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101.
Rhizosphere effects on Cu availability and fractionation in sewage sludge‐amended calcareous soils
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Rhizosphere processes have a major impact on copper (Cu) availability and its fractions in soils. A greenhouse experiment with wheat was performed to investigate availability (using seven chemical procedures) and fractionation of Cu in the rhizosphere of ten agricultural soils (Typic Calcixerepts) amended with sewage sludge (1% w/w) using rhizoboxes. The results show that available Cu concentrations in rhizosphere soils were significantly (P < 1%) lower than in bulk soils. In comparison with the bulk soils, in the rhizosphere soils the concentration of Cu associated with organic matter and residual Cu increased by 24 and 4%, respectively, whereas exchangeable Cu, Cu associated with iron‐manganese oxides, and Cu associated with carbonate decreased by 20, 14, and 12%, respectively. Dissolved organic carbon (DOC) and Cu associated with iron‐manganese oxides and Cu associated with organic matter in the rhizosphere and bulk soils were significantly correlated (P < 5%). The results show that the differences between rhizosphere and bulk soils in chemical conditions such as DOC concentrations can change the proportion of soil Cu fractions and, therefore, Cu availability for wheat in calcareous soils amended with sewage sludge. The results show that the wheat root‐induced modifications of chemical and biological soil conditions do not only lead to Cu depletion in mobile soil Cu fractions, but also to modification in soil Cu fractions which are commonly considered as more stable. 相似文献
102.
伊犁河谷土壤含盐量空间变异和格局分析 总被引:4,自引:0,他引:4
基于区域变量理论,在GPS和GIS技术支持下,通过地统计学的半变异函数和Kriging空间插值,以察布查尔县为例,定量分析伊犁河谷不同层次土壤盐分的空间异质性.结果表明:0~20 cm、20~40 cm、60~80 cm层土壤盐分的半变异函数符合球状模型,40~60 cm层符合高斯模型.不同层次土壤盐分之间的空间自相关... 相似文献
103.
根据研究区地质地貌,将整个研究区划分为三层阶地,通过对三层阶地的地下水盐动态进行实时监测,运用双因子方差分析方法,详细论述了地下水电导率随地下水位在不同时期及不同分布条件下的变化情况.结果表明,地下水电导率变化与水位变化有很大关系,且表现出很强的区域特征:各阶地电导率(EC)值均随水位的上升而增加,高EC值出现在高水位... 相似文献
104.
Hamid R. Roosta Musa Jalali Seyyed Mohammad Ali Vakili Shahrbabaki 《Journal of plant nutrition》2015,38(14):2176-2184
In order to investigate the effects of different iron (Fe) sources (nano iron (Fe)-chelate, Fe- ethylenediamine-di(o-hydroxy phenyl acetic acid (EDDHA) and iron (II) sulfate (FeSO4)) on lettuce (Lactuca sativa) growth in alkaline solutions, an experiment was arranged in hydroponic system. This study showed that leaf Fe content and overall plant growth was significantly increased by Fe-chelate application, and the highest values of leaf Fe, plant pigments and vegetative growth were recorded in plants treated with nano Fe-chelate. The lowest Fe, chlorophyll, carotenoids and soluble sugars in leaves were observed in FeSO4 treatment. There were no difference in soluble sugars contents of plants between nano Fe-chelate and Fe-EDDHA treatments. Fertilization of lettuce plants with different Fe-chelate sources had a beneficial effect on the manganese (Mn) and zinc (Zn) uptake in plants. It is concluded that application of chelated form of Fe (especially nano Fe-chelate) must be performed in hydroponic system with alkaline water, to overcome Fe deficiencies and to make better nutritional status. 相似文献
105.
We studied the effects of 15N-labelled ammonium nitrate and urea on the yield and uptake of labelled and unlabelled N by wheat (Triticum aestivum L., cv. Mexi-Pak-65) in a field experiment. The dry matter and N yields were significantly increased with fertilizer N application compared to those from unfertilized soil. The wheat crop used 33.6–51.5 and 30.5–40.9% of the N from ammonium nitrate and urea, respectively. Splitting the fertilizer N application had a significant effect on the uptake of fertilizer N by the wheat. The fertilizer N uptake showed that ammonium nitrate was a more available source of N for wheat than urea. The effective use of fertilizer N (ratio of fertilizer N in grain to fertilizer N in whole plant) was statistically similar for the two N fertilizers. The application of fertilizer N increased the uptake of unlabelled soil N by wheat, a result attributed to a positive added N interaction, which varied according to the fertilizer N split; six split applications gave the highest added N interaction compared to a single application or two split applications for both fertilizers. Ammonium nitrate gave 90.5, 33.5, and 48.5% more added N interaction than urea with one, two, and six split N applications. A values were not significantly correlated with the added N interaction (r=0.557). The observed added N interaction may have been the result of pool substitution, whereby added labelled fertilizer N replaced unlabelled soil N. 相似文献
106.
