Enhancing the Productivity and Water Productivity of Lemon Using Partial Root Drying and Adding Biochar

Abstract

Background and Objective: Enhancing the sustainable management of irrigation deficit is the main goal for all dry areas that suffer from limited irrigation water. The aim of this study was to study the performance of the partial root drying technique (PRD) for providing 50% of the water needs required to irrigate lemon using the addition of organic biochar to sandy soils as sustainable materials. Materials and Methods: Two field experiments were carried out during the 2019 and 2020 seasons, at the experimental farm of Al-Nubariya area in Beheira Governorate, Egypt, for studying the impact of partial roots drying (PRD) technique and the addition of biochar (made from corn straws) on the efficiency of adding irrigation water (WAE), Water stress within the roots zone of lemon trees, productivity, water productivity (WP) and the impact of these factors on some quality characteristics of lemon fruits under the conditions of dry sandy areas. The PRD technique was applied with the study of the impact of five biochar rates [0 (control), 4, 6, 8 and 10 t ha-1]. Results: The yield of lemon (LY), WP, vitamin C (VC) and total soluble solids (TSS) of lemon was increased and improved with increasing rates of biochar under the PRD technique. Whereas, the highest values for the productivity of lemon trees were obtained at 50% of the necessary irrigation water using PRD technique, compared to the full irrigation under drip irrigation system. So, despite the increase in moisture stress on one side of roots spread area in exchange with the other side when irrigating by PRD technique and consequently water application efficiency (WAE) was decreased, there were many advantages of applying this technique. Significant differences were obtained between PRD and full irrigation (FI) in terms of production values. Increasing the biochar rate led to enhancing soil water holding capacity within the root zone hence, improving WAE. Also, biochar degradation has increased the availability of nutrients. Conclusion: Results indicated that using of irrigation with 50% of FI using PRD with a biochar application rate of 10 t ha-1 is considered to be the most effective treatment because it provides 50% of the water requirement for irrigating lemon trees and thus can be recommended for application with the highest rate of biochar in the same dry sandy soil conditions in Egypt.