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

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

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

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

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

Evaluation of semi-arid arable soil heavy metal pollution by magnetic susceptibility in the Linfen basin of China

The values of magnetic susceptibility and Cu, Zn, Ni, Pb, Cr, Cd concentrations of 70 topsoil samples were analyzed and assessed for soil contamination in the Linfen basin of China. The contamination factor (CF) and pollution load index (PLI) were used to assess the degree of heavy metal pollution. All heavy metal concentrations in the soil were greater than the background values of Shanxi agricultural soils. PLI values ranged from 1.27 to 2.18 indicating significant soil contamination. Principal component analyses and correlation analyses were adopted for data treatment to identify heavy metal sources. Cu, Zn, Ni, and Pb were responsible for 31.2% of the total variance suggesting that these elements mainly originated from agrochemistry and atmospheric deposition. A positive correlation of magnetic susceptibility with Cu and PLI were observed in cultivated soils. This study shows that magnetic susceptibility measurements can be used as a technique in which different types of soil pollution can be distinguished and can also be used to rapidly monitor anomalies in areas that might require expensive and time consuming detailed chemical analyses

Effects of biochar application on Suaeda salsa growth and saline soil properties

Pot experiments were conducted to study the effects of biochar application rates (5, 10, 20 g/kg) and types of wheat straw biochar (WS), corn stalk biochar (CS) and peanut shell biochar (PS) on Suaeda salsa (S. salsa) growth and properties of saline soil in Yellow River Delta. It was found that S. salsa yield increased from 11.7 to 115 % under WS application at a range of 5-10 g/kg compared with control. As biochar rate increased to 20 g/kg, the increment decreased to 102 %. The underground biomass of S. salsa only increased at 20 g/kg rate. The S. salsa growth respond to biochar followed the order of PS > WS > CS. Biochar application generally reduced saline soil pH and the effect was more obvious for WS. The content of total organic matter increased significantly at biochar rate of 10-20 g/kg. WS at higher application rate (20 g/kg) significantly increased available phosphorus content. At the same time, CS increased more available phosphorus content while PS decreased more of exchange sodium percentage. In generally, biochar application improved saline soil quality and enhanced plant growth although these effects should be tested in long-term period

KvLEA, a New Isolated Late Embryogenesis Abundant Protein Gene from Kosteletzkya virginica Responding to Multiabiotic Stresses

The LEA proteins are a kind of hydrophilic proteins, playing main functions in desiccation tolerance. However, their importance as a kind of stress proteins in abiotic stress is being clarified little by little. In this study we isolated, cloned, and identified the first KvLEA gene in Kosteletzkya virginica. Bioinformatic analysis showed that the protein encoded by this gene had common properties of LEA proteins and the multiple sequences alignment and phylogenetic analysis further showed that this protein had high homology with two Arabidopsis LEA proteins. Gene expression analysis revealed that this gene had a higher expression in root and it was induced obviously by salt stress. Moreover, the transcripts of KvLEA were also induced by other abiotic stresses including drought, high temperature, chilling, and ABA treatment. Among these abiotic stresses, ABA treatment brought about the biggest changes to this gene. Collectively, our research discovered a novel LEA gene and uncovered its involvement in multiabiotic stresses in K. virginica. This research not only enriched studies on LEA gene in plant but also would accelerate more studies on K. virginica in the future

Effects of salt stress on eco-physiological characteristics in Robinia pseudoacacia based on salt-soil rhizosphere

Robinia pseudoacacia is the main arbor species in the coastal saline-alkali area of the Yellow River Delta. Because most studies focus on the aboveground parts, detailed information regarding root functioning under salinity is scare. Root traits of seedlings of R. pseudoacacia including morphological, physiological and growth properties under four salinity levels (CK, 1 parts per thousand, 3 parts per thousand and 5 parts per thousand NaCl) were studied by the pot experiments to better understand their functions and relationships with the shoots. The results showed that seedling biomass decreased by the reduction of root, stem and leaf biomass with the increase of salinity levels. With increasing salinity levels, total root length (TRL) and total root surface area (TRSA) decreased, whereas specific root length (SRL) and specific root area (SRA) increased. Salt stress decreased root activity (RA) and the maximum net photosynthetic rate (Amax) and increased the water saturation deficit (WSD) significantly in the body. Correlation analyses showed significantly correlations between root morphological and physiologic-al parameters and seedling biomass and shoot physiological indexes. R. pseudoacacia seedlings could adapt to 1% salinity by regulating the root morphology and physiology, but failed in 5%. salinity. How to adjust the water status in the body with decreasing water uptake by roots was an important way for R. pseudoacctcict seedlings to adapt to the salt stress. (C) 2016 Published by Elsevier B.V