One of the most important factors to obtain high yield is a good root system development. The exploration of a greater soil mass allows a higher water and nutrient uptake and increases crop yield. Numerous authors noticed a significant correlation between yield and root system dimension. The growing environment, and therefore the agronomic technique, affect root system development. Traditionally rice is grown by flooded irrigation that, due to oxygen lack in deep soil layers, brings to a low root system deepening. In upland rice, where the growing does not take place with continuous flooding, some authors noticed a good root system development. A comparison trial, with national and selected for upland conditions rice cultivars, was carried out to evaluate root system development adopting both traditional flooded irrigation and sprinkler irrigation. Root density was determined by Newman method for different soil depths. Results highlight a greater root density in flooded crop in comparison to sprinkler irrigation. The higher yield obtained with sprinkler irrigation, even higher than flooding irrigation, suggest a greater efficiency of the root system in water and nutrient uptake in oxidized environment.
Roots system development in flooded and sprinkler irrigated rice cultivars / Spanu, A; Murtas, A; Ledda, L; Ballone, F. - (2004), pp. 217-225.