Zhang Huan, Wang Lei, Fu Weiguo, Xu Cong, Zhang Hui, Xu Xianju, Ma Hongbo, Wang Jidong, Zhang Yongchun
School of Agricultural Equipment Engineering, Jiangsu University, Zhenjiang 212013, China.
National Agricultural Experimental Station for Agricultural Environment, Luhe, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Plants (Basel). 2024 Jun 24;13(13):1740. doi: 10.3390/plants13131740.
Soil acidification is a significant form of agricultural soil degradation, which is accelerated by irrational fertilizer application. Sweetpotato and wheat rotation has emerged as an important rotation system and an effective strategy to optimize nutrient cycling and enhance soil fertility in hilly areas, which is also a good option to improve soil acidification and raise soil quality. Studying the effects of different fertilization regimes on soil acidification provides crucial data for managing it effectively. An eight-year field experiment explored seven fertilizer treatments: without fertilization (CK), phosphorus (P) and potassium (K) fertilization (PK), nitrogen (N) and K fertilization (NK), NP fertilization (NP), NP with K chloride fertilization (NPK1), NP with K sulfate fertilization (NPK2), and NPK combined with organic fertilization (NPKM). This study focused on the soil acidity, buffering capacity, and related indicators. After eight years of continuous fertilization in the sweetpotato-wheat rotation, all the treatments accelerated the soil acidification. Notably, N fertilization reduced the soil pH by 1.30-1.84, whereas N-deficient soil showed minimal change. Organic fertilizer addition resulted in the slowest pH reduction among the N treatments. Both N-deficient (PK) and organic fertilizer addition (NPKM) significantly increased the soil cation exchange capacity (CEC) by 8.83% and 6.55%, respectively, compared to CK. Similar trends were observed for the soil-buffering capacity (pHBC). NPK2 increased the soil K content more effectively than NPK1. NPKM reduced the sodium and magnesium content compared to CK, with the highest magnesium content among the treatments at 1.60 cmol·kg. Regression tree analysis identified the N input and soil magnesium and calcium content as the primary factors influencing the pHBC changes. Structural equation modeling showed that the soil pH is mainly influenced by the soil ammonium N content and pHBC, with coefficients of -0.28 and 0.29, respectively. Changes in the soil pH in the sweetpotato-wheat rotation were primarily associated with the pHBC and N input, where the CEC content emerged as the main factor, modulated by magnesium and calcium. Long-term organic fertilization enhances the soil pHBC and CEC, slowing the magnesium reduction and mitigating soil acidification in agricultural settings.
土壤酸化是农业土壤退化的一种重要形式，不合理施肥会加速这一过程。甘薯与小麦轮作已成为一种重要的轮作体系，也是优化养分循环和提高丘陵地区土壤肥力的有效策略，同时也是改善土壤酸化和提高土壤质量的良好选择。研究不同施肥制度对土壤酸化的影响可为有效管理土壤酸化提供关键数据。一项为期八年的田间试验探究了七种施肥处理：不施肥（CK）、磷（P）钾肥（PK）、氮（N）钾肥（NK）、氮磷肥（NP）、氮磷加氯化钾施肥（NPK1）、氮磷加硫酸钾施肥（NPK2）以及氮磷钾与有机肥配施（NPKM）。本研究聚焦于土壤酸度、缓冲容量及相关指标。在甘薯-小麦轮作连续八年施肥后，所有处理均加速了土壤酸化。值得注意的是，施氮使土壤pH值降低了1.30 - 1.84，而缺氮土壤变化极小。在施氮处理中，添加有机肥导致pH值下降最慢。与CK相比，缺氮（PK）和添加有机肥（NPKM）处理分别使土壤阳离子交换量（CEC）显著增加了8.83%和6.55%。土壤缓冲容量（pHBC）也呈现类似趋势。NPK2比NPK1更有效地提高了土壤钾含量。与CK相比，NPKM降低了钠和镁含量，各处理中镁含量最高为1.60 cmol·kg。回归树分析确定氮输入以及土壤镁和钙含量是影响pHBC变化的主要因素。结构方程模型表明，土壤pH值主要受土壤铵态氮含量和pHBC影响，系数分别为 - 0.28和0.29。甘薯-小麦轮作中土壤pH值的变化主要与pHBC和氮输入有关，其中CEC含量是主要因素，受镁和钙的调节。长期施用有机肥可提高土壤pHBC和CEC，减缓镁含量降低，减轻农业土壤酸化。
