Context

To ensure food security in sub-Saharan Africa, it is necessary to improve crop yields while minimizing environmental impacts. Intercropping has been demonstrated to deliver such outcomes, but their performance in smallholder fields has received limited attention therefore insufficient to capture the complexity of real-world crop fields run by smallholder farmers.

Objective

This study examines the benefits and management of intercropping practices in real smallholder fields in Malawi.

Methods

We collected field data on intercrop types, the number of intercropped species and maize yield in intercropped maize fields. Field data was then combined with geospatial and household survey data to investigate the yield benefits, agricultural inputs, and factors related to intercropping choices. We used Pearson correlation and Tukey’s test to test the statistical significance in the difference between intercropped fields and monoculture fields.

Results

We found that more intercrops were planted in fields with smaller sizes, drier conditions, and higher soil erosion levels, with adoption rates increasing from 75 % in 2010 to 84 % in 2020. In addition, our field data shows that intercropping is associated with reduced primary maize yield (2.7 t/ha) compared to pure maize yield (3.8 t/ha). Conversely, satellite data demonstrates an improvement in overall field yield in intercropped fields. Meanwhile, intercropped fields require higher labor inputs (11 h more per season) and increased weeding times than monocultures, however agrochemical inputs (fertilizers and pesticides) do not necessarily decrease in intercropped fields compared to monocultures.

Conclusions

Our results suggest that while smallholder farmers in Malawi adopt intercropping to improve land use efficiency, drought resilience, and soil fertility, they are not realizing the full benefits observed in experimental trials.

Implications

More evidence on the benefits and best practices of intercropping in smallholder fields is necessary in order to better understand this practice as an option for sustainable intensification.

中文翻译：

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小农田间作做法的环境和产量效益有限：来自多源数据的证据

语境

为确保撒哈拉以南非洲的粮食安全，有必要提高作物产量，同时尽量减少对环境的影响。间作已被证明可以带来这样的结果，但它们在小农田中的表现受到的关注有限，因此不足以捕捉小农经营的现实世界农田的复杂性。

客观的

本研究考察了马拉维真实小农田间作做法的好处和管理。

方法

我们收集了间作玉米田间作类型、间作物种数量和玉米产量的田间数据。然后将实地数据与地理空间和家庭调查数据相结合，以调查产量效益、农业投入和与间作选择相关的因素。我们使用 Pearson 相关性和 Tukey 检验来检验间作田和单作田之间差异的统计显着性。

结果

我们发现，更多的间作作物种植在面积较小、条件较干燥和土壤侵蚀程度较高的田地中，采用率从 2010 年的 75% 增加到 2020 年的 84%。此外，我们的实地数据显示，间作与减少相关与纯玉米产量（3.8 吨/公顷）相比，初级玉米产量（2.7 吨/公顷）。相反，卫星数据显示间作田地的整体田间产量有所提高。同时，与单作相比，间作田需要更多的劳动力投入（每季多 11 小时）和更多的除草时间，但与单作相比，间作田的农药投入（化肥和农药）并不一定减少。

结论

我们的研究结果表明，尽管马拉维的小农采用间作来提高土地利用效率、抗旱能力和土壤肥力，但他们并未充分意识到在实验试验中观察到的好处。

启示

需要更多关于小农田间作的好处和最佳做法的证据，以便更好地理解这种做法作为可持续集约化的一种选择。