Application of Directly Brewed Compost Extract Improves Yield and Quality in Baby Leaf Lettuce Grown Hydroponically

Almudena Giménez,Juan A Fernández,Catalina Egea-Gilabert,Margarita Ros,José A Pascual

doi:10.3390/agronomy10030370

Almudena Giménez, Juan A Fernández + Show 3 more

Open Access

https://doi.org/10.3390/agronomy10030370

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Abstract

The aim of this work was to study whether the application of a directly brewed compost extract (added in the nutrient solution or by microsprinkler) could be used to improve the yield and quality of baby leaf red lettuce growing in a floating system, and to control the incidence of Pythium irregulare. Its effect on the quality of fresh-cut red lettuce was also studied. For this, two experiments were carried out over two growing cycles (winter–spring and autumn). The results showed that the use of compost extract added to the nutrient solution improved baby leaf lettuce growth and quality, reducing the nitrate content and enhancing the content of potentially health-promoting compounds such as phenols and flavonoids and the antioxidant capacity. Microbial quality was maintained during storage and the compost extract had no negative effect on the microbial load of the final product. In addition, application of the compost decreased the population of P. irregulare in the water. It is concluded that the application of directly brewed compost extract is of potential use in a sustainable soilless production system for baby leaf red lettuce, since it improves the yield and quality of the product and is able to control the incidence of P. irregulare.

Highlights

The use of compost in agriculture is gradually gaining in popularity, mainly due to its environmental and agronomic benefits
We studied the effect of two different ways of applying a directly brewed compost extract added in the nutrient solution (CENS) or by microsprinkler (CEMP) on the yield and quality of baby leaf red lettuce growing in a floating system, and the effect on the incidence of Pythium irregulare
The higher values of dry matter were obtained in control inoculated plants and those treated by CENS

Summary

Introduction

The use of compost in agriculture is gradually gaining in popularity, mainly due to its environmental and agronomic benefits. Composts from the fruit and vegetable processing industry are used as a nutrient-rich fertilizer or soil amendment to improve crop production and quality [2,3,4]. Such composts present a lower risk of containing pathogens, heavy metals or pharmaceuticals as components [5], and have interesting biological activities [6]. It has been demonstrated that the suppressive effect of composts depends on the raw material origin, the pathogen to be controlled and the plant being cultivated [7]

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