*Article* **Response of Chosen American** *Asparagus officinalis* **L. Cultivars to Drip Irrigation on the Sandy Soil in Central Europe: Growth, Yield, and Water Productivity**

**Roman Rolbiecki 1, Stanisław Rolbiecki 1, Anna Figas 2, Barbara Jagosz 3, Piotr Prus 4, Piotr Stachowski 5, Maciej J. Kazula 6, Małgorzata Szczepanek 7,\*, Wiesław Ptach 8, Ferenc Pal-Fam 9, Hicran A. Sadan <sup>1</sup> and Daniel Liberacki <sup>5</sup>**

	- UTP University of Science and Technology in Bydgoszcz, 85-029 Bydgoszcz, Poland

**Abstract:** The aim of this study was to verify the response of 13 American asparagus cultivars cultivated for green spear on surface postharvest drip irrigation. Irrigation, used to compensate for periodic deficiencies in precipitation, allows for high- and good-quality crops for many species. The field experiment was carried out in 2006–2008 on a very light sandy soil in central Europe (Poland). Irrigation treatments were applied using the tensiometer indications. Water requirements of asparagus were calculated on the base of reference evapotranspiration and crop coefficients. The following evaluations were made: Height, diameter, and number of summer stalks, as well marketable yield, weight, and number of consumption green spears. Drip irrigation applied for 2 years (2006–2007) in the postharvest period had a positive effect on all studied traits in both summer stalks and green spears in 2007–2008. A significant increase in the height, number, and diameter of summer stalks, as well an increase in the marketable yield, weight, and number of green spears was observed for most of the cultivars. In general, postharvest drip irrigation of asparagus cultivated in very light sandy soil significantly contributes to the increase in productivity of American cultivars of this species.

**Keywords:** *Asparagus officinalis* L.; cultivars; spears yield; sandy soil; water requirements; IWUE
