Pasture response to fertiliser inputs under dairy grazing
Abstract
Conversion of sheep and beef farms into dairy
units has resulted in research on appropriate
fertiliser rates and pasture species to achieve
maximum productivity in minimum time. An onfarm
trial involving five different mixtures of
pasture species (based on fescue, prairie grass, an
improved mixture, farmer mixture or original
pasture), three rates of nitrogen as urea (0, 50 or
100 kg/ha of N applied half in March and half in
August) and four rates of superphosphate (0, 250,
500 or 1000 kg/ha applied annually in March) was
established in Canterbury on a Waimakariri sandy
silt loam with border-dyke irrigation and an Olsen
P of 5 pg/ml. The trial was grazed by dairy cattle
as part of the general rotation; plots were not fenced
individually. Pasture growth rates were measured
pre- and post-grazing using a calibrated pasture
probe. Botanical dissections ,were made seasonally
and soil samples were taken annually. Pasture dry
matter production was greatest from the prairie
grass, “improved” mixture and the original pasture, reaching 13,000, 11,000 and 16,000 kg/ha in years one, two and three, respectively; production from the fescue increased with time; the ‘farmer’ mix
performed poorly. Nitrogen at 50 kg/ha was
generally sufficient to produce maximum yield
increases. Increasing superphosphate increased
production; this effect decreased with time. Change
in Olsen P reflected superphosphate inputs and
after three years of differential superphosphate
application the Olsen P status was 8, 14, 27 or 42
(corresponding to 0, 250, 500 or 1000 kg/ha
superphosphate).... [Show full abstract]
Keywords
Bromus willdenowii; dairy conversion; dry matter production; Festuca arundinacea; Olsen P; superphosphate; nitrogen; Lolium perenneFields of Research
079902 Fertilisers and Agrochemicals (incl. Application); 070306 Crop and Pasture NutritionDate
1996Type
Conference Contribution - publishedCollections
Copyright © The Authors and New Zealand Grassland Association.