Validation of Nitrogen Management Recommendations for Irrigated Chiles in the Desert Southwest.

A field study was conducted in an irrigated chile (Capsicum annum L.) production system to validate and test recently developed nutrient management guidelines. Soil and tissue test samples were analyzed for a full spectrum of nutrients for two different sites in southwestern New Mexico. Soil samples were collected just after planting and at the end of the season. Plant tissue samples for all plots were collected at the following four stages of growth: first bloom, early bloom , peak bloom , and physiological maturity.  All fertilizer and nutrient inputs were monitored, managed, and recorded within current Extension guidelines for irrigated chiles. Nutrients tested included N, Ca, Mg, P, K, Zn, Fe, and B, with the objective of evaluating soil and tissue nutrient concentrations at various stages of crop growth and development. This study also provided the opportunity to compare the use of  a nitrate-N based fertilizer (CaN-17) with a more conventional mixed blend N fertilizer ( UAN-32). The application of the current chile management  guidelines and recommendations with respect to yield potentials were evaluated. Results for soil and tissue analysis were  evaluated in relation to yield results. Grower standard test fields received a total of 139.6 kg N/ha (4 applications of UAN-32, 5 if CaN-17). Demonstration test fields received a total of 82.21 kg N/ha (2 applications of UAN-32 and 7 of CaN-17). Yield levels were not significantly different, with the grower standard fields  averaging  4,672.51 kg/ha and the demonstration fields averaging 4,503.98 kg/ha. These soil test and plant nutrients values will be evaluated in subsequent experiments in an effort to better define  N fertilizer nutrient inputs in order to gain better nutrient management efficiencies in irrigated chile production systems.