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Nitrate (NO3–) and ammonium (NH4+) are two main inorganic nitrogen (N) sources during crop growth. Here, we enhanced the expression of OsAMT1.1, which encodes a NH4+ transporter, using the NO3–-inducible promoter of OsNAR2.1 and an ubiquitin promoter in transgenic rice plants. Under field condition of 120 kg /hm2 N, agronomic N use efficiency, N recovery efficiency and N transport efficiency, and grain yield of the pOsNAR2.1:OsAMT1.1 transgenic lines were increased compared with those of the wild type (WT) and the pUbi:OsAMT1.1 transgenic plants. Under 2.0 mmol/L NO3– + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ conditions of hydroponic culture, compared with the WT, both biomass and total N content were increased in the pOsNAR2.1:OsAMT1.1 transgenic lines. However, biomass was significantly reduced in pUbi:OsAMT1.1 transgenic plants under 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ condition. The lines expressing pOsNAR2.1:OsAMT1.1 exhibited increased OsAMT1.1 expression and 15NH4+ influx in roots under both 2.0 mmol/L NO3– + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3– + 2.0 mmol/L NH4+ conditions. Our study showed that expression of OsAMT1.1 can be promoted when driven by the OsNAR2.1 promoter, especially under high-level nitrate condition, leading to enhancement of NH4+ uptake, N use efficiency and grain yield.

Water-extractable colloids (WECs) serve as crucial micro-particulate components in soils, playing a vital role in the cycling and potential bioavailability of soil phosphorus (P). Yet, the underlying information regarding soil P species and P-transformation microorganisms at the microparticle scale under long-term straw retention and mineral fertilization is barely known. Here, a fixed field experiment (∼ 13 years) in a Vertisol was performed to explore the impacts of straw retention and mineral fertilization on inorganic P, organic P, and P-transformation microorganisms in bulk soils and WECs through a sequential extraction procedure, P K-edge X-ray absorption near-edge structure (XANES), 31P nuclear magnetic resonance (NMR), and metagenomics analysis. In bulk soil, mineral fertilization led to increases in the levels of total P, available P, acid phosphatase (ACP), high-activity inorganic P fractions (Ca2-P, Ca8-P, Al-P, and Fe-P), and organic P (orthophosphate monoesters and orthophosphate diesters) but significantly decreased the abundances of P-cycling genes including P mineralization, P-starvation response regulation, and P uptake and transport by decreasing soil pH and increasing total P. Straw retention had no significant effects on P species and P-transformation microorganisms in bulk soils but led to increases in organic carbon, total P, and available P concentrations in WECs. Furthermore, compared with mineral fertilization, straw retention caused significantly greater differences in the relative abundances of P-cycling genes between WECs and bulk soils. The abundances of phoD gene and phoD-harboring Proteobacteria in WECs increased significantly under straw retention, suggesting that the P-mineralizing capacity increased. Thus, mineral fertilization reduced microbial P-solubilizing and mineralizing capacity in bulk soil. Straw retention could potentially accelerate the turnover, mobility, and availability of P by increasing the nutrient contents and P-mineralizing capacity at the microscopic colloidal scale. [ABSTRACT FROM AUTHOR]

