Effects of water-fertilizer coupling on the yield of spring maize under shallow-buried drip irrigation in semi-arid region of western Liaoning Province

Abstract

To reveal the coupling effect of water and fertilizer on the yield of spring maize under shallow-buried drip irrigation in semi-arid area of western Liaoning, a field experiment was conducted with the quadratic regression orthogonal design of three factors (water, nitrogen and potassium) crossed with five levels in 2017-2018. A quadratic regression model was established with yield (Y) as the dependent variable and irrigation amount (W), nitrogen (N) and potassium (K) application amounts as independent variables to analyze the coupling relationships between Y and W, N and K, respectively. The results showed that the shallow-drip irrigation water-fertilizer coupling had significant impact on yield. The single factor of W, N and K promoted the yield, with their effects ranking as W>N>K. The effect of two-factor interaction on yield increased first and then decreased which ranked as WN>WK>NK. Considering the three-factor coupling effect on yield, the combination of abundant water, nitrogen and potassium was the highest, followed by high water, nitrogen and potassium, and low water, nitrogen and potassium the lowest. As the optimal treatments found by the model, we obtained the suitable water-fertilizer application range of shallow-buried drip irrigation with higher target yield of 8000-8810 kg·hm-2, that was, the irrigation amount was 43-61 mm, nitrogen 138-343 kg·hm-2 and potassium 79-163 kg·hm-2 under the ambient natural rainfall. The results provided a referable basis for application of water-fertilizer integrated cropping pattern under shallow-buried drip irrigation in semi-arid area of northern China.