In recent years, research on organ-on-a-chip technology has been flourishing, particularly for drug screening and disease model development. Fibroblasts and vascular endothelial cells engage in crosstalk through paracrine signaling and direct cell–cell contact, which is essential for the normal development and function of the heart. Therefore, to faithfully recapitulate cardiac function, it is imperative to incorporate fibroblasts and vascular endothelial cells into a heart-on-a-chip model. Here, we report the development of a human heart-on-a-chip composed of induced pluripotent stem cell (iPSC)-derived cardiomyocytes, fibroblasts, and vascular endothelial cells. Vascular endothelial cells cultured on microfluidic channels responded to the flow of culture medium mimicking blood flow by orienting themselves parallel to the flow direction, akin to in vivo vascular alignment in response to blood flow. Furthermore, the flow of culture medium promoted integrity among vascular endothelial cells, as evidenced by CD31 staining and lower apparent permeability. The tri-culture condition of iPSC-derived cardiomyocytes, fibroblasts, and vascular endothelial cells resulted in higher expression of the ventricular cardiomyocyte marker IRX4 and increased contractility compared to the bi-culture condition with iPSC-derived cardiomyocytes and fibroblasts alone. Such tri-culture-derived cardiac tissues exhibited cardiac responses similar to in vivo hearts, including an increase in heart rate upon noradrenaline administration. In summary, we have achieved the development of a heart-on-a-chip composed of cardiomyocytes, fibroblasts, and vascular endothelial cells that mimics in vivo cardiac behavior.

Phosphorus application is widely regarded as a key measure for improving crop resistance to drought. This study investigated the effect of appropriate phosphorus fertilization on photosynthesis, physiological traits, and yield under water stress during the soybean flowering stage and selected the drought-sensitive soybean variety “Sui Nong 26” as the pot experiment object under a completely randomized design. The experiment was designed with three irrigation lower limits, corresponding to 70%, 60%, and 50% of the field capacity (FC), referred to as T1, T2, and T3. Four phosphorus fertilizer applications were also included: 0, 40, 50, and 60 mg·kg (designated as P0, P1, P2, and P3), resulting in a total of 12 treatments. Photosynthetic parameters, antioxidant enzyme activities, membrane lipid peroxidation, osmotic adjustment substances, yield, and yield components were measured to assess the effects of phosphorus fertilization on drought resistance. Results showed that under water stress, moderate phosphorus application (P1 and P2) enhanced photosynthetic capacity, antioxidation, osmotic adjustment, and yield, particularly by scavenging excess reactive oxygen species, protecting cells from oxidative damage, and maintaining metabolic balance, leading to increased yield. The average net photosynthetic rate and yield per plant under P1 and P2 levels increased by 33.53% and 37.67%, and 20.7% and 15.6%, respectively, compared to P0. In contrast, excessive phosphorus application (P3) improved the above parameters but had a significantly lower effect than moderate phosphorus application. Thus, appropriate phosphorus application is crucial for soybeans under water stress. Moderate application not only alleviates drought stress but also boosts soybean yield. This study highlights the importance of appropriate phosphorus use for mitigating water stress, offering scientific evidence for its practical application in agriculture. At the same time, with the increasing severity of climate change and water scarcity, phosphorus fertilizer application strategies under varying water conditions provide critical support for the application of precision agriculture technologies and ensuring food security.

Crop water production function models (WPFMs) are required methods to study the relationships between yield and water consumption under regulated deficit irrigation (RDI). In this study, a pot experiment was established to study the effect of water deficit during both individual growth stages and across two consecutive growth stages of rice on yield, water consumption, and water use efficiency (WUE) in 2017 and 2018. Light, medium, and severe water deficits were set as 80~90%, 70~80%, and 60~70% of saturated soil moisture content, respectively. The accuracies of five WPFMs were tested based on the experimental results. The results showed that yields and WUE of a light water deficit were higher than those of medium and severe water deficits at each growth stage. The yields and WUE of light drought stress treatments in the flowering and milky stages were higher than the saturated soil moisture control by 4~7.4% and 5.3~20.6%, respectively. Water consumption decreased with increasing water deficit across two consecutive growth stages. The Minhas model had the highest simulation accuracy of the five WPFMs, with relatively lower AE, RMSE, C_v, CRM, and higher R², which were 0.0002, 0.0634, 6.9965, 0.0002, and 0.9951 in 2017 and 0.0110, 0.0760, 8.9882, 0.0131, and 0.9923 in 2018, respectively. The sensitivity indices for the Minhas model more accurately reflected the sensitivity of rice yield to water deficit at different growth stages in 2017 and 2018, compared with the Jensen model, Stewart model, Blank model, and Singh model. Rice yield was most sensitive to water deficit at the jointing and booting stage. The results indicate that the Minhas model is the most suitable WPFM for guiding rice irrigation practices in cold and black soil regions of China.

Soil quality degradation and low nutrient use efficiency constrain sustainable maize–soybean rotation in the Albic soil region of Northeast China. A field experiment was conducted in 2023–2024 at Qixing Farm (Jiansanjiang, Heilongjiang, China) to evaluate chemical fertilizer combined with cattle manure or microbial inoculants. Five treatments were established: no fertilization (CK), chemical fertilizer alone (CF), chemical fertilizer combined with cattle manure (CF+CM), chemical fertilizer combined with a Bacillus subtilis inoculant (CF+CRA), and chemical fertilizer combined with a Bacillus megaterium inoculant (CF+CRB). Soil available nutrient dynamics, crop nutrient accumulation and translocation, fertilizer use efficiency, and yield were assessed. In maize, CF+CRB significantly enhanced pre-anthesis N translocation and post-anthesis P accumulation, increasing grain yield to 14,533 kg ha⁻¹ (+28.6% vs. CF). In soybean, CF+CRB produced 3328.15 kg ha⁻¹, 15.8% higher than CF. CF+CRA significantly increased soil available P during the soybean flowering-pod stage and improved K allocation at later stages. Overall, integrating chemical fertilizer with CRB improved yield and nutrient use efficiency. Based on crop-specific nutrient requirements, CRB is recommended for the maize season to strengthen nutrient translocation, whereas cattle manure or CRA can be applied in the soybean season to sustain K supply.

In this study, we investigated the effects of different tillage measures on soil environment and soybean yield. We chose a combination of eight tillage treatments using Heihe 43 as the test variety in order to correlate the yield with tillage practices. Our study design involved tilling and rototilling as primary treatments in combination with the following secondary treatment methods: advance deep loosening, advance cultivation, conventional deep loosening, and conventional cultivation. We investigated the effects of the above tillage treatments on soil physicochemical properties and soil biological activity. We also analyzed how tillage treatments impacted the morphology, photosynthetic characteristics, and yield of soybean. Our results indicated that tilling was more beneficial than rototilling in terms of increase in soil water content; the water content at the seedling stage increased from 5.80 to 17.13 in the 05cm soil layer which was subjected to tilling. Under tilling conditions, the Pn, Tr, and Gs values of soybean plants were higher compared to those of soybean cultivated in soil subjected to rototilling. However, Ci values of soybean were higher in rototilled soil. In 2018, we observed an increase in the number of pods and grains per plant in PT1 and PT2 of tilling compared to that of RT1 and RT2 of rototilling. PT1 and PT2 showed a percentage increase of 9.12 and 7.33, respectively. T1 and T2 both increased the number of pods and grains per plant of soybean under the same tillage conditions, which in turn increased the yield.