Accumulation capacity of ions in cabbage (Brassica oleracea L.) supplied with sea water

Cabbage seedlings were grown hydroponically to study the effects of different concentrations of seawater on the seedling growth, ion content under one-fourth strength Hoagland's nutrient solution in the greenhouse. The biomass of various organs of cabbage seedlings as well as the whole plants was significantly higher in the treatments with 1 g and 2 g sea salt/L than the no-salt control, but the treatments with 4, 5 or 6 g sea salt/L caused a decrease in growth. Root/shoot ratio remained at the level of control regardless of the sea salt treatment. Na+ and Cl- concentration in different parts of cabbage seedlings increased significantly, whereas K+ and Ca2+ concentration generally increased at low concentrations of sea salt and then decreased with increasing seawater concentration. Sodium and K+ concentrations were significantly higher in the stems than roots and leaves regardless of the sea salt treatment. The sea salt treatment increased Mg2+ concentration in stems and leaves of cabbage seedlings. An increase in Na+ and Cl- concentration in roots, stems and leaves of cabbage seedlings was the main contributor to declining ratios of K+/Na+, Ca2+/Na+ and Mg2+/Na+. The obtained data suggest that cabbage seedlings have strong ability to sustain seawater stress by the regulation of transport and distribution of ions

Soil-water interacting use patterns driven by Ziziphus jujuba on the Chenier Island in the Yellow River Delta, China

The determination of water use patterns of plants in a coastal ecosystem is critical to our understanding of local eco-hydrological processes and predicting trends in ecological succession under the background of global climate change. The water use patterns of Ziziphus jujuba, the dominant species on the Chenier Island in the Yellow River Delta, were examined following summer rainfall events. Stable oxygen isotope analysis was employed to analyze the effects of rainfall on the stable isotopic composition in potential water sources in Z. jujuba. The IsoSource model was used to estimate the contributions of potential water sources for xylem water in Z. jujuba. The results showed heavy rainfall could recharge both soil and groundwater but contributed little to the O-18 values in deep soil water (60-100cm) and groundwater. Light rainfall had an effect only on surface soil water (0-40cm). Z. jujuba mainly absorbed deep soil water on non-rainy days. Rainwater became the predominant water source for Z. jujuba during and immediately after heavy rainfall. Switching the plant's main water source between deep soil water and rainwater provided Z. jujuba with a competitive advantage and improved the water use efficiency of Z. jujuba in this coastal ecosystem

NAC transcription factors in plant multiple abiotic stress responses: progress and prospects

Abiotic stresses adversely affect plant growth and agricultural productivity. According to the current climate prediction models, crop plants will face a greater number of environmental stresses, which are likely to occur simultaneously in the future. So it is very urgent to breed broad-spectrum tolerant crops in order to meet an increasing demand for food productivity due to global population increase. As one of the largest families of transcription factors (TFs) in plants, NAG TFs play vital roles in regulating plant growth and development processes including abiotic stress responses. Lots of studies indicated that many stress-responsive NAG TFs had been used to improve stress tolerance in crop plants by genetic engineering. In this review, the recent progress in NAG TFs was summarized, and the potential utilization of NAG TFs in breeding abiotic stress tolerant transgenic crops was also be discussed. In view of the complexity of field conditions and the specificity in multiple stress responses, we suggest that the NAG TFs commonly induced by multiple stresses should be promising candidates to produce plants with enhanced multiple stress tolerance. Furthermore, the field evaluation of transgenic crops harboring NAG genes, as well as the suitable promoters for minimizing the negative effects caused by over-expressing some NAG genes, should be considered.Abiotic stresses adversely affect plant growth and agricultural productivity. According to the current climate prediction models, crop plants will face a greater number of environmental stresses, which are likely to occur simultaneously in the future. So it is very urgent to breed broad-spectrum tolerant crops in order to meet an increasing demand for food productivity due to global population increase. As one of the largest families of transcription factors (TFs) in plants, NAG TFs play vital roles in regulating plant growth and development processes including abiotic stress responses. Lots of studies indicated that many stress-responsive NAG TFs had been used to improve stress tolerance in crop plants by genetic engineering. In this review, the recent progress in NAG TFs was summarized, and the potential utilization of NAG TFs in breeding abiotic stress tolerant transgenic crops was also be discussed. In view of the complexity of field conditions and the specificity in multiple stress responses, we suggest that the NAG TFs commonly induced by multiple stresses should be promising candidates to produce plants with enhanced multiple stress tolerance. Furthermore, the field evaluation of transgenic crops harboring NAG genes, as well as the suitable promoters for minimizing the negative effects caused by over-expressing some NAG genes, should be considered

