In order to realize the absorption， recovery and utilization of nutrients in biogas slurry,the magnetic micro-nano biochar zeolite composite materials were prepared by solvothermal method in this study. The nutrient release characteristics of the composite materials recovered after adsorption of biogas slurry were then investigated through nutricnt extraction test. Pot experiments were carried out to study the impacts on the growth of lettuce and the physical and chemical properties of soil. The results showed that, the synthesized magnetic micro-nano biochar zeolite composite had a specific surface area of 187.6 m2/g,and the average particle size in water was 1.48 μ.m. The loaded iron oxide was present as nanoscale Fe3O, with a grain size of around 9.5 nm. The saturation magnetization strength of the composite material was 13.4 emu/g, which could be separated and recovered from water through an external magnetic field.After 30 days of leaching test, the nutrient accumulation dissolution rate of the solid biogas fertilizer was 71.97% ， which had better nutrient slow-release performance compared to ordinary fertilizers. The pot experiment result showed that when compared with the non-fertilized control, the treatments with solid biogas fertilizers which replacing nitrogen fertilizer in different proportions, could significantly increase the biomass and chlorophyll content of lettuce, and incrcase soil pH by 0.13 -0.44 units,organic matter content by3.0%-20.0%，total nitrogen and total phosphorus content by 17.8%-27.1% and 26.5%-45.5%，respectively, and effective nitrogen and phosphorus content by 22.0%-49.8%.In comparison to applying fertilizer and biogas slurry treatment, the treatment which replacing 40% of the nitrogen fertilizer by solid biogas fertilizer was superior. Therefore, the magnetic micro-nano biochar zeolite composite prepared in this study could be used for nutrient adsorption and recovery in biogas slurry, and the obtained solid biogas fertilizer presents good nutrient release performance and high fertilizer efficiency value.

Dispersants containing lignosulfonale were commonly used in pesticides, but they failed to meet the requirements for nanoparticle pesticide dispersion. Lignin samples with varying molecular weights and degrees of sulfonation were prepared through the process of sulfomethylationcombined with alkyl bridging. The influence of molecular weight and degree of sulfonation on their dispersion stability in nanopesticide suspensions was explored. The results indicated that, at the same dcgree of sulfonation, the dispersion stability of lignin dispersants was initially improved and then decreased with increasing molecular weight. To achieve the best dispersion effect, the sulfonation degree and molecular weight of lignin needed to be coordinated. As the sulfonation degree increased, the appropriate molecular weight should also increase accordingly.GCL4-Nano, with a sulfonation degree of 1.58 mmol/g and a molecular weight of 14 897 Da, was found to exhibit excellent dispersion stability for nanopesticides of different varieties.The nanopesticide suspensions prepared had an average particle size ranging from 165 nm to 206 nm,with a suspension rate exceeding 95%.Additionally,they demonstrated excellent wetting propertics,resistance to rainwater washing,and photostability.

In order to solve the problems of poor solubility , easy metabolism by plants, concentration dependence and low bioavailability of brassinolide(BR)，a nanosystem of zein (Z-COS)modified with chi tosan oligosaccharide(COS)and ethylene glycol diglycidyl ether ( EGDE) to load BR(BR@ Z-COS)was constructed. The structure and morphology of Z-COS and the effects of BR@ Z-COS on cucumber seed germination and seedling under salt stress were studied. The results showed that the solubility of ZCOS in water reached 13% , the average particle size of BR@Z-COS was 98 nm, and the PDI value was less than 0.2. Z-COS had a certain sustained release effect on BR, and the cncapsulation efficiency and drug loading of BR reached 17.81%and 6.85 μg/mg,respectively. When the concentration of BR@ Z- COS was 0.1mg/L，the proline content in plants could be increased, thus effectively alleviating the damage to plant growth under salt stress environment.

In order to improve the targeted accumulation of fungicides on the lesion locations against Fusarium wilt in bananas,polymer nanocarriers(PSI-PHE) were constructed with polysuccinimide(PSI) and phenylalanine(PHE).Then fludioxonil(FLU) was loaded into the nanocarriers to produce PHE-guided nanoparticles(FLU @ PSI-PHE).The infrared spectroscopy,hydrodynamic size,zeta potential,thermogravimetricanalysis and X-ray diffraction analysis were explored to characterize the interaction and loading capacity between nanocarriers and FLU. The results showed that the loading capacity of FLU@ PSI-PHE nanoparticles with 531 nm by hydrodynamic size was up to 45.96% , and the translocation dose of the castor phloem was 1.27 μg/mL,showing cfficient phlocm delivery effect.Compared with low doses of FLU, FLU@ PSI-PHE nanoparticles with the same active ingredient content showed basically equal antifungal activity against Fusarium wilt in bananas. Amino acid-mediated FLU@ PSI-PHE could be efficiently translocated in plant vascular tissues,which provides new technology for targeted treatment of banana Fusarium wilt.

