Enhancing Yield, Nutrient Uptake, and Agronomic Efficiency of Wheat and Maize through Diatomite, Bentonite, and Compost Amendments in a Sandy Soil

This study evaluated the effects of three soil amendments—compost (24, 48, 72 m³ ha⁻¹), diatomite (0.5958, 1.190, 1.785 Mg ha⁻¹), and bentonite (9, 18, 27 Mg ha⁻¹)—on grain yield, nutrient uptake, and agronomic efficiency (AE) of wheat and maize grown in sandy soil under arid conditions. A control (no amendment) was also included. The field experiment was conducted in Ismailia, western Suez Canal, Egypt, using a randomized complete block design with three replicates.The results showed that all amendments significantly affected both crops, but the responses varied depending on crop type and amendment used. In wheat, the highest grain yield (10.100 Mg ha⁻¹) was recorded with diatomite at 1.785 Mg ha⁻¹, outperforming compost (9.880 Mg ha⁻¹ at 72 m³ ha⁻¹). In maize, compost was most effective, with a maximum yield of 17.265 Mg ha⁻¹ at 72 m³ ha⁻¹, followed by 15.319 Mg ha⁻¹ at 48 m³ ha⁻¹.Nutrient uptake followed similar trends. In maize, compost (72 m³ ha⁻¹) increased N, P, and K uptake to 231.3, 49.5, and 297.5 kg ha⁻¹, respectively. In wheat, compost enhanced N (201.1 kg ha⁻¹) and P (45.7 kg ha⁻¹) uptake, while diatomite improved K uptake (236.1 kg ha⁻¹).Agronomic efficiency also varied significantly. Compost gave the highest AE in maize, while diatomite led in wheat. These findings highlight the crop-specific effectiveness of diatomite and compost in improving yield and nutrient use efficiency in sandy soils under arid conditions.