Effects of Tomato-Based Rotations with Diversified Pre-Planting on Soil Health in the Mediterranean Soils of Western Turkey

Abstract Turkey ranks fourth among the tomato (Lycopersicon lycopersicum L.) producers in the world and the tomato varieties extend to 40 % of the total vegetable yield of the country. Farmers have continued to cultivate tomato due to the economic potential of this crop in the main vegetable growing regions of Turkey. Intensive agriculture without employing crop rotations and the inclusion of the excessive and the same type of chemical fertilizers continuously regardless of the soil properties reduces the productive capacity of the soil and adversely affects its ecosystem functions. A three-year (2016−18) diversified cropping system combined with field experiments and employing reduced tillage was conducted in Izmir, a semiarid region in Western Turkey, adopting the randomized complete block design with three replications. Six different tomato-based rotations with diversified pre-planting comprising two, three and four different plant species [CR1 (tomato / corn / mustard); CR2 (tomato / bean / mustard); CR3 (tomato/corn/wheat/mustard); CR4 (tomato / bean / wheat / mustard); CR5 (tomato / corn / fallow); CR6 (tomato / bean / fallow)] were employed to evaluate the impact on the parameters of soil health such as basal soil respiration, nitrogen mineralization, and the activities of the enzymes dehydrogenase and β-glucosidase. In the tomato phases, soil samples were drawn on the 16th day after planting of the seedlings at 0−20 cm depth in April 2016 and April 2018. The multivariate analysis of variance revealed that different crop rotations (Treatment: CRs), and their interaction (TreatmentxYear) on the soil microbial characteristics were significantly different in terms of the dependent variables (P