Increasing the sustainability of vegetable crops production by using intercropping

L. Lepse* and S. Zeipiņa

Institute of Horticulture, Graudu iela 1, Ceriņi, Krimūnu pag., Dobeles nov., LV–3701, Latvia
*Correspondence: liga.lepse@llu.lv

Abstract:

Some scientific reports support the idea of using plant interactions to promote the growth and yielding of vegetable crops. The plant interactions in vegetable production under intercropping conditions were investigated in ERDF funded project ‘Elaboration of environment-friendly crop growing technologies identified by the Green Deal and their implementation in horticultural production in Latvia (GreenHort)’ implemented in Latvia Institute of Horticulture with the aim to introduce strip cropping in the vegetable production. The investigations were carried out at the Institute of Horticulture, Latvia (57°03’44.6’’N, 22°54’53.2’’E), during the growing seasons of 2021 and 2022. The vegetable crops (carrots, cabbage, onions, and pumpkins) were grown in intercropping with agroecological service plants or aromatic plants as companion plants (white clover, marigolds, tagetes, lavender, sage, coriander). The investigated variants were compared with the control, where vegetable crops were grown in monoculture as usual. Each intercrop variant consists of 7 alternating rows (each 0.6 m wide) – 4 rows of service crop and 3 rows of vegetable. There was observed significant influence of the growing system on the plants productivity. The sharpest differences between variants were observed for cabbage – marigold, sage and lavender had a positive influence on the cabbage yield formation, but white clover had an extremely negative influence on the cabbage plant growth. White clover had a negative influence also on carrot and pumpkin productivity. Sage had a yield-promoting influence on the carrot crop. There was not found any significant influence of the agroecologial crops on onion productivity.

Key words:

Anaerobic digestion of vegetables processing wastes with catalyst metaferm

V. Dubrovskis* and I. Plume

Latvia University of Agriculture, Faculty of Engineering, Institute of Agriculture Energetics, 5, Cakstesblvd, LV3001 Jelgava, Latvia *Correspondence: vilisd@inbox.lv

Abstract:

There are 54 active biogas plants in Latvia today. It is necessary to investigate the suitability of various biomasses for energy production. Maize is the dominating crop for biogas production in Latvia. The cultivation of more varied crops with good economical characteristics and a low environmental impact is thus desirable. One of the ways for improving biogas yield in Latvian conditions is using biological catalysts. This paper explores the results of the anaerobic digestion of vegetables’ processing wastes using the new biological catalyst Metaferm. The digestion process was investigated in view of biogas production in sixteen 0.7 l digesters operated in batch mode at the temperature of 38 ± 1.0 °C. The average methane yield per unit of dry organic matter added (DOM) from the digestion of onions was 0.433 l g–1DOM; with 1 ml ofMetaferm: 0.396 l g–1–1DOM, and with 2 ml of Metaferm: 0.394 l gDOM . The average methane yieldfrom the digestion of carrots was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.498 l gDOM , and with2 ml of Metaferm: 0.426 l g–1DOM. The average additional methane yield per unit of dry organicmatter from the digestion of 50%:50% mixed onions and carrots was 0.382 l g–1DOMwith 2 mlof Metaferm. The average additional methane yield per unit of dry organic matter from the digestion of cabbage leftovers was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.375 l gDOM , andwith 2 ml of Metaferm: 0.415 l g–1DOM. The average additional methane yield per unit of dryorganic matter from the digestion of potato cuttings was 0.570 l g–1DOM; with 1 ml ofMetaferm: 0.551 l g–1–1DOM, and with 2 ml of Metaferm:0.667 l gDOM . The average additionalmethane yield per unit of dry organic matter from the digestion of 50%:50% mixed cabbages and potatoes was 0.613 l g–1DOMwith 2 ml of Metaferm. All investigated vegetable wastes canbe successfully cultivated for energy production under agro-ecological conditions in Latvia. Adding the catalyst Metaferm increased methane yield, except for onions.

Key words:

anaerobic digestion, biogas, biological catalyst., cabbage, carrot, methane, onion, potato