توصيفگر ها :
آبياري قطره اي نواري , كم آبياري , آرايش كاشت , ذرت , كارايي مصرف آب , بهره وري اقتصادي آب
چكيده انگليسي :
Drip-tape irrigation is one of the most popular irrigation systems in arid and semi-arid areas with water scarcity. In this study, we investigated the effect of planting array, irrigation levels, N fertilizer split, and Zn-Fe application on total biomass (TB), water, and economic productivity (WP, WPE). The planting array includes single-row cultivation with a drip line space of 70cm (DS70) and two-row cultivation with a distance of 30 cm, and a drip line space140cm (DS140). Irrigation levels were deficit irrigation (W1=0.85ET) and full irrigation (W2=ET). Four fertilizer management, including three N fertilizer splits (T1), nine N fertilizer splits (T2), three N fertilizer splits in addition to the application of Zn-Fe (T3), and nine N fertilizer splits in addition to the application of Zn-Fe (T4). Irrigation was planned based on soil moisture content monitoring using taken soil samples, tensiometer readings, and evapotranspiration calculation under full irrigation treatments. For the first-year effect of irrigation levels, planting array, and Fe-Zn were significant (P < 0.01) on TB, WP, and WPI. As well, the nitrogen fertilizer splits had a significant effect (P < 0.01) on TB and WPI but did not significant effect on WP. In second year the effect of irrigation levels on TB, WP, and WPI were significant (P < 0.01) and effect of planting array on TB and WPI (P < 0.01) and WP (P < 0.05) were significant. However, nitrogen fertilizer splits and Fe-Zn application did not affect remarkably on any of the indices. For two years study, a reduction in the irrigation amount caused a decrease in TB, WP, and WPI. The lowest and highest average amount of the indices were observed in W1 and W2 levels, respectively. The maximum value of TB, WP, and WPI was observed in the planting array of DS70 with three-splits N fertilizer treatment. In the first year, the effect of irrigation levels, planting array, splits of nitrogen fertilizer, and Fe-Zn were significant (P <0.01) on gross economic irrigation water productivity (GEWPI), the net economic irrigation water productivity (NEWPI), economic crop water productivity (EWPC), economic irrigation water productivity (EWPI), and economic crop water productivity and irrigation water with 50% free government facilities (EWPCS and EWPIS). In the second year, the effect of irrigation levels, nitrogen fertilizer splits, and Fe-Zn were significant (P < 0.01) on all mentioned economic indicators. However, the effect of the planting array on any of the examined economic indicators was not remarkable. Overall, the three N fertilizer splits treatment had the highest value for all economic indices in two years. In deficit irrigation levels the highest TB, WP, WPE, and benefit were observed at the DS70 planting array, in two years. Overall, planting an array of DS70 and the three nitrogen fertilizer splits increased crop production, water productivity, and economic water productivity. In conclusion, deficit irrigation management reduces TB, WP, WPE, and profit in agriculture under drip-tape irrigation systems in an arid and semi-arid areas.
