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.

摘要

有机改良剂可以改善土壤氮 (N) 的有效性和转化特征，从而减少因氮过量施用引起的土壤剖面内的 N 损失。2018 年在石墙村设计了一项田间试验，采用不同的有机改良剂：（i）对照（CK）；(ii) 化肥（NPK）；(iii) 1200 kg C ha ^-1加 NPK (NPKM) 和 (iv) 40 kg 腐植酸 ha ^-1加 NPK (NPKH)。与 NPK 处理相比，在 0~30 cm 土壤中，NPKM 和 NPKH 处理的 NH ₄ ⁺ -N 含量分别增加 9.15% 和 13.36%，NO ₃ ^- N 含量分别增加 11.44% 和 12.85%，而在30–60 cm 土壤，NO ₃ ^–NPKM 和 NPKH 处理的 N 含量分别降低了 13.51% 和 8.54%，因为有机改良剂抑制了 N 向更深土壤的淋溶。NPKH处理土壤脲酶和蔗糖酶活性分别比NPK处理高9.52%和8.31%，随着土层深度的减小而降低。NPKM和NPKH处理分别增加了14.17%和23.87%的籽粒产量。因此，腐植酸肥料通过提高氮素转化和酶活性提高小麦产量的效果较好，可以增加华北平原小麦对氮素的吸收，抑制氮素流失。