Continuous cropping (CC) obstacle is a major threat in legume crops production; however, the underlying mechanisms concerning the roles allelochemicals play in CC obstacle are poorly understood. The current 2-year study was conducted to investigate the effects of different kinds and concentrations of allelochemicals, p-hydroxybenzoic acid (H), cinnamic acid (C), phthalic acid (P), and their mixtures (M) on peanut root growth and productivity in response to CC obstacle. Treatment with H, C, P, and M significantly decreased the plant height, dry weight of the leaves and stems, number of branches, and length of the lateral stem compared with control. Exogenous application of H, C, P, and M inhibited the peanut root growth as indicated by the decreased root morphological characters. The allelochemicals also induced the cell membrane oxidation even though the antioxidant enzymes activities were significantly increased in peanut roots. Meanwhile, treatment with H, C, P, and M reduced the contents of total soluble sugar and total soluble protein. Analysis of ATPase activity, nitrate reductase activity, and root system activity revealed that the inhibition effects of allelochemicals on peanut roots might be due to the decrease in activities of ATPase and NR, and the inhibition of root system. Consequently, allelochemicals significantly decreased the pod yield of peanut compared with control. Our results demonstrate that allelochemicals play a dominant role in CC obstacle-induced peanut growth inhibition and yield reduction through damaging the root antioxidant system, unbalancing the osmolytes accumulation, and decreasing the activities of root-related enzymes.

Plant growth regulators (PGRs) enhance crop stress resistance but their roles in microbial-mediated phosphorus cycling within intercropping systems are unclear. Thus, We conducted a two-year field study using corn (Zea mays L. cv. Denghai 605) and soybean (Glycine max L. cv. Hedou 22) in fluvisols and luvisols soil according to World Reference Base for Soil Resources (WRB) standard. Under a 4-row corn and 6-row soybean strip intercropping system, three treatments were applied: a water control (CK), and two plant growth regulators—T1 (EC: ethephon [300 mg/L] + cycocel [2 g/L]) and T2 (ED: ethephon [300 mg/L] + 2-Diethyl aminoethyl hexanoate [10 mg/L]). Foliar applications were administered at the V7 stage (seventh leaf) of intercropped corn plants to assess how foliar-applied PGRs (T1/T2) modulated the soil phosphorus availability, microbial communities, and functional genes in maize intercropping systems. PGRs increased the soil organic phosphorus and available phosphorus contents, and alkaline phosphatase activity, but not total phosphorus. PGRs declined the α-diversity in fluvisols soil but increased the α-diversity in luvisols soil. The major taxa changed from Actinobacteria (CK) to Proteobacteria (T1) and Saccharibacteria (T2) in fluvisols soil, and from Actinobacteria/Gemmatimonadetes (CK) to Saccharibacteria (T1) and Acidobacteria (T2) in luvisols soil. Functional gene dynamics indicated soil-specific regulation, where fluvisols soil harbored more phoD (organic phosphorus mineralization) and relA (polyphosphate degradation) genes, whereas phnP gene dominated in luvisols soil. T1 stimulated organic phosphorus mineralization and inorganic phosphorus solubilization in fluvisols soil, upregulating regulation genes, and T2 enhanced polyphosphate synthesis and transport gene expression in luvisols soil. Proteobacteria, Nitrospirae, and Chloroflexi were positively correlated with organic phosphorus mineralization and polyphosphate cycling genes, whereas Bacteroidetes and Verrucomicrobia correlated with available potassium (AP), total phosphorus (TP), and alkaline phosphatase (ALP) activity. Thus, PGRs activated soil phosphorus by restructuring soil type-dependent microbial functional networks, connecting PGRs-induced shifts with microbial phosphorus cycling mechanisms. These findings facilitate the targeted use of PGRs to optimize microbial-driven phosphorus efficiency in strategies for sustainable phosphorus management in diverse agricultural soils.

Water-based resin-coated controlled-release fertilizer (CRF) is valued for its safety, environmental benefits, and water absorption/retention properties. To improve the productivity of alfalfa (Medicago sativa L.) and the soil quality in coastal saline–alkali land at the Yellow River Delta, in this work, we carried out field experiments to study how the application of CRF (water-based resin-coated urea) and soil conditioner, both developed in-house, affected the alfalfa harvest and the soil properties. The following five treatments were tested from 2022 to 2023: T0, no fertilization; T1, urea with P&K fertilizers; T2, CRF with P&K fertilizers; T3, urea, P&K fertilizers, and soil conditioner; T4, CRF, P&K fertilizers, and soil conditioner. The results showed that the simultaneous application of CRF and soil conditioner (i.e., T4) had the most obvious effect on improving the yield and quality of alfalfa. In 2022, T4 had 6.3% higher total alfalfa yield than T0. In 2023, T4 had 14.2% and 8.4% higher total alfalfa yield than T0 and T1, respectively. The alfalfa from T4 had higher crude protein content and relative feeding value (RFV), lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) content. The combined application of CRF and soil conditioner reduced the salinity of the surface soil and increased the soil organic matter, available nitrogen, and phosphorus at the 0~40 cm layer. Therefore, the application of soil conditioner and CRF can improve the use of coastal saline–alkali land for the cultivation of alfalfa.

