<b>Data from: ‘Integrated crop-livestock effects on soil carbon and nitrogen in a semiarid region’</b>

Understanding integrated crop-livestock (ICL) management effects on soil carbon and nitrogen can help inform the design of agricultural practices that maintain key soil functions and contribute to agricultural sustainability. In the semiarid northern Great Plains, ICL management effects on soil carbon and nitrogen occur slowly, underscoring the importance of long-term experiments where biophysical metrics are measured consistently over time. In 1999, an ICL experiment was initiated approximately 5 km southwest of Mandan, ND USA on a Temvik-Wilton silt loam soil (USDA: Fine-silty, mixed, superactive frigid Typic and Pachic Haplustoll). The experiment included three residue management treatments, replicated twice: CONTROL (no residue removal), GRAZE (residue removed by livestock grazing), and REMOVED (residue removed by mechanical harvest). Soil properties measured during the study included soil bulk density, total soil nitrogen, soil organic carbon, and soil inorganic carbon. Measurements were made in 1999 (baseline) and 2014. Samples were collected using a hydraulic probe in depth increments of 0-8, 8-15, 15-31, 31-61, 61-91, 91-122 cm. Three cores from each treatment were composited by depth during each sampling. Soil carbon and nitrogen were quantified by the dry combustion method, while soil inorganic carbon was quantified using the volumetric calcimeter method. Data may be used to understand soil property responses to residue management for ICL production systems. Data are generally applicable to cropland under a semiarid Continental climate for the following soil types: Grassna, Linton, Mandan, Temvik, Williams, and Wilton.探明农牧综合系统（integrated crop-livestock, ICL）管理措施对土壤碳、氮的影响，可为维持关键土壤功能、助力农业可持续发展的耕作模式设计提供科学依据。在美国半干旱北大平原地区，ICL管理措施对土壤碳、氮的影响进程相对缓慢，这凸显了长期定位试验的重要性——此类试验需长期持续测定生物物理指标。1999年，一项ICL试验在美国北达科他州（North Dakota, ND）曼丹市西南约5公里处启动，试验田土壤为Temvik-Wilton粉砂壤土（美国农业部（United States Department of Agriculture, USDA）分类：Fine-silty, mixed, superactive frigid Typic and Pachic Haplustoll）。该试验设置3种残茬管理处理，均设置2次重复：对照组（无残茬移除）、放牧组（通过家畜放牧移除残茬）、机械移除组（通过机械收割移除残茬）。本试验测定的土壤属性包括土壤容重、土壤全氮、土壤有机碳与土壤无机碳。测定分别于1999年（基线采样）与2014年开展。采用液压钻采集土壤样品，采样深度分层为0-8 cm、8-15 cm、15-31 cm、31-61 cm、61-91 cm、91-122 cm。每次采样时，将各处理的3个土壤钻芯按土层混合制成复合样品。土壤碳、氮采用干燃法定量测定，土壤无机碳则采用容量钙量计法测定。本数据集可用于解析ICL生产系统中残茬管理措施下的土壤属性响应规律。该数据集适用于半干旱大陆性气候区的下述农田土壤类型：Grassna、Linton、Mandan、Temvik、Williams及Wilton。