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Yang H.-J.,Xinjiang Institute of Ecology and Geography | Liu L.-J.,Xinjiang Institute of Ecology and Geography | Ma J.-L.,Xinjiang Institute of Ecology and Geography | Wang J.,Wulanwusu Agro meteorological Experiment Station | Li X.-Y.,Xinjiang Institute of Ecology and Geography
Chinese Journal of Ecology | Year: 2016

Remote sensing is one of widely used data source of landscape analysis with different resolutions. Predominant ground object could be different on various scales. Multi-scale analysis has become a necessary method in the field of landscape ecology because a single scale could not describe or explain many environmental problems. The data, which were aggregated by average with different resolutions (30, 150, 330, 660, 990, 1650, 1980 and 3300 m) based on the Landsat 8 remote sensing images with original 30 m resolution of 2013, were input to remote sensing model to simulate multi-scale NPP. The results showed that, with scaling up, NPP of crop increased, but NPP of forest, grassland and bare land almost remained unchanged. Average stimulated NPP of 30 m resolution was 5.36% higher than that of 990 m resolution. Upscaling induced the change of mean estimated NPP in Mans River Watershed, producing scale effect, due to land cover change. However, the spatial patterns of NPP in Mans River Watershed were similar on various scales and their characteristics remained unchanged with scaling up. © 2016, editorial Board of Chinese Journal of Ecology. All Rights Reserved. Source


Liu M.-X.,CAS Nanjing Institute of Soil Science | Liu M.-X.,CAS Institute of Subtropical Agriculture | Yang J.-S.,CAS Nanjing Institute of Soil Science | Li X.-M.,CAS Nanjing Institute of Soil Science | And 2 more authors.
Pedosphere | Year: 2013

Drip irrigation under plastic mulch has been widely applied in arid Northwest China as a water-saving irrigation technology. A comprehensive knowledge of the distribution and movement of soil water in root zone is essential for the design and management of irrigation regimes. Simulation models have been proved to be efficient methods for this purpose. In this study, the numerical model Hydrus-2D was used to simulate the temporal variations of soil water content in a drip irrigated cotton field under mulching. A concept of partitioning coefficient, calibrated to be 0.07, was introduced to describe the effect of plastic mulch on prevention of evaporation. The soil hydraulic parameters were optimized by inverse solution using the field data. At the optimized conditions, the model was used to predict soil water content for four field treatments. The agreements between the predictions and observations were evaluated using coefficient of determination (R2) and root mean square error (RMSE). The results suggested that the model fairly reproduced the variations in soil water content at all locations in four treatments, with R2 ranging from 0.582 to 0.826 and RMSE from 0.029 to 0.050 cm3 cm-3, indicating that the simulations agreed well with the observations. © 2013 Soil Science Society of China. Source


Ma J.-L.,Xinjiang Institute of Ecology and Geography | Liu L.-J.,Xinjiang Institute of Ecology and Geography | Li X.-Y.,Xinjiang Institute of Ecology and Geography | Wang J.,Wulanwusu Agro meteorological Experiment Station | Yang H.-J.,Xinjiang Institute of Ecology and Geography
Chinese Journal of Ecology | Year: 2015

Water resources are a major constraint on agricultural development in arid areas. In recent years, with the development of water-saving irrigation technology, the contradiction between supply and demand of water resources was alleviated and the irrigation area was expanded. Understanding the evapotranspiration process of cropland under non-full irrigating has great scientific significance to reveal the water cycle process and guide water-saving practices. In this paper, based on eddy covariance data in 2012 from Wulanwusu Agro-meteorological Experiment Station, the evapotranspiration process of cotton filed in the different growth stages under mulched drip irrigation in Manas River basin of Xinjiang were analyzed. Furthermore, the crop coefficients of cotton under mulched drip irrigation were calculated based on the estimated evapotranspiration of reference crop by FAO-56 Penman-Monteith equation. The results showed that evapotranspiration and its rate of cotton field under mulched drip irrigation in oasis peaked in the flowering stage, with the phasic evapotranspiration of 248.51 mm and average daily evapotranspiration rate of 3.94 mm·d-1. Followed by the values in the budding stage, the phasic evapotranspiration was 98.34 mm, and the average daily evapotranspiration rate was 3.18 mm·d-1. The minimum values occurred in the sowing and seeding stages, the phasic evapotranspiration was 10.70 mm, and the average daily evapotranspiration rate was 1.07 mm·d-1. In summary, the amount of evapotranspiration was 487.14 mm during the whole growing period, and the average crop coefficient was 0.42. The results of evapotranspiration and crop coefficients of cotton at different stages provide a scientific basis not only for rating and timing of irrigation of cotton at different growth stages but also for field water management. © 2015, editorial Board of Chinese Journal of Ecology. All rights reserved. Source


Liu M.,CAS Nanjing Institute of Soil Science | Yang J.,CAS Nanjing Institute of Soil Science | Li X.,CAS Nanjing Institute of Soil Science | Liu G.,CAS Nanjing Institute of Soil Science | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

The effects of different drip irrigation parameters on crop growth and transportation of soil water and salinity are important for designing scientific irrigation strategies and rational utilization of water resources in arid area. Drip tape arrangement and irrigation water quality are two important factors of mulched drip irrigation. In order to investigate their influences on distribution of soil salinity and roots, and water use efficiency, field experiment was conducted in the north of Xinjiang in 2010. Two drip tape arrangements (a tap for four lines, Ms; a tap for two lines, Md) and three levels of irrigation water quality (0.24 dS/m, 4.68 dS/m, 7.42 dS/m) were designed. The results showed that drip tape arrangement played an important role in change of soil salinity and cotton roots distribution. Under the same condition of water quality, Ms reduced the salinity accumulation in root zone, and lower salinity concentration was observed in 0 ~ 40 cm soil layer of Ms treatment than that in Md treatment. Cotton roots mainly distributed in 0~40 cm layer in all the treatments. Stronger stress on cotton root growth was observed in Md treatment than in Ms treatment under irrigated with the same saline water. However, the saline water only affected the distribution area where the cotton root density was higher than 0.5 kg/m 3. The cotton water consumption appeared no significant relationship with the drip tape arrangement under the same irrigation amout, and decreased with the increase of irrigation salinity. Moreover, the saline water reduced the cotton yield but improved the water use efficiency (WUE); saline water irrigation reduced both the WUE and cotton yield in Md. Source


Liu M.-X.,CAS Nanjing Institute of Soil Science | Yang J.-S.,CAS Nanjing Institute of Soil Science | Li X.-M.,CAS Nanjing Institute of Soil Science | Yu M.,Water Conservancy Bureau of Yuhuatai | Wang J.,Wulanwusu Agro meteorological Experiment Station
Journal of Integrative Agriculture | Year: 2012

More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels (0.24, 4.68, and 7.42 dS m-1). Results showed that, soil moisture content (SMC) directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement (Ms) plot was obviously lower than that in the double tapes arrangement (Md) plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield. © 2012 Chinese Academy of Agricultural Sciences. Source

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