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[学术文献 ] 黄土高原不同降水量区苹果园土壤干燥化效应及生产水足迹模拟 进入全文
应用生态学报
为探明黄土高原地区旱作苹果园深层土壤干燥化效应和生产水足迹动态变化，选择半湿润区洛川和半干旱区米脂两个典型苹果种植区，采用WinEPIC模型定量模拟分析两个区域1980—2020年旱作苹果园0～15 m土壤水分动态变化和苹果生产水足迹演变规律。结果表明：洛川和米脂成龄果园年产量大致呈“S”型趋势变化，年均值分别为24.64和18.42 t·hm-2；年均蒸散量分别为623.82和458.97 mm，年均干旱胁迫日数分别为20.40和52.73 d，年均水分过耗量分别为167.94和121.15 mm。洛川1～25龄、米脂1～23龄果树土壤有效含水量下降趋势明显，土壤干燥化速率分别为64.60和68.03 mm·a-1；洛川和米脂深层土壤干层形成的时间为第13年和第7年，并分别于第23年和第22年后达到稳定，降水量高的地区形成和达到稳定土壤干层的时间较晚，如果土壤水分长期处于亏缺状态，最终会形成不可逆转的土壤干层。洛川和米脂苹果生产水足迹均呈前期低后期高的特征，年均生产水足迹值分别为0.187和0.194 m3·kg-1。苹果产量和生产水足迹受降水影响，在水资源短缺的黄土高原地区，为了苹果产业能够持续健康发展，建议苹果树最佳种植年限为23年左右，最多不应超过25年。
[学术文献 ] 不同改良材料对苏打盐碱化耕地甜菜叶片光合特性、干物质积累和分配的影响 进入全文
生态学杂志
针对苏打盐碱化耕地作物生长受抑制、产量低的生产现状，选取应用较广泛的3种改良材料——有机硅肥（SF）、腐植酸肥（HF）和微生物菌肥（MF），以不施用改良材料（CK）为对照，探讨不同改良材料对甜菜光合特性、干物质积累和分配的影响，以期筛选出适宜内蒙古西辽河平原区苏打盐碱化耕地的改良材料。结果表明：3种改良材料不同程度改善苏打盐碱化耕地甜菜光合特性。与对照相比，有机硅肥在全生育时期表现出显著调控效果，腐植酸肥在叶丛快速生长期后表现显著，微生物菌肥则在生育前期表现显著，有机硅肥调控效果显著优于腐植酸肥和微生物菌肥；与CK相比，处理SF净光合速率(Pn)、胞间CO2浓度(Ci)、蒸腾速率(Tr)、气孔导度(Gs)和叶片SPAD值分别提高10.32%～21.77%、9.08%～19.62%、23.14%～43.35%、17.44%～40.93%和23.15%～28.87%；处理HF分别提高5.63%～12.33%、2.37%～13.60%、4.22%～31.01%、14.65%～32.79%和7.93%～20.06%；处理MF分别提高3.82%～10.36%、4.51%～10.14%、1.46%～26.54%、6.72%～20.45%和5.54%～18.18%。3种改良材料通过对光合特性的调控，促进甜菜单株干物质积累，以有机硅肥效果优于腐植酸肥和微生物菌肥；与CK相比，处理SF、MF和HF甜菜单株干物质积累量全生育时期分别提高12.20%～58.06%、3.15%～13.06%和5.91%～20.96%。与对照相比，仅有机硅肥具有调节干物质在不同器官分配的显著效果，叶丛快速生长期促进干物质从叶片向叶柄转运，块根及糖分增长期后促进干物质由叶片、叶柄向块根转运；与CK相比，叶丛快速生长期至收获期，处理SF叶片干物质比例降低4.01%～17.43%、叶柄干物质比例降低7.40%～15.87%、块根干物质比例提高3.34%～5.01%，块根及糖分增长期后甜菜根冠比显著提高，提高幅度10.88%～23.34%。甜菜叶片光合特性指标、不同器官干物质分配比例与甜菜产量和含糖率之间均存在着显著（P<0.05）或极显著（P<0.01）相关关系，改良材料的施用可以通过调节光合特性、改善干物质积累和分配实现甜菜产质量的提升，其中以有机硅肥表现最优。
[学术文献 ] 植物无土栽培技术研究进展 进入全文
中国农业大学学报
为了解植物无土栽培技术的发展，以“无土栽培”、“基质栽培”、“雾培”和“水培”为关键词，依据Web of Science、Pub-Med和知网等数据库，检索了1989—2021年发表的相关文献，对无土栽培发展历程、主要技术以及未来趋势进行了总结和分析。结果表明：1)无土栽培包括水培、雾培、基质栽培等，其中成本低、操作简单的基质栽培是主要方式，而操作、成本均更高的雾培和水培在高效植物栽培工厂建设上潜力巨大；2)探索高效、节水、可持续有机种植技术，融合人工智能和物联网技术，发展适配常规环境和恶劣环境的智慧农业是发展趋势之一；3)针对室内及楼宇空间等个体化种植需求，发展小型化、家庭化、精致化、智能化无土栽培技术是发展趋势之二；4)密闭空间种植和太空种植技术的研究也将受到更多关注。
[学术文献 ] Proximal sensor data fusion for tropical soil property prediction: Soil fertility properties 进入全文
ScienceDirect
Proximal sensors have proven capable of predicting multiple soil properties under different conditions. However, doubts remain about which sensor is preferable for delivering optimal prediction models and which preprocessing methods produce the most accurate results. Portable X-ray fluorescence (pXRF) spectrometry and visible near-infrared (Vis-NIR) diffuse reflectance spectroscopy have been widely used, while the NixProTM color sensor has been explored more recently. This study evaluated the use of pXRF, Vis-NIR, and NixProTM data to predict soil organic matter content (SOM), pH, base saturation (BS), the sum of bases (SB), cation exchange capacity (CEC) at pH = 7 and effective CEC (eCEC), via each sensor in isolation, and via combined sensors data. Moreover, variables interfering in the prediction models' accuracy (data preprocessing methods, soil horizon, soil class, parent material) were used as auxiliary variables. 604 soil samples were collected in Brazil, encompassing ten soil orders and 19 parent materials. Numerical and categorical prediction models (7,980) were created for six soil properties using a random forest algorithm, totaling 7980 models, delivering almost 24,000 results, including coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), residual prediction deviation (RPD) for validation of numerical predictions, and overall accuracy and kappa coefficient for categorical predictions. Although the combination of sensors provided most of the best predictions, pXRF in isolation achieved accuracies close to the three sensors combined. NixProTM offered superior contributions to SOM and CEC predictions, but pXRF and Vis-NIR were responsible for the best results of most studied variables. On average, by adding pXRF to Vis-NIR data, predictive accuracy improved 32%; while adding Vis-NIR to pXRF data increased accuracy by c. a. 6%. Soil-order-specific models improved predictions for Ultisols compared to general models (without soil order distinction), reaching R2 > 0.90. Soil parent material and horizon did not improve models significantly. Categorical predictions improved the accuracy for some properties, reaching an overall accuracy of 100% and kappa index of 1.0 for pH in A horizons of Ultisols via pXRF + Vis-NIR data. Proximal sensor data with no auxiliary variables provided almost all the best results. The fusion of proximal sensors can provide better predictions, but pXRF alone can deliver satisfactory results in most cases for the six soil properties.
