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1.
Sarah M. Collier Sophie M. Green Alex Inman David W. Hopkins Hazel Kendall Molly M. Jahn Jennifer A. J. Dungait 《Soil Use and Management》2021,37(1):49-62
There are few reliable data sets to inspire confidence in policymakers that soil organic carbon (SOC) can be measured on farms. We worked with farmers in the Tamar Valley region of southwest England to select sampling sites under similar conditions (soil type, aspect and slope) and management types. Topsoils (2–15 cm) were sampled in autumn 2015, and percentage soil organic matter (%SOM) was determined by loss on ignition and used to calculate %SOC. We also used the stability of macroaggregates in cold water (WSA) (‘soil slaking’) as a measure of ‘soil health’ and investigated its relationship with SOC in the clay‐rich soils. %SOM was significantly different between management types in the order woodland (11.1%) = permanent pasture (9.5%) > ley‐arable rotation (7.7%) = arable (7.3%). This related directly to SOC stocks that were larger in fields under permanent pasture and woodland compared with those under arable or ley‐arable rotation whether corrected for clay content (F = 8.500, p < .0001) or not (F = 8.516, p < .0001). WSA scores were strongly correlated with SOC content whether corrected for clay content (SOCadj R2 = .571, p < .0001) or not (SOCunadj R2 = 0.490, p = .002). Time since tillage controlled SOC stocks and WSA scores, accounting for 75.5% and 51.3% of the total variation, respectively. We conclude that (1) SOC can be reliably measured in farmed soils using accepted protocols and related to land management and (2) WSA scores can be rapidly measured in clay soils and related to SOC stocks and soil management. 相似文献
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为研究不同贮藏方式对鲜食核桃在贮藏过程中品质的影响,以“清香”核桃鲜果为试材,分别采用青果贮藏((0±1) ℃、相对湿度70%~80%)、去青皮的湿果贮藏((-7±1) ℃、相对湿度70%~80%)及湿果真空贮藏((-7±1) ℃、相对湿度70%~80%)3种方式贮藏,每15 d对其品质指标进行观察测定。结果表明:随着贮藏时间的延长,所有贮藏方式处理的鲜食核桃的感官品质和营养成分均呈一定的下降趋势。其中,青果贮藏能较好地保持核仁的含水量,维持粗脂肪、蛋白质及可溶性糖含量的稳定性,贮藏后种皮色泽较好,核仁容易剥皮、风味较好,但果壳容易产生霉变;湿果贮藏和湿果真空贮藏可以减轻鲜核桃的霉变,延长了鲜核桃贮藏期,但随着贮藏时间的延长,湿果贮藏核仁水分散失较快,粗脂肪、蛋白质及可溶性糖含量变化较大,使得种皮色泽降低,核仁剥皮困难、风味下降。 相似文献
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为了探讨起垄方式与移栽方式对河南省周口市烟区植烟土壤物理特性和烤后烟叶产质量的影响,以筛选适合周口烟区烤烟产质量和土壤物理特性同步提高的起垄与移栽处理组合模式。采用田间试验法,以‘中烟100’为研究材料,依据起垄方式与移栽方式设置龟背型膜上移栽(T1)、龟背型膜下移栽(T2)、中凹型膜下移栽(T3)和中凹型膜上移栽(T4)4个试验处理,研究不同起垄方式对土壤物理特性和烤后烟叶产质量的影响。结果显示,中凹型起垄的单独和复合处理均可以有效地改善土壤的物理特性和提高烟叶的产质量,其中以中凹型起垄配合膜下移栽处理(T3)效果最好。与T1相比,T3处理可以显著提高各土层土壤含水率和总孔隙度,降低土壤容重,明显促进烤后烟叶中化学成分更加协调,上部叶中性致香物质含量较T1提高了15.96%,产量和产值较T1处理显著提高。因此,中凹型起垄膜下移栽处理更有利于改善植烟土壤物理特性和提高烤后烟叶产质量,是最佳种植模式,结果为河南省周口烟区适宜的烟草种植模式提供理论依据。 相似文献
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Ikabongo Mukumbuta 《Soil Science and Plant Nutrition》2020,66(1):76-83
