Dryland wheat ( Triticum aestivum L.) is the principal crop grown on 3.35 million ha (8.28 million ac) of the semiarid Inland Pacific Northwest of the United States. In areas with less than 300 mm (12 in) of annual precipitation, challenges for wheat production are similar to those found in the Mediterranean region and Australia. Successful crop production depends on adequate precipitation capture and storage and weed control, which prove problematic under no-tillage (NT), the most effective soil conservation practice. Sweep-tillage (ST) is proposed as an equally effective conservation system, with local conventional wisdom saying that it produces higher yields than NT systems. A study established in 2006 and concluded in 2018 evaluated the performance of NT and ST winter wheat–summer fallow production systems. The null hypothesis for this research assumed no statistically significant differences in any of the soil and plant characteristics measured between NT and ST treatments. Sixteen 0.04 ha (0.10 ac) plots were established in a randomized complete block design, with two rotation entry points for a total of four treatment plots per year replicated in four blocks. Data were analyzed using a generalized linear mixed model. The NT system produced significantly higher crop yields and higher precipitation use efficiencies than the ST system (NT 3.38 ± 0.33, ST 2.66 ± 0.27 Mg ha–1 [NT 50 ± 5, ST 40 ± 4 bu ac–1]). Infiltration rates were higher and soil temperatures were lower in the NT system. The higher yields and lower soil temperatures in the NT system were unexpected and contrary to previous research conducted in this region.

中文翻译：

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低降水量地区冬小麦-免耕的最小耕作和免耕期

旱地小麦（Triticum aestivum L.）是美国半干旱内陆太平洋西北部的335万公顷（828万英亩）的主要作物。在年降水量不足300毫米（12英寸）的地区，小麦生产面临的挑战与地中海地区和澳大利亚面临的挑战相似。成功的农作物生产取决于足够的降雨捕获，储存和杂草控制，这在最有效的土壤保护措施免耕（NT）下被证明是有问题的。推荐使用扫耕（ST）作为同等有效的保护系统，当地的传统观点认为，此方法产生的收益比NT系统更高。2006年建立并于2018年结束的一项研究评估了NT和ST冬小麦-夏季休耕生产系统的性能。本研究的零假设假设在NT和ST处理之间测得的任何土壤和植物特性均无统计学上的显着差异。在随机完整区组设计中建立了16个0.04公顷（0.10 ac）地块，其中有两个轮换进入点，每年总共四个地块在四个区块中重复。使用广义线性混合模型分析数据。与ST系统相比，NT系统产生的农作物产量和降水利用效率显着提高（NT 3.38±0.33，ST 2.66±0.27 Mg ha-1 [NT 50±5，ST 40±4 bu ac-1]）。在NT系统中，入渗率较高而土壤温度较低。NT系统中的高产和较低的土壤温度是出乎意料的，这与之前在该地区进行的研究相反。