Enhancing Cantaloupe and Broccoli Water Productivity Under Arid Climate Conditions in Arizona

The present study was conducted to evaluate the effect of three irrigation methods: flood (F), subsurface drip (D), and center pivot (CP) on yield (Y) and water productivity (WP). Each irrigation method was tested at two application rates, 100% and 80% of crop evapotranspiration (ETc), denoted as “100” and “80”, respectively, under both amended (denoted as “a”) and non-amended soil conditions. Treatments were arranged in a randomized complete block design (RCBD) with three replicates during the 2024-2025 cantaloupe and broccoli growing seasons in Arizona, USA. Our results illustrated that the flood irrigation system achieved the highest cantaloupe yield (65.7 t ha^-1 under F80a treatment). In contrast, the lowest cantaloupe yields (25.6 t ha^-1 and 26.7 t ha^-1) were achieved under CP80 and D80a treatments, respectively. Application of soil amendment, Liquid Natural Clay (LNC), resulted in slight to moderate increases in cantaloupe yields under flood irrigation and center pivot irrigation systems (1.3%-15.1%). However, under D80a treatment, cantaloupe yield declined by 2.4% compared to the non-amended D80 treatment, indicating a minimal or adverse response under the reduced irrigation rate. For broccoli, LNC improved yield for most treatments, with increases ranging from 5.8% to 13.6%, except under F80a where yield declined by 7.1%. Notable gain was observed under F100a (6.7%), D100a (9.6%) and CP100a (11.1%) treatments, compared to the corresponding non-amended treatments (F100, D100 and CP100). At the reduced (80%) irrigation rate, yield improvements were also evident under D80a (5.8%) and CP80a (13.6%). This highlights the potential of combining good irrigation strategies with soil amendments to improve crop yield. Our results indicated that within the scope of this study, the subsurface drip irrigation system showed the highest water productivity under deficit irrigation conditions, applying 80% of calculated ETc, both with and without soil amendment (6.25 kg m⁻³ and 6.62 kg m⁻³ for broccoli under the D80a and D80, respectively), followed by the center pivot and flood.