In the northern Great Plains vast amounts of native grassland have given way to crops, mostly small grains and corn, over the past half century. It is well understood that over the long-term, grassland conversion accelerates erosion and generally decreases many soil functions. It is less clear, however, what short-term effects occur to the soil from grassland conversion; after the first or second year of conversion. The objectives of this study were to assess the short-term (first year) effects of converting land that is considered long-term grassland to small grain production through either conventional tillage (CT) or no-till (NT) practices using various indicators of soil health and to demonstrate how tools such as the Comprehensive Assessment for Soil Health (CASH), can be used to document soil health indicator decline immediately upon conversion from grassland to small grains. The CASH offers a suite of chemical, physical and biological soil tests to broadly assess soil health. In general, these indicators showed a more rapid decline in soil health under CT than NT. After the first year of grassland conversion, aggregate stability declined by 7% and 19% in the NT and CT plots, respectively when compared to the grassland control. Likewise, CT produced significantly greater declines in permanganate oxidizable carbon (POX-C) and soil protein (ACE-Protein), particularly under reduced precipitation. This study highlights how the CASH can provide an intuitive framework for monitoring the effects of land use change and can be used by land managers to identify potential soil constraints and formulate potential interventions.

在过去的半个世纪里，大平原北部的大量原生草原已经让位于农作物，主要是小谷物和玉米。众所周知，从长远来看，草地转化会加速侵蚀并普遍降低许多土壤功能。然而，不太清楚草地转化对土壤的短期影响是什么？在转换的第一年或第二年之后。本研究的目的是评估将被认为是长期草地的土地通过常规耕作 (CT) 或免耕 (NT) 做法使用各种土壤健康，并展示土壤健康综合评估 (CASH) 等工具如何，可用于记录从草地转变为小谷物后土壤健康指标立即下降。CASH 提供一套化学、物理和生物土壤测试，以广泛评估土壤健康。总的来说，这些指标显示 CT 下土壤健康的下降速度比 NT 下更快。在草地转换的第一年之后，与草地对照相比，NT 和 CT 样地的聚集体稳定性分别下降了 7% 和 19%。同样，CT 显着降低了高锰酸盐可氧化碳 (POX-C) 和土壤蛋白质 (ACE-蛋白质)，尤其是在降水减少的情况下。