College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi, 712100, China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Chemosphere. 2021 Jul;275:130093. doi: 10.1016/j.chemosphere.2021.130093. Epub 2021 Feb 24.
The objective of this present study was to understand the distribution patterns of various forms of soil phosphorus (P) and the biotic and abiotic factors affecting the soil P fractions under long-term cover crops. Here, we investigated the characteristics of soil P forms, community structure of P-solubilizing bacteria (using 16S rRNA) and the related enzyme activity under clean tillage (CT), 14 years of white clover (WC, Trifolium repens L.) and orchard grass (OG, Dactylis glomerata L.) cover crops in a rain-fed apple orchard on the Weibei Loess Plateau, China. Relative to CT treatment, long-term cover crops enhanced the bioavailability of soil P by increasing the contents of total phosphorus (TP), microbial phosphorus (MBP), organic phosphorus (Po) and certain forms of inorganic phosphorus (e.g. Al-P, Ca-P, Ca-P and Fe-P) in the surface soil, in addition, WC treatment also increase the available P (AP) contents in the topsoil. A redundant analysis (RDA) showed that soil organic matter (SOM), NH-N and pH were the key environmental factors affecting the morphological changes of soil P. In addition, the effects of long-term cover crops on soil P forms were mainly concentrated in the topsoil, and the WC treatment had a greater impact on soil P composition than the OG treatment. Interestingly, long-term cover crops effectively increased the abundances of P-solubilizing bacteria, such as Streptomyces, Sphingomonas, Nocardioides and Haliangium, and enhanced the alkaline phosphatase (ALP) activity. Overall, long-term cover crops were an effective strategy to activate soil P as they improve the soil environment.
本研究旨在了解长期覆盖作物下土壤磷（P）各种形态的分布模式以及影响土壤磷分的生物和非生物因素。在这里，我们调查了清洁耕作（CT）、14 年白三叶草（Trifolium repens L.）和果园草（Dactylis glomerata L.）覆盖作物下土壤磷形态特征、解磷细菌（16S rRNA）群落结构及相关酶活性的特征，在中国渭北黄土高原的一个雨养苹果园中。与 CT 处理相比，长期覆盖作物通过增加表层土壤中总磷（TP）、微生物磷（MBP）、有机磷（Po）和某些无机磷（如 Al-P、Ca-P、Ca-P 和 Fe-P）的含量，提高了土壤 P 的生物有效性，此外，WC 处理还增加了表土中有效 P（AP）的含量。冗余分析（RDA）表明，土壤有机质（SOM）、NH4-N 和 pH 是影响土壤 P 形态变化的关键环境因素。此外，长期覆盖作物对土壤 P 形态的影响主要集中在表层土壤中，WC 处理对土壤 P 组成的影响大于 OG 处理。有趣的是，长期覆盖作物有效地增加了解磷细菌（如链霉菌属、鞘氨醇单胞菌属、诺卡氏菌属和海杆菌属）的丰度，并增强了碱性磷酸酶（ALP）活性。总体而言，长期覆盖作物是一种有效的激活土壤 P 的策略，因为它改善了土壤环境。