ABSTRACT Conversion of grassland to cropland is widely reported to deplete soil organic carbon (SOC) largely due to tillage effects on the decomposition of SOC. However, most studies report on long-term changes in SOC following the conversion and little is known about the changes in the short term. Net ecosystem carbon budget (NECB) measures the difference between total C input (i.e., manure, above- and below-ground plant residues) and C loss through heterotrophic respiration (RH). However, most studies that report temporal SOC do not report other components of the NECB like RH, total C inputs and often do not include the cumulative annualized change of these components. This review evaluated the change in C input, RH, NECB and SOC after conversion of permanent/continuous grassland to cropland within 5 years after the conversion. We also reviewed and compared no-tillage and conventional tillage on SOC storage and accumulation. Total C input was higher in grassland than cropland largely due to high root biomass, as opposed to aboveground residue, and therefore grassland tended to have higher NECB. Despite higher NECB in grassland, the SOC stocks in cropland (cornfield) converted from grassland were greater than that in continuous grassland within first 2–3 years of conversion. The combination of manure C addition and tillage in cropland showed potential to maintain NECB and increase SOC. Within the continuous grassland C addition alone increased NECB but did not result in a corresponding increase in SOC. Residue retention and manure addition are recognized as good practices for increasing SOC, this study however, shows that combining them with occasional tillage, especially in managed grasslands, could increase the rate of SOC storage in soils. 相似文献
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Iwona Jaskulska Anna Gałązka 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2019,69(6):516-527
The tillage system, which joins soil tillage, fertilisation, and seed sowing in one pass of a machine, is rarely used in cereal cultivation. This research aimed to study whether strip-till and conventional tillage (post-harvest ripping and mixing of stubble, ploughing, pre-sowing fertilisation, and seedbed preparation) differ in plant density, yield components, and grain yield of winter barley cultivated on Cambisol in a region with low rainfall, the annual average is about 500?mm. To reach this aim, a two-year, large-plot experiment was conducted in a production field. The soil within the field was spatially variable in texture, moisture, and chemical and biological properties, CV 2.3% do 29.6%. Strip-till had lower within-field spatial variability of winter barley grain yield than conventional tillage. The standard deviation was 0.36?t?ha?1, 0.67?t?ha?1 in the first year and 0.12?t?ha?1, 0.30?t?ha?1 in the second year, respectively. During the period of limited rainfall, strip-till had greater uniformity of plants after emergence; after the winter with low air temperature and a low amount of snow, it had greater plant density. Thus, strip-till can reduce variability of plants and their yield within a field, especially in adverse environmental conditions. 相似文献
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生态系统服务权衡最新研究进展 总被引:1,自引:0,他引:1
生态系统服务权衡研究对协调生态环境保护和社会经济发展至关重要。为推动生态系统服务管理和提升人类福祉,本文以Web of Science核心合集(WOS)和中国科学引文数据库(CSCD)为数据源,运用文献计量分析法,系统梳理和总结生态系统服务权衡研究的学科知识基础、科学领域结构和热点变化等发展现状以及最新研究进展。研究表明:1)不同研究层面上,生态系统服务间的权衡关系受外部风险和人类需求、参数选取和服务提供者及区域差异性和不均衡性的影响。2)研究方法主要有基于关系识别和具体表征的权衡分析、权衡模拟和预测的模型量化分析和生态系统服务权衡管理优化的多准则分析3类。3)生态系统服务权衡关键驱动因子为城市化、生态工程和气候变化。基于此,我们认为把握生态系统服务权衡不同研究层面的关联特征、创新和优化生态系统服务权衡研究方法、准确甄别生态系统服务权衡关键驱动因子以及充分整合多维生态系统服务权衡资源搭建数据共享平台是未来研究的重点。 相似文献