Assessing the precision irrigation potential for increasing crop yield and water savings through simulation

In regions such as the Brazilian Cerrado where water availability is low and disputes for water resources are increasing, it is important to evaluate technologies that can increase the efficiency of irrigation. In this scenario, precision irrigation has great potential. However, studies that evaluate the real benefits of precision irrigation are necessary. The present work aimed to assess the precision irrigation potential for increasing crop yield and water savings. To evaluate the possible precision irrigation benefits, two center pivots, acting over soils that had different hydro-physical characteristics, were studied. The available water in the soil (AWC) was used as a reference for irrigation management in two conditions, one considering and one disregarding soil spatial variability. In the management under homogeneous soil conditions, the lowest, the average and the highest AWC values were considered. Management under variable conditions was carried out individually for each pixel with a dimension of 25 m2 (5 × 5 m), considering its real AWC value. Also, four soybean crop sowing dates were considered in a rainy and a dry year. A specific precision irrigation module was developed in Python language to carry out the simulations. The results obtained indicated an average water savings potential of 4.5% in a rainy year and 4.3% in a dry year. The average increased yield potential was 6.4% in the rainy year and 4.0% in the dry year.