Effects of irrigation strategies and soils on field grown potatoes: Root distribution 总被引:1,自引:0,他引:1
Seyed Hamid Ahmadi Finn PlauborgMathias N. Andersen Ali Reza SepaskhahChristian R. Jensen Søren Hansen 《Agricultural Water Management》2011,98(8):1280-1290
Root distribution of field grown potatoes (cv. Folva) was studied in 4.32 m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm root per cm3 soil) compared with root development in fully irrigated (FI) potatoes. Highest RLD existed in the top 30-40 cm of the ridge below which it decreased sharply. The RLD was distributed homogenously along the ridge and furrow but heterogeneously across the ridge and furrow with highest root density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30-70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below the furrows compared with the corresponding layers below the ridges. The RLD values in the soil profile of the ridges and the furrows followed the Gerwitz and Page model: RLD = α × exp(−β × z). The highest value of surface root density (α) and rate of change in density (β) was found in coarse sand while the lowest values of α and β were found in the sandy loam and loamy sand. The model estimated the effective rooting depth in coarse sand and sandy loam quite well but did slightly overestimate it in the loamy sand. Statistical analysis showed that one α and β value can be used for each soil irrespective of the irrigation treatment. Thus, the effective rooting depths corresponding to root length densities of 0.1 and 0.25 cm cm−3 for sandy loam, loamy sand, and coarse sand soils were 99, 141, and 94 cm, and 80, 115, and 78 cm, respectively, calculated from top of the ridge. The findings of this study can be used in practice for efficient use of water and nutrients in the field. 相似文献
107.
Seyyed Gholam Reza Moosavi Seyyed Hamid Reza Ramazani Saeid Sadeghzadeh Hemayati Hamid Gholizade 《Journal of Crop Science and Biotechnology》2017,20(3):167-174
To study the effects of different levels of drought stress on root yield and some morpho-physiological traits of sugar beet genotypes, a study was conducted in the research farm of Islamic Azad University of Birjand, Iran in 2013 as strip-split plot experiments based on randomized complete block design. Different levels of drought stress were considered as vertical factor in three levels including normal irrigation, moderate stress, and severe stress. Horizontal factor was assigned to five varieties of sugar beet. Drought stress had a significant effect on root dry weight, total dry weight, root yield, and leaf temperature at 1% probability level and on leaf dry weight, crown dry weight, and harvest index at 5% probability level. Drought stress had an adverse effect on root yield of investigated genotypes of sugar beet. Under normal conditions, the mean of root yield was higher than middle and severe drought stress. Different investigated genotypes of sugar beet responded to drought stress based on their yield potential. The highest positive correlation of root yield was observed with root dry weight (r=0.977**). Stepwise regression analysis and path coefficient analysis showed that root dry weight and petiole dry weight are the most important traits that can affect root yield of sugar beet under drought stress and can used as selection criteria in investigated cultivars of sugar beet. Finally, 7221 genotypes can be considered as tolerant genotypes in the next studies. In comparison, Jolgeh cultivar (as susceptible control) yielded well in areas with normal irrigation, but under moderate and severely stresses its root yield was reduced. 相似文献
108.
Mahdi Najafi-Ghiri Boostani Hamid Reza Mirsoleimani Abbas Mohaviye-Asadi Negin Beizavi Majid Shafiei Mina Mirdoraghi Maryam 《Eurasian Soil Science》2020,53(7):978-985
Eurasian Soil Science - Arid and semiarid soils of southern Iran may fix a large content of applied potassium (K), but the fixed K may be gradually supplied to plants. Sixteen representative soils... 相似文献
109.
Genetic Resources and Crop Evolution - Throughout history, territories under the rule of ancient Persian empires, including the plateau of Iran, parts of Central Asia and Transcaucasia, have been... 相似文献
110.
Khadijeh Golabgir Khademi Ali Mohammad Foroughmand Hamid Galehdari Saied Yazdankhah Mahdi Pourmahdi Borujeni Zahra Shahbazi Parvaneh Dinarvand 《Iranian Biomedical Journal》2016,20(2):122-127