Best Management Practice of Nutrient of Olive Orchards in Rainfed and Irrigated Areas of Morocco

Introduction
In Morocco, olive trees area is currently estimated at around one million hectares of which 80% are in the productive age. The Green Morocco Plan expects the extension of these groves to more than 1.2 million hectares within 2020. The olive’s average production between 2009 and 2012 was 1.2 million tons in average against 700,000 tons between 2005 and 2008. The increase of the production is mainly due to the efforts of planting, while yields remain low. The average yield of olives is about 1 t ha^-1 under rainfed and 2 t ha^-1 under irrigation system respectively. Among olive orchards areas more than half of the olive orchards is conducted in association with other crops such as cereals.

The low olive yields are explained by many factors:
• The use of not selected plant materials;
• Some olive orchards are planted in unfavorable conditions: low rainfall, poor soils, topography ...;
• The dominance of a traditional olive orchard management;
• The field technical management used by farmers is often failed.

In fact, we note that the tillage is conducted in an arbitrary way, fertilization supplies are not adequate, phytosanitary treatments are rarely executed, weed control is absent and the irrigation is mostly traditional.

In most cases, fertilizers are applied with an irrational and uncontrolled system. Farmers do not carry out any diagnosis to justify fertilizer inputs. In the case where annual crops are planted between olive rows, olive orchards receive inputs indirectly from these crops. Diagnostic studies conducted in various regions of Morocco showed that less than 10% of farmers apply specific fertilizer to olive (1% in Ouarzazate, 4% in Er-Rachidia, 10% in Tadla, 15% in Haouz...). Except some olive orchards conducted in intensive or super intensive systems, foliar diagnosis to establish a fertilizer plan is not used by producers. This collaborative study between INRA Morocco and IPNI North Africa Program aims to conduct studies on the best management practice of fertilization of the olive trees. Three components will be studied:
• Diagnosis of the current nutritional status of olive
• Conduct tests on fertilization
• Develop fact sheets on fertilization of olive.

Global objective:
Increasing farmers' incomes by improving yields and quality of olive products (olives and oils in irrigated and rainfed areas) by adopting a best nutrient management practice.

Specific Objectives:

· Diagnosis the nutritional status of some representative olive groves in the main production areas.
· Demonstrate the interest of best nutrient management practice of olive groves to increase yields and for improving the quality of olive oil.
· Generalize the diagnostic methods to detect nutrient deficiencies and the establishment of a plan of nutrients management at farm level.
· Make farmers aware with good olive trees fertilization according to the concept of the four "R" : right source, right rate, right time and right place.

Component 1: Diagnosis of the nutritional status of olive orchards (irrigated and rainfed areas) (2013-2016)
Foliar diagnosis is based on the analysis of leaves, which replace the whole plant (total nutrient removed by the whole plant). It is the analysis of nutrition status "in-situ" in the natural conditions of the vegetation. Assumptions that allow the use of foliar analysis are: (a) the leaf is the main organ of plant metabolism, (b) changes in the supply of nutrients is often reflected in the composition of the leaf (c) these changes are more pronounced at certain stages than others (d) the levels of nutrients (macro and micro) in the leaf at specific times are related to the yield.

Foliar analyzes should be performed annually to know the normal response of the olive trees to the fertilization plan and correct deficiencies that could occur. Sampling of leaves is done between mid-June and mid-July at the stage of stone sclerotization.

This study will give an idea on the nutritional status of olive groves in different homogeneous areas of Marrakech and Essaouira regions. Both irrigated and rainfed areas will be considered.

Activities :
Activity 1-1: Delimitation of olive representative areas and identification of homogeneous samples of olive groves for the implementation of foliar diagnosis.
Expected result 1-1: homogeneous areas are delimited and samples of olive to diagnose nutritional status are established.
Timeframe: April-July 2013.
Conduct of the activity 1-1: data collection, consultation with experts and executives from ORMVA Haouz, surveys, types of olive groves, visual symptoms prospecting prospective sampling groves will be diagnosed. Data on yields and amounts of fertilizers applied by farmers will also be collected.
Activity 1-2 - Implementation of foliar diagnosis
Expected Result 1-2: The nutritional status of olive groves determined.
Schedule: October-November 2013

Conduct of activity 1-2:

• Collection of leaves samples according to the standards of the age and position on the tree and appropriate stage.
• Preparation of leaves for analysis
• Analysis of leaves contents on macro and micronutrients elements
• Interpretation of results
• Recommendations and proposition of fertilizer plans.

Component 2: fertilization trials of olive orchards (2013-2016)
The objective is to demonstrate the effect of various fertilizers input on the production of olives and oil quality.

On farm trials will be installed under rainfed and irrigated systems, representing the different cropping systems

These trials will be conducted in a randomized complete block with a variable number of repetitions. The treatments proposed are:

1. Plots without fertilization (control)
2. Farmer use
3. Plots fertilized according to nutrient removed method
4. Plots fertilized according to foliar diagnosis

Fertilization treatments will be applied at the beginning of 2014.
Activity 2-1: Identification of the on-farm experiment
Result 2-1: Representative orchards for conducting for on-farm trials are identified with farmers in rainfed and irrigated areas respectively in Essaouira and Marrakech regions.
Schedule 2-1: April2013 and October 2013
Conduct of the activity 2-1: The selection will be olive orchards with a minimum surface of 1 ha. This choice will be made in collaboration with the managers of the ORMVA El Haouz (irrigated trial) and DPA Essaouira (rainfed trial). The plot should be in full production and available. The selection criteria will be based on the receptivity of the farmer.
Activity 2-2 – Experimental design established
Expected result 2-2:
Conduct of activity 2-2: In accordance with the owner, the trial will be installed with an appropriate experimental design.
Activity 2-3: Effect of fertilization management on growth and fruiting of olive trees.
Result 2-3 : from 2014, the effect of fertilization management on vegetative growth and olive and oil yields are studied
Conduct of the activity 2-3: observations will be carried out on a sample of pre-established trees. Parameters that will be measured are vegetative growth of yearly shoots, phenological stages, and parameters of flowering, fruiting and production. Yields of different sub plots will be evaluated.
Activity 2-4: Study of the effect of fertilization on fruit pomology, oil yields and olive oil quality.
Result 2-4 - the initial status of fruit and olive oil in both sites (irrigated and rainfed area) will be determined at the end of 2013. From 2014, after the introduction of fertilization treatments, pomology fruit, oil yields and quality of olive oil determined.
Schedule: 2013-2016
Conduct of the activity 2-4: In 2013, from fruit samples fruit weight will be measured, the maturity index, the ratio flesh / stone. The oil extraction will evaluate the oil content. On oil samples will be studied various physico-chemical parameters and sensorial quality. According to fertilization treatments, the previous cited parameters will be studied from 2014 to 2016.