University of Kassel
Ferdowsi University of Mashhad, Faculty of Agriculture
Purpose Four diferent types of composts were assessed in two methods of application for their potential to support organic tomato yield. Methods A 2-year experiment was conducted using four diferent soil conditioners: cow manure (CM), household compost (HC), spent mushroom compost (SMC), and vermicompost (VC). Three diferent application rates (10, 20, and 30 t ha−1 for all composts except VC and 3, 6, and 9 t ha−1 for VC) were included as a second factor. Two methods of fertilizer placement (as a row behind the root area and broadcast on the feld) were considered as a third factor. Results The yield was infuenced by diferent soil conditioners and placement method in the frst year; in the second year, just interactions were signifcantly diferent. Treatments with CM showed signifcantly higher tomato yield in the frst year (103 t ha−1) compared to other composts, but in the second year, SMC produced a higher yield (58 t ha−1). The experiment indicated that the treatment with CM in high level with broadcast application had higher dry matter (DM) production (3.1 t ha−1) in 2014, and treatment with CM in low rate and broadcast application had higher DM production (5.8 t ha−1) in 2015. Conclusion Compost broadcast on the plots showed a higher yield production in case of similar rates and compost type. The proper rate of compost application is dependent on the method of compost placement.