Does irrigation method affect both root physiology and orchard ecology?

Irrigation methods differ in terms of fraction of wetted soil surface. Soil moisture is among the most dominant variable affecting plant water relations, and other soil processes which ultimately affect CO2 soil emissions. This study compared the influence of microjet (MJ) and drip irrigation method (D) on levels of absisic acid concentration in roots ([ABA]) and on soil CO2 emissions. Two plots were identified at a nectarine orchard (1666 p ha-1) located in southern Italy, and irrigated by MJ (~35 L h-1) and D (~16 L h-1). Plant water status (pre-dawn leaf water potential) was kept optimal in both plots. Preliminary results revealed that ABA increased in inter-row roots at the D plot (D-inter) being 2.35-fold higher than those of MJ, despite both plots having similar water status. The CO2 soil emissions were substantially 27.78% lower in D plot compared to the MJ one. Information on impact of irrigation methods on shoot elongation, fruit size are also discussed.