Sweet maize growth and yield response to organic and mineral fertilizers, N rates and soil water regimes

Abstract

Sweet maize is an underutilized vegetable in European temperate areas, and its consumption is increasing. For better understanding of cultivation practices, this pot experiment aimed to determine the eff­ects of diff­erent water regimes and nitrogen (N) rates calculated from N target values. N rates of 0 (control), 0.6 and 2 g N pot -1 were applied as organic by-products pumpkin cake and pig manure digestate, and mineral fertilizers CAN 27 and ENTEC ® 26. Treatments of water supply were based on measured soil matric potentials of 2.8 pF (drought stress), 2.6 pF (optimal water) and 2.4 pF (overwatered). In comparison to mineral fertilizers, pumpkin cake proved to be equal in eff­ectiveness in plant height (155.8 cm), cob (85.8 g), green (124.9 g) and leaf mass per plant (44.2 g), or even better in root (72.3 g) and broom mass per plant (3.0 g). Yield parameters, cob mass (70.1 g), its length (6.3 cm) and diameter (2.0 cm), as well as the residual mineral N (59 mg N kg -1 ) significantly increased at the highest N rate. Significantly lower values of the evaluated morphological parameters and photosynthetic rates (at brooming and harvesting) were associated with drought stress. The matric tension of 2.6 pF was established as an appropriate water regime for sweet maize growth.