Techniques for controlling soil crusting and its effect on corn emergence and production

Abstract

Soil crusting is a serious problem in numerous irrigated soils of Aragon. It reduces water infiltration rate, seedlingemergence and crop establishment, and enhances runoff and soil erosion. This paper analyses the efficiency ofsoil conservation practices (direct drilling and mulching) and chemical amendments (gypsum) on the control of soilcrusting, and its effect on seedling emergence and corn production. The experiments were carried out in Sierra deLuna (Zaragoza) in a soil prone to crusting. The experimental design was a randomised complete block with six treatmentsand three replications: T1 (sowing and several irrigations until emergence, a practice known as «aguacivera» in Aragon; considered as the control treatment), T2 (sowing and delayed irrigation until post-emergence), T3 (directdrilling over nearly bare soil), T4 (direct drilling over legumes), T5 (T1 + gypsum), and T6 (T2 + gypsum). Inall the treatments, except for T1 and T5, irrigation was delayed until post-emergence. Measurements were made onplant emergence, penetration resistance of the crust, final infiltration rate and corn production. All variables weresignificantly affected by the treatments. T6 was the most effective treatment in reducing soil crusting and enhancingwater infiltration into the soil, whereas both T6 and T2 were the most effective at enhancing seedling emergence andcorn production. The «aguacivera» treatments (T1 and T5) induced the highest crusting and emergence reductionand, together with T3, they were the least productive, whereas the direct drilling treatments (T3 and T4) followed anintermediate pattern. For crusting reduction, treatment T4 was more effective than treatment T3. The addition ofgypsum coupled to a delay in irrigation until corn emergence was thus the most effective treatment of those testedin this work to reduce soil crusting.