Introduction: Optimizing water and nitrogen management is crucial for the sustainable development of wheat–maize rotation system. This study systematically examined the impacts of various water and nitrogen management strategies on the wheat–maize rotation system, with the aim of identifying integrated practices that can simultaneously improve yield, resource use efficiency, economic returns, and environmental outcomes. Methods: A field experiment was conducted from 2022 to 2024 in Tai’an, Shandong Province, China. Strategies involved different nitrogen fertilizers (compound fertilizer, urea, and controlled-release fertilizer) and irrigation methods (flood, drip irrigation DI, and micro-sprinkler irrigation SI). Outcomes were assessed based on yield, water and nitrogen use efficiency, economic benefits, and environmental performance, using entropy-weighted TOPSIS comprehensive evaluation. This research aiming to identify an optimized management practice that can simultaneously. enhance both economic and carbon benefits(carbon sequestration/emission ratio). Results and discussion: Drip irrigation with 60% basal controlled-release fertilizer and 40% top-dressed urea (T4) yielded optimal results. Compared to conventional flood irrigation with 50% basal compound fertilizer and 50% top-dressed urea, T4 synergistically increased annual system yield by 1.08–3.99%, improved water use efficiency to 9.42 kg·m ^-3 and nitrogen use efficiency to 34.75%, achieved the highest net income (24,347.9 CNY·ha ^-1 ), and raised carbon benefits to 21.38. Entropy-weighted TOPSIS comprehensive evaluation further demonstrated that the T4 treatment under drip irrigation obtained the highest closeness coefficient (0.702). These findings show that integrating drip irrigation with the split application of controlled-release fertilizer and urea can facilitate the efficient alignment of water and nitrogen resources. This approach is a viable technical pathway for promoting sustainable and low-carbon production under the wheat–maize rotation system in the Huang–Huai–Hai region of China.

Peanut (Arachis hypogaea L.) is one of the most important crops for oil and protein production. The unique characteristic of peanut is geocarpy, which means that it blooms aerially and the peanut gynophores (pegs) penetrate into the soil, driving the fruit underground. In order to fully understand this phenomenon, we investigated the dynamic proteomic and phosphoproteomic profiling of the pegs aerially and underground in this study. A total of 6859 proteins and 4142 unique phosphoproteins with 10,070 phosphosites were identified. The data were validated and quantified using samples randomly selected from arial pegs (APs) and underground pegs (UPs) by parallel reaction monitoring (PRM). Function analyses of differentially abundant proteins (DAPs) and differentially regulated phosphoproteins (DRPPs) exhibited that they were mainly related to stress response, photosynthesis, and substance metabolism. Once the pegs successfully entered the soil, disease-resistant and stress response proteins, such as glutathione S-transferase, peroxidase, and cytochrome P450, significantly increased in the UP samples in order to adapt to the new soil environment. The increased abundance of photosynthesis-associated proteins in the UP samples provided more abundant photosynthetic products, which provided the preparation for subsequent pod development. Phosphoproteomics reveals the regulatory network of the synthesis of nutrients such as starch, protein, and fatty acid (FA). These results provide new insights into the mechanism, indicating that after the pegs are inserted into the soil, phosphorylation is involved in the rapid elongation of the pegs, accompanied by supplying energy for pod development and preparing for the synthesis of metabolites during pod development following mechanical stimulation and darkness.

Introduction: High-temperature stress severely restricts the growth, development and yield formation of summer maize. Foliar application of exogenous melatonin has been widely demonstrated to enhance stress tolerance and alleviate abiotic stress in crops. However, the physiological and molecular mechanisms underlying melatonin-mediated thermotolerance in summer maize under post-flowering high-temperature stress remain unclear. Methods: In this study, field experiments were conducted using foliar application of melatonin at different concentrations on maize. By integrating agronomic, physiological and transcriptomic approaches, we systematically investigated the mechanisms by which melatonin improves the adaptation of summer maize to post-flowering high-temperature stress. Results and Discussion: The results showed that exogenous melatonin increased the net photosynthetic rate of ear leaves and maintained high photosynthetic capacity. Melatonin treatment also significantly increased the activities of key antioxidant enzymes and the contents of antioxidant substances in the maize ear leaves, thereby enhancing the antioxidant defense capacity of the plant. Transcriptomic analysis further revealed that melatonin upregulated the expression of key genes involed in the photosynthetic and antioxidant defense systems of maize. In summary, exogenous melatonin application improved the resistance of summer maize to natural post-flowering high-temperature stress by optimizing photosynthetic function and reinforcing the antioxidant defense system, effectively reducing the damage of high-temperature to maize growth, biomass accumulation and grain yield. The 150 µmol L-1 melatonin treatment exerted the optimal mitigating effect under field conditions. These findings help to elucidate the key mechanisms by which exogenous melatonin enhances thermotolerance in maize under post-flowering high-temperature stress, and provide a theoretical basis for research on of maize stress resistance, disaster reduction, yield improvement, and efficient chemical regulation strategies.