Effect the distance between the drippers of border drip irrigation system and soil conditioners on some soil properties and the productivity of corn plants (Zea mays L.)
Abstract
A field experiment was conducted at the Agricultural College Research Station, University of Basra, Karmat Ali, during the spring season of 2023–2024 to evaluate the effects of emitter distance and soil conditioners on water productivity, water use efficiency, and plant biomass under border drip irrigation. The study included three emitter distances: 20 cm (X1), 30 cm (X2), and 40 cm (X3), along with three soil conditioner treatments: (1) 3% crushed corn cobs, (2) a mixture of 3% crushed corn cobs and 0.3% used fuel oil, and (3) 0.3% used fuel oil alone, in addition to a control treatment. The experiment was designed as a factorial arrangement using a randomized complete block design (RCBD).
The results indicated that water productivity, water use efficiency, and plant biomass increased as emitter distance decreased. Treatment X1 (20 cm emitter distance) recorded the lowest water productivity (0.78 m³ kg⁻¹), while X3 (40 cm emitter distance) exhibited the highest (0.84 m³ kg⁻¹). Among the soil conditioners, the mixture treatment (3% crushed corn cobs + 0.3% used fuel oil) resulted in the lowest water productivity (0.70 m³ kg⁻¹), followed by the crushed corn cobs and oil treatments, all of which showed significant differences compared to the control (0.90 m³ kg⁻¹).
Water use efficiency also increased with decreasing emitter distance, with values of 12.92 kg ha⁻¹ mm⁻¹, 12.45 kg ha⁻¹ mm⁻¹, and 12.06 kg ha⁻¹ mm⁻¹ for emitter distances of 20 cm, 30 cm, and 40 cm, respectively. The mixture treatment achieved the highest water use efficiency (14.22 kg ha⁻¹ mm⁻¹), followed by the crushed corn cobs and oil treatments, while the control had the lowest value (11.16 kg ha⁻¹ mm⁻¹).
Similarly, plant wet and dry weight increased with decreasing emitter distance. The 20 cm emitter distance recorded the highest wet weight (21.73-ton ha⁻¹) and dry weight (14.30-ton ha⁻¹), while the 40 cm emitter distance recorded the lowest (19.16-ton ha⁻¹ and 12.33-ton ha⁻¹, respectively). The addition of soil conditioners further enhanced plant biomass, with the mixture treatment (CO+O) resulting in the highest biomass values (24.02-ton ha⁻¹ wet weight and 15.61-ton ha⁻¹ dry weight), followed by the crushed corn cobs and oil treatments. The control exhibited the lowest biomass (16.67-ton ha⁻¹ wet weight and 10.90-ton ha⁻¹ dry weight).
These findings highlight the positive effects of reducing emitter distance and using organic soil conditioners on water efficiency and plant growth, contributing to more sustainable agricultural practices.
