No abstract

In order to reveal the regulating capacity of organic fertilizers on sandy soil, pots experiments were carried out. The growth of tomatoes planted on sandy soil amended by organic fertilizers was measured. Organic fertilizers can be helpful to improve the plant height, stem diameter, the aerial parts fresh weight, root fresh weight, leaf photosynthetic rates and photosynthesis, and lay a good foundation for the growth of tomatoes. The effect of organic fertilizer is the most significant. Among all the treatments of adding 2.5%, 5%, 10% organic fertilizers, adding 10% organic fertilizers are the best. It can significantly enhance the growth and photosynthesis of tomatoes, and it is among the best of these three soil treatments for sandy soil.

Natural colloids are widely distributed in soil and groundwater. Due to their specific characteristics, colloids can actively involve various transport contaminants, resulting in a complicated fate and the transport of heavy metals to the environment. This study investigated the effects of soil colloids on the adsorption and transport of Ni2+ in saturated porous media under different conditions, including pH, ion strength (IS), and humic acid (HA), because these indexes are non-negligible in the fates of various organic or inorganic matters in the subsurface environment. The results indicate that Ni2+ adsorption by soil colloids slightly increased from 17% to 25% with the increase of pH from 5.5 to 7.5 at the IS of 30 mmol·L−1, whilst it significantly reduced from 55% to 17% with the increase of IS from 0 to 30 mmol·L−1 at a pH of 5.5. Both Langmuir and Freundlich models can fit the adsorption isotherms of Ni2+ on soil colloids and quartz sand. According to the column experiment, the presence of soil colloids increased the initial penetration rate, but could not increase the final transport efficiency of Ni2+ in the effluent. The presence of soil colloids has weakened the effect of IS on Ni2+ transport in the sand column. Moreover, this experiment implies that HA remarkably decreased the Ni2+ transport efficiency from 71.3% to 58.0% in the presence of soil colloids and that there was no significant difference in the HA effect on the Ni2+ transport in the absence of soil colloids.

PTMs extraction capacity and selectivity mechanism of STC[4]A were investigated by the determination of log K and the metal speciation.

The genetic variability and differentiation among 101 sunflower Sclerotinia sclerotiorum isolates collected from four different geographic regions of China were analyzed using mycelial compatibility groupings (MCGs) and microsatellite markers. Twenty three MCGs were identified among all tested isolates. The majority of isolates collected from the same region were grouped in to the same MCGs, indicating less genetic variation of S. sclerotiorum within the same region. But there still have exceptions for some isolates. Also microsatellite marker data revealed that all tested isolates from four geographic populations could be divided into three distinct clusters, isolates from Inner Mongolia and Ninxia regions formed cluster I, isolates from Heilongjiang and Xinjiang formed separate clusters II and III . The percentage of variance within and among different geographic populations was 84.54% and 15.46% respectively and both variances were significantly different from each other (p0.01). Meanwhile, association between the microsatellite haplotype and MCGs was observed but not so significant; majority isolates from the same MCG showed the same haplotype, but certain samples showed different haplotypes, although they belonged to the same MCG. Based on the virulence test results, we also found that MCGs not only represent the genetic variation of tested isolates, but also reflect their pathogenic ability to a certain extent.