Depletion of soil nutrient is a major impediment for food production in sub-Saharan Africa, but little is known about nutrient dynamics at the farm level. Therefore, the objective of this study was to evaluate nutrient management on a range of contrasting farms by estimating balances of N, P and K. Representative farmers of three wealth classes (rich, medium and poor) were selected from two different agro-ecological regions (Alaje and Raya Azebo) in northern Ethiopia. The MonQI model based on data obtained from farm questionnaires was used for processing and analysis of partial nutrient balances (input from mineral and organic fertilizer minus output with crop and straw) and full balances (all input sources minus output with crop, erosion, leaching and gaseous losses). Partial N, P and K balances were 25.6, 6.3 and 7.8 kg ha⁻¹ in Alaje and −7.1, 10.6 and −6.7 kg ha⁻¹ in Raya Azebo. Full N, P and K balances were −26.2, 6.7 and 2.9 kg ha⁻¹ in Alaje and −17.9, 11.1 and −5.3 kg ha⁻¹ in Raya Azebo. Partial N and K and full K balances were different (p < .05) between the regions. Farms owned by rich and poor farmers differed in full N balances in Alaje and in partial N balances in Raya Azebo (p < .05). With the use of more fertilizer, N losses to the environment also increased. Generally, soil stocks of N and K are further declining. There is a need for socio-economic policies to introduce effective nutrient management on the farms and to provide poorer farmers' access to fertilizer.

中文翻译：

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埃塞俄比亚北部小农农场的营养平衡

土壤养分的枯竭是撒哈拉以南非洲粮食生产的主要障碍，但对农场层面的养分动态知之甚少。因此，本研究的目的是通过估计 N、P 和 K 的平衡来评估一系列对比农场的养分管理。 从两个不同的农业生态区域中选出三个财富等级（富裕、中等和贫困）的代表性农民（Alaje 和 Raya Azebo）在埃塞俄比亚北部。以农户问卷调查数据为基础的MonQI模型，对部分养分平衡（矿物和有机肥料的投入减去作物和秸秆的产出）和全平衡（所有投入源减去作物、侵蚀、淋溶和秸秆的产出）进行处理和分析。气态损失）。部分 N、P 和 K 平衡为 25.6、6.3 和 7.8 kg ha^-1在 Alaje 和 -7.1、10.6 和 -6.7 kg ha ^-1在 Raya Azebo。完整的 N、P 和 K 平衡在 Alaje 为 -26.2、6.7 和2.9 kg ha ^-1，在 Raya Azebo 为 -17.9、11.1和 -5.3 kg ha ^-1。部分 N 和 K 以及全 K 平衡 在区域之间不同 ( p < .05)。贫富农民拥有的农场在 Alaje 的全氮平衡和 Raya Azebo 的部分 N 平衡方面存在差异 ( p  < .05)。随着肥料的使用，氮对环境的损失也增加了。一般而言，N 和 K 的土壤储量进一步下降。需要制定社会经济政策，对​​农场进行有效的养分管理，并为贫困农民提供肥料。