Oxygen enrichment of nutrient solution of substrate-grown vegetable crops under Mediterranean greenhouse conditions: oxygen content dynamics and crop response

Abstract

This work assessed the seasonal dynamics of the substrate oxygen content and the response to oxygen enrichment of nutrient solution (oxyfertigation) of autumn-winter sweet pepper and spring melon crops grown on rockwool slabs (2003/04 season) and perlite grow-bags (2004/05), compared to non-enriched crops. Dissolved Oxygen (DO) values in the nutrient solution were higher for all the oxygen enriched treatments (> 20 mg L -1 ) than for the non-enriched ones (~4 mg L -1 ), but no significant differences were found in the substrate solution. For pepper crops, DO values were highest at the onset and, especially, at the end of the cycle in winter, while the lowest DO values (3 to 4 mg L -1 ) occurred during September and October. For melon, DO values decreased progressively from the onset of the cycles to values ≤ 3 mg L -1 during the second half of the cycles. For pepper crops, there were no significant differences between oxygen treatments for fruit production, which could be attributed to the fact that DO values were > 3 mg L -1 throughout each crop cycle. However, a significant 7% increase in total and marketable yield, associated with a higher fruit number, was observed for the oxygen enriched melon grown on rockwool slabs, whereas no significant differences were found for the melon grown on perlite grow-bags. In conclusion, the use of inexpensive systems of substrate oxygen enrichment should be restricted to rockwool substrates and to crop periods when a high oxygen demand coincides with low oxygen availability, such as the period from melon flowering phase.Additional key words: Capsicum annuum; Cucumis melo; dissolved oxygen; hypoxia; melon; perlite grow-bag; rockwool slab; sweet pepper. ResumenContenido de oxígeno y respuesta de cultivos hortícolas en sustrato e invernadero al enriquecimiento de oxígeno de la solución nutritiva

Níveis e Frequências de Fertirrigação Nitrogenada no Crescimento Inicial da Goiabeira “Paluma”

“…Tais resultados estão conforme relatado por Bonachela et al (2010), os quais relatam que o uso de vasos de pequeno volume aliado a elevada frequência de irrigação pode reduzir a taxa de difusão e a disponibilidade de oxigênio para as raízes das plantas. Além disso, a absorção de água e nutrientes um processo dependente de energia e são reduzidos quando as raízes são expostas em ambientes saturados (Morard e Silvestre, 1996).…”

Construction Characteristics and Management Practices of In‐farm Irrigation Ponds in Intensive Agricultural Systems — Agronomic and Environmental Implications

“…The tendency to construct larger and deeper ponds, such as the PET and PET-G ones, could be related to the positive correlation found between pond volume and irrigated surface area. The slope of the linear relationship observed between these two variables indicates that irrigation ponds can guarantee covering the irrigation water requirements of greenhouse crops for 22-26 days, considering maximum daily evapotranspiration values of 5-6 mm in spring cycles (Orgaz et al, 2005;Bonachela et al, 2010). Pond depth can limit the potential of SAV colonisation due to underwater light attenuation, which is more likely to occur in the relatively deeper PET ponds.…”

Pengaruh Campuran Pasir dan Serat Aren pada Kailan (Brassica oleraceae) dengan Hidroponik Substrat

“…Substrat dalam masa pertanaman biasanya meningkatkan bahan organik dan aktivitas mikroorganisme, yang dimungkinkan meningkatkan kompetisi oksigen dalam lingkungan akar. Kompetisi tersebut menyebabkan akar mengikat substrat, agar mendapatkan suplai oksigen (Bonachela et al 2010…”