Nutrient uptake of catch crops under non‐limiting growth conditions

Abstract

AbstractBackgroundCatch crops enhance nutrient cycling of cropping systems. Considering possible limitations of catch crop studies in field and greenhouse experiments, a new approach was chosen to combine the advantages of both systems in quantifying the potential for nutrient retention by catch crops.AimsThis study aimed at identifying N, P, and K uptake of different catch crop species grown in monoculture and as a mixture under non‐limiting growth conditions in terms of water and nutrient availability.MethodsCatch crops were cultivated under semi‐controlled conditions in large containers (August to November 2020). Shoot N, P, and K uptake, leachate accumulation, and soil Nmin, CAL‐P, and CAL‐K (0–30 cm) were quantified after harvest. After washing, root parameters were quantified with a root scanner.ResultsNutrient uptake of N, P, and K was highest for phacelia. The mixture of seven different catch crops performed equally well. Nutrient uptake was closely related to root length and root surface area.ConclusionsUnder non‐limiting growth conditions, phacelia has the highest potential to conserve N, P, and K for a succeeding crop; however, the low C : N ratio of the frost‐sensitive crop could promote nutrient losses during winter. We conclude that growing a single catch crop can be as effective in reducing the nutrient leaching potential as cultivating a mixture of catch crops when nutrients and water are no growth‐limiting factors.