Comparative effects of agricultural biowaste recycling practices and inorganic fertilization on basil (Ocimum basilicum L.) growth and soil fertility: Modelling plant growth

Introduction In modern societies, the disposal of ever more increasing biowaste is a serious threat [1]. Furthermore, the exploitation of soils that are unsuitable for cultivation (poor in nutrients due to intensive cultivation or polluted with organometallic pollutants) is an ongoing challenge [2]. One green and sustainable solution seems to be the disposal of biowaste, a rich source of nutrients, which might be exploited to produce biofertilizers in these soils [3-4]. The use of these organic amendments in agriculture is a common practice due to their ability to increase crop productivity, enhance soil health and improve soil physicochemical properties [5-6]. Methods This study investigates the effects of organic soil amendments with: compost from plants; chickens’ manure; sewage sludge; as well as a chemical fertilizer on basil (Ocimum basilicum L.) growth and soil fertility, whilst the expected effects of the abiotic and biotic environment, including effects of organic soil amendments, on plant growth were modelled using a Richards growth model [7]. Results The results showed that the best plant growth was achieved in the sludge-modified soils, whilst the poorest plant growth was noted in the chemical fertilizer-modified soil (Fig. 1). Moreover, the results of foliar diagnostics indexes showed that the plants of organic soil amendments with chemical fertilizer have low values, at the level of malnutrition, in several elements such as Phosphorus (P) and Copper (Cu) (Table 1). Conclusions This work confirms that the organic soil amendments generally result in beneficial effects with regard to plant growth and other soil properties. Our findings are significant for sustainable agriculture regarding the sustainable use of organic wastes in problematic soils. Acknowledgments: A part of the research project was co-funded by the University of Patras, in theframework of the program “MEDIKOS”. References [1] Giannakopoulos, E., et al., (2017). Jour. Environnemental Management, 195,186-194. [2] Ahmad, R., et al., (2007). Annals of Microbiology 57, 471-479. [3] Khadem, S.A., et al., (2010). Australian Journal of Crop Science, 4, 642-647. [4] Mullins, G.L., et al., (1996). Techn. Publication No. 424-034, Virginia State University, Blackburg, VA, USA. [5] Pervez, M.A., et al., (2000). International Journal of Agriculture and Biology, 2, 1-2. [6] Farrag, Κ., et al. (2016). Clean-Soil Air Water, 44 (9), 1174-1183. [7] Damgaard, C. (2004). Comptes Rendus Biologies,327(3),255-260.