Assessment of microirrigation for sugarbeet production
2000
Sharmasarkar, F.C. | Sharmasarkar, S. | Miller, S.D. | Held, L.J. | Vance, G.F. | Zhang, R.
Sugarbeet (SB) is a major value-crop in many furrow (Fu) irrigated areas of Wyoming where nitrate (NO3) contamination prevails. Microirrigation (M) may be an option for managing such pollution while sustaining SB production. With the goal of evaluating efficacy of M for SB production, in comparison to Fu practice, studies were conducted through field experiments, computer simulations, and economic assessments. The field study with SB consisted of a Fu and three M treatments (M1, M2, and M3 representing a management allowable depletion factor of 0.20, 0.35, and 0.50, respectively) and three fertilizer doses. Water use, post-harvest soil NO3 concentrations, SB yields, and water percolation were measured. Computer simulations were performed using a transport and irrigation model to predict soil NO3 concentrations and the results were compared with the experimental data. The economic feasibility of adopting M for 10 to 40 ha area was evaluated using a capital budgeting analysis. Results of field studies indicated lower water use, higher soil NO3 levels, less water percolation and greater SB yields with M than under Fu practice. The yields increased as management allowable depletion factor and fertilizer rate augmented. Computer simulations predicted that post-harvest soil NO3 concentrations were higher when SB were irrigated with M rather than Fu practice. Simulation results were comparable with the field data. The economic analysis indicated that irrigation costs decreased and SB returns increased with M practice. Results of capital budgeting showed that adoption of M in Wyoming was feasible for small-scale SB production. The profitability of the M system was dependent on the irrigation regime and the conversion area.
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