Time filter

Source Type

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

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

Li X.-M.,CAS Nanjing Institute of Soil Science | Li X.-M.,Shaanxi Province Shaanxi Estate Development Service Corporation | Yang J.-S.,CAS Nanjing Institute of Soil Science | Liu M.-X.,CAS Nanjing Institute of Soil Science | And 2 more authors.
Journal of Integrative Agriculture | Year: 2012

The aim of this paper was to research the spatio-temporal changes in total soluble salt content (TS) in a typical arid region of South Xinjiang, China, where the climate is arid and soil salinization happens easily. The total soluble salt content was interpreted by measurements made in the horizontal mode with EM38 and EM31. The electromagnetic induction (EM) surveys were made three times with the apparent soil electrical conductivity (ECa) measurements taken at 3 873 locations in Nov. 2008, 4 807 locations in Apr. 2009 and 6 324 locations in Nov. 2009, respectively. For interpreting the ECa measurements into total soluble salt content, calibtion sites were needed for EM survey of each time, e.g., 66 sites were selected in Nov. 2008 to measure ECa, and soils-core samples were taken by different depth layers of 0-10, 10-20 and 20-40 cm at the same time. On every time duplicate samples were taken at five sites to allevaite the local-scale variability, and soil temperatures in different layers through the profiles were also measured. Factors including TS, pH, water content, bulk density were analyzed by lab experiments. ECa calibration equations were obtained by linear regression analysis, which indicated that soil salinity was one primary concern to ECa with a determination coefficient of 0.792 in 0-10 cm layer, 0.711 in 10-20 cm layer and 0.544 in 20-40 cm layer, respectively. The maps of spatial distribution were predicted by Kriging interpolation, which showed that the high soil salinity was located near the drainage canal, which validated the trend effect caused by the irrigation canal and the drainage canal. And by comparing the soil salinity in different layers, the soluble salt accumulated to the top soil surface only in the area where the soil salinization was serious, and in the other areas, the soil salinity trended to increase from the top soil surface to 40 cm depth. Temporal changes showed that the soil salinity in November was higher than that in April, and the soil salinization trended to aggravate, especially in the top soil layer of 0-10 cm. © 2012 Chinese Academy of Agricultural Sciences. 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.,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.
Irrigation Science | Year: 2013

A 2-year experiment was carried out to investigate the effects of different drip irrigation regimes on distribution and dynamics of soil water and salt in north Xinjiang, China. Five treatments-F7 (0.24 dS m-1 + Once every 7 days), B7 (4.68 dS m-1 + Once every 7 days), S7 (7.42 dS m-1 + Once every 7 days), F10 (0.24 dS m-1 + Once every 10 days) and F3 (0.24 dS m-1 + Once every 3 days)-were designed. For all treatments, additional 150-mm fresh water was applied on 10th November in 2009 (winter irrigation) to leach the accumulated salt. The results revealed that irrigation frequency and water quality had significant effects on the spatial distribution and change of soil water content, soil salt and the crop water consumption rate, but had a limited impact on the seasonal accumulative water consumption, and the cotton yield decreased with the decrease in irrigation frequency and water quality on the whole. During the cotton growing season, results showed that the salt mainly accumulated in the 0- to 60-cm soil layer, while the soil salt in 60- to 100-cm layer changed slightly, indicating that the drip irrigation could not leach the soil salt out of the root zone under the irrigation regimes. Therefore, salt leaching was necessary to maintain the soil water-salt balance and to prevent excessive salt accumulation in the root zone. After the 150-mm winter irrigation and subsequent thawing, soil salts were leached into the deeper layers (below 60 cm), and the soil salt content (SSC) (EC1:5) in root zone in the next year was about 0.2 dS m-1. Moreover, compared to 2009 season, the SSC within the root zone did not increase even the EC of the irrigation water was up to 7.42 dS m-1. Additionally, it is important to note that the results were concluded based on the data of the 2-year experiment; further studies are need to optimize winter irrigation amount and assess the sustainability of saline water irrigation since long-term utilization of saline water may lead to soil degradation. © 2012 Springer-Verlag. Source

Discover hidden collaborations