van Groenigen Jan Willem, Lubbers Ingrid M, Vos Hannah M J, Brown George G, De Deyn Gerlinde B, van Groenigen Kees Jan
Department of Soil Quality, Wageningen University, PO Box 47, 6700AA Wageningen, The Netherlands.
CNPq fellow, Embrapa Forestry, CEP 83411-000, Colombo, PR, Brazil.
Sci Rep. 2014 Sep 15;4:6365. doi: 10.1038/srep06365.
To meet the challenge of feeding a growing world population with minimal environmental impact, we need comprehensive and quantitative knowledge of ecological factors affecting crop production. Earthworms are among the most important soil dwelling invertebrates. Their activity affects both biotic and abiotic soil properties, in turn affecting plant growth. Yet, studies on the effect of earthworm presence on crop yields have not been quantitatively synthesized. Here we show, using meta-analysis, that on average earthworm presence in agroecosystems leads to a 25% increase in crop yield and a 23% increase in aboveground biomass. The magnitude of these effects depends on presence of crop residue, earthworm density and type and rate of fertilization. The positive effects of earthworms become larger when more residue is returned to the soil, but disappear when soil nitrogen availability is high. This suggests that earthworms stimulate plant growth predominantly through releasing nitrogen locked away in residue and soil organic matter. Our results therefore imply that earthworms are of crucial importance to decrease the yield gap of farmers who can't -or won't- use nitrogen fertilizer.
为了以最小的环境影响应对养活不断增长的世界人口这一挑战，我们需要全面且定量地了解影响作物生产的生态因素。蚯蚓是最重要的土壤栖息无脊椎动物之一。它们的活动会影响土壤的生物和非生物特性，进而影响植物生长。然而，关于蚯蚓存在对作物产量影响的研究尚未进行定量综合分析。在此我们通过荟萃分析表明，平均而言，农业生态系统中蚯蚓的存在会使作物产量提高25%，地上生物量增加23%。这些影响的程度取决于作物残茬的存在、蚯蚓密度以及施肥类型和速率。当更多残茬归还土壤时，蚯蚓的积极作用会更大，但当土壤氮素有效性较高时，这种作用就会消失。这表明蚯蚓主要通过释放残茬和土壤有机质中锁定的氮来刺激植物生长。因此，我们的研究结果意味着蚯蚓对于缩小那些无法或不愿使用氮肥的农民的产量差距至关重要。
