Cape Verde is a semiarid country where lack of rainfall exacerbates the scarce resources available for livestock which, therefore, make it very vulnerable to climate change. By providing reclaimed water (RW) for irrigation, it is possible to decrease forage importation. Subsurface drip irrigation (SDI) improves health security by preventing contact between water and harvested plants. Sorghum is a water-efficient crop that provides good nutritional value. The aim of this experiment was to study the nutrient and fiber contents of the Sorghum Payenne variety using subsurface (T1) and surface (T2) drip irrigation by RW vs. conventional water (T3) and plant maturity to assure the feasibility of water reuse to produce forage. Ntot–Ptot–Ca–Mg and Na were significantly higher in the RW plants than in the conventional water ones. Ntot–Ptot–K and Fe contents significantly lowered, while Ca–Na and Mn significantly rose as plant maturity increased. All the fiber values meet the Nos. 2 and 3 quality standards, and the Prime and No. 1 for NDF and ADF, respectively. The obtained good forage quality let to avoid the competence of conventional water and to reuse nutrients added by RW. If generalized, this solution would reduce forage importation by improving food sovereignty and farmers’ profitability, and would enhance resilience against climate change effects.

Treated water use for agriculture will promote sustainable irrigation development and food sovereignty. The aim of this study is to assess the feasibility of subsurface drip irrigation (SDI) compared to drip irrigation (DI) and of reclaimed water (RW) versus conventional groundwater (CW), to produce forage sustainably in a warm arid region. A sorghum experiment was conducted in a field on Santiago Island (Cape Verde). A forage yield of 200 t fresh matter·ha−1·year−1, irrigated by RW, was obtained. Considering Cape Verde regulations, it is possible to irrigate sorghum using a drip system and RW without adding fertilizers. Soil fertility (OM and Ntot) increased, while risk parameters (EC, nitrate, and Na) returned to their initial values after the rainy season. The best irrigation water use efficiency was obtained by RWSDI (200 L·kg−1 DM) compared to RWDI, which needed 34% more water. According to the results, a high nitrate elimination rate in treatment plants might not be desirable if agricultural reuse is planned to irrigate high-N-demanding species. Establishing new salinity tolerance levels under reuse conditions with SDI, and irrigating in rainy months to promote the lixiviation of salts in arid regions are also necessary.