Effects of plastic mulching on productivity and profitability of cotton (Gossypium hirsutum) in Uzbekistan

抄録

Irrigation shortage causes to use only 10% (4.65 million ha) of land of total cultivable area in Uzbekistan. Out of the area, cotton plantation is about 1.45 million ha. Hence, developing water-saving technology in cotton production is one of the crucial aims in Uzbek agriculture. One of main reasons of water shortage is improper water use by farmers. Mulch is defined as a coating material spread over the soil surface, and it helps to improve crop growth and yield as well as optimises water use efficiency. However, its effect on cotton production has not been studied very well in Uzbekistan. Field experiment was conducted in typical gray soil of Tashkent Province, Uzbekistan. Plastic mulching treatment (MT) and without plastic mulch treatment (control, CT) were tested in three replications in paired comparison design. In MT, polyethylene film was mulched on the brooklets before the first irrigation. The amount of water input by flush irrigation was measured with Thompson instrument. The average water input was two times less in MT (591 m³/ha) than in CT (1035 m³/ha) while cotton yield in MT (3.53 t/ha) was significantly larger than in CT (2.7 t/ha). Consequently, the water productivity (yield/water input) in MT (5.99 kg/m³ ) was significantly larger than in CT (2.60 kg/m³ ). Thus, the net profit in MT was 2765.8 USD/ha, which was 28% higher than in CT (2160 USD/ha). These results suggested that mulching soil surface with black polyethylene film in cotton cultivation contributes to saving more water in irrigation and leads to increase yield in Uzbekistan.