Field and Modeling Study for Integrated N-Fertilization and Organic Mulching to Improve the Productivity and Water Productivity of Tomatoes under Arid Egyptian Conditions

Abstract

Due to the limited water resources in Egypt and its occurrence in the driest areas in the world, in addition to climatic changes and rising temperatures, which negatively affect the increase in water needs required to irrigate crops, it was necessary for us to think about applying the most sustainable technologies available, which will face all these challenges in an environmentally friendly manner. One of the most sustainable, cheap and available techniques is the recycling of organic agricultural waste, from which organic fertilizers can be produced and also can be used as organic mulching as a sustainable alternative to plastic mulching. Soil moisture content (SMC),Water application efficiency (WAE), soil organic matter content (SOMC), and activity of microorganisms (AM), soil electrical conductivity (SEC), yield (Y Tomato ) and water productivity of tomato (WP Tomato ) are investigated with organic mulching and integrated N-fertilization treatments under dry Egyptian conditions and also, the previous evaluation criteria were modeled using the SALTMED simulation model. The results indicated that, using of organic mulching also led to a decrease in the evaporation rate thus, the soil surface remains moist for as long as possible, and the accumulation of salts in sandy soils decreases which mean, protecting the soil surface and the root zone from increasing water and salt stress. The results also showed the importance of the integrated nitrogen fertilization, which increases the proportion of adding the organic component. Using of organic mulching and integrated nitrogen fertilization led to an increase in the SMC, WAE, SOMC and an increase in biological activity, as well as a decrease in the accumulation of salts in the soil. It combines with the application of these techniques all the encouraging benefits of sustaining, increasing and improving the productivity of tomatoes and any other crop in dry sandy soils with limited irrigation water and drought. The study concluded that relying on organic mulching and integrated nitrogen fertilization increased the productivity and water productivity of tomatoes, where the highest values were when using organic mulching and adding 50% of organic nitrogen + 50% of mineral nitrogen fertilizers. The results also showed the accuracy of the SALTMED simulation model in simulating the evaluation criteria that were studied using drip irrigation system under sandy soils in Egypt.