Crop-yield/water-use production functions of potatoes (Solanum tuberosum, L.) grown under differential nitrogen and irrigation treatments in a hot, dry climate

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• 作者：T.C. Ferreira ; D.A. Gonç ; alves
• 关键词：Irrigation ; Water-use ; Production functions ; Potatoes ; Nitrogen ; Hot dry climate ; N.E. Portugal
• 刊名：Agricultural Water Management
• 出版年：2007
• 期刊代码：5_03783774
• 类别：abs
• 出版时间：24 May 2007
• 卷：90
• 期：1-2
• 页码：45-55
• 文件大小：647 K

摘要

During two consecutive years (1988–1989) field experiments were conducted in the region of Trás-os-Montes, N.E. Portugal. The work formed part of a wider research programme assessing the effects of water and nitrogen (N) on the productivity of potatoes in a hot, dry environment. Line-source experiments were carried out using potato crops (Solanum tuberosum, L.) subjected to four N levels (N₀, N₁, N₂ and N₃) and five irrigation (I) treatments (I₄–I₀). The main aims were to characterise crop productivity and develop the drought response factor K_y and the crop yield production functions in relation to rainfall and irrigation (P + I) and to total water-use (ET_c), that could be used to assess the benefits of irrigation and fertilisation practices in the region. ET_c was monitored by intensive field measurement of soil water content using a neutron probe device. Single values of total water applied (P + I) ranged from 148 to 387 mm in 1988 and from 295 to 724 mm in 1989. By contrast, single values of ET_c (including the contribution from soil water storage), ranged from 230 to 504 mm in 1988 and from 330 to 802 mm in 1989. Full irrigation increased mean yields of fresh tubers from 11.8 to 24.7 t/ha in 1988 and from 13.6 to 49.8 t/ha in 1989. Total fresh tuber yield from droughted crops tended to decline with increasing N fertiliser up to 80 kg/ha. Yield responses to P + I (52–91 kg/(ha mm)) and to ET_c (62–105 kg/(ha mm)) varied with fertiliser application. In both years, the relative values of K_y were similar for all three fertilised crops (N₁, N₂ and N₃) regardless of nitrogen dosage. The mean K_y value in 1988 was 0.71 and 1.12 in 1989.