Arid Zone Research ›› 2021, Vol. 38 ›› Issue (6): 1750-1759.doi: 10.13866/j.azr.2021.06.27

• Soil Resources • Previous Articles     Next Articles

Effects of water and nitrogen regulation on soil and leaf stoichiometric characteristics of spring wheat in dry farming

ZHANG Juan1(),LI Guang1(),YUAN Jianyu1,YAN Lijuan2,WEI Xingxing1,LIU Shuainan1   

  1. 1. College of Forestry, Gansu Agricultural University, Lanzhou 730070, Gansu, China
    2. College of Agriculture, Gansu Agricultural University, Lanzhou 730070, Gansu, China
  • Received:2021-06-08 Revised:2021-08-01 Online:2021-11-15 Published:2021-11-29
  • Contact: Guang LI E-mail:1627835969@qq.com;lig@gsau.edu.cn

Abstract:

Soil moisture and nutrients are deemed as key factors affecting crop growth. A reasonable combination of water and fertilizer can improve the soil nutrient status and lead to high and stable crop yield. In this study, spring wheat in the dryland of the Loess Plateau in Central Gansu Province was examined by combining field sampling with an indoor experiment to further clarify the response mechanism of water and nitrogen regulation in soil, leaf nutrient content, stoichiometry ratio, and yield of spring wheat. Various characteristics of soil and leaf carbon (OC), nitrogen (TN), and phosphorus (TP) contents under different irrigation rates (W1: 50 mm; W2: 100 mm; W3: 150 mm; W4: 200 mm) and nitrogen application rates (N1: 62.5 kg·hm-2; N2: 102.5 kg·hm-2; N3: 152.5 kg·hm-2) were analyzed, and the correlation between soil and leaf nutrient contents and yield was examined. Results show that (1) the OC, TN, and TP contents decreased as soil depth increased. The OC and TN contents in soil initially increased and subsequently decreased as the amounts of irrigation and nitrogen application increased. Their maximum values were obtained under the W3N2 treatment. By comparison, the TP content of soil did not change remarkably. The ranges of C:N, C:P, and N:P were 5.81-8.24, 8.35-13.75, and 1.23-1.95, respectively, which were less than the national average. (2) The TN content of spring wheat leaves at the mature stage increased first and then decreased as the amount of irrigation increased. It gradually increased as the nitrogen application rate increased, reaching the maximum under the W3N2 treatment. Conversely, the OC and TP contents did not vary considerably. (3) The number of spikes and the number of grains per spike of spring wheat increased initially and decreased subsequently as the amount of irrigation increased. They gradually increased as the nitrogen application rate increased. Similarly, the 1000-grain weight and yield increased first and then decreased as the amounts of irrigation and nitrogen application increased. Their maximum values were observed in the W3N2 treatment, suggesting that W3N2 was the best water nitrogen coupling model for the growth and development of spring wheat. (4) Correlation analysis showed that spring wheat yield was significantly correlated with soil and leaf nutrient contents, which could be improved by changing the water and fertilizer supply. In conclusion, the amounts of irrigation and nitrogen application controlled at W3 (150 mm) and N2 (102.5 kg·hm-2) levels, which were a better combination of water and nitrogen in line with local production conditions, could satisfy the demand for the nutrient content of spring wheat during growth. Thus, its yield could be improved.

Key words: water and nitrogen regulation, spring wheat, carbon,nitrogen and phosphorus, stoichiometry