The use of non-destructive devices like Delta-T-Leaf-Area-Meter and Canegro Models can help farmers to manage their cane crops and have an understanding of the importance of measurement of physiological parameters so as to maximize cane and sugar yields. This study was conducted on sandy clay loams of the lithosol group under the Zimbabwe soil classification system at The Zimbabwe Sugar Association Experiment Station (ZSAES). The main aim of this study was to establish the most economic rate of N fertilizer when vegetable and grain soybean are used as fallow crops in sugarcane production systems. The following cane parameters were measured: LAI, biomass, N in leaves and sugarcane and sugar yields. Sugarcane variety N14 was used in the experiment. Post vegetable soybean cane topdressed with 80 kg Nha 1 had the greatest LAI at 150 DAE. The highest biomass was realized on sugarcane topdressed with 80 and 120 kg Nha 1. At final tiller stability post vegetable cane top dresses with 80 kg Nha 1 had the most tiller population. N in leaves and cane and sugar yields were also highest on post vegetable soybean cane and topdressed with kg Nha 1. Tiller density or population and biomass production are important crop variables that are used to estimate the final cane stalk population and sucrose yields. So farmers can top-dress their cane with 80 kg Nha 1 when vegetable soybean are used as fallow crops. This will help them save about 40 kg Nha 1.
