A field study on the effect of organic soil conditioners with different placements on dry matter and yield of tomato (Lycopersicon esculentum L.)

Four different types of composts were assessed in two methods of application for their potential to support organic tomato yield. A 2-year experiment was conducted using four different soil conditioners: cow manure (CM), household compost (HC), spent mushroom compost (SMC), and vermicompost (VC). Three different 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 field) were considered as a third factor. The yield was influenced by different soil conditioners and placement method in the first year; in the second year, just interactions were significantly different. Treatments with CM showed significantly higher tomato yield in the first 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. 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.