Nano-controlled release formulation based on mesoporous silica nanoparticles(MSNs)provides an effective way for accurate pesticide delivery. In this study, temperature-responsive emamectin benzoate (EB) nano-controlled release formulation ( EB@ MSNs@ K(NIPAAM-MAA))was prepared by sol-gel method. The appearance, release behavior, insecticidal activity and safety to non-target organisms were studied systematically. The results of TEM showed that the unloaded particles MSNs@K( NIPAAM-MAA)were round in shape, uniform in size and rough in surface, and the particle size is distributed in the range of 150~170 nm. The results of BET, FTIR and TGA showed that the thermosensitive polymer was successfully grafted ( grafting rate of 19.5%)and EB was successfully loaded into MSNs ( drug load- ing of 15.7% ). Release behavior studies showed that higher temperatures(28 ℃ and 24 ℃ ) were benefical for the release of EB.Both EB@ MSNs@ K( NIPAAM-MAA)and commercial EB@ EC had reasonable control effect against Spodoptera frugiperda at the same concentration, but the insecticidal effect of EB@ EC was lower than that of EB@ MSNs@ K( NIPAAM-MAA) with time extension,indicating that EB@ MSNs@ K( NIPAAM-MAA)had a longer effective duration. The biosafety test showed that the LCso of EB@ MSNs@ K( NIPAAM-MAA)was 26.62 mg/kg at 14 d on carthworms, which showed low toxicity. In addition, EB@ MSNs@K(NIPAAM-MAA) had no significant effect on the changes in chlorophyll content of corn leaves at a range of concentrations.

Nano pesticides have the advantages of small particle size, good dispersibility, and high utilization rate, making them a hot topic in the research of development of pesticide formulations in recent years. In this work, a liquid chromatography-mass spectrometry method was established to analyze the retention dose of pyraclostrobin and tebuconazole on pepper leaves. The recovery rates were83.9%~ 108.5%，and the relative standard deviation was 4.3% ~9.9%. The relention performance of 30% pyraclostrobin·tebuconazole nanosuspension on pepper leaves studied by foliar spray, with 30% pyra- clostrobin tebuconazole suspension as control. The results showed that after 3 and 7 days of treatment, the pesticide retention on the pepper leaves treated with the control group was 0.042 ~2.71 mg/kg,which was lower than that of the nanosuspension treatment(0.064 ~4.93mg/kg).Nanosuspension had better retention performance on pepper leaves.

Chitosan and gelatin come from natural sources and have good film-forming properties, but both have poor bacteriostatic performance, which limits their application in food packaging. In order to enhance antimicrobial activity of the film, nano-zinc oxide was incorporated in gelatin/chitosan composite film. In this study, chitosan and gelatin were used as film-forming materials and nano-zinc oxide was added as antibacterial material, and the composite film was prepared by blending method. The effects of nano-zinc oxide content on the structure ,mechanical properties and antibacterial properties of chitosan/gelatin/nano-zinc oxide composite films were investigated. The results showed that the introduction of nano-zinc oxide effectively improved the mechanical properties,water vapor permeability ,thermal stabilily and antibacterial properties of the composite film. When the content of nano-zinc oxide in the composite film is 0.5% , the antibacterial performance of the composite film was the best, with the water solubil-ity of 17.3% , the water absorption rate of 100.0% , the tensile strength of 5.5 MPa, the elongation at break of 8.0% , the water vapor transmittance of 94.72 g·m 2 . hˉ'， the water vapor permcability of 2.44 x10-" g?cm'·s'·Pa', and the diameter of the zone of inhibition of Staphylococcus aureus of(37.8±0.1) mm and Escherichia coli of (25.7±0.1) mm. These findings indicate that chitosan/gelatin/nano-zinc oxide composite films have great potential to be developed as biodegradable alternative for postharvest packaging of fresh fruits and vegetables.

In order to solve the problems of short persistence, low utilization efficiency, high residue levels, and certain toxicity to target crops and non-target organisms during the use of hexaconazole,four kinds of hexaconazole polyurea microcapsules with different shell structures were prepared via interfacial polymerization using isophorone diisocyanate(IPDI)as the wall material and a mixture of triethylenetet ramine (TETA) and TETA with ethylenediamine(EDA)，piperazine (PIP)，and lysine (LYS) as the curing agents. The prepared microcapsules were characterized using dynamic light scattering,infrared spectroscopy, and scanning electron microscopy. The results showed that the microcapsules had a spherical shape with a uniform particle size distribution,an average particle size of approximately 2 μm, encapsulation efficiency ranging from 89% to 97%，and drug loading ranging from 65% to 76%. The release behaviors of the four different microcapsules were investigated, and the cumulative relcase rate in mcthanol solution ranged from 29%to 65%after 30 hours,indicating good sustained-release properties. The sustained release rateand cumulative release amount decreased with increasing crosslinking degree and chain segment rigidity of the microcapsule wall,suggesting that the release behavior of the microcapsules can be controlled by regulating the chain scgment structure of the wall. The microcapsules prepared using interfacial polymerization had a uniform particle size distribution,high encapsulation efficiency, strong drug loading capacity, and good sustained-release properties, and the synthesis process was simple as well as the reaction conditions were mild, which could provide a reference for the development of hexaconazole microcapsule formulations.

Nanocarriers possess the controllable pore structure, which can significantly enhance the water solubility and dispersion of pesticides, promote the entry of pesticides into target pests, and contribute to the accurate pesticide relcase, application reduction and efficiency enhancement. Nanocarriers broad application prospects in the agricultural field. At present, the synergies between nano delivery system and promoting plant absorption and conduction, enhancing leaf surface wetlability，resistance to ultraviolet photolysis and intelligent response release of pesticides are rarely summarized, and the application safety evaluation of nano pesticides is insufficient. In view of this, the current review summarized the types of agricultural nano-delivery systems and their applications in plant discase and pest management, analyzed the effect of surface-modified nano-carriers on pesticide synergism, pointed out the possible application risks of nano-pesticide, which will provide reference for the development of nano-delivery syslem to control plant pathogens and insect pests.

As a new nanomaterial with enzyme-like activity , nanozymes had great application potential in stress resistance improvement, food testing,food processing and preservation, plant protection, seed treatment and other directions. This article reviewed the definition，classification and application of nanozymes in agriculture, discussed the current problems, and looked forward to their future development directions.