Diagnosis of Soil Fertility and Nutritional Status and Characterization of Olive Orchard in Central Morocco

This study was conducted in 2009/2010 with 58 olive orchards randomly selected at the Sais region. The main objectives of this work are: i) Characterization of olive orchard ii) Determining the soil fertility levels and the assessment of nutritional status of these olive orchards. Composite soil samples from two depths (0-30 cm and 30-60 cm) and composite leaf samples were collected during the December/January period. Surveys were conducted on these orchards to collect data for characterization and analysis of different fertilization modes adopted in relation to olive yield. More than half of the surveyed groves (57%) are conducted in rain fed conditions. The surveys have revealed shortcomings as regards fertilization practices of olive cultivation. Indeed, approximately 48.3% of the farmers surveyed provide no fertilizer for their olive trees. The laboratory analyzes of soil and leaf samples collected in these orchards have confirmed this. The study showed no correlation between the olive yield and soil fertility parameters and between the olive yield and the olive leaf parameters. The relationship between the olive nutrition parameters and the soil fertility parameters, at the 0-30 cm horizon, showed that olive leaf parameters were not linked to those of soil fertility. However, much of the leaf nitrogen content (about half) has been explained by the soil nitrate content in irrigated orchards. The determination of the olive tree fertilization standards is a necessary step for a rational management of fertilizers for the olive trees. These standards should be developed through field trials.