Soil with low fertility is a big problem for achieving citrus productivity. In this regard, the management of macro and micronutrients is essential. Macro and micronutrient deficiency decreased the yield and the quality of citrus fruit. It is the need of the hour to classify the soil fertility status under changing climatic scenarios. The current soil fertility survey was conducted to examine the macro and micronutrient status in the citrus production area. In soil, three depths (0–15, 15–30, and 30–45 cm) were taken for sampling. For leaves, 4–6-months-old non-bearing twigs were sampled from 20 trees per orchard at breast height. Results showed that soil pH (7.1–8.4) was slightly alkaline, electrical conductivity (EC) was non-saline (<4 dSm⁻¹), soil organic matter (SOM) was deficient (<0.86%), and calcium carbonate (CaCO₃) was slight calcareous (<8%), at 0–15, 15–30, and 30–45 cm depths. The majority of soil samples were low in nitrogen (N) contents at all depths, i.e., (<0.043) 0–15 (85%), 15–30 (97%), and 30–45 (100%) cm depths. Phosphorus (P) was medium (7–15 mg kg⁻¹) at 0–15 cm (60%) but low (<7 mg kg⁻¹) at 15–30 (63%) and 30–45 cm (82%) depths. Potassium (K) was medium (80–180 mg kg⁻¹) at 0–15 (69%), 15–30 (69%), and 30–45 cm (10%) depths. Boron (B) and manganese (Mn) were medium, and Cu was high in 0.15 cm, but all were low at 15–30 and 30–45 cm depths. Iron (Fe) and zinc (Zn) were low at depths of 0–15, 15–30, and 30–45 cm. Most citrus leaves were deficient in N (94%), Fe (76%), Zn (67%), and B (67%). In conclusion, soil fertilization is not sufficient for optimum citrus yield because of alkaline pH and slight calcareous soil conditions in this region. Foliar application of nutrients is suggested instead of only soil fertilization, for better nutrient management in citrus orchards.

Increasing soil and water salinity threatens global agriculture, particularly affecting rice. This study investigated the residual effects of microbial biochar and nitrogen fertilizer in mitigating salt stress in paddy soil and regulating the biochemical characteristics of rice plants. Two rice varieties, Shuang Liang You 138 (SLY138), a salt-tolerant, and Jing Liang You 534 (JLY534), a salt-sensitive, were grown under 0.4 ds/m EC (S0) and 6.84 ds/m EC (S1) in a glass house under controlled conditions. Three types of biochar—rice straw biochar (BC), fungal biochar (BF), and bacterial biochar (BB)—were applied alongside two nitrogen (N) fertilizer rates (60 kg ha⁻¹ and 120 kg ha⁻¹) in a previous study. The required salinity levels were maintained in respective pots through the application of saline irrigation water. Results showed that residual effects of microbial biochars (BF and BB) had higher salt mitigation efficiency than sole BC. The combination of BB and N fertilizer (BB + N120) significantly decreased soil pH by 23.45% and Na⁺ levels by 46.85%, creating a more conducive environment for rice growth by enhancing beneficial microbial abundance and decreasing pathogenic fungi in saline soil. Microbial biochars (BF and BB) positively improved soil properties (physicochemical) and biochemical and physiological properties of plants, ultimately rice growth. SLY138 significantly had a less severe response to salt stress compared to JLY534. The mitigation effects of BB + N120 kg ha⁻¹ were particularly favorable for SLY138. In summary, the combined residual effect of BF and BB with N120 kg ha⁻¹, especially bacterial biochar (BB), played a positive role in alleviating salt stress on rice growth, suggesting its potential utility for enhancing rice yield in paddy fields.

