Data from: Soil strength after 21 years of conventional and organic cropping practices in the Mid-Atlantic region, USA

The data in this repository were used to compare soil compaction among the five crop management systems (2 conventional and 3 organic) in the Farming Systems Project at the Beltsville Agricultural Research Center, Beltsville, MD (39.0°N, 76.9°W). Soil compaction is a concern for producers because it negatively impacts crop yields. Differences between organic and conventional cropping systems practices, like organic matter inputs and tillage management, can result in differences in soil compaction. Soil penetrometer measurements (cone index, CI) were collected using a tractor-mounted hydraulic five-probe penetrometer in April 2017 prior to planting corn. Data on soil water content, soil C and soil bulk density were evaluated for relationship to soil compaction. The two conventional systems were 3-yr corn/rye cover crop–soybean/wheat/soybean rotations that used no-tillage (NT) or chisel tillage (CT). The three organic systems had different crop rotation lengths and used tillage of varying intensities and timing for seedbed preparation and weed control. The three organic systems were: 2-yr hairy vetch cover crop–corn/rye cover crop–soybean (Org2); 3-yr hairy vetch cover crop–corn/rye cover crop–soybean/wheat (Org3); and 6-yr corn/rye cover crop–soybean/wheat/alfalfa–alfalfa–alfalfa (Org6). Cropping systems management details, data collection methods, results and interpretations are presented in the associated manuscript. The Word document file “2017 FSP Penetrometer Meta DATA.docx” contains a list of the six data tables deposited with AgData Commons as Excel files. The Excel files contain raw and summarized data used in the manuscript. Tables in the Word document contain variable names and short descriptions/definitions of each variable in the Excel data files.

本仓库收录的数据用于对比马里兰州贝尔茨维尔农业研究中心（Beltsville Agricultural Research Center）作物系统项目（Farming Systems Project）下5种作物管理系统（2种常规系统、3种有机系统）的土壤压实情况，该中心坐标为北纬39.0°、西经76.9°。土壤压实会对作物产量产生负面影响，因此是种植者重点关注的问题。有机与常规作物耕作系统的管理措施差异（如有机质输入、耕作管理方式），可能会导致土壤压实程度的差异。2017年4月玉米播种前，研究人员采用搭载于拖拉机的液压五探针土壤硬度计（soil penetrometer）采集了土壤锥尖指数（cone index, CI）数据。研究人员还评估了土壤含水量、土壤有机碳及土壤容重与土壤压实度的相关性。2种常规耕作系统均采用3年轮作模式：玉米/黑麦覆盖作物→大豆/小麦/大豆，分别采用免耕（no-tillage, NT）和凿式耕作（chisel tillage, CT）。3种有机耕作系统的作物轮作周期各不相同，且为制备种床与防控杂草所采用的耕作强度与耕作时机也存在差异，具体包括：2年轮作模式（毛叶苕子覆盖作物→玉米/黑麦覆盖作物→大豆，记为Org2）、3年轮作模式（毛叶苕子覆盖作物→玉米/黑麦覆盖作物→大豆/小麦，记为Org3）以及6年轮作模式（玉米/黑麦覆盖作物→大豆/小麦/苜蓿→苜蓿→苜蓿，记为Org6）。相关手稿已详细阐述了各作物管理系统的操作细节、数据采集方法、研究结果与解读。Word文档"2017 FSP Penetrometer Meta DATA.docx"中列出了6份上传至AgData Commons的Excel格式数据表，这些Excel文件包含了手稿中所用的原始数据与汇总统计数据。该Word文档中的表格则列明了Excel数据文件中各变量的变量名与简要描述/定义。