No abstract

Land reclamation may expand the supply of usable land for food security. Immature soil is not suitable for plant growth and needs to be amended by the addition of organic matter and plant growth-promoting (PGP) microorganisms. However, the effects of different PGP fungi on plant growth in immature soil are largely unexplored. In order to obtain beneficial soil microorganisms with a good PGP ability in new reclamation land, 162 fungal isolates were isolated from different abandoned wastelands, four isolates of which were obtained in this study by the screening of P solubilization, siderophore production, and indole acetic acid (IAA) production. The result of this study revealed that isolate HZ123 had the highest ability to solubilize P and produce siderophores and IAA, followed by HZ23, HZ10, and HZ06. Based on the results of morphological and molecular analyses, isolate HZ06 was identified as Penicillium oxalicum, isolates HZ23 and HZ10 were identified as Aspergillus brunneoviolaceus, and isolate HZ123 was identified as Aspergillus tubingensis. Furthermore, the results of in vivo PGP assays demonstrated that isolate HZ123 has a minimal negative effect on the growth of eggplant; however, the other three isolates, particularly isolate HZ06, caused the greatest increase in eggplant biomasses. Overall, these results indicate that isolate HZ06 has great potential as a PGP fungus to develop biofertilizer for application in eggplant production in immature soil from new reclamation land.

It is well known that soil fertility is poor in most newly reclaimed land, which has been developed as an effective way to compensate farmland occupation. In order to ameliorate the soil quality of the newly reclaimed land, this study investigated the effect of commercial organic fertilizer (COF) (0.45, 0.90, 1.35 and 1.80 kg/m2), sheep manure (SM) (0.45, 0.75, 1.05 and 1.35 kg/m2), mushroom residue (MR) (1.50, 2.25, 3.00 and 3.75 kg/m2), and chemical compound fertilizer (CCF) (0.075 kg/m2) on the growth of sweet potato, soil pH, organic matter content (OMC), available phosphate, total nitrogen, available potassium, exchangeable Ca and Mg, as well as bacterial and fungal microbial composition during 2019–2021. The results from this study indicated that the COF, SM, MR, and CCF did not significantly change the soil pH, but significantly increased the OMC, which has been regarded as the most significant soil quality parameter. This suggests that the soil amendments used in this study have great potential to improve the soil quality in newly reclaimed land. However, these soil amendments exhibited a differential effect on sweet potato biomass, nutrient elements and the microbial community of the newly reclaimed soil, which depend on the kind and concentration of organic/chemical fertilizer, the application time, as well as the plant and soil parameters. The change was also observed on the bacterial and fungal soil microbial community, which provides us with a microbial basis to understand why organic fertilizer has a great effect on soil improvement. Overall, our results suggest that soil amended with organic fertilizers has great potential for the production of sweet potato in immature soil from the new reclamation land.

β-CD modified plasmonic Pickering emulsions were synthesized for interfacial reaction monitoring as well as for kinetic study.

Although technical advances in hydraulically fracturing and drilling enable commercial production from tight reservoirs, oil/gas recovery remains at a low level. Due to the technical and economic limitations of well-testing operations in tight reservoirs, rate-transient analysis (RTA) has become a more attractive option. However, current RTA models hardly consider the effect of the non-uniform production on rate decline behaviors. In fact, PLT results demonstrate that production profile is non-uniform. To fill this gap, this paper presents an improved RTA model of multi-fractured horizontal wells (MFHWs) to investigate the effects of non-uniform properties of hydraulic fractures (production of fractures, fracture half-length, number of fractures, fracture conductivity, and vertical permeability) on rate transient behaviors through the diagnostic type curves. Results indicate obvious differences on the rate decline curves among the type curves of uniform properties of fractures (UPF) and non-uniform properties of fractures (NPF). The use of dimensionless production integral derivative curve magnifies the differences so that we can diagnose the phenomenon of non-uniform production. Therefore, it's significant to incorporate the effects of NPF into the RDA models of MFHWs, and the model proposed in this paper enables us to better evaluate well performance based on long-term production data.

Land reclamation may expand the supply of usable land for food security. Soil microorganisms have been considered as an amendment in immature soil to improve its quality. However, different microbial fertilizers’ effects on plant growth in immature soil have largely been unexplored. In order to evaluate the effects of different microbial fertilizers on immature soil, the soil quality and microbial community structure of corn rhizosphere soil samples under different microbial fertilizers were investigated. The results revealed a significant difference between microbial fertilizers (especially seaweed microbial fertilizer, SMF) and commercial chemical compound fertilizers in the soil properties and microbial community structure. Indeed, SMF caused a 486.21%, 23.17%, 21.08%, 38.33%, and 482.39% increase in Flavobacteriaceae, Planctomycetaceae, Chitinophagaceae, Acidobacteria_Gp3, and Mortierellaceae but a 23.82%, 18.66%, 42.36%, 29.12%, 81.97%, 42.19%, and 99.33% reduction in Cytophagales, Comamonadaceae, Rhodospirillaceae, Sinobacteaceae, Aspergillaceae, Myrmecridiaceae, and Typhulaceae, respectively; while CCF caused an 85.68% and 183.22% increase in Xanthomonadaceae and Mortierellaceae but a 31.29%, 36.02%, and 65.74% reduction in Cytophagales, Spartobacteria, and Cyphellophoraceae compared with the control based on 16S and ITS amplicon sequencing of soil microflora. Furthermore, redundancy discriminant analysis of the microbial communities and soil properties indicated that the main variables of the bacterial and fungal communities included exchangeable Ca, organic matter content, total N, and available P. Overall, the results of this study revealed significant changes under different fertilizer conditions in the microbiota and chemical properties of corn soil. Microbial fertilizers, particularly SMF and SM, can be used as a good amendment for newly reclaimed land.

In recent years, the optimum development of land resources has become an important task for ensuring the security of food production in China. Soil microorganisms have been considered to play an important role in conferring soil fertility and productivity. In order to obtain the plant-growth-promoting bacteria in newly reclaimed land, a total of 988 bacterial strains were isolated from nine soil samples collected from different sites in wastelands in Hangzhou (Zhejiang Province, China), a rural mountainous area. Among them, five strains exhibited substantial potential of phosphate solubilization, nitrogen fixation, siderophore production and indole acetic acid production at both pH 5.0 and pH 7.0, and also promoted eggplant growth in immature soil from newly reclaimed land. Furthermore, bacterial strains ZJ62 and ZJ3-12 were identified as Pantoeadispersa and Pantoea ananatis, respectively, while strains ZJ5, ZJ9 and ZJ174 were identified as Burkholderiaarboris, Burkholderia pyrrocinia and Burkholderia pyrrocinia, respectively, based on colony morphology observation and phylogenetic analysis of 16S rDNA and the housekeeping genes sequences. Overall, the result of this study showed that the 5 obtained bacterial strains have a great potential in promoting plant growth in immature soil from newly reclaimed land.

Due to the development of urbanization and industrialization, a large amount of cultivated land resources has been occupied, while new reclamation land could expand the supply of usable land for food security. Organic fertilizers, such as crop residues, biosolids, sheep manure, mushroom residue, and biogas liquid, have been considered as an effective amendment in immature soil to improve its quality. Recently, two kinds of commercial organic fertilizers, pig manure and mushroom residue organic fertilizer (PMMR-OF), and sheep manure organic fertilizer (SM-OF), have been more regularly applied in agriculture production. However, the information available on effect of the two kinds of fertilizers on plant growth and rhizosphere soil properties in immature field is very limited. In order to evaluate PMMR-OF and SM-OF on immature soil, the soil quality and microbial community structure of corn rhizosphere soil samples under the two kinds of organic fertilizers at different concentrations was investigated. The results revealed a significant difference between commercial organic fertilizers (especially SM-OF) and chemical compound fertilizers (CCF) in soil properties and microbial community structure. Indeed, compared with the control based on16S and ITS amplicon sequencing of soil microflora, SM-OF caused a 10.79–19.52%, 4.33–4.39%,and 14.58–29.29% increase in Proteobacteria, Actinobacteria, and Ascomycota, but a 5.82–20.58%, 0.53–24.06%, 10.87–16.79%, 2.69–10.50%, 44.90–59.24%, 8.88–10.98%, and 2.31–21.98% reduction in Acidobacteria, Gemmatimonadetes, Bacteroidetes, Verrucomicrobia, Basidiomycota, Mortierellomycota, and Chytridiomycota, respectively. CCF caused a 24.11%, 23.28%, 38.87%, 19.88%, 18.28%, and 13.89% reduction in Acidobacteria, Gemmatimonadetes, Bacteroidetes, Verrucomicrobia, Basidiomycota, Chytridiomycota, but a 22.77%, 41.28%, 7.88%, and 19.39% increase in Proteobacteria, Actinobacteria, Ascomycota, and Mortierellomycota, respectively. Furthermore, redundancy discriminant analysis of microbial communities and soil properties of PMMR-OF, SM-OF, CCF, and the control treatments indicated that the main variables of bacterial and fungal communities included organic matter content, available P, and available K. Overall, the results of this study revealed significant changes under different fertilizer conditions (PMMR-OF, SM-OF, CCF, under different concentrations) in microbiota and chemical properties of corn soil. Commercial organic fertilizers, particularly SM-OF, can be used as a good amendment for the new reclamation land.