Effect of dung, ash and runoff water on wheat and barley grain sizes and stable isotope ratios: Experimental studies in ancient desert agriculture (Negev, Israel)

Archaeological excavations in the central Negev desert terraced wadi fields at Horvat Haluqim revealed remains of two ancient fertilizers: charred plant ash and animal dung. Average annual rainfall area is 94 mm. Runoff rainwater from natural hillside catchments, captured by terrace walls, augmented soil moisture valleys to enable agriculture. Some are farmed Bedouin, who grow wheat barley. Using these cereal varieties, we conducted novel investigations this arid environment about effect ash, sheep dung runoff water on grain sizes, δ13C, Δ13C, δ15N. Our study included both controlled pot experiments traditional farming Bedouin. The pots were filled with local loess investigate four different fertilizer treatments – (1) “None” for baseline data, (2) “Ash”, (3) “Dung”, (4) “Ash & Dung combined” above varieties. largest grains produced treatment 4 (ash dung), which a remarkable result, because it independently corroborates archaeological findings. received equal amounts tap water, totalling 240 mm barley 325 wheat. Δ13C values ranged 15.62 17.47‰. Concerning δ15N, small increase, as compared but caused decrease. Ash together (treatment 4) yielded variable δ15N results. Stable isotopes same varieties also studied context Bedouin area. reception nature highly variable. A negative correlation was found between δ13C moisture. 12.59 17.44‰. drier had comparatively high values, while wetter lowest values. Nevertheless, other quite high, indicating additional factors besides water. Though do not add fertilizers fields, their goats graze stubble after harvest. This leads spatially random spotty distribution manure, may explain diverging