Carbon sequestration and Jerusalem artichoke biomass under nitrogen applications in coastal saline zone in the northern region of Jiangsu, China

Agriculture is an important source of greenhouse gases, but can also be a significant sink. Nitrogen fertilization is effective in increasing agricultural production and carbon storage. We explored the effects of different rates of nitrogen fertilization on biomass, carbon density, and carbon sequestration in fields under the cultivation of Jerusalem artichoke as well as in soil in a coastal saline zone for two years. Five nitrogen fertilization rates were tested (in g ure m(-2)): 4 (N1), 8 (N2), 12 (N3), 16 (N4), and 0 (control, CK). The biomass of different organs of Jerusalem artichoke during the growth cycle was significantly higher in N2 than the other treatments. Under different nitrogen treatments, carbon density in organs of Jerusalem artichoke ranged from 336 to 419 g C kg(-1). Carbon sequestration in Jerusalem artichoke was higher in treatments with nitrogen fertilization compared to the CK treatment. The highest carbon sequestration was found in the N2 treatment. Soil carbon content was higher in the 0-10 cm than 10-20 cm layer, with nitrogen fertilization increasing carbon content in both soil layers. The highest soil carbon sequestration was measured in the N2 treatment. Carbon sequestration in both soil and Jerusalem artichoke residue was increased by nitrogen fertilization depending on the rates in the coastal saline zone studied. (C) 2016 Elsevier B.V. All rights reserved

Integration into plant biology and soil science has provided insights into the total environment

The total environment includes 5 closely-linking circles, in which biosphere and lithosphere are the active core. As global population increases and urbanization process accelerates, arable land is gradually decreasing under global climate change and the pressure of various types of environmental pollution. This case is especially for China. Land is the most important resources for human beings' survival. How to increase and manage arable land is the key for sustainable agriculture development. China has extensive marshy land that can be reclamated for the better potential land resources under the pre- condition of protecting the environment, which will be a good way for enlarging globally and managing arable land. Related studies have been conducted in China for the past 30years and now many results with obvious practical efficiency have been obtained. For summarizing these results, salt-soil will be the main target and related contents such as nutrient transport, use types, biodiversity and interactions with plants from molecular biology to ecology will be covered, in which the interactions among biosphere, lithosphere, atmosphere and anthroposphere will be focused on. (C) 2016 Elsevier B.V. All rights reserved

Negative interactive effects between biochar and phosphorus fertilization on phosphorus availability and plant yield in saline sodic soil

Little is known about the interactive effects between biochar application and phosphorus (P) fertilization on plant growth and P uptake. For this purpose, five wheat straw biochars (produced at 25 degrees C, 300 degrees C, 400 degrees C, 500 degrees C and 600 degrees C for 4 h) with equal P (36 mg kg(-1)) amount, with and without additional P fertilization (100 mg kg(-1)) were applied in a pot experiment to investigate the growth of Suaeda salsa and their uptake of P from biochar and P fertilization amended saline sodic soil. Soil P fractions, dry matter yield, and plant P concentrations were determined after harvesting 90 days. Our results confirmed that relatively lower pyrolysis temperature ( B (0.569) approximate to P (0.568) based on the partial Eta squared values whereas the order changed as P (0.782) > B (0.562) > B x P (0.515) for plant P concentration. When biochar and P fertilization applied together, phosphate precipitation/sorption reaction occurred in saline sodic soil which explained the decreased plant P availability and plant yield in saline sodic soil. The negative interaction effects between biochar and P fertilization indicated limited utility value of biochar application in saline sodic soil. (C) 2016 Elsevier B.V. All rights reserved

Temperature and moisture responses to carbon mineralization in the biochar-amended saline soil

This study assessed the effects of temperature and moisture on carbon mineralization (C-min) in a saline soil system with biochar amendment. The dynamics of Cmin were monitored in a biochar-amended saline soil for 220 days by incubation experiments under different conditions of temperature (15 degrees C, 25 degrees C and 35 degrees C) and moisture (30%, 70% and 105% of the water-holding capacity). Results showed that as the incubation temperature rose, cumulative Cmin consistently increased in soil added with 0-4% biochar. The two-compartment model could well describe the dynamics of Cmin. The temperature rise increased the concentration of labile C in soil, but reduced the turnover time of labile and recalcitrant C pools and the value of temperature coefficient Q(10). The response of Cmin to moisture was varying in soil amended with different levels of biochar. In the control treatment (soil alone), cumulative Cmin increased only when soil moisture was >105%. In the biochar treatments, however, 70% of water holding capacity was optimal for Cmin, except for 2%-biochar treatment at 35 degrees C. The findings highlight the necessity to consider the combined effects of soil moisture, temperature and the amount of biochar added for assessing Cmin in biochar-amended saline soils. (C) 2016 Elsevier B.V. All rights reserved

