Organic amendment increases wheat yield by improving soil N transformations and reducing N loss in North China Plain

ABSTRACT

Organic amendments could improve soil nitrogen (N) availability and transformation characteristics, which decreases the N loss within soil profile induced by N excessive application. A field experiment was designed in Shiqiang village with different organic amendments in 2018: (i) control (CK); (ii) chemical fertilizer (NPK); (iii) 1200 kg C ha⁻¹ plus NPK (NPKM) and (iv) 40 kg humic acid ha⁻¹ plus NPK (NPKH). Compared with NPK treatment, in 0–30 cm soil, NH₄⁺-N content in NPKM and NPKH treatments was increased by 9.15% and 13.36% and NO₃ ^– N content was increased by 11.44% and 12.85%, respectively, while in 30–60 cm soil, NO₃ ^– N content in NPKM and NPKH treatments was decreased by 13.51% and 8.54%, because organic amendments inhibited N leaching to deeper soil. Soil urease and invertase activity in NPKH treatment was 9.52% and 8.31% higher than that in NPK treatment, which was decreased with the decreasing soil depth. The grain yield was increased by 14.17% and 23.87% in NPKM and NPKH treatments, respectively. Thus, humic acid fertilizer was better in increasing wheat yield by improving N transformation and enzyme activities, which could increase wheat N uptake and inhibit N loss in North China Plain.

KEYWORDS:

• Organic amendment
• N transformation
• mineral N
• yield

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported in part by the National Key Research and Development Projects (2018YFD0800303/2017YFD0200208-3), the Soil and Cultivation Position of Modern Agricultural Technology System Innovation Team in Shandong Province (SDAIT-17-05), the Natural Science Fund of Shandong Province (ZR2020MC154), the Graduate Innovation Program Project of Qingdao Agricultural University (QNYCX20079).