College of Life Sciences, Shihezi University, Shihezi, Xinjiang, China.
Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, Pharmacy School, Shihezi, Xinjiang, China.
PeerJ. 2022 Feb 16;10:e12928. doi: 10.7717/peerj.12928. eCollection 2022.
Long-term and widespread cotton production in Xinjiang, China, has resulted in significant soil degradation, thereby leading to continuous cropping obstacles; cotton stalk biochar (CSB) addition may be an effective countermeasure to this issue, with effects that are felt immediately by root systems in direct contact with the soil. In this study, we assess the effects of different CSB application rates on soil nutrient contents, root morphology, and root physiology in two soil types commonly used for cotton production in the region. Compared with CK (no CSB addition), a 1% CSB addition increased total nitrogen (TN), available phosphorus (AP), and organic matter (OM) by 13.3%, 7.2%, and 50% in grey desert soil, respectively , and 36.5%, 19.9%, and 176.4%, respectively, in aeolian sandy soil. A 3% CSB addition increased TN, AP, and OM by 38.8%, 23.8%, and 208.1%, respectively, in grey desert soil, and 36%, 13%, and 183.2%, respectively, in aeolian sandy soil. Compared with the aeolian sandy soil, a 1% CSB addition increased TN, OM, and AP by 95%, 94.8%, and 33.3%, respectively, in the grey desert soil , while in the same soil 3% CSB addition increased TN, OM, and AP by 108%, 21.1%, and 73.9%, respectively. In the grey desert soil, compared with CK, a 1% CSB application increased the root length (RL) (34%), specific root length (SRL) (27.9%), and root volume (RV) (32.6%) during the bud stage, increased glutamine synthetase (GS) (13.9%) and nitrate reductase (NR) activities (237%), decreased the RV (34%) and average root diameter (ARD) (36.2%) during the harvesting stage. A 3% CSB addition increased the RL (44%), SRL (20%), and RV (41.2%) during the bud stage and decreased the RV (29%) and ARD (27%) during the harvesting stage. In the aeolian sandy soil, 1% CSB increased the RL (38.3%), SRL (73.7%), and RV (17%), while a 3% caused a greater increase in the RL (55%), SRL (89%), RV (28%), soluble sugar content (128%), and underground biomass (33.8%). Compared with the grey desert soil, a 1% CSB addition increased the RL (48.6%), SRL (58%), and RV (18.6%) in the aeolian sandy soil, while a 3% further increased the RL (54.8%), SRL (84.2%), RV (21.9%), and soluble sugar content (233%). The mechanisms by which CSB addition improves the two soils differ: root morphology changed from coarse and short to fine and long in the grey desert soil, and from fine and long to longer in the aeolian sandy soil. Overall, a 3% CSB addition may be a promising and sustainable strategy for maintaining cotton productivity in aeolian sandy soil in the Xinjiang region.
长期广泛的棉花种植在中国新疆导致了严重的土壤退化，从而导致了连作障碍；棉花秸秆生物炭（CSB）的添加可能是解决这个问题的有效对策，其效果立即体现在与土壤直接接触的根系上。在这项研究中，我们评估了不同 CSB 施用量对该地区常用的两种土壤类型的土壤养分含量、根系形态和根系生理的影响。与 CK（不添加 CSB）相比，1%的 CSB 添加量分别使灰色荒漠土的总氮（TN）、有效磷（AP）和有机质（OM）增加了 13.3%、7.2%和 50%，在风积沙土中分别增加了 36.5%、19.9%和 176.4%。3%的 CSB 添加量使灰色荒漠土的 TN、AP 和 OM 分别增加了 38.8%、23.8%和 208.1%，在风积沙土中分别增加了 36%、13%和 183.2%。与风积沙土相比，1%的 CSB 添加量使灰色荒漠土的 TN、OM 和 AP 分别增加了 95%、94.8%和 33.3%，而在同一土壤中，3%的 CSB 添加量使 TN、OM 和 AP 分别增加了 108%、21.1%和 73.9%。在灰色荒漠土壤中，与 CK 相比，1%的 CSB 处理在萌芽期增加了根长（RL）（34%）、比根长（SRL）（27.9%）和根体积（RV）（32.6%），增加了谷氨酰胺合成酶（GS）（13.9%）和硝酸还原酶（NR）活性（237%），在收获期降低了 RV（34%）和平均根直径（ARD）（36.2%）。3%的 CSB 添加量在萌芽期增加了 RL（44%）、SRL（20%）和 RV（41.2%），在收获期降低了 RV（29%）和 ARD（27%）。在风积沙土中，1%的 CSB 增加了 RL（38.3%）、SRL（73.7%）和 RV（17%），而 3%的 CSB 导致 RL（55%）、SRL（89%）、RV（28%）、可溶性糖含量（128%）和地下生物量（33.8%）的增加幅度更大。与灰色荒漠土壤相比，1%的 CSB 添加量在风积沙土中增加了 RL（48.6%）、SRL（58%）和 RV（18.6%），而 3%的 CSB 添加量进一步增加了 RL（54.8%）、SRL（84.2%）、RV（21.9%）和可溶性糖含量（233%）。CSB 添加改善这两种土壤的机制不同：在灰色荒漠土壤中，根系形态从粗短变为细而长，在风积沙土中，根系形态从细而长变为更长。总体而言，3%的 CSB 添加可能是维持新疆风积沙土棉花生产力的一种有前途和可持续的策略。
