Competition between white clover ‘Grasslands Huia’ and Lotus pendunculatus ‘Grasslands Maku’ II. Effects of phosphorus and lime

Abstract

The effects of superphosphate and lime on competition between Lotus pedunculatus Cav. cv. Grasslands Maku and Trifolium repens L. cv. Grasslands Huia (white clover) were studied by comparing species production as monocultures and bicultures in undisturbed turves of a Waipori upland YBE (pH 4.6) transferred to a glasshouse. Seedlings were planted at 2.5 cm inter- and intra-row spacings with species alternating across and down rows in the biculture. Measurement of competitive ability (‘aggressivity index’) based on proportionate yield differences showed lotus to be the aggressor and white clover the subordinate species under low levels of applied P (30 kg/ha). Application of 100 kg P/ha reversed the competitive order with white clover becoming the aggressor. Associated changes in herbage P and N concentrations and P uptake are presented. Surface-applied lime did not change the nature of competition between white clover and lotus although it is possible that any such effect may not have been detected because of a high variance ratio.

Keywords:

• White clover
• Trifolium repens L.
• plant growth nutrients (plant)
• fertiliser rate
• phosphorus
• Lotus pedunculatus
• agricultural lime