Effect of Irrigation Periods and Organic Fertilization on Some Soil Properties and Lettuce Production

Abstract

          The study was conducted in Baghdad Governorate, Al-Mahmoudiya District, Al-Yusufiyah Sub-district (Al-Qasr Al-Awsat) during the 2021 growing season to evaluate the effects of irrigation intervals and organic fertilization on selected soil properties and lettuce production. The experiment included two factors: the first factor was irrigation intervals, consisting of watering the crop every 3, 5, and 7 days (denoted as I3, I5, and I7, respectively). The second factor was the application of organic fertilizer to the soil at rates of 0, 10, 20, and 30 kg ha⁻¹ (denoted as H0, H1, H2, and H3, respectively). The experiment was arranged in a randomized complete block design (RCBD) with three replicates, encompassing a total of 36 experimental units, each with an area of 3 m². The results indicated that the I3 treatment (irrigating the crop every 3 days) resulted in the highest green yield productivity, reaching 205.775 µg ha⁻¹. Conversely, the I7 treatment (irrigating the crop every 7 days) produced the best soil aggregate stability, achieving 59.590%. Regarding organic fertilization, the H3 treatment (30 kg h⁻¹ of organic fertilizer) demonstrated superiority across all studied characteristics. This treatment significantly reduced soil bulk density to 1.260 µg m⁻³ compared to the control treatment (H0) at 1.362 µg m⁻³. Furthermore, total soil porosity increased to 52.633% under H3 compared to 48.793% for the control. The H3 treatment also resulted in the highest soil aggregate stability, reaching 56.593%, compared to 48.177% in the control treatment. Additionally, H3 achieved the highest vegetative yield of lettuce plants, at 165.727 megagrams ha⁻¹, compared to 119.780 megagrams ha⁻¹ in the control.