Aims

Agricultural practices often have persistent effects on soil physicochemical properties and soil biota, which can feedback to influence plant performance. We investigated management-induced differences in soil fertility and soil microbiota for their legacy effects on plant nutrient acquisition and crop/weed competition.

Methods

Sorghum bicolor (L.) Moench (sorghum), Ambrosia artemisiifolia (L) (ragweed), and Amaranthus powellii S. Wats. (pigweed) were grown as monocultures and mixtures in the greenhouse in soils with distinct management histories. Cross inoculations of sterilized soils were used to quantify biotic vs. abiotic influence on plant growth, nutrient uptake and competitive outcomes.

Results

Differences in management history led to a two-fold difference in soil organic matter (OM), and a 37% increase in N acquisition in all species in the high OM soil. The increase in N availability preferentially benefitted pigweed growth at the expense of sorghum. However, microbiota from the high OM soil alleviated the negative effects of pigweed competition on sorghum. Soil management legacy also affected sorghum tiller production and mycorrhizal colonization.

Conclusion

Management-induced differences in soil biotic and abiotic factors altered plant performance in a species-specific manner. Management legacy effects on soil microbiota have the potential to increase crop competitiveness against some weed species.

中文翻译：

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土壤管理的遗产通过生物和非生物途径改变了杂草/作物的竞争

目的

农业实践通常会对土壤理化特性和土壤生物区系产生持续影响，而这些影响可以通过反馈来影响植物生长。我们调查了管理引起的土壤肥力和土壤微生物区系差异对植物营养获取和作物/杂草竞争的传统影响。

方法

高粱双色（L.）Moench（高粱），青蒿（L）（豚草）和Amaranthus powellii S.Wats。（猪草）在温室中有不同的经营历史，以单一栽培和混合物的形式在温室中生长。无菌土壤的交叉接种用于量化生物与非生物对植物生长，养分吸收和竞争结果的影响。

结果

管理历史的差异导致高有机质土壤中所有物种的土壤有机质（OM）增长了两倍，氮素吸收增加了37％。氮素供应的增加优先以高粱为代价，有利于杂草的生长。然而，高土壤肥力土壤中的微生物群减轻了杂草竞争对高粱的负面影响。土壤管理的遗留问题也影响了高粱分er的生产和菌根定植。

结论

管理引起的土壤生物和非生物因子差异以植物特异性的方式改变了植物的生长性能。对土壤微生物群的管理遗留效应有可能提高作物对某些杂草物种的竞争力。