Smallholder maize growers are experiencing significant yield gaps due to sub-optimal agricultural practices. Adequate agricultural inputs, particularly nutrient amendments and best management practices, are essential to reverse this trend. There is a need to understand the cause of variations in maize yield, provide reliable early estimates of yields, and make necessary recommendations for fertilizer applications. Maize yield prediction and estimates of yield gaps using objective and spatial analytical tools could provide accurate and objective information that underpin decision support. A study was conducted in Rwanda at Nyakiliba sector and Gashora sector located in Birunga and Central Bugesera agro-ecological zones, with the objectives of (1) determining factors influencing maize yield, (2) predicting maize yield (using the Normalized Difference Vegetation Index (NDVI) approach), and (3) assessing the maize yield gaps and the impact on food security. Maize grain yield was significantly higher at Nyakiliba (1.74 t ha−1) than at Gashora (0.6 t ha−1). NDVI values correlated positively with maize grain yield at both sites (R2 = 0.50 to 0.65) and soil fertility indicators (R2 = 0.55 to 0.70). Maize yield was highest at 40 kg P ha−1 and response to N fertilizer was adequately simulated at Nyakiliba (R2 = 0.85, maximum yield 3.3 t ha−1). Yield gap was 4.6 t ha−1 in Nyakiliba and 5.1 t ha−1 in Gashora. Soil variables were more important determinants of social class than family size. Knowledge that low nutrient inputs are a major cause of yield gaps in Rwanda should prioritize increasing the rate of fertilizer use in these agricultural systems.

中文翻译：

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确定和管理卢旺达的玉米产量差距

由于次优农业实践，小农玉米种植者正在经历显着的产量差距。充足的农业投入，尤其是营养补充剂和最佳管理实践，对于扭转这一趋势至关重要。需要了解玉米产量变化的原因，提供可靠的早期产量估算，并为施肥提出必要的建议。使用客观和空间分析工具对玉米产量进行预测和估计，可以提供支持决策支持的准确和客观的信息。在卢旺达位于比伦加和布杰塞拉中部农业生态区的 Nyakiliba 部门和 Gashora 部门进行了一项研究，其目标是 (1) 确定影响玉米产量的因素，(2) 预测玉米产量（使用归一化植被指数 (NDVI) 方法），以及 (3) 评估玉米产量差距及其对粮食安全的影响。Nyakiliba (1.74 t ha-1) 的玉米产量明显高于 Gashora (0.6 t ha-1)。NDVI 值与两个地点的玉米产量（R2 = 0.50 至 0.65）和土壤肥力指标（R2 = 0.55 至 0.70）呈正相关。玉米产量在 40 kg P ha-1 时最高，并且在 Nyakiliba 充分模拟了对氮肥的响应（R2 = 0.85，最大产量 3.3 t ha-1）。Nyakiliba 的产量差距为 4.6 t ha-1，Gashora 的产量差距为 5.1 t ha-1。土壤变量是比家庭规模更重要的社会阶层决定因素。