Simulation of tomato growth, water and N dynamics using the EU-Rotate_N model in Mediterranean greenhouses with drip irrigation and fertigation

Abstract

The EU-Rotate_N simulation model was evaluated with tomato grown in Mediterranean greenhouses to simulate (i) dry matter production (DMP), (ii) crop N uptake, (iii) marketable fresh yield, (iv) ETc, (v) drainage, (vi) NO3− leaching, and (vii) soil water and mineral N dynamics. Crops were grown with frequent drip irrigation and fertigation, N was applied in all irrigations. Ten treatments were examined in four years with differences in irrigation, applied N and soil mineral N at planting. Given that (a) EU-Rotate_N default values are for open field crops and (b) that there are clear differences in management and growing conditions between greenhouse and open field tomato, it was necessary to calibrate relevant model parameters. Where N was not limiting, simulations of seasonal DMP and N uptake were very accurate with linear relationships between simulated and measured values having slopes of 1.0 and coefficients of determination (R2) of 0.97 for DMP and of 0.95 for N uptake. Under N-limited conditions, simulated values of these parameters were underestimated by an average of 37%. Results for simulations of marketable yield were similar. ETc was very accurately simulated for all treatments. Simulation of drainage was acceptable for nine treatments with drainage values <60mm, it was overestimated for one treatment with drainage >60mm. Simulation of NO3− leaching was less accurate, on average, total NO3− leaching was underestimated by 31%. There was generally good simulation of soil water dynamics. In 8 of 10 treatments, soil mineral N (0–60cm depth) was accurately simulated. In two treatments, soil mineral N was substantially underestimated which appeared to be associated with inaccurate simulation of N mineralization under warm conditions. Comparison of simulations between three treatments with substantial differences in irrigation, N management and in soil mineral N at planting, demonstrated the usefulness of EU-Rotate_N to examine the effects of crop management on drainage, NO3− leaching, and soil mineral N dynamics associated with tomato grown in greenhouse conditions. Following calibration, EU-Rotate_N can be an effective tool for evaluating management practices and for demonstration purposes.