Trifolium repens, Lotus pedunculatus and Holcus lanatus were oversown on two recent
soil slip surfaces at AgResearch’s Ballantrae pastoral hill‐country farm near Woodville.
The two slip surfaces were located on (Manamahu steepland soil) sedimentary
mudstone. One slip had a north aspect and the other had a south aspect. Both slips were
located on a land class 6 with slope 28‐330.
The pasture species were oversown during early spring and the percentage seedling
emergence and early establishment from viable seeds oversown was analysed at early
spring (Day 15), late spring (Day 45), early summer (Day 90), and late summer (Day 120).
The slip surfaces showed micro‐climatic extremes in terms of both soil moisture and
surface temperatures during the summer period. Significant differences (P < 0.05) were
found in soil moisture between north and south facing slip surfaces. Higher soil moisture
and lower soil mean temperature were recorded on the south aspect slip surface.
Significant differences (P < 0.05) were found between the three pasture species in terms
of seedling emergence and early establishment. Significant differences (P < 0.05) were
also found with aspect. The south aspect slip surface had a higher percentage of seedling
emergence and earlier establishment for all the species. Interaction between species by
aspect became significantly different (P < 0.05) at Day 90 and Day 120. The main effects
of time and species were also significantly different (P < 0.05) illustrating seedling
emergence and establishment as a race against time.
Trifolium repens was a more successful pasture specie, than L. pedunculatus and H.
lanatus due to its higher consistency on both north and south slip surfaces. Oversowing
T. repens during early spring is a viable option for rehabilitation of recent soil slips in