The integration of rubber plantations with agroforestry systems, or the under-forest economy, represents a pivotal shift towards sustainable agriculture in China. This paper reviews the latest research on agroforestry practices and innovations within China's rubber plantation under-forest economy, with a focus on the balance between economic productivity and environmental sustainability. We explore the adoption of diverse agroforestry models that incorporate rubber trees with other valuable plant species, aiming to enhance ecosystem services, biodiversity, and farmers' livelihoods. The review highlights significant advancements in sustainable management practices, including species selection, planting designs, and soil and water conservation techniques that contribute to the resilience of these systems against environmental stresses. Economic analyses underscore the potential for rubber agroforestry systems to improve income diversification and stability for rural communities while also navigating market challenges. Environmental assessments reveal the positive impacts of these practices on carbon sequestration, biodiversity preservation, and soil health, positioning rubber agroforestry as a beneficial strategy for mitigating climate change effects. However, the review also identifies challenges, including the need for supportive policy frameworks, access to knowledge and technology for smallholders, and further research on long-term sustainability outcomes. Future directions for research are proposed, emphasizing the integration of ecological, economic, and social dimensions to fully realize the potential of the rubber under-forest economy in China.

Plant membrane transporters are essential components in the regulation of nutrient uptake, ion homeostasis, and adaptive responses to environmental stress. These transport processes are tightly coordinated by complex phytohormonal signaling networks. This review provides an in-depth examination of the molecular mechanisms through which major plant hormones including auxins, cytokinins, brassinosteroids, ethylene, abscisic acid, gibberellins, jasmonates, strigolactones, melatonin, karrikins, and gamma-aminobutyric acid (GABA) modulate transporter activity. Each hormone activates distinct signaling pathways that alter the transcription, localization, and functional dynamics of membrane transport proteins, enabling plants to fine-tune physiological responses in accordance with developmental needs and environmental stimuli. Special attention is given to the integration of hormonal signals and how this interplay governs key processes such as stomatal movement, nutrient transport, and hormonal cross-regulation. The review also highlights the role of hormone–transporter crosstalk in optimizing plant performance under both normal growth conditions and various abiotic or biotic stresses. By dissecting these regulatory mechanisms, we offer insights into how phytohormonal control of membrane transport contributes to overall plant fitness. Understanding the coordination between hormonal signaling and transporter networks opens new avenues for crop improvement strategies. Leveraging this knowledge can support the development of resilient plant varieties with enhanced nutrient use efficiency, stress tolerance, and yield potential. This review underscores the significance of transporter–hormone interactions as central elements in plant development and environmental adaptation, positioning them as key targets for future agricultural innovations.

Soil salinity severely limits rice productivity by impairing photosynthesis, disturbing ion homeostasis and accelerating oxidative injury. The study aimed to evaluate the comparative efficacy of biochar (BC), SiO₂ nanoparticles (Si-NPs) and their combined composite SiO₂ nano-modified biochar (SBC) in enhancing salt tolerance in rice. Material characterization (SEM, TEM, FTIR, XRD) confirmed successful anchoring of SiO₂ onto the biochar matrix, forming a highly reactive nano-carbon composite. In this study rice plants under moderate salinity (EC ≈ 7 dS m^-1) conditions exhibited pronounced growth inhibition, excessive Na⁺ accumulation, elevated oxidative damage and impaired photosynthetic performance. In contrast, application of SBC substantially outperformed BC and Si-NPs and markedly alleviated stress symptoms. Relative to the CK-S, SBC reduced H₂O₂ and MDA by 55.4 % and 38.2 %, respectively, and enhanced SOD, POD and CAT activities by 39.5, 47.3 % and 31.3 %. Photosynthetic performance also improved significantly, with increase of 72.5 % in Pn, 77.2 % in Gs, 178.6 % and in ETR. SBC also improved the osmotic adjustment raising starch and sucrose content by 62.1 % and 70.9 % while reducing excessive proline accumulation by 30.6 %. Ion homeostasis improved through lower Na⁺ uptake and higher K⁺ retention resulting in a markedly higher K⁺/Na⁺ ratio through application of SBC. Furthermore, SEM imaging and transcript analysis revealed improved stomatal structure and root anatomical resilience while qRT-PCR showed upregulation of key stress-responsive genes associated with antioxidant and ion-transport pathways. These findings demonstrate that SBC provides a synergistic biochar-nanoparticle mechanism that comprehensively enhances rice tolerance to salinity, offering a promising and sustainable amendment for improving productivity in salt-affected agricultural systems.