The Conservation Reserve Program (CRP) is a United.States of Americae government program that provides financial incentives to transition marginal croplands to permanent grass cover to conserve soil and water. Few studies have evaluated the best tillage system that maintains soil properties when converting CRP back to cropland. Our objective was to determine how converting CRP to cropland under different tillage practices after three years affects soil C (carbon) stocks, physical and chemical properties, and winter wheat () and corn (.) grain yields after 4 yr. We also reviewed literature on the topic to compare previous results against our findings. This experiment was conducted in Sidney, NE, USA on CRP that was converted to production farmland through four tillage practices no-till (NT), disk-sweep (DS), plow-sweep (PS) and deep plow-sweep (DPS) in 2017 and planted to a wheat-corn-fallow rotation. Organic C stock was reduced by 6% in PS and 15% in DPS compared to CRP in the 0–10 cm depth but not in the 0–60 cm. Tillage practice did not affect grain yields in our study but had inconsistent effects according to previous literature. In the upper 10 cm, wet aggregate stability was reduced by 41% in DS, 51% in PS, and 58% in DPS, dry aggregate stability was reduced by 66% in NT, 71% in DS, 74% in PS and 77% in DPS, and plant available water was reduced by 45% in NT, 50% in DS, 39% in PS and 43% in DPS treatment relative to CRP. However, treatments had no effect on cumulative infiltration rate and bulk density. The use of DS or NT when converting CRP to cropland caused the least negative impacts on soil properties when CRP was converted to cropland in our study and in previous studies reported in the literature. Minimizing soil disturbance by reduced or no tillage maintained relevant soil properties 3 yr after CRP conversion to cropland.

中文翻译：

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确定最佳耕作系统，以在保护保护区计划草地转变后保持土壤特性和作物产量

保护储备计划 (CRP) 是美国政府的一项计划，旨在提供财政激励措施，将边际农田转变为永久草地覆盖，以保护水土。很少有研究评估将 CRP 转化为农田时保持土壤特性的最佳耕作系统。我们的目标是确定三年后在不同耕作方式下将 CRP 转为农田如何影响四年后的土壤碳储量、物理和化学特性以及冬小麦 () 和玉米 (.) 粮食产量。我们还回顾了有关该主题的文献，将以前的结果与我们的发现进行比较。该试验在美国内布拉斯加州悉尼进行，通过四种耕作方式将 CRP 转变为生产农田：免耕（NT）、圆盘清扫（DS）、犁扫（PS）和深犁清扫（DPS） 2017 年，实行小麦-玉米-休耕轮作。与 CRP 相比，0-10 cm 深度的 PS 有机碳库减少了 6%，DPS 的有机碳库减少了 15%，但 0-60 cm 深度则没有。在我们的研究中，耕作做法并不影响粮食产量，但根据以前的文献，其效果不一致。在上部 10 cm 中，湿集料稳定性 DS 降低了 41%，PS 降低了 51%，DPS 降低了 58%，干集料稳定性 NT 降低了 66%，DS 降低了 71%，PS 降低了 74%，DPS 降低了 77%。相对于 CRP，DPS 处理中植物可利用水减少了 45%，DS 减少了 50%，PS 减少了 39%，DPS 处理减少了 43%。然而，处理对累积渗透率和堆积密度没有影响。在我们的研究和文献报道的先前研究中，当 CRP 转化为农田时，使用 DS 或 NT 对土壤性质造成的负面影响最小。CRP 转化为农田后 3 年，通过减少耕作或免耕来最大限度地减少土壤干扰，保持了相关的土壤特性。