CONTEXT

Declining rainfall with increasing variability, increasing temperature extremes, and declining soil fertility are threatening crop production and ultimately food security in the rainfed Mediterranean environment in Morocco. Conservation agriculture (CA) practices such as reduced tillage, soil cover, and appropriate crop rotation are recognized as a set of adaptive agricultural systems in such climate-sensitive regions. Systematic evaluation of agronomic, economic, and soil fertility indicators with medium-and long-term adoption of CA in different crop rotations in such variable climatic conditions is needed to drive wider adoption of CA in the region.

OBJECTIVE

The objective of this study was to systematically evaluate agronomic, economic, and soil fertility indicators under CA and conventional tillage (CT) using field experimentation (medium-term) and simulation modeling (long-term) for a clay soil of a rainfed Mediterranean environment.

METHODS

Methodologies included the following: 1) Field experimentation for 5 years (2015–2019), comparing CA and CT in four major food crops: wheat, barley, lentil, and chickpea, conducted in Merchouch, Morocco. The objective was to determine the effect of CA on crop productivity, yield stability, profitability, precipitation use efficiency, and soil fertility indicators of individual crops and cropping systems. (2) Dynamic simulation modeling to understand the long-term effect of adopting CA and CT under cereal–legume and cereal–cereal rotation systems. Using 5 years of experimental data, we calibrated and validated a Decision Support System for Agrotechnology Transfer (DSSAT) model for four crops; and ran the model for 36 years for two major rotations.

RESULTS AND CONCLUSIONS

Across the five contrasting rainfall years, in comparison to CT, CA had greater yield stability and increased wheat grain yield by 43%, barley by 8%, lentil by 11%, and chickpea by 19%. In 5 years of cereal-legume rotation cycle, CA resulted in increased system yield (by 20%), total benefits (by 40%), precipitation use efficiency (by 13%), and available soil moisture (by14%) with production cost reduced by 14.5%. The CA system had higher soil organic matter (+7%), available phosphorus (+3%), and exchangeable potassium (+15%) than in CT, although all differences were non-significant. Our field experiment and long-term simulation results suggest that CA adoption improves a range of agronomic and economic, and soil fertility indicators compared to CT in the clay soil of a rainfed Mediterranean environment.

SIGNIFICANCE

The outcomes of this experimental and simulation study on the multiple benefits of CA provide evidence for extensionists, policymakers, and farmers to drive its wider adoption in Morocco and similar production environments.

中文翻译：

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保护性农业改善了摩洛哥雨养地中海气候中粘土的农艺、经济和土壤肥力指标

语境

降雨量减少，变化性增加，极端温度增加，土壤肥力下降，威胁着摩洛哥雨水养分的地中海环境中的作物生产和最终的粮食安全。保护性农业 (CA) 做法，如减少耕作、土壤覆盖和适当的作物轮作，被认为是此类气候敏感地区的一组适应性农业系统。需要对农艺、经济和土壤肥力指标进行系统评估，在这种多变的气候条件下，在不同轮作中采用 CA 的中长期情况，以推动该地区更广泛地采用 CA。

客观的

本研究的目的是使用田间试验（中期）和模拟建模（长期）对地中海雨养环境的粘土进行农艺、经济和土壤肥力指标的系统评估。 .

方法

方法包括以下内容：1) 为期 5 年（2015-2019 年）的田间试验，比较了四种主要粮食作物的 CA 和 CT：小麦、大麦、小扁豆和鹰嘴豆，在摩洛哥 Merchouch 进​​行。目的是确定 CA 对单个作物和种植系统的作物生产力、产量稳定性、盈利能力、降水利用效率和土壤肥力指标的影响。(2) 动态模拟建模，了解在谷-豆类和谷-谷轮作系统下采用 CA 和 CT 的长期效果。利用 5 年的实验数据，我们校准并验证了适用于四种作物的农业技术转让决策支持系统 (DSSAT) 模型；并将该模型运行了 36 年，进行了两次主要轮换。

结果和结论

在五个对比降雨年中，与 CT 相比，CA 的产量稳定性更高，小麦产量增加了 43%，大麦增加了 8%，小扁豆增加了 11%，鹰嘴豆增加了 19%。在 5 年的谷豆轮作周期中，CA 导致系统产量（增加 20%）、总效益（增加 40%）、降水利用效率（增加 13%）和有效土壤水分（增加 14%）和生产成本增加减少 14.5%。CA 系统的土壤有机质 (+7%)、有效磷 (+3%) 和交换性钾 (+15%) 高于 CT，尽管所有差异均不显着。我们的田间试验和长期模拟结果表明，在地中海雨养环境的粘土中，与 CT 相比，CA 的采用改善了一系列农艺和经济以及土壤肥力指标。

意义

这项关于 CA 多重好处的实验和模拟研究的结果为推广者、政策制定者和农民提供了证据，以推动其在摩洛哥和类似的生产环境中得到更广泛的采用。