Soil nitrogen (N) is the main limiting nutrient for plant growth, which is sensitive to variations in the soil oxygen environment. To provide insights into plant N accumulation and yield under aerated and drip irrigation, a greenhouse tomato experiment was conducted with six treatments, including three fertilization types: inorganic fertilizer (NPK); organic fertilizer (OM); chemical (75% of applied N)+organic fertilizer (25%) (NPK+OM) under drip irrigation (DI) and aerated irrigation (AI) methods. Under AI, total soil carbon mineralization (Cmin) was significantly higher (by 5.7–7.0%) than under DI irrigation. Cmin in the fertilizer treatments followed the order NPK+OM>OM>NPK under both AI and DI. Potentially mineralizable C (C0) and N (N0) was greater under AI than under DI. Gross N mineralization, gross nitrification, and NH4+ immobilization rates were significantly higher under the AINPK treatment than the DINPK treatment by 2.58–3.27-, 1.25–1.44-, and 1–1.26-fold, respectively. These findings demonstrated that AI and the addition of organic fertilizer accelerated the turnover of soil organic matter and N transformation processes, thereby enhancing N availability. Moreover, the combination of AI and organic fertilizer application was found to promote root growth (8.4–10.6%), increase the duration of the period of rapid N accumulation (ΔT), and increase the maximum N accumulation rate (Vmax), subsequently encouraging aboveground dry matter accumulation. Consequently, the AI treatment yield was significantly greater (by 6.3–12.4%) than under the DI treatment. Further, N partial factor productivity (NPFP) and N harvest index (NHI) were greater under AI than under DI, by 6.3 to 12.4%, and 4.6 to 8.1%, respectively. The rankings of yield and NPFP remained consistent, with NPK+OM>OM>NPK under both AI and DI treatments. These results highlighted the positive impacts of AI and organic fertilizer application on soil N availability, N uptake, and overall crop yield in tomato. The optimal management measure was identified as the AINPK+OM treatment, which led to more efficient N management, better crop growth, higher yield, and more sustainable agricultural practices.
Phosphorus (P) is a finite natural resource and is increasingly considered to be a challenge for global sustainability. Agriculture in China plays a key role in global sustainable P management. Rhizosphere and soil-based P management are necessary for improving P-use efficiency and crop productivity in intensive agriculture in China. A previous study has shown that the future demand for phosphate fertilizer by China estimated by the LePA model (legacy phosphorus assessment model) can be greatly reduced by soil-based P management (the building-up and maintenance approach). The present study used the LePA model to predict the phosphate demand by China through combined rhizosphere and soil-based P management at county scale under four P fertilizer scenarios: (1) same P application rate as in 2012; (2) rate maintained same as 2012 in low-P counties or no P fertilizer applied in high-P counties until targeted soil Olsen-P (TPOlsen) level is reached, and then rate was the same as P-removed at harvest; (3) rate in each county decreased to 1–7 kg ha–1 yr–1 after TPOlsen is reached in low-P counties, then increased by 0.1–9 kg ha–1 yr–1 until equal to P-removal; (4) rate maintained same as 2012 in low-P counties until TPOlsen is reached and then equaled to P-removal, while the rate in high-P counties is decreased to 1–7 kg ha–1 yr–1 until TPOlsen is reached and then increased by 0.1–9 kg ha–1 yr–1 until equal to P-removal. Our predictions showed that the total demand for P fertilizer by whole China was 693 Mt P2O5 and according to scenario 4, P fertilizer could be reduced by 57.5% compared with farmer current practice, during the period 2013–2080. The model showed that rhizosphere P management led to a further 8.0% decrease in P fertilizer use compared with soil-based P management. The average soil Olsen-P level in China only needs to be maintained at 17 mg kg–1 to achieve high crop yields. Our results provide a firm basis for government to issue-relevant policies for sustainable P management in China.
Computer vision is widely recognized as an influential technology in the field of precision management of animals. Emerging studies have demonstrated the potential to improve pig health and welfare through animal surveillance systems and computer vision (CV) algorithms. However, the lack of benchmark datasets and robust fundamental algorithms restrict CV applications for the commercial use. This study aims to bridge the gap between technology development and commercial applications in pig farming scenarios by introducing a general-purpose dataset (PigLife), comparing benchmark performances of foundational CV algorithms and model development workflows. The PigLife dataset contains video clips and images (38 short video clips, 2K image frames, 22K pig instances) across most pig production phases in a typical commercial pig farm: Breeding and Gestation, Farrow to Wean, Weaning & Nursery, and Growth to Finish. Three detection algorithms (Faster R-CNN, RetinaNet, TridentNet) and three segmentation algorithms (Mask R-CNN, MViTv2, Point-Rend) were trained on the PigLife dataset from scratch. Fine-tuning of pre-trained models (YOLO8-m, Faster-RCNN-r50) and no-training from zero-shot models (CLIP-SAM, Grouddino-HQSAM) were also evaluated to suggest faster CV development workflows for commercial applications in pig farming. This study emphasizes the necessity of a benchmark dataset for evaluating the robustness of algorithms and identifying the remaining difficulties and challenges across various algorithms. Furthermore, developing CV models from pre-trained algorithms or zero-shot models showed better performance and a faster process, which could reduce barriers when developing high-performance CV products in pig production industry
Nitrogen use efficiency in rice is lower than in upland crops, likely due to differences in soil nitrogen dynamics and crop nitrogen preferences. However, the specific nitrogen dynamics in paddy and upland systems and their impact on crop nitrogen uptake remain poorly understood. The N dynamics and impact on crop N uptake determine the downstream environmental pollution from nitrogen fertilizer. To address this poor understanding, we analyzed 2,044 observations of gross nitrogen transformation rates in soils from 136 studies to examine nitrogen dynamics in both systems and their effects on nitrogen uptake in rice and upland crops. Our findings revealed that nitrogen mineralization and autotrophic nitrification rates are lower in paddies than in upland soil, while dissimilatory nitrate reduction to ammonium is higher in paddies, these differences being driven by flooding and lower total nitrogen content in paddies. Rice exhibited higher ammonium uptake, while upland crops had over twice the nitrate uptake. Autotrophic nitrification stimulated by pH reduced rice nitrogen uptake, while heterotrophic nitrification enhanced nitrogen uptake of upland crops. Autotrophic nitrification played a key role in regulating the ammonium-to-nitrate ratio in soils, which further affected the balance of plant nitrogen uptake. These results highlight the need to align soil nitrogen dynamics with crop nitrogen preferences to maximize plant maximize productivity and reduce reactive nitrogen pollution.