Chicken manure is helping to ameliorate sandy soils on South Australia’s Yorke Peninsula. Trial results over three years indicate that high-rate surface applications combined with deep ripping are delivering the highest marginal returns.
The marginal returns from applying chicken litter (or a comparable, inorganic fertiliser), and deep ripping, ranged from $934 per hectare to $1249/ha. This was cumulative over the three seasons. Depending on treatment cost, these delivered a return on investment ranging from 142 per cent to 521 per cent.
Agronomist Sam Trengove, Trengove Consulting, began the trials at Bute in 2015 with funding from GRDC. The trials were continued in 2016 and 2017 with funding from NLP and South Australian Grain Industry Trust. Common constraints experienced at the trial site included low plant available water holding capacity, low organic matter, low nutrient availability, compaction, non-wetting and high risk for wind erosion. Annual rainfall average is 390mm and about 280mm for the growing season.
The trials tested applications of the following treatments:
- Deep ripping
- Annual fertiliser
- Clay (130 tonnes per hectare)
- Chicken litter – 0, 5 or 20t/ha
- Placement of chicken litter or fertiliser, either on the surface or in subsoil at 30-40 cm deep
- Matching the nutrition of 20t/ha chicken litter with 1,026 kilograms per hectare urea, 800kg/ha mono-ammonium phosphate, 420kg/ha sulphate of ammonia and 704kg/ha muriate of potash.
The crops trialled were barley, wheat and lentils. The trials were repeated in 2016 and 2017 and will continue until 2020.