Beninese smallholders associate food crops and cash crops with immature oil palms to reduce field maintenance costs and gain income before the palms reach productive phase. Little is known about the effects of these crops on the nutritional status and growth of the palms in their immature phase even though the yield of adult palms can be affected by the management practices during this phase. The objective of this study was to evaluate the most common oil palm-based intercropping systems found in southern Benin in terms of nutritional status and growth of the palm. Within 15 oil palm farms, we compared 15 immature oil palm fields where the crop succession associated with the oil palms was dominated by maize, cassava, tomato, and pineapple. The nutrient concentrations in the soil and the palm leaves, and growth indicators were measured at the end of the immature phase. We found that the palm growth indicators were the lowest in the successions with pineapple. N and P nutrition of the immature palms was satisfactory but K was deficient in all systems, especially in those with pineapple. The K levels in the soils and palm leaves were correlated. Rough field budgets comparing the amounts of N and K applied to the crop successions with their N and K exports from non-returning products indicated that soil indigenous K supply would be particularly depleted in the systems with pineapple. We concluded that the young oil palms were affected by the competition for K exerted by the crop successions with pineapple even though they were the most fertilized in the region. The high profitable crop is therefore associated with the lowest growth rates of the immature palms. The mineral fertilizer management in these oil palm temporary intercropping systems should be improved.

中文翻译：

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贝宁南部不同间作系统未成熟油棕营养状况及生长情况比较分析

贝宁小农将粮食作物和经济作物与未成熟的油棕树联系起来，以降低田间维护成本并在棕榈树达到生产阶段之前获得收入。尽管成年棕榈树的产量可能会受到此阶段管理实践的影响，但人们对这些作物对未成熟期棕榈树的营养状况和生长的影响知之甚少。本研究的目的是评估在贝宁南部发现的最常见的油棕间作系统的营养状况和棕榈生长情况。在 15 个油棕农场中，我们比较了 15 个未成熟的油棕地，其中与油棕相关的作物演替以玉米、木薯、番茄和菠萝为主。土壤和棕榈叶中的养分浓度，在未成熟期结束时测量生长指标。我们发现棕榈树的生长指标在菠萝的演替中最低。未成熟棕榈的N和P营养令人满意，但K在所有系统中都缺乏，特别是在菠萝中。土壤和棕榈叶中的钾含量是相关的。粗略的田间预算比较了施用于作物演替的 N 和 K 的量与它们从非返回产品中的 N 和 K 出口量，表明土壤本地 K 供应在菠萝系统中将特别枯竭。我们得出的结论是，尽管在该地区施肥最多的油棕树，但它们仍受到菠萝作物连续性对 K 的竞争的影响。因此，高利润作物与未成熟棕榈树的最低增长率有关。应改进这些油棕临时间作系统中的矿物肥料管理。