[学术文献 ] Strategies for agricultural production management based on land, water and carbon footprints on the Qinghai-Tibet Plateau 进入全文
ScienceDirect
Agricultural production consumes land and water resources, and contributes to greenhouse gas emissions. Optimizing agricultural management to reduce environmental impacts is essential for regional ecological security. An evaluation framework was applied to assess the greenhouse gas emissions, water utilization, and land use of agricultural production in a typical agricultural region of the Huangshui River Basin on the Qinghai-Tibet Plateau, using footprint analysis. The results showed that agricultural production released 1.73 × 109 kg carbon equivalent (CO2-eq), and used 8.39 × 108 m3 of water and 2.96 × 105 ha of land. For the carbon footprint, agricultural material inputs (such as electricity, machinery, diesel, and nitrogen fertilizer) were the largest emission sources. For the water footprint, the blue water footprint was larger than the green water footprint. In addition, suitable management options were explored by establishing six scenarios according to the key factors influencing greenhouse gas emissions and water consumption. For technical strategy management options, using cleaner electricity in irrigation can reduce greenhouse gas emissions by 25.53%. Comprehensive strategies, including fertilizer application optimization and technical strategy management, proved to be more effective and reduced greenhouse gas emissions by 32.41%. The results of this study help to determine optimal agricultural management options for achieving both food security and environmental sustainability in agricultural areas on the Qinghai-Tibet Plateau.
[学术文献 ] The effect of soil organic matter on long-term availability of phosphorus in soil: Evaluation in a biological P mining experiment 进入全文
ScienceDirect
The plant uptake of legacy phosphorus (P) from over-fertilised agricultural soils could offer a solution to decrease dependency on finite mineral P resources. This study evaluated the long-term availability of legacy P in soils with an accelerated biological mining assay, thereby testing to what extent this availability is affected by soil organic carbon (SOC). A 15-month-long pot trial was set-up, in which 25 soils with 1.2–24% SOC were mined for P by continuous cropping and harvesting of ryegrass (Lolium perenne) in a plant growth cabinet. The cumulative uptake of P was, on average, 19% of the P associated with poorly crystalline iron (Fe) and aluminium (Al) (oxy)hydroxides (oxalate-extractable P; Pox). On average, half of this P could be taken up at rates fast enough to maintain crop production at > 90% of its potential. This P taken up before a 10% reduction in yield occurred, termed the critical cumulative P uptake (CCP), strikingly matched with the isotopically exchangeable P or “E value” of a soil (median CCP/E24h = 0.81), whereas it was markedly underestimated by Olsen P (median CCP/POlsen = 1.51). The fractions of plant-available Pox increased at increasing ratios of either P or SOC to the sum of Feox and Alox, suggesting that enhanced SOC contents reduce ageing of P by preventing its diffusion into micropores. That effect of SOC on P availability was more pronounced in soils with a low initial P saturation status. The comparison of the results from biological mining with available soil P pools determined in a (sterile) P desorption experiment could not confirm a significant contribution of organic P to plant P supply. Based on the set of soils in our study, our findings suggest that legacy P in well-fertilised agricultural soils could act as a sufficient P source for plants for several years to decades, and that this long-term availability is positively affected by SOC as long as the soil is not saturated with P.
