Nitrate Leaching in Pepper Cultivation with Organic Manure and Supplementary Additions of Mineral Fertilizer

Abstract

Nitrate leaching frequently is attributed to the excessive application of mineral nitrogen fertilizers and also to the organic matter incorporated in the soil. A lysimeter experiment was conducted in a greenhouse to evaluate nitrate leaching and pepper productivity in an organically fertilized substrate (prepared by application of 4 kg · m⁻² horse manure and subsequent solarization) to which three different doses of mineral fertilizers were added at 0 (T1), 157 (T2), and 313 (T3) kg N · ha⁻¹. The results confirmed the high contribution of organic matter to nitrate leaching, although nitrate losses in T2 and T3 were around 33% and 100% greater than in T1. Furthermore the application of mineral fertilizers (T2 and T3) combined with organic manure led to a decrease in pepper fruit productivity. The use of porous ceramic water samplers for measuring fertilizer leaching is questioned. The results also point to the need for a revaluation of irrigation and N fertilization procedures when organic manure is used in order to improve pepper yield and reduce the contamination of ground water by nitrates.

Keywords:

• Nitrate leaching
• soil organic matter
• drip‐fertigation
• pepper
• lysimeter
• ceramic cup

Acknowledgments

The authors wish to thank Natalio Alcaráz for his contribution in the experiment and Fulgencio Contreras for correction of this manuscript.