Coupling effects of depth of film-bottomed tillage and amount of irrigation and nitrogen fertilizer on spring wheat yield

Abstract

The crop cultivation with film-bottomed tillage may benefit more, but little is known about the coupling effects of depth of film-bottomed tillage (DFBT) and amount of irrigation and nitrogen (N) fertilizer on spring wheat yield. A field quadratic regression orthogonal design experiment was conducted to determine the effects of DFBT, irrigation and N fertilization on seed yield of spring wheat ( Triticum aestivum L.) in the Hexi Corridor, China from 2002 to 2005. Five levels of irrigation (143, 165, 225, 285, and 306 mm), five levels of N (45, 70, 140, 210, and 235 kg N ha −1) and five DFBT (46, 60, 70, 80, and 94 cm) were investigated. Irrigation (44 mm ≤ irrigation ≤ 300 mm), DFBT (46 cm ≤ DFBT ≤ 80 cm), and N (≤160 kg N ha −1) significantly increased wheat yield. DFBT, N and irrigation had a positive effect on wheat yield, in the order: irrigation > N > DFBT. The coupling between DFBT × N and, between N × irrigation had a synergistic effect on spring wheat yield. The coefficient of DFBT × irrigation was negative showing the coupling of DFBT × irrigation had a reciprocal inhibition or substitution effect. The findings suggest that spring wheat should be irrigated with 300 mm of water, with an application of 160 kg N ha −1 and a 70 cm DFBT in the arid climate and sandy soil areas of China, to obtain the highest wheat yield with maximum economic benefit. The assessment with respect to N fertilizer use efficiency, environmental pollution need further research.