To improve the potassium availability of feldspar at ordinary temperatures, the mechanical grinding and addition of sodium hydroxide/salts were employed to study the effects of mechanical activation and strong alkali addition on particle characteristics, water-soluble potassium, and the available potassium of feldspar. A laser particle size analyzer was utilized for the direct determination of particle size distribution (PSD) using ground samples. The Brunauer–Emmett–Teller (BET) method was employed for specific surface areas. X-ray diffraction (XRD) was employed for structural characterization, scanning electron microscopy (SEM) for morphology exploration, and energy dispersive spectroscopy (EDS) to determine the chemical composition of potassium feldspar powder. The results revealed that the mechanical activation of potassium feldspar could reduce the particle size and produce agglomerated nanoparticles in the later period. The addition of NaOH and sodium salt did not cause agglomeration, and NaOH dissolved the nanoparticles. The water-soluble potassium content of feldspar in each treatment increased during mechanical grinding, from 21.64 mg kg⁻¹ to 1495.81 mg·kg⁻¹, by adding NaOH 5% weight of potassium feldspar powder and to 3044.08 mg·kg⁻¹ by adding NaOH 10% weight with effects different from those of mechanical shaking. By comparison, only 162.93 mg·kg⁻¹ water-soluble potassium was obtained by adding NaOH 5% weight. The dissolved potassium in the former case was significantly higher than in the latter, and the addition of NaOH and sodium salts significantly enhanced the water-soluble potassium contents due to ion exchange. Furthermore, the addition of sodium hydroxide improved the water-soluble potassium due to its mechanochemical action on potassium feldspar. The mechanical energy changed the crystal structure of potassium feldspar, explaining the increase in available potassium. The addition of sodium salts did not promote change in the feldspar’s structure, thereby did not raise the available potassium content. The reason for this was related to the mechanochemical action on sodium hydroxide and feldspar, which could promote the dissolution of fine particles, thereby incrementing the available potassium.

Understanding soil phosphorus (P) distribution and its key drivers is fundamental for sustainable P management. In this study, a 21-year fertilization experiment on black soil was carried out, setting up five fertilization treatments: unfertilized control (CK), nitrogen and potassium (NK), nitrogen, P and potassium (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM). The distribution and effecting factors of P pools within soil aggregates were investigated. Compared to CK, the NK and NPK treatments decreased calcium-associated P concentration in all aggregate fractions. Meanwhile, the NPK treatment significantly increased the organic P extracted from NaOH in unaggregated particles (<0.053 mm). This was mainly due to the reduction in soil pH. The NPKS and NPKM treatments increased almost all P forms in aggregates, especially Ca-P. For the NPKM treatment, inorganic P extracted from resin, NaHCO₃, and NaOH increased as aggregate size increased. This was mainly because straw or manure addition promoted soil organic carbon (SOC) storage in aggregates, creating more sorption sites via association with amorphous metallic minerals, and, thus, facilitating P accumulation. In conclusion, decreasing soil pH by chemical fertilizers is an effective strategy for mobilizing soil P, whereas increasing SOC by straw or manure facilitates P accumulation.

Humic acid is a macromolecular organic compound with active groups that, when applied to the soil, can regulate the storage and release of nutrient elements. The effects of a humic acid application at two application rates (F-1: 15 t·hm⁻² and F-2: 30 t·hm⁻²) on soil physicochemical properties and plant growth and yield were compared in field experiments to explore the impact of the humic acid dosage on the soil fertility of aeolian sandy soils. The CEC, EC, pH, organic matter, and available nutrient content were measured in the 0~20 cm and 20~40 cm soil before and after the humic acid application. The results showed that the soil organic matter and available nutrient content increased significantly with an increased humic acid application rate. In the 0~20 cm soil layer, the contents of soil alkaline-hydrolyzable nitrogen, available potassium, and organic matter were the highest in the F-2 treatment, at 24.97, 207.66 mg·kg⁻¹, and 8.99 g·kg⁻¹, respectively, which increased by 76%, 66%, and 54% compared with the control treatment. On the other hand, the content of available phosphorus was the highest in the F-1 treatment, at 13.23 mg·kg⁻¹, which was 38% higher than the control. In the 20~40 cm soil layer, the contents of soil alkaline-hydrolyzable nitrogen, available phosphorus, and available potassium were the highest after the F-2 treatment, at 16.33, 8.51, and 17.14 mg·kg⁻¹, respectively, which increased by 19%, 113%, and 58% compared with the control. The organic matter content was the highest in the F-1 treatment, at 7.61 g·kg⁻¹. After the humic acid application, the CEC and EC increased significantly, and the pH decreased. In addition, the growth status (leaf length, tillering number, and chlorophyll content) and yield of the Cyperus plants significantly increased with an increase in the humic acid dosage. In short, adding humic acid can effectively improve the physical and chemical properties of aeolian soils, regulate the nutrient circulation in the soil, and increase the yield and income from Cyperus cultivation.

