A fourth principle is required to define Conservation Agriculture in sub-Saharan Africa: The appropriate use of fertilizer to enhance crop productivity
A fourth principle is required to define Conservation Agriculture in sub-Saharan Africa: The appropriate use of fertilizer to enhance crop productivity
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DOI：
10.1016/j.fcr.2013.10.002
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发表时间：
2014
影响因子：
5.8
通讯作者：
B. Vanlauwe;J. Wendt;K. Giller;M. Corbeels;B. Gérard;C. Nolte
中科院分区：
文献类型：
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作者：
B. Vanlauwe;J. Wendt;K. Giller;M. Corbeels;B. Gérard;C. Nolte
撒哈拉以南非洲农业系统的集约化被认为是减轻农村贫困的先决条件。保护性农业（CA）已被推广以实现这一目标，其基础是三个原则：最少耕作、土壤表面覆盖和多样化的作物轮作。CA起源于肥料普遍使用和作物生产力高的地区，确保了作物残留物的丰富。相比之下，SSA和有机残留物的作物产量普遍较低，供应短缺，农民面临对其使用的竞争需求。由于不加地膜的少耕通常会导致产量下降，因此使用肥料来提高作物生产力和有机残留物利用率对于小农从事CA至关重要。这一点尤其正确，因为增加有机物质利用率的其他方法在很大程度上失败了。肯尼亚的一个案例研究清楚地表明，肥料如何将玉米秸秆生产力提高到启动CA所需的最小初始土壤覆盖阈值以上（约3吨公顷）。我们的结论是，在SSA中使用CA的战略必须整合第四个原则——适当使用肥料——以增加小农受益的可能性。
Intensification of agricultural systems in sub-Saharan Africa (SSA) is considered a pre-condition for alleviation of rural poverty. Conservation Agriculture (CA) has been promoted to achieve this goal, based on three principles: minimum tillage, soil surface cover, and diversified crop rotations. CA originated in regions where fertilizer is commonly used and crop productivity is high, ensuring an abundance of crop residues. By contrast, crop yields are generally low in SSA and organic residues in short supply and farmers face competing demands for their use. Since minimal tillage without mulch commonly results in depressed yields, the use of fertilizer to enhance crop productivity and organic residue availability is essential for smallholder farmers to engage in CA. This is especially true since alternative ways to increase organic matter availability have largely failed. A case study from Kenya clearly demonstrates how fertilizer increases maize stover productivity above thresholds for minimal initial soil cover required for initiating CA (about 3 tonne ha−1). We conclude that strategies for using CA in SSA must integrate a fourth principle – the appropriate use of fertilizer – to increase the likelihood of benefits for smallholder farmers.