No abstract

An experiment was conducted to investigate the influence of different levels of water deficit on yield and crop water requirement of soya beans in a sub‐humid environment (Southern Marmara region, Bursa, Turkey) in 2005 and 2006. One full‐irrigated treatment (T1), one non‐irrigated treatment (T5) and three different deficit irrigation (T2 = 25 % water deficit, T3 = 50 % water deficit, T4 = 75 % water deficit) treatments were applied to ‘Nova’ soya bean planted on a clay soil. Non‐irrigated and all deficit irrigation treatments significantly reduced biomass and seed yield and yield components. The full‐irrigated (T1) treatment had the highest yield (3760 kg ha−1), while the non‐irrigated (T5) treatment had the lowest yield (2069 kg ha−1), a 45.0 % seed yield reduction. T2, T3 and T4 deficit irrigation treatments produced 11.7–27.4 % less seed yield than the T1 treatment. Harvest index showed less and irregular variation among irrigation treatments. Both leaf area per plant and leaf area index were significantly reduced at all growth stages as amount of irrigation water was decreased. Evapotranspiration increased with increased amounts of irrigation water supplied. Our results indicate that higher amounts of irrigation resulted in higher seed yield, whereas water use efficiency and irrigation water use efficiency values decreased when irrigation amount increased.

This study examined the effects of different irrigation levels and nitrogen rates on perennial ryegrass (Lolium perenne L.) evapotranspiration and quality in a sub-humid climate over a two-year period (2007)(2008). Nitrogen treatment (25 kg N ha -1 ; N 1 and 50 kg N ha -1 ; N 2 ) varied among main plots and irrigation levels (25%; I 1 , 50%; I 2 , 75%; I 3 , 100%; I 4 and 125%; I 5 of the Class A pan evaporation) by subplot. Irrigation was performed at 3-day intervals during May-September using a pop-up sprinkler irrigation system, and N applied as a monthly rate during the irrigation period. Seasonal turfgrass evapotranspiration was found to vary by treatment from 309-1178 mm in 2007 and from 379-1097 mm in 2008. Turfgrass visual color, quality and clipping yield were shown to decrease significantly with decreases in irrigation water and N fertilizer. The study findings demonstrated that under a non-limiting water supply, irrigation could be decreased by adjusting N fertilizer rates according to turfgrass visual color and quality and that N 1 I 4 or N 2 I 3 treatments can maintain acceptable turfgrass visual color and quality under sub-humid climatic conditions.

No abstract

No abstract