Arid Zone Research ›› 2021, Vol. 38 ›› Issue (5): 1367-1375.doi: 10.13866/j.azr.2021.05.18

• Soil Resources • Previous Articles     Next Articles

Effects of early sowing and tillage measures on nitrogen and phosphorus in the soil supporting spring wheat in the semi-arid area of the Loess Plateau

LIU Shuainan(),LI Guang(),SONG Liangcui,YUAN Jianyu,XIE Mingjun,WEI Xingxing   

  1. College of Forestry, Gansu Agricultural University, Lanzhou 730070, Gansu, China
  • Received:2021-05-14 Revised:2021-06-22 Online:2021-09-15 Published:2021-09-24
  • Contact: Guang LI E-mail:2298243583@qq.com;lig@gsau.edu.cn

Abstract:

To study the effects of early sowing and tillage measures on soil nitrogen and phosphorus in a farmland ecosystem, 0-40 cm of soil supporting spring wheat (Triticum aestivum) in the semi-arid region of the Loess Plateau was collected and analyzed. Under early sowing and normal sowing conditions, the different tillage measures were as follows: traditional tillage (T), traditional tillage + straw returning (TS), no tillage (NT), and no tillage + straw mulching (NTS). Results were as follows. (1) Under different treatments, the contents of N (TN, $NO_3^--N$, and $NH_4^+-N$) and P (TP) in spring wheat-related soil had the characteristics of surface aggregation. The average value of soil N:P (1.713) was lower than the national average value (5.2) and the coefficient of variation was 26.99%-77.28%, which belonged to the medium variation level. (2) In the 0-40 cm soil layer, the TN,$NH_4^+-N$, and N:P levels of early sowing spring wheat were significantly lower than the levels found with normal sowing (i.e., by 23.1%-32.5%), which was not conducive to the accumulation of TN and $NH_4^+-N$, whereas $NO_3^--N$ and $NO_3^--N$:N levels were significantly higher in early sowing spring wheat than the levels achieved with normal sowing (i.e., by 30.5% and 41.5%, respectively), which was conducive to the retention of $NO_3^--N$ in the soil. (3) The contents of TN and TP under straw mulching conditions (NTS and TS) were higher than those under NT and T, but the contents of available nitrogen ($NO_3^--N$ and $NH_4^+-N$) showed the opposite trend. (4) Under different treatments, the contents of TP in the soil tended to be stable during the growth period, whereas the contents of N changed significantly at the tillering and flowering stages. Therefore, selecting suitable sowing times and tillage management measures will help to improve the accumulation and transformation efficiency of N and P elements in crop soil and will accelerate the restoration process of farmland ecosystems in the semi-arid area of the Loess Plateau.

Key words: semiarid region of Loess Plateau, early sowing, tillage measures, spring wheat, soil nitrogen and phosphorus