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Journal of Agriculture ›› 2023, Vol. 13 ›› Issue (3): 21-29.doi: 10.11923/j.issn.2095-4050.cjas2021-0198

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Effects of Supplementary Irrigation Volume and Straw Mulching on Leaf Area Index of Spring Wheat in Dryland

ZHANG Lei(), NIE Zhigang()   

  1. College of Information Science and Technology, Gansu Agricultural University, Lanzhou 730070, Gansu, China
  • Received:2021-11-25 Revised:2021-12-20 Online:2023-03-20 Published:2023-04-04

Abstract:

The changes of supplementary irrigation volume and straw mulching have great impact on leaf growth in no-tillage mulching. Based on the historical meteorological data of Anding District of Dingxi City in Gansu Province from 1979 to 2019, the leaf area index of dryland spring wheat under the coupling change of supplementary irrigation volume and mulching was simulated by APSIM model, and the influencing mechanism of supplementary irrigation volume and mulching on dryland spring wheat leaf area was studied by means of variance analysis, quadratic polynomial regression and single factor analysis. The results showed that within the scope of the experimental design, the leaf area index of spring wheat in dryland increased first and then decreased in a quadratic parabola with the opening downward from tillering to jointing stage with the change of supplementary irrigation volume. When the supplementary irrigation volume was 252.09 mm, the value of spring wheat leaf area index was the maximum of 1.83, and the leaf area index increased in a quadratic parabola with the opening upward in other stages. With the change of straw mulching, the leaf area index increased first and then decreased in a quadratic parabola with opening downward in the seedling emergence to tillering stage, and when the straw mulching was 2397.09 kg/hm2 in the experimental design range, the leaf area index of spring wheat was the maximum of 0.59, and the leaf area index had a quadratic parabola increase from the tillering to the jointing stage with the opening downward; the leaf area index of all other stages showed an increase with upward quadratic parabola. At the same stage, the leaf area index of spring wheat increased by 13.95% for every 50 mm of supplementary irrigation; the leaf area index of spring wheat increased by 3.7% for every 1000 kg/hm2 increase of straw mulching. The effect of supplementary irrigation volume on leaf area index of spring wheat was much greater than that of straw mulching. In no-tillage mulching, reasonable straw mulching and supplementary irrigation volume could maintain the water in the soil, which was conducive to the leaf growth of spring wheat in dryland.

Key words: leaf area index, supplementary irrigation volume, straw mulching, APSIM, dryland spring wheat