Effects of nitrogen input on soil bacterial community structure and soil nitrogen cycling in the rhizosphere soil of Lycium barbarum L.

Abstract

Lycium barbarum L., goji berry, is a precious traditional Chinese medicine and it is homology of medicine and food. Its growth is heavily dependent on nitrogen. The use of chemical fertilizers has significantly promoted the yield of goji berry and the development of the L. barbarum L. industry. However, crop plants are inefficient in the acquisition and utilization of applied nitrogen, it often leads to excessive application of nitrogen fertilizers by producers, which cause negatively impact to the environment ultimately. The exploration of an interaction model which deals with crops, chemical fertilizers, and rhizosphere microbes to improve nitrogen use efficiency, is, therefore, an important research objective to achieve sustainable development of agriculture greatly. In our study, we explored the effects of nitrogen input on soil microbial community structure, soil nitrogen cycling, and the contents of nutrients in L. barbarum fruits. The structure and composition of the bacterial community in the rhizosphere soil of L. barbarum were significantly different under different nitrogen supply conditions, and high nitrogen addition inhibited the diversity and stability of bacterial communities. Low nitrogen input stimulated the relative abundance of ammonia-oxidizing bacteria (AOB), such as Nitrosospira, catalyzing the first step of the ammonia oxidation process. The results of the GLMM model showed that the level of nitrogen fertilizer (urea) input, the relative abundance of AOB, the relative abundance of Bradyrhizobium, and their combinations had significant effects on the soil nitrogen cycling and contents of nutrients in L. barbarum fruits. Therefore, we believe that moderately reducing the use of urea and other nitrogen fertilizers is more conducive to improving soil nitrogen use efficiency and Goji berry fruit quality by increasing the nitrogen cycling potential of soil microorganisms.

Optimizing the Nitrogen Use Efficiency in Vegetable Crops

“…High chemical N fertilizer inputs, common in commercial operations, tend to decrease the soil microbial activity and diversity [43]. Current research efforts aim to identify nutrient and management practices, such as vegetational diversity, grazing, tillage, and the application of organic amendments, that reduce the reliance on chemical N inputs, reduce N losses, and improve the soil microbial activity, which has a positive impact on the system NUE [86,190,301].…”

Effect of potassium on the agronomic traits and fruit quality of Lycium barbarum L

“…The soil PH was detected using a DDSJ-319L electrode pH meter. In addition, total N (TN), total P (TP), total K (TK), available N (AN), available P (AP), available K (AK), total salt (TS), and soil organic matter (OM) were evaluated by using the standard test methods of the Chinese national standard [30] . Therefore, the conditions of the soil were: pH, 7.84; EC, 0.068 dS/m; TS, 0.42 g/kg; OM, 5.12 g/kg; TN, 0.44 g/kg; TP, 0.72 g/kg; TK, 7.50 g/kg; AN, 23.00 mg/kg, AP, 12.00 mg/kg; AK, 15.00 mg/kg.…”

Foliar Fertilizer Application Alters the Effect of Girdling on the Nutrient Contents and Yield of Camellia oleifera

“…Therefore, reasonable foliar fertilizer application can effectively improve the nutrient content of plant organs and promote the growth and development of plants [ 15 ]. Urea has a high N content and is often used as a common fertilizer for plant nitrogen supplementation [ 17 ]. Potassium dihydrogen phosphate contains P and K, and the plant utilization rate is high, which can promote the absorption of N and P by plants, and it has good water solubility, which is the first choice for foliar fertilizer [ 18 ].…”