The construction of a plant rhizosphere system enriched with beneficial microbes (BMs) can efficiently help plants defend against phytophagous insects. However, our comprehensive understanding of this approach is still incomplete. In this review, we methodically analyzed the progress made over the last decade, identifying both challenges and opportunities. The main methods for developing a BMs‐enriched rhizosphere system include inoculating exogenous BMs into plants, amending the existing soil microbiomes with amendments, and utilizing plants to shape the soil microbiomes. BMs can assist plants in suppressing phytophagous insects across many orders, including 13 Lepidoptera, seven Homoptera, five Hemiptera, five Coleoptera, four Diptera, and one Thysanoptera species by inducing plant systemic resistance, enhancing plant tolerance, augmenting plant secondary metabolite production, and directly suppressing herbivores. Context‐dependent factors such as abiotic and biotic conditions, as well as the response of insect herbivores, can affect the outcomes of BM‐assisted plant defense. Several challenges and opportunities have emerged, including the development of synthetic microbial communities for herbivore control, the integration of biosensors for effectiveness assessment, the confirmation of BM targets for phytophagous insect defense, and the regulation of outcomes via smart farming with artificial intelligence. This study offers valuable insights for developing a BM‐enriched rhizosphere system within an integrated pest management approach. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To study the effects of one-off application of slow-release nitrogen (N) fertilizer or controlled release urea on yield, N utilization efficiency and economic benefits of summer maize in Huanghuai regions, field experiments with one-off fertilization of controlled release urea or slow release urea blended with normal urea were conducted at 6 experimental sites in Henan province in 2021. 9 treatments were set under field condition: no nitrogen fertilizer (CK), normal urea alone (U1), farmers' fertilization practices (U2), controlled release urea blended with normal urea (CRU) including 3 ratios of 3:7 (CRU1), 5:5 (CRU2), 7:3 (CRU3), slow release urea blended with normal urea (LCU) including 3 ratios of 3:7 ( LCU1), 5:5 (LCU2) and 7:3 (LCU3) . The effects of controlled release urea or slow release urea blended with normal urea on yield, N utilization and economic efficiency of summer maize were studied. The results showed that N application treatments increased yield by 11.6%~49.1% compared with CK. The average yield of N application treatments was in the order of CRU>LCU>U (U1, U2) . The average yield of CRU and LCU was 23.3% and 9.7% higher than U, respectively, with CRU2 having the highest yield of 9 444.0 kg·hm-2, 8.0%~33.6% higher than other N application treatments, followed by LCU2. Dry matter accumulation, grain number per spike and 1 000-grain weight were significantly higher under CRU and LCU treatments compared with U. The highest N recovery efficiency was 36.9% under CRU2 treatment, followed by LCU2 at 33.2%. Compared with U, CRU and LCU treatments had higher NO-3-N content in 0-40 cm and significantly lower NO-3-N content in deeper soils (40-100 cm), which resulted in an average revenue increase of 2 186 and 995 yuan·hm-2, respectively. The sustainable yield index of summer maize was correlated with high yield and coefficient of variation. CRU2 and LCU2 treatments had more stable yields and better sustainability. Combining yield, N utilization and economic efficiency, the N fertilizer management model of 5:5 combination of controlled release urea and normal urea was recommended for one-off application in summer maize production in Huanghuai regions. Above results could provide a basis for simplified production techniques of summer maize and high yield and efficiency of N fertilizer. [ABSTRACT FROM AUTHOR]

Long-term excessive application of mineral fertilizer leads to phosphorus (P) accumulation, increasing the risk of P migration and loss from the soil profile. The colloids in the soil profile are important carriers for P migration due to their high P adsorption and transport capacity. It is not clearly understood how colloidal P (CP) is distributed in subsoils (<1.2 m) of a Vertisol, contributing to subsurface P loss. Understanding the depth sequence distribution and speciation of colloidal P in the soil profile is critical for a comprehensive assessment of P loss. In this study, water-extractable colloids (WECs) with the size of 0.35–2 µ m were obtained from a 0–120 cm soil profile by a sedimentation and centrifugation scheme. The dissolved reactive P (DRP) and dissolved total P (DTP) in soil supernatant with particle sizes <0.35 µ m were measured by molybdate blue colorimetry. Solution 31 P nuclear magnetic resonance (NMR) and P K-edge XANES (X-ray absorption near-edge structure) were used to characterize the species and distribution of CP in the soil profile of fertilized farmland. Total and available P in bulk soil and colloids decreased with soil depth. The organic P (OP) contained 97–344 mg kg -1 per bulk soil and 110–630 mg kg -1 per WEC. The OP in soil profile consists of orthophosphate mono-esters and diesters primarily according to NMR results. It suggested that OP in WECs from subsoils might be affected by the translocation of CP from surface soils, probably due to soil acidification and preferential flow caused by swelling–shrinkage clays, including montmorillonite and nontronite detected by X-ray powder diffractometer (XRD) results. Additionally, the more negative zeta potential of surface soil colloids suggests the high mobility of colloidal P towards the subsoils. The CP concentration for <2 µ m was about 38–93 mg P kg -1 per bulk soil, which is 6–37 times that of DRP, suggesting that CP plays a dominant role in P transport within the soil profile. The relatively small fraction of orthophosphate diesters suggests limited P assimilation by microorganisms for the accumulation of WECs containing organically bound P in subsoils. The P K-edge XANES results indicated that the proportions of Al-P, Fe-P, and inositol hexakisphosphate (IHP) of WECs decreased, but hydroxyapatite (HAP) increased with soil depth. This study showed that inorganic and organic P migrated from the surface to deeper layers along the soil profile, with soil colloids having a significant effect on P migration from both surface and subsurface layers. The findings have an important significance for soil P migration evaluation and agricultural non-point source pollution control in Vertisols. [ABSTRACT FROM AUTHOR]

