DOI: 10.5593/SGEM2016/B41/S17.079


G.Dicu, A.G.Basa, D.State, V.Ion, L.I. Epure
Wednesday 7 September 2016 by Libadmin2016

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-63-6 / ISSN 1314-2704, June 28 - July 6, 2016, Book4 Vol. 1, 609-614 pp

Sunflower (Helianthus annuus L.) is one of the crops with the potential to produce biomass which could be used as substrate for biogas production. It can be part of the energy crop rotations, respectively it can be included into the structure of the energy crops that could be used for producing biomass for biogas production. Apart its potential to produce biomass, respectively the capacity to give high yields of above-ground dry matter, sunflower has also the advantage to be a better adapter crop to water stress than other crops.
The aim of this paper is to present the results we have obtained related to the biomass yield that could be obtained at sunflower at different plant density and row spacing conditions. The plant density and row spacing are important elements within the crop technology because they give the so-called nutritional space of the plants, respectively the dimension and the shape of the space corresponding to each plant. In view to get the highest biomass yield in an efficient way, the plants have to have the optimum nutritional space according to growing conditions, respectively the appropriate plant density and row spacing.
In order to identify the biomass yield that could be obtained at different plant density and row spacing conditions, the sunflower hybrid Pro 144 SU was studied at different plant densities (70,000, 80,000, 90,000, 100,000, 110,000, and 120,000 plants.ha-1) and under two row spacing conditions (75 cm and 37.5 cm). Researches were performed in a field experiment, under rainfed conditions, in the year 2015, the experiment being located in South Romania at Fundulea (44o28’ N latitude and 26o28’ E longitude).
The biomass determinations were performed in the early dough - dough plant growth stages, respectively in the growth stages of the sunflower plants when the above-ground biomass could be used as raw material for biogas production. For each experimental variant, there was determined the biomass yield (expressed in tons.ha-1), as fresh and dry matter. The obtained data showed that narrow rows can provide higher biomass yields than wider rows but at higher plant densities. Increasing of plant density determined an increase of the biomass yield up to a threshold beyond which the biomass yield started to decrease, this threshold being different according to row spacing.

Keywords: biomass yield, sunflower, plant density, row spacing, renewable energy.