Assessment of Sowing Density Impact on Water Front Advancement and Infiltration in Furrow Irrigation

Abstract

This research aims to evaluate the impact of durum-wheat sowing density on wetting front advancement and water infiltration rate along the furrow length. In addition, durum wheat yield and furrow irrigation performance under the different sowing densities were assessed. For that purpose, a field experiment was conducted under semi-arid conditions in Tunisia using four durum-wheat sowing densities: SD1 (250 seeds m−2), SD2 (350 seeds m−2), SD3 (450 seeds m−2) and SD0 (bare soil). The results reveal that water front advancement tends to be inversely proportional to sowing density. In fact, under the SD3 treatment, both irrigation duration and applied water volume increased about twofold compared to those recorded under SD0, resulting in an increasing soil infiltration rate. Furthermore, the two-point method performed well in estimating water front advancement, with an R2 value close to 1. Regarding durum wheat yield, values varied between 3.5 and 4.9 t ha−1 with the highest value attributed to the SD3 treatment. Meanwhile, higher irrigation water productivity was recorded under SD1. Considering irrigation performance indicators, the results indicate that distribution uniformity (DU) increases with increasing sowing density. Moreover, the lowest application efficiency values (75%) were recorded under the SD0 and SD3 treatments as compared to 82% for SD2 and 80% for SD1.