Response to nitrogen fertilization and irrigation management of common bean cultivars in central Chile

Four of the most frequently grown varieties of common bean cultivated in Chile were evaluated in a Mediterranean zone of central Chile. The primary objective was to investigate yield potential and morphological and nutritional characteristics through agronomic management improvement programs, including irrigation and nitrogen (N) fertilization. For this purpose, in 2018/19, an experiment was arranged in a randomized complete block split-split plot design with two irrigation treatments, two fertilization rates, and four varieties. The Zorzal variety obtained the highest grain yield (GY) (4.7 Mg ha^–1) when applying 5,400 m³ ha^–1 of water and 120 kg N ha^–1. However, the N doses did not produce differences in GY. In 2019/20, a demonstration plot (DP) was established to compare the best agronomic management derived from the first experiment with the current practices of four farmers. In the DP, GY reached 4 Mg ha^–1 with an N dose of 90 kg ha^–1, while the highest GY (5.4 Mg ha^–1) was obtained by Farmer 1 using an N dose of 130 kg ha^–1 and 9,000 m³ ha^–1 of water. The irrigation, N dose, and cultivars affected the length and width of grains, while the 100-grains weight was affected by N dose and cultivars. Although Zorzal and Torcaza cultivars did not achieve the highest mineral contents, they have high yield potential and higher protein and mineral by sown surface. Finally, the DP demonstrated that reducing the amount of water and N commonly applied by producers in central Chile produces yields similar to those of the most productive farms.