, maize, and winter cabbage, water-soluble sugar, Vc, and nitrate content of vegetables were observed. The results showed that soil Nmin had a remarkable influence on the MYNR in the first spring cabbage season. The MYNR for spring cabbage lessened in the soil with high Nmin. Soil Nmin, could be helpful to N recommendation only for the seasonal growing crop because its effects on the following crop yield was less with the active transformation of soil Nmin. The farmer＇s practice was 1.8-3.2 times higher than the MYNR of cabbage resulted in the nitrate enrichment of groundwater. Both N application rate and Nmin. in the soil profile affected N recovery, whereas, the relay intercropping maize in the cabbage field increased the N recovery at a higher N application rate. Lower N rate （less than 90 kg ha-1） improved the yield and quality of cabbage at the same time; higher N rates increased cabbage yield, but decreased the quality; extremely high N rates of application deceased both yield and quality of cabbage. It was concluded that the soil Nmin had close correlations with MYNR and N recovery of the seasonal growing cabbage. Although the residual effects of the N fertilizer were obvious in Shajiang black meadow soil, cabbage-maize rotation increased the N recovery in treatments with higher N rates. Considering the effects of N rates on cabbage yield and quality, it is necessary to reduce the N rate and lower the yield target for

关键词： cabbage rotation system N rate Shajiang black meadow soil

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Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed rotation system

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Rice science 2014年第4期21卷 210-216页

作者： DU Xing-bin CHEN Chen LUO Li-jun XIA Long-ping LIU Kang CHEN Yin-hua YU Xin-qiao Shanghai Seed Control Station Shanghai Agrobiological Gene Center

To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.

关键词： no-tillage direct seeding rice yield soil physiochemical property water-saving and drought-resistance rice rotation system

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Experimental Fault Detection in rotation system Using State Observers by LMIs

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Journal of Mechanics Engineering and Automation 2012年第8期2卷 470-475页

作者： Edson Hideki Koroishi Gilberto Pechoto de Melo School of Mechanical Engineering-Campus Santa M6nica Federal University of Uberldndia Uberldndia-MG 38400-902 Brazil Department of Mechanical Engineering Faculty of Engineering Sao Paulo State University (UNESP) llha Solteira-SP15385-000 Brazil

Rotating systems have many applications in wide-ranging industrial contexts. The breakdown of this equipment results in economic wastes and leads to dangerous situations. To avoid such problems is very important, and it can be done through tools that inform about the existence of faults, as well as, about their progress in time. A review of the modeling process used for rotor-support-structure shows that the finite element method is the maj or method employed. In this paper, with the aid of well defined theoretical models, obtained using the finite element technique, and the state observer method for the identification and location of faults, it is possible to monitor the parameters of a rotor-support-structure system, including the foundation effects. In order to improve safety, these parameters must be supervised in case of the occurrence of failures or faults. The state observers are designed using Linear Matrix Inequalities （LMIs）. Finally, experimental results （using for this a rotation system in the mechanical vibrations laboratory at Ilha Solteira＇s Mechanical Engineering Department） demonstrate the effectiveness of the methodology developed.

关键词： rotation system fault detection state observers linear matrix inequalities (LMIs).

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Changes of Labile Organic Carbon Fractions in Soils Under Different rotation systems

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Pedosphere 2004年第1期14卷 103-109页

作者： NIJin-Zhi XUJian-Ming XIEZheng-Miao WANGDe-Jian SchoolofEarthandSpaceSciences UniversityofScienceandTechnologyofChinaHefei230026（China） DepartmentofResourceScience CollegeofEnvironmentalandResourceSciencesZhejiangUniversityHangzhou310029（China） InstituteofSoilScience ChineseAcademyofSciencesNanjing210008（China）

Soil labile (biologically active) organic carbon fractions under different crop rotation systems in Jiangsu Province, China, were investigated after 10 years of rotation. The rotation systems, including green manurerice-rice (GmRR), wheat-rice-rice (WRR), wheat-rice (WR) and wheat/corn intercrop-rice (WCR) rotations,were established on paddy soils using a randomized complete block design with three replicates. The total organic carbon (TOC), total nitrogen (TN) and water-soluble organic carbon (WSOC) in the soils under different systems were greater in the GmRR and WRR than in the WR and WCR rotation systems because the soils under triple cropping often received more crop residues than the soils under double cropping. Both the WSOC and the microbial biomass carbon (MBC) contents in the soils of the GmRR rotation system were significantly greater than those in the other crop rotation systems, which was due to the return of green manure to the fields of the GmRR rotation system. The results of a 13C nuclear magnetic resonance (13C-NMR) analysis indicated that the structural characteristics of soil WSOC were similar under the four crop rotation systems with carbohydrates and long-chain aliphatics being the major components. Correlation analysis showed that the content of the WSOC was positively correlated with that of the MBC (P ＜0.01),and all had significantly positive correlations with TOC and TN. The coefficients of variation (CVs) for WSOC and WSOC/TOC were greater than the other indices (e.g, MBC, TOC and TN), suggesting that WSOC in the soils was more sensitive to these rotation systems. The results above indicated that the soil amended with green manure could not only increase the usable C source for soil microorganisms, but could also enhance soil organic matter content; hence, rotation with green manure would be a good strategy for sustainable agriculture.