This study aims to quantify the effects of three fertilization patterns—“chemical fertilizer alone,” “organic fertilizer alone,” and “mixed application of organic and inorganic fertilizers”—on soil fertility and crop yields. It also assesses the relationships among baseline soil properties, climatic factors, and fertilization effects in the North China Plain. By compiling relevant literature on these three fertilization patterns over the past 30 years in the region and employing meta-analysis methods, this study incorporated 63 wheat-related studies (1,065 datasets) and 34 maize-related studies (631 datasets). The analysis examined the effects of different fertilization methods on crop yield, soil nutrients, microbial carbon and nitrogen content, and soil enzyme activity, as well as the relationships between baseline soil properties, climatic factors, and fertilization outcomes. Results revealed: 1) Short-term application of chemical fertilizers and organic-inorganic composite fertilizers significantly increased wheat yields more than maize yields, whereas organic fertilizer application boosted maize yields more than wheat yields. Organic-inorganic composite fertilization most significantly enhanced soil microbial biomass and key soil enzyme activities, while chemical fertilizer alone showed the weakest improvement effects. 2) Fertilization impacts yield under baseline conditions of soil pH 6–8, soil organic matter content below 15 g/kg, annual mean temperature of 13°C–14°C, and annual precipitation exceeding 500 mm. 3) Long-term application of chemical fertilizers alone shows slowing yield increases, whereas organic-inorganic composite fertilization sustainably boosts yields and mitigates the impact of single factors on production. Unified comprehensive fertilization rates for wheat and maize are recommended as follows: nitrogen fertilizer application of 150–225 kg·ha ^⁻¹ , phosphorus fertilizer of 60–90 kg·ha⁻¹, potassium fertilizer of 30–60 kg·ha⁻¹, supplemented with 7.5–9 tons·ha⁻¹ of organic fertilizer. This approach outperforms single-fertilizer regimes in improving soil microbial properties and enzyme activity, serving as the key to superior yield maintenance. The recommended integrated fertilization rates strike a balance between reducing chemical fertilizer use, stabilizing yields, and enhancing soil fertility, providing practical guidance for fertilizer management in the North China Plain.

Brominated butyl rubber (BIIR) is a derivative of butyl rubber, with the advantage of high physical strength, good vibration damping performance, low permeability, aging resistance, weather resistance, etc. However, it is hard to avoid BIIR fiber sticking together due to serious swelling or merging, resulting in few studies on BIIR electrospinning. In this work, brominated butyl rubber membrane (mat) with BIIR microfiber has been prepared by electrospinning. The spinnability of elastomer BIIR has been explored. The factors influencing the morphology of BIIR microfiber membranes have been studied, including solvent, electrospinning parameters, concentration, and the rheological property of electrospinning solution. The optimal parameters for electrospinning BIIR have been obtained. A BIIR membrane with the ideal microfiber morphology has been obtained, which can be peeled from aluminum foil on a collector easily without being broken. Anti-bacterial property, the electrical conductivity of these membranes, and the mechanical properties of these samples were studied. The optimized BIIR electrospinning solution is Bingham fluid. The results of these experiments show that a BIIR membrane can be used in the field of medical prevention, wearable electronics, electronic skin, and in other fields that require antibacterial functional polymer materials.