The effect of plant density with different row spacing on quality of the fatty acid composition and grain yield of sunflower

This research was aimed to assess the influence of density with different row spacing on sunflower crop in two different locations in southern Italy. The experiment was laid out in a randomized block design with four replicates. It involved the comparison of sunflower grown in the field on 25 m2-2), obtained by keeping a constant number of plants within the row (3 plants m-1) and varying the spacing between rows (0.4, 0.6 and 0.8 m). In the crops grown at the density of 7.5 plants m-2 (0.4 m row spacing) achene and oil yields were significantly lower as compared to the other treatments. Therefore, the mean values of the two trials did not show any statistical difference between the two densities of 3.75 and 5 plants m-2 (0.8 and 0.6 m row spacing, respectively). However, the superiority in the quality of the fatty acid composition was observed in the crops grown at lower density. Therefore, the row spacing of 0.8 m seems to be a good compromise between achene production and good acid composition of oil.Key words: Helianthus annuus L, plant distribution, plant density, achene yield, oil fatty acid composition

Effects of organic fertilization from wet olive pomace on emmer wheat (Triticum dicoccum Shrank) grain yield and composition

In a circular economy framework, the evaluation of waste by-product use as fertilizer is essential to promote sustainable agriculture. Olive oil wet pomace can be a valuable alternative as organic fertilizer on cereal crops. Aim of the study is to evaluate the effects of organic (with olive oil waste pomace) fertilization, on grain yield, protein and polyphenol content of emmer wheat grown in Southern Italy. Different amounts, time and amount of application of organic fertilizer were compared to a traditional mineral fertilizer treatment. The chemical analysis, mainly grain protein content and phenolic acids contents, were carried out on the hulled seeds. Agronomic traits showed that the application of olive wet pomace at 140 Mg ha−1 in the first year and 70 Mg ha−1 in the second year, gave the best grain yield than an annual amount application of 70 Mg ha−1. No difference between organic and mineral fertilization was observed when the latter was carried 1 or 2 years before, and the organic fertilization increased grain protein content respect to mineral one. Polyphenol content was not significantly affected by fertilization treatments, while ferulic acid in the emmer grain recently fertilized with wet pomace showed a higher content than emmer fertilized 2–3 years before

Spatial distribution of roots and cracks in soils cultivated with sunflower

The aim of this research was to investigate the spatial distribution of roots and cracks in two clay soils cropped with sunflower under different inter-row spacing in order to identify the optimal management. A latin square experimental design was applied to compare bare soil and soil cropped with sunflower, with three plant densities, obtained by keeping constant the number of plants on the row (3 plants m−1) and varying the row spacing (0.4, 0.6, 0.8 m). The presence of the crop and the different distance between rows influenced soil moisture content as well as the root spatial distribution and thus the structural features of cracks. Increasingly lower values of moisture were found in both soils as the distance between rows decreased; an opposite trend was observed for both root density and crack size. The volume of cracks in the soil grown with sunflower at 0.4 m row spacing was 201.4 m3 ha−1, thus 8 times higher than the value on the bare soil and 2.5 times higher compared to the one grown at 0.8 m between rows. Optimal results in terms of root density, soil moisture and crack size were obtained with an inter-row spacing of 0.6 m