Comparative study of qualitative traits of lentil accessions grown in outdoor hydroponic and soil conditions in Armenia

Abstract

Introduction: One major global challenge of this century is achieving a Second Green Revolution, focusing on enhancing food security through legumes such as lentils. Legumes are vital for low- and middle-income countries due to their nitrogen-fixing properties and contribution to sustainable agriculture. However, legumes are underutilized in the human diet despite their health benefits. To address this, alternative farming technologies such as hydroponics are necessary to boost yields. Climate change, technological advancements, and the need for self-sufficiency highlight the importance of introducing lentils in Armenian farming practices. These products can serve as a valuable and nutritious crop.

Objective: This study uses traditional farming methods and a controlled hydroponic system to evaluate the feasibility and efficiency of cultivating lentils in the Ararat Valley, including the mountainous foothill zone. It also aims to evaluate the nutritional value of lentil seeds. These products' biochemical and bioactive components, such as proteins, fats, carbohydrates, and dietary fiber, were assessed.

Methods: Experiments were conducted in 2022-2023 in outdoor hydroponics, using current soil conditions in the Ararat and Gegharkunik regions of Armenia. Several genetic resources of lentils from ICARDA, including Flip 2007-12, Flip 2006- 4L, Flip 2007- 3L, Flip 2007- 30L, Ep-54, SellFrom 1767LL, and local varieties Talini 6 and Haykakan 88 (controls) were used. The protein content was determined using the Micro-Kjeldahl method. Total sugars were determined using the Bertrand method. Fats were determined by the Soxhlet extraction method. Dietary fiber was analyzed according to the American and International Standards.

Results: The results show that the protein, total sugar, crude fat, and total fiber contents of lentils grown under the soil conditions of the Ararat region ranged from 20.1 to 26.5%, 6.0 to 6.7%, 1.1 to 1.5%, and 9.0 to 13%, respectively. Outdoor hydroponics in the same region yielded lentils with 20,1-26,1% protein, 6.0-6.8% total sugar, 1.2-1.9% crude fats, and 9.5-11% total fiber. The lentils raised in the Gegharkunik region contain 20,1-26,5% protein, 6.2-6.8% total sugars, 1.2-1.5% fats, and 10.5-12.5% dietary fiber. Under hydroponic conditions in Ararat Valley, lentil yield increased, with seed weight per plant ranging from 14.9-21.0 g, compared to 4.3-7.7 g in soil conditions in Ararat and Gegharkunik.

Conclusion: Several genetic resources of lentils from ICARDA (Flip 2007-12, Flip 2006-4L, Flip 2007-30L, Flip2007-3L, Ep-54, Sell from1767L) and local varieties (Talini 6, Haykakan 88) exhibited high levels of biochemical properties (protein, total sugars, fats, dietary fiber) when grown in the outdoor hydroponics of the Ararat region. This method contributed to increased yields; the seed weight per plant in open hydroponics reached 14.9-21.0 grams, and in soil conditions (4.3-6.2 grams, compared to 5.4-7.7 grams in soil conditions of the Gegharkunik region of Armenia).

Keywords: lentil, outdoor hydroponic, protein, monosaccharides, fats, dietary fiber.