Plant relations in mixtures of trifolium subterraneum cv mt barker and loliumm ultiflorum cv Midmar: I. dry matter production, crude protein content and crude protein production

Abstract

The interaction between Trifolium subterraneum cv Mt Barker and Lolium multiflorum cv Midmar was measured in a field trial in terms of dry matter production, crude protein content and crude protein production. The treatments included five different seeding rates of the grass component, four rates of nitrogen application and two defoliation heights. The pure clover outyielded the pure grass and the mixtures at all levels of applied nitrogen, while the total DM production of the pure grass at 240 kg N/ha, did not differ appreciably from the mixtures receiving 120–240 kg N/ha. Apart from the 20 kg grass/ha mixture, receiving 240 kg N/ha, the weighted crude protein content of the mixtures surpassed that of the pure grass at all levels of applied nitrogen. Crude protein production of the mixtures, receiving 0 to 120 kg N/ha compared well with pure grass receiving 240 kg N/ha, but was significantly less than pure clover receiving no nitrogen.

Uittreksel

Die wisselwerking tussen Trifolium subterraneum cv Mt Barker en Lolium multiflorum cv Midmar is in terme van droe massaproduksie, ruproteïeninhoud en ruproteïenproduksie in ‘n veldproef gemeet. Die behandelings het vyf verskillende saai‐digthede van die graskomponent, vier stikstofpeile en twee ontblaringshoogtes ingesluit. Die totale droë massaproduksie van die suiwer klawer was betekenisvol hoër as dié van die suiwer gras en die mengsels oor alle peile van stikstoftoediening, terwyl die totale droe massaproduksie van die suiwer gras, wat 240 kg N/ha ontvang het, min verskil het van die mengsels wat 120–240 kg N/ha ontvang het. Behalwe vir die 20 kg graslha mengsel wat 240 kg N/ha ontvang het, was die geweegde ruproteïeninhoud van die mengsels by alle stikstofpeile betekenisvol hoër as dié van die suiwer gras. Ruproteïenproduksie van die mengsels wat 0–120 kg N/ha ontvang het, het goed vergelyk met suiwer gras wat 240 kg N/ha ontvang het, maar was betekenisvol laer as dié van suiwer klawer wat geen stikstof ontvang het nie.

Additional index words:

• Association
• competition

Notes

Present address: Grassland Research Centre, Private Bag X05, Lynne East, 0039.