Effect of Organic Amendment on Soil Fertility, Mineral Nutrition, and Yield of Majhoul Date Palm Cultivar in Drâa-Tafilalet Region, Morocco

Abstract

The low fertility in soils where date palms are grown in Morocco is the first cause leading to low yields when compared to other producing countries. The aim of this study is to investigate the effect of organic amendment on mineral nutrition and yield of Majhoul date palm cultivar under Moroccan oasis conditions in relation with soil fertility. A field study was carried out for 2 years at two farms located at different sites in Drâa-Tafilalet region (Jorf and Tinjdad). The effect of different fertilization treatments on soil organic matter mineralization, soil mineral nutrients, plant nutrition, and date palm yield was investigated. The four treatments that were studied in this experiment are described as follows: mineral nitrogen (urea), organic amendment (compost), organic amendment combined with mineral nitrogen, and control with no fertilization. The compost, alone or combined with urea, enhanced the soil fertility through the improvement of the soil organic matter content and its mineralization and the increase in soil macro- and microelement concentrations at two depths compared to the urea alone and the control. The mineral nutrition of date palms was significantly enhanced by applying compost and/or urea. The application of compost combined with urea, for 2 years, increased the yield at Jorf farm by more than 78% and at Tinjdad farm by 41%. The adoption of the fertilization management, based on the application of both compost and urea, could restore the degraded soils, increase the date palm yield, and ensure more returns to farmers.