Recycled organics compost - on a Sydney spinach farm

The incorporation of compost into the Portellis’ cropping schedule yielded a significant improvement in crop performance. 
  • Compost applied at 5 tonnes per ha increased silverbeet growth from an average 27g (dry weight) per plant to 36g, an increase of 33%. Applying compost at 10 tonnes per ha resulted in a further 14% growth to 41g dry weight per plant 
  • Compost applied at 5 tonnes per ha increased silverbeet height from 36cm to 44cm, an increase of 23%; there was little additional benefit from increasing the rate to 10 tonnes per ha 
  • Leaf colour was measured, however, there was no significant difference between the compost rates indicating that there was minimal nitrogen drawdown occurring, which can be a risk when applying additional organic matter. Some growers will increase their nitrogen fertiliser rate if signs of nitrogen deficiency are observed. 


 This project is supported by the NSW Environment Protection Authority as part of Waste Less, Recycle More, funded from the waste levy.