Establishment and dry matter production if kale supplied with banded or broadcast phosphorus (P) fertiliser

Abstract

Adequate phosphorus (P) supply is vital for all crops. There are conflicting reports of the effects of P supply on establishment and dry matter (DM) production of kale (Brassica oleracea var. acephala L.). In this study the effects of banded or broadcast P fertiliser (0, 20, 40 or 60 kg P/ha) at establishment on subsequent crop growth and development were assessed in a field trial at Lincoln, New Zealand. The moderate fertility soil had an initial Olsen P of 9-17 mg/kg for individual plots. Seedling DM at 10 and 17 days after emergence (DAE) increased linearly from the control up to 40-60 kg P/ha applied, predominantly a result of an increase in root relative to shoot production. The leaf: stem ratio declined from 2.7 at 24 DAE to 0.64 at the final harvest (122 DAE) but did not respond to either the method or rate of P of application. Final DM yield increased from 8710 kg DM/ha for the non-fertilised control to a mean of 11,200 kg DM/ha for all P treatments. Dry matter yield was unaffected by the method of P application. These results indicate up to 40 kg P/ha should be applied to kale crops at establishment, to improve yields, even on moderately fertile soils.