Biochar, as a soil conditioner, has been widely used to promote the growth of maize, but most of the current research is short-term experiments, which limits the research on the long-term effects of biochar, especially the physiological mechanism of biochar on maize growth in aeolian sandy soil is still unclear. Here, we set up two groups of pot experiments, respectively after the new biochar application and one-time biochar application seven years ago (CK: 0 t ha^-1, C1: 15.75 t ha^-1, C2: 31.50 t ha^-1, C3: 63.00 t ha^-1, C4: 126.00 t ha^-1), and planted with maize. Subsequently, samples were collected at different periods to explore the effect of biochar on maize growth physiology and its after-effect. Results showed that the plant height, biomass, and yield of maize showed the highest rates of increase at the application rate of 31.50 t ha^-1 biochar, with 22.22% increase in biomass and 8.46% increase in yield compared with control under the new application treatment. Meanwhile, the plant height and biomass of maize increased gradually with the increase of biochar application under the one-time biochar application seven years ago treatment (increased by 4.13%-14.91% and 13.83%-58.39% compared with control). Interestingly, the changes in SPAD value (leaf greenness), soluble sugar and soluble protein contents in maize leaves corresponded with the trend of maize growth. Conversely, the changes of malondialdehyde (MDA), proline (PRO), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) manifested an opposite trend to the growth of maize. In conclusion, 31.50 t ha^-1 biochar application can promote the growth of maize by inducing changes in its physiological and biochemical characteristics, but excessive biochar application rates ranging from 63.00-126.00 t ha^-1 inhibited the growth of maize. After seven years of field aging, the inhibitory effect of 63.00-126.00 t ha^-1 biochar amount on maize growth disappeared and changed to promoting effect.

Environmental managers and policymakers increasingly discuss trade-offs between ecosystem services (ESs). However, few studies have used nonlinear models to provide scenario-specific land-use planning. This study determined the effects of different future land use/land cover (LULC) scenarios on ESs in the Yili River Valley, China, and analyzed the trade-offs and synergistic response characteristics. We simulated land-use changes in the Yili River Valley during 2020–2030 under three different scenarios using a patch-generating land-use simulation (PLUS) model—business as usual (BAU), economic development (ED), and ecological conservation (EC). Subsequently, we evaluated the water yield (WY), carbon storage (CS), soil retention (SR), and nutrient export (NE) ESs by combining the PLUS and integrated valuation of ecosystem services and trade-offs (InVEST) models, thus exploring multiple trade-offs among these four ESs at a regional scale. For the BAU scenario, there are some synergistic effects between WY and SR in the Yili River Valley, in addition to significant trade-off effects between CS and NE. For the ED scenario, the rapid expansion of cropland and constructed land is at the expense of forested grassland, leading to a significant decline in ESs. For the EC scenario, the model predicted that the cumulative regional net future carbon storage, cumulative water retention, and cumulative soil conservation would all increase due to ecological engineering and the revegetation of riparian zones and that formerly steep agricultural land can be effective in improving ESs. Meanwhile, the trade-off effect would be significantly weakened between CS and NE. These results can inform decision makers on specific sites where ecological engineering is implemented. Our findings can enhance stakeholders’ understanding of the interactions between ESs indicators in different scenarios.

Aeolian sandy soil is a key resource for supporting food production on a global scale; however, the growth of crops in Aeolian sandy soil is often impaired due to its poor physical properties and lack of nutrients and organic matter. Biochar can be used to enhance the properties of Aeolian sandy soil and create an environment more suitable for crop growth, but the long-term effects of biochar on Aeolian sandy soil and microbial communities need to be clarified. Here, a field experiment was conducted in which biochar was applied to a maize (Zea mays L.) field in a single application at different rates: CK, 0 Mg ha⁻¹; C1, 15.75 Mg ha⁻¹; C2, 31.50 Mg ha⁻¹; C3, 63.00 Mg ha⁻¹; and C4, 126.00 Mg ha⁻¹. After 7 years of continuous maize cropping, verify the relationship between root architecture and soil microbial communities under biochar application using a root scanner and 16S/ITS rRNA gene sequencing. The application of biochar promoted the growth of maize. Specifically, total root length, total root surface area, total root volume, and root biomass were 13.99–17.85, 2.52–4.69, 23.61–44.41, and 50.61–77.80% higher in treatments in which biochar was applied (C2, C3, and C4 treatments) compared with the control treatment, respectively. Biochar application increased the diversity of bacterial communities, the ACE index, and Chao 1 index of C1, C2, C3, and C4 treatments increased by 5.83–8.96 and 5.52–8.53%, respectively, compared with the control treatment, and significantly changed the structure of the of bacterial communities in rhizosphere soil. However, there was no significant change in the fungal community. The growth of maize roots was more influenced by rhizosphere bacteria and less by fungal community. A microbial co-occurrence network revealed strong associations among rhizosphere microorganisms. The core taxa (Module hubs taxa) of the bulk soil microbial co-occurrence network were closely related to the total length and total surface area of maize roots, and the core taxa (Connectors taxa) of the rhizosphere soil were closely related to total root length. Overall, our findings indicate that the application of biochar promotes the growth of maize roots in aeolian sandy soil through its effects on bacterial communities in rhizosphere soil.

Biochar derived from chicken manure, as an effective metal adsorbent, was prepared through a pyrolysis method at different pyrolytic temperatures (200, 400, 600, and 800 °C). The physicochemical characteristics of chicken manure biochar (CMB) and its lead (Pb²⁺) adsorption mechanisms were studied by batch adsorption experiments, DTA/TGA, XRD, SEM-EDS, FTIR and an analysis of the composition of their mineral ash. Results showed that the best-fit for the Pb²⁺ adsorption data was achieved using a Langmuir isotherm and a pseudo-second-order model. The maximum adsorption capacities of Pb²⁺ increased with increasing of pyrolytic temperatures of the CMB, being 180.21, 200.80, 239.59, and 242.57 mg g⁻¹, respectively, for CMB-200, CMB-400, CMB-600 and CMB-200. Although Pb²⁺ adsorption on CMB revealed that adsorption was controlled by multiple mechanisms, (e.g. surface complexation, ion exchange, surface precipitation, electrostatic attraction, physical adsorption, and co-precipitation), the ion exchange and surface precipitation played a dominant role in Pb²⁺ sorption. Using CMB for the removal of Pb from water is proposed as an effective, environmentally protective, novel approach.