关键词： 13C-NMR rotation system soil microbial biomass carbon soil water-soluble organic carbon

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Responses of Soil Nematode Abundance and Diversity to Long-Term Crop rotations in Tropical China

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Pedosphere 2015年第6期25卷 844-852页

作者： ZHONG Shuang ZENG Huicai JIN Zhiqiang Haikou Experimental Station Chinese Academy of Tropical Agricultural Sciences Hainan Key Laboratory of Banana Genetic Improvement Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences

A field experiment was carried out from 2003 to 2013 in the Wanzhong Farm of the Hainan Island, China, to determine the effects of two long-term banana rotations on the abundance and trophic groups of soil nematode communities in the island. The experiment was set out as a randomized complete block design with three replications of three treatments： banana-pineapple rotation （AB）, banana-papaya rotation （BB） and banana monoculture （CK） in a conventional tillage system. Soil samples were taken at depths of 0-10, 10-20 and 20-30 cm, and nematodes were extracted by a modified cotton-wool filter method and identified to the genus level. Nematode ecological indices of Shannon-Weaver diversity （Ht）, dominance index （A）, maturity index （MI）, plant parasite index （PPI）, structure index （SI）, enrichment index （EI）, and channel index （CI） were calculated. A total of 28 nematode genera with relative abundance over 0.1% were identified, among which Tylenchus and Paratylenchus in the AB, Thonus in the BB, Tylenchus and Helicotylenchus in the CK were the dominant genera. The rotation soils favored bacterivores, fungivores and omnivores-predators with high colonizer-persister （c-p） values. Soil food web in the rotation systems was highly structured, mature and enriched as indicated by SI, MI and EI values, respectively. Higher abundance of bacterivores and lower values of CI suggested that the soil food web was dominated by a bacterial decomposition pathway in rotation soils. Nematode diversity was much higher after a decade of rotation. Soil depth had significant effects on the abundance of soil nematodes, but only on two nematode ecological indices （λ and MI）.

关键词： banana ecological index nematode community rotation system taxon trophic group

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Agronomic and Economic Efficiency of Manure and Urea Fertilizers Use on Vertisols in Ethiopian Highlands

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Agricultural Sciences in China 2009年第3期8卷 352-360页

作者： Teklu Erkossa Hailemariam Teklewold International Water Management Institute School of Business Economics and Law University of Gothenburg

Soil fertility depletion is among the major impediments to sustained agricultural productivity especially in the less developed countries because of limited application of fertilizers. Soil fertility maintenance requires a balanced application of inorganic and organic nutrient sources. This study was conducted on a Vertisol in Ethiopia to determine the optimum farm yard manure （M） and nitrogen （N） application rates for maximum return under cereal-pulse-cereal rotation system. The main and interaction effects of M and N significantly affected biomass, grain and straw yields of wheat （Triticum durum） and tef （Eragrostis tear）, but the residual effect on chickpea （Cicer arietinum） was not significant. Application of 6 t M ha^-1 and 30 kg N ha^-1, gave the largest grain yield of both crops but a comparable result was obtained due to 3 t M ha^-1 and 30 kg N ha^-1. The economic analysis revealed that 6.85 t M ha^-1 and 44 kg N ha^-1 for wheat, and 4.53 t M ha^-1 and 37 kg N ha^-1 for tef were the economic optimum rates. The additional benefit obtained due to these rates was about 450 USD ha^-1. Therefore, application of the economic optimum combination of both organic and inorganic sources of nitrogen is recommended for use on cereals in the cereal-legume-cereal rotation system.

关键词： Ethiopia vertisol productivity manure economic optimum rotation system

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Changes and determining factors of crop evapotranspiration derived from satellite-based dual crop coefficients in North China Plain

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The Crop Journal 2022年第5期10卷 1496-1506页

作者： Qinghua Tan Yujie Liu Tao Pan Xianfang Song Xiaoyan Li Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Evaluating actual crop evapotranspiration(ET) variations and their determining factors under changing climates is crucial for agricultural irrigation management and crop productivity improvement in nonhumid *** study analyzed the spatiotemporal characteristics and detected the determining factors of ETfor winter wheat and summer maize rotation system from 2000 to 2017 in the North China Plain(NCP),by combining the FAO-56 dual crop coefficient approach with remotely sensed vegetation indices(VIs).The results indicated that daily air temperature increased in varying degrees while wind speed and sunshine hours decreased slightly during the growing season of winter wheat and summer maize over the study *** trends of relative humidity and effective precipitation varied in crop growing *** on the validated relationship of dual crop coefficients and VIs,the estimated multi-year average ETof winter wheat(370.29±31.28 mm) was much higher than summer maize(281.85±20.14 mm),and the rotation cycle was 652.43±27.67 *** ETof winter wheat and the rotation cycle increased by 2.96 mm aand 1,77 mm a,***,the ETof summer maize decreased with distinct spatial ***,winter wheat ETincreased significantly in the northeast NCP,covering the Beijing-Tianiin-Hebei ***,significant increases in summer maize ETwere detected in the southwest *** sensitivity and contribution analysis showed that ETof winter wheat and summer maize was positively sensitive to temperature,wind speed,and sunshine hours while negatively to relative ***,wind speed and sunshine hours contributed most to changes in ET(around 20%-40%).

关键词： Actual crop evapotranspiration Determining factor North China Plain rotation system Spatiotemporal variation

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