Soil enzymes as indicators of saline soil fertility under various soil amendments

Soil salinity, caused by natural of anthropogenic factors, has been recognized as a challenge to cultivation. Coastal saline soil is widely distributed in China. The relationships between soil properties and enzyme activities under different amendment types were investigated in Yellow River Town, Kenli County, Shandong Province. The aim of our study was to determine the appropriate treatments for alleviating salinity. Hekang (a saline soil modifier), chemical fertilizers, microbial inoculant, and organic fertilizer were applied to coastal saline soil in this study. The results showed that urease and catalase activities were improved under conditions of Hekang, organic fertilizer and microbial inoculant, but not under single chemical fertilizer applications. All the amendment applications improved alkaline phosphatase activity. Urease activity, alkaline phosphatase activity and catalase activity were all significantly positively correlated with soil organic matter (SOM) or soil nitrogen (N), and were negatively correlated with soil salinity or pH. In addition, Catalase activity was significantly negatively correlated with available phosphorus (P); urease activity showed a significantly positive correlation with soil available nitrogen (N) and a negative correlation with available P or available potassium (K). (C) 2017 Elsevier B.V. All rights reserved

Correlating between evapotranspiration and precipitation provides insights into Xilingol grassland eco-engineering at larger scale

The Xilingol Grassland in Northern China is the largest grassland ecosystem of Inner Mongolia and plays an important role in the local ecosystem. However, grassland desertification and degradation are quite severe in this area. Therefore, we simulated the daily actual evapotranspiration (ET) and soil water content in a representative area of the Xilingol Grassland, West Ujimqin Balaguer River basin, during the grass growth period by using the dual crop coefficient model. In addition, we compared the simulation results with actual data and found that the R-2 value between the actual measurement data and simulation data for soil water content was 0.662 with an error of 4.14%. The simulated total ET during the entire growth period in 2013 was 332.41 mm, including 215.13 mm grassland transpiration (64.7%) and 117.28 mm soil evaporation. Then we randomly selected precipitation and ET values for different growth periods for analysis. The results showed that the absolute R values are all higher than 0.5, which indicates that variations in ET are highly correlated with precipitation over time. By reducing the precipitation to half the actual values, the model predicts 257.71 mm ET (22.5% less than the value in natural conditions), 176.84 mm transpiration (17.8% less than the value in natural conditions), and 80.87 mm soil evaporation (31% less than the value in natural conditions). By assuming that the precipitation was reduced by half, the model predicts 274.89 mm ET (17.3% less than the actual value), 190.05 mm grassland transpiration (11.7% less than the actual value), and 84.85 mm soil evaporation (27.7% less than the actual value). (C) 2015 Elsevier B.V. All rights reserved.The Xilingol Grassland in Northern China is the largest grassland ecosystem of Inner Mongolia and plays an important role in the local ecosystem. However, grassland desertification and degradation are quite severe in this area. Therefore, we simulated the daily actual evapotranspiration (ET) and soil water content in a representative area of the Xilingol Grassland, West Ujimqin Balaguer River basin, during the grass growth period by using the dual crop coefficient model. In addition, we compared the simulation results with actual data and found that the R-2 value between the actual measurement data and simulation data for soil water content was 0.662 with an error of 4.14%. The simulated total ET during the entire growth period in 2013 was 332.41 mm, including 215.13 mm grassland transpiration (64.7%) and 117.28 mm soil evaporation. Then we randomly selected precipitation and ET values for different growth periods for analysis. The results showed that the absolute R values are all higher than 0.5, which indicates that variations in ET are highly correlated with precipitation over time. By reducing the precipitation to half the actual values, the model predicts 257.71 mm ET (22.5% less than the value in natural conditions), 176.84 mm transpiration (17.8% less than the value in natural conditions), and 80.87 mm soil evaporation (31% less than the value in natural conditions). By assuming that the precipitation was reduced by half, the model predicts 274.89 mm ET (17.3% less than the actual value), 190.05 mm grassland transpiration (11.7% less than the actual value), and 84.85 mm soil evaporation (27.7% less than the actual value). (C) 2015 Elsevier B.V. All rights reserved