Contribution to the optimization of citrus (Citrus clementina Hort. Ex Tanaka) fruit fertilization using mobile lysimetry in orchards of the Souss-Massa region, Morocco

The growth and development of citrus trees and the quality of their fruits are significantly influenced by the essential role of mineral plant nutrition. This study aimed to improve the productivity of the citrus (Citrus clementina Hort. Ex Tanaka) orchards by optimizing mineral nutrition through well-monitored fertilization and fertigation aspects using lysimetry. The first phase consisted of studying the behavior of the nutrients in the soil solution at the high root concentration level, analysis of the nutritional status of five varieties of clementines (Sidi Aissa, Cadoux, Orogrande, Nules, and Nour), and the variation of leaf composition in major elements (Nitrogen, phosphorus, potassium, magnesium, and calcium) for the five varieties along phenological stages, through the exploitation of the results of analyses carried out for the management of mineral nutrition in 47 plots of citrus fruit in the Souss-Massa region with the use of lysimetry. The results obtained in this first part revealed an important variation of the nutrients in the soil solution (55.24%) in terms of water inputs, fertilizers, and edaphic conditions, as well as a large variation of foliar compositions (62.98%). The second phase, consisting of regular monitoring of the mineral nutrition dynamics targeting the “Nules” variety grafted on “Citrus macrophylla” affirmed the importance of the citrus fertilization approach for determining the availability, distribution, nutrient interactions in soil solution and plant response by regular leaf diagnostics. Thus, mobile lysimetry offered a powerful tool for achieving both productivity and sustainability in citrus fertilization programs.