Effect of organic and mineral fertilization on root growth and mycorrhizal colonization of pea crops (Pisum sativum L.).

To evaluate the effects of organic and conventional fertlization on root and soil quality of four different pea varieties ( Pisum sativum L.), a spilt-plot experiment with four replications was conducted in 2014-15 in central Greece. The experimental factors were organic manure 1000 kg ha - 1 and NPK fertilizer 600 kg ha - 1 , in the main plots and four  pea varieties: Onward (commercial variety), Amorgos, Andros and Schinousa (local varieties) as subplots. The soil and root parameters that were determined are the following: mean weight diameter, macroporosity, penetration resistance, total nitrogen, organic matter, root density and arbuscular mycorrhizal (AMF) root colonization. The results indicated that the soil and root  properties were influenced by organic fertilization but this effect is in direct correlation with the different pea varieties. The soil parameters of organic matter and penetration resistance influenced by the type of fertilization regardless of pea variety, with the values of organic matter to be significantly higher by using of organic fertilization compare to conventional and the values of penetration resistance to be significantly higher by conventional fertilization. While regarding the parameters of mean weight diameter of soil aggregates (MWD), soil macroporosity and soil total nitrogen were observed differences between the varieties, but independent of the type of fertilization. As concerns the root properties, the values of root density were different in all four pea varieties, but only for the variety Schinousa there were an increase of the root density derived from the type of fertilization and specifically from organic fertilization. As concerns the percentage of abscular muccorhizal fungi (AMF) colonization the highest percentace were recorded, in all four pea varieties, in organic fertilization compared to conventional, and in all traditional varieties.