Long-term, excessive application of synthetic N fertilizers will reduce soil aggregate stability and N supply capacity in corn–wheat (Zea mays L. – Triticum aestivum L.) rotation. This study aimed to determine the effects of soybean (Glycine max L.) on soil aggregation, soil organic N (SON) and net amount of N mineralization (NANM) in wheat season compared with corn. Three rotation systems, corn–wheat (C-W), soybean–wheat (S-W) and soybean inoculated with Rhizobium-wheat (SR-W) were established in 2017. In wet screening, compared with C-W rotation, the mass proportions of large macro-aggregates (LM%) + small macro-aggregates (SM%) at 0–20 cm was increased by 51.9% and 16.6% under S-W and SR-W rotations, respectively, and was increased by 50.6% and 59.8%, respectively, in the 20–40 cm. The proportions of LM + SM-associated N (LMN% + SMN%), ammonium N (AN) and amino acid N (AAN) were higher under the S-W and SR-W rotations. Furthermore, the NANM of S-W and SR-W rotations increased by 34.1% and 28.6% compared with C-W rotation, respectively, and the non-N benefits of soybean played an important role. In conclusion, the improvement degree of soil aggregation by soybean is an important factor affecting soil N mineralization in wheat season. [ABSTRACT FROM AUTHOR]

Long-term excessive application of mineral fertilizer leads to accumulation of phosphorus (P) in lime concretion black soil, which increases the risk of P migration and loss from soil profile. The colloids in the profile are important carriers for P migration due to high P adsorption and transport capacity. In this study, water extractable colloids (WECs) were obtained from 0 ~ 120 cm soil profile by soil fractionation method, and their physicochemical properties were analyzed. Solution 31P nuclear magnetic resonance (NMR) and P K-edge XANES were used to characterize the species and distribution of colloidal P in fertilized farmland soil profile. Total and available P in bulk soil and colloids decreased with soil depth. The organic P (OP) contained ~97 to 344 mg kg-1 per bulk soil and 110–630 mg/kg per WECs in soil profile with composition of orthophosphate monoesters and diesters according to NMR results. It suggested that OP in WECs from subsoils might be affected by the translocation of colloidal P (CP) from surface soils probably due to soil acidification and preferential flow caused by swelling-shrinkage clays including montmorillonite and nontronite. Additionally, the more negative zeta potential of surface soil colloids suggests the high mobility of colloidal P to the subsoils. The CP concentrations for <2 µm was about 38–93 mg/kg per bulk soil, which is 6–37 folds of dissolved reactive P (DRP) concentrations, suggesting that the role of CP for P transport in the soil profile is dominated. This study showed that inorganic and organic P migrated from surface to deeper layer along the lime concretion black soil profile, with soil colloids having a significant effect on P migration from both surface and subsurface layers. The results have an important significance for soil P migration evaluation and agricultural non-point source pollution control in lime concretion black soil. [ABSTRACT FROM AUTHOR]

Understanding soil phosphorus (P) transformation and turnover under various fertilization managements is important for evaluating sustainable P fertility and potential bioavailability in agriculture managements. Thus, long-term fertilization experiments (∼ 38 years) with the application of different inorganic and organic fertilizers in paddy red soils were conducted to determine the effect of different fertilizer applications on P pool accumulation and microbial communities, especially for phosphate-solubilizing microorganisms (PSMs). Long-term inorganic P (IP) fertilization increased the concentrations of total P (TP) (∼ 479 mg kg -1), available P (AP) (∼ 417 mg kg -1) and inorganic P (∼ 18 mg kg -1), but manure fertilization accelerated the accumulation of organic P, especially for orthophosphate monoesters (e.g., myo-IHP, ∼ 12 mg kg -1). Long-term mineral fertilization decreased bacterial richness, evenness and complexation of bacterial networks. In contrast, long-term manure fertilization and rhizosphere accumulated more amounts of total carbon, total nitrogen, and organic carbon, as well as regulated the soil pH, thus improving the separation of bacterial communities. Furthermore, PSM compositions were greatly influenced by fertilization managements and rhizosphere. For example, inorganic P fertilization increased the abundance of Thiobacillus (i.e., the most abundant phosphate-solubilizing bacteria (PSB) in this study) and shifted the community structure of PSB. Correspondingly, the concentrations of inorganic and total P were the key factors for the variation of the PSB community structure. These findings are beneficial for understanding the variation of inorganic and organic P pools and the microbial community, especially for PSMs under long-term inorganic and/or organic fertilization. [ABSTRACT FROM AUTHOR]

Fertilization managements have important impacts on soil P transformation, turnover, and bioavailability. Thus, long-term fertilization experiments (~38 years) with the application of different inorganic and organic fertilizers in paddy red soils were conducted to determine their effect on P pool accumulation and microbial communities, especially for phosphate solubilizing microorganisms (PSM). Long-term inorganic P fertilization increased the concentrations of total P (~479 mg/kg), available P (~417 mg/kg), and inorganic P (~18 mg/kg), but manure fertilization accelerated the accumulation of organic P, especially for orthophosphate monoesters (e.g. myo-IHP, ~12 mg/kg). Long-term mineral fertilization decreased bacterial richness, evenness, and complexation of bacterial networks. In contrast, long-term manure fertilization and rhizosphere accumulated more amounts of total carbon, total nitrogen, and organic carbon, as well as regulated the soil pH, thus improving the separation of bacterial communities. Unlike bacteria, the responses of fungi to those factors were not sensitive. Furthermore, PSM compositions were greatly influenced by fertilization managements and rhizosphere. For example, inorganic P fertilization increased the abundance of Thiobacillus (i.e. the most abundant phosphate solubilizing bacteria (PSB) in this study) and shifted the community structure of PSB. Correspondingly, the concentrations of inorganic and total P were the key factors for the variation of PSB community structure. These findings are beneficial for understanding P accumulation, responses of PSB, and soil P sustainable fertility under different fertilization strategies. [ABSTRACT FROM AUTHOR]

Background: Traditional chemical pesticides are easily lost by surface runoff and only small quantities reach the target, thus causing serious environmental pollution. In this work, dinotefuran@zeolitic imidazolate framework-8@polydopamine@zein (DNF@ZIF-8@PDA@zein), was constructed to deliver DNF with pH and enzyme double response of release, thereby achieving targeted release and efficient long-term pest control., Results: DNF@ZIF-8@PDA@zein was synthesized with three hydrated diameters (249.73 ± 9.99 nm, 142.94 ± 5.63 nm and 75.16 ± 4.66 nm, respectively). The release of DNF from DNF@ZIF-8@PDA@zein after 28 h was significantly higher at pH 5.0 (89.22 ± 7.18%) compared to that at pH 8 (81.8 ± 6.11%). Protease-assisted release of DNF was notably higher than that without protease (pH 5: 89.22 ± 5.55% versus 27.19 ± 3.22%; pH 8: 81.8 ± 6.11% versus 25.39 ± 3.87%). The stimuli-responsive release of DNF from DNF@ZIF-8@PDA@zein increased with decreased particle size due to increased pore size, reduced binding forces (i.e., weaker π-π stacking, hydrogen bonding, and Zn-N covalent bonding), and the shortening of diffusion path, leading to faster disintegration and drug release. Additionally, the anti-photolysis ability of DNF@ZIF-8@PDA@zein was 3.2 times that of pure DNF. The insecticidal activity improved with smaller nanoparticles due to higher drug release rate and greater inhibition of detoxification enzyme activity by more zinc ion (Zn 2+ ) dissolution., Conclusion: The pH and enzyme dual-responsive release as well as insecticidal activity of DNF@ZIF-8@PDA@zein increase with decreased nanoparticle size, showing effective pest management in long-term and potential application prospects in sustainable agriculture. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Bio-solubilization of lignite is a promising technology to transform coal into humic acids (HAs) which are broadly used in agriculture. In this work, HAs were extracted from lignite using the cell-free filtrate (CFF) of Penicillium ortum MJ51. The extraction method was optimized using response surface methodology (RSM) based on the interactive effects of nitric acid concentrations, coal loading ratio, extraction temperature and time as input factors, and the absorbance of HAs at 450 nm wavelength as the output response. Under optimized conditions (lignite pretreated with 4.7 N HNO 3 , coal loading ratio of 4.9%, temperature of 77.3 °C and time of 8.6 hours), the absorbance at 450 nm peaked at 70.28, and the concentration and extraction yield of HAs were 31.3 g L -1 and 63.9%, respectively, which were dramatically higher than those observed for traditional biological methods (0.7 g L -1 and 14.1%, respectively). The qualities of HAs produced under optimized conditions were evaluated and compared with those extracted by the conventional chemical method. The optimized process resulted in better HA quality indices, including lower molecular mass; higher nitrogen; less aromatic carbon; more aliphatic and carboxylic carbon; and higher bioactivity for promoting plant growth. Moreover, the anti-flocculation ability was improved, thereby supporting its applicability in agriculture. Extraction of HAs from lignite using the CFF of P. ortum MJ51 provides a novel technological approach for the efficient conversion of lignite to bio-active HAs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

The eco-physiology and productivity of 6-2-2 wheat-early maturing cotton-middle maturing cotton were studied in comparison with traditional 6-2 wheat-middel maturing cotton. The results showed that after wheat harvested, the LAI of cotton increased fast, the leaf area duration(LAD) and CGR were raised obviously, the dry matter rose rapidly, and the accumulated amount was larger than CK. Light use efficiency was 1.13%, 21% more than CK. The effective blossom period was extended 18 d, and the lint yield in both 1998 and 1999 was over 2250 kg.hm-2, 21-22% more than CK.