Effect of soil biosolarization with different amendments during high-temperature conditions on greenhouse pepper yield in southeastern Spain

In this study, the effect of soil biosolarization with different organic amendments was evaluated on the yield of a greenhouse pepper crop when it was carried in July-August in the cultivation area of Cartagena field (southeast of Spain). The amendments used for soil biosolarization were: T1: wheat husk + semi-composted sheep manure at 3.5 kg m (1+2.5); T2: sunflower pellets (Alimer SCoop, Alimentos del mediterraneo, S. Coop.) at 3.5 kg m; T3: semi-composted sheep manure at 3.5 kg m; and T4: control (non-amendment and non-plastic). At 15 and 30 cm soil depth, soil temperatures above 42°C were reached in all the biosolarization treatments, for more than 300 h, while in the control treatment only 60 h above this temperature were reached. No differences in yield were observed among the three biosolarization amendments. Pepper yield was greater in all the biosolarization treatments when compared to the control treatment. The amendments with manure did not produce an improvement in yield compared to the amendment without manure, an interesting fact for vulnerable areas to groundwater contamination due to nitrate leaching, such as